mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Christoph Hellwig](/assets/img/avatar_default.png)
[ Upstream commit2c14f0ffdd
] Also clear the uptodate bit to make sure the page isn't seen as uptodate in the page cache if fsverity verification fails. Fixes:146054090b
("btrfs: initial fsverity support") CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
5044 lines
137 KiB
C
5044 lines
137 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
#include <linux/bitops.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/bio.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/page-flags.h>
|
|
#include <linux/sched/mm.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/swap.h>
|
|
#include <linux/writeback.h>
|
|
#include <linux/pagevec.h>
|
|
#include <linux/prefetch.h>
|
|
#include <linux/fsverity.h>
|
|
#include "misc.h"
|
|
#include "extent_io.h"
|
|
#include "extent-io-tree.h"
|
|
#include "extent_map.h"
|
|
#include "ctree.h"
|
|
#include "btrfs_inode.h"
|
|
#include "bio.h"
|
|
#include "check-integrity.h"
|
|
#include "locking.h"
|
|
#include "rcu-string.h"
|
|
#include "backref.h"
|
|
#include "disk-io.h"
|
|
#include "subpage.h"
|
|
#include "zoned.h"
|
|
#include "block-group.h"
|
|
#include "compression.h"
|
|
#include "fs.h"
|
|
#include "accessors.h"
|
|
#include "file-item.h"
|
|
#include "file.h"
|
|
#include "dev-replace.h"
|
|
#include "super.h"
|
|
#include "transaction.h"
|
|
|
|
static struct kmem_cache *extent_buffer_cache;
|
|
|
|
#ifdef CONFIG_BTRFS_DEBUG
|
|
static inline void btrfs_leak_debug_add_eb(struct extent_buffer *eb)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&fs_info->eb_leak_lock, flags);
|
|
list_add(&eb->leak_list, &fs_info->allocated_ebs);
|
|
spin_unlock_irqrestore(&fs_info->eb_leak_lock, flags);
|
|
}
|
|
|
|
static inline void btrfs_leak_debug_del_eb(struct extent_buffer *eb)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&fs_info->eb_leak_lock, flags);
|
|
list_del(&eb->leak_list);
|
|
spin_unlock_irqrestore(&fs_info->eb_leak_lock, flags);
|
|
}
|
|
|
|
void btrfs_extent_buffer_leak_debug_check(struct btrfs_fs_info *fs_info)
|
|
{
|
|
struct extent_buffer *eb;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* If we didn't get into open_ctree our allocated_ebs will not be
|
|
* initialized, so just skip this.
|
|
*/
|
|
if (!fs_info->allocated_ebs.next)
|
|
return;
|
|
|
|
WARN_ON(!list_empty(&fs_info->allocated_ebs));
|
|
spin_lock_irqsave(&fs_info->eb_leak_lock, flags);
|
|
while (!list_empty(&fs_info->allocated_ebs)) {
|
|
eb = list_first_entry(&fs_info->allocated_ebs,
|
|
struct extent_buffer, leak_list);
|
|
pr_err(
|
|
"BTRFS: buffer leak start %llu len %lu refs %d bflags %lu owner %llu\n",
|
|
eb->start, eb->len, atomic_read(&eb->refs), eb->bflags,
|
|
btrfs_header_owner(eb));
|
|
list_del(&eb->leak_list);
|
|
kmem_cache_free(extent_buffer_cache, eb);
|
|
}
|
|
spin_unlock_irqrestore(&fs_info->eb_leak_lock, flags);
|
|
}
|
|
#else
|
|
#define btrfs_leak_debug_add_eb(eb) do {} while (0)
|
|
#define btrfs_leak_debug_del_eb(eb) do {} while (0)
|
|
#endif
|
|
|
|
/*
|
|
* Structure to record info about the bio being assembled, and other info like
|
|
* how many bytes are there before stripe/ordered extent boundary.
|
|
*/
|
|
struct btrfs_bio_ctrl {
|
|
struct btrfs_bio *bbio;
|
|
enum btrfs_compression_type compress_type;
|
|
u32 len_to_oe_boundary;
|
|
blk_opf_t opf;
|
|
btrfs_bio_end_io_t end_io_func;
|
|
struct writeback_control *wbc;
|
|
};
|
|
|
|
static void submit_one_bio(struct btrfs_bio_ctrl *bio_ctrl)
|
|
{
|
|
struct btrfs_bio *bbio = bio_ctrl->bbio;
|
|
|
|
if (!bbio)
|
|
return;
|
|
|
|
/* Caller should ensure the bio has at least some range added */
|
|
ASSERT(bbio->bio.bi_iter.bi_size);
|
|
|
|
if (!is_data_inode(&bbio->inode->vfs_inode))
|
|
bbio->bio.bi_opf |= REQ_META;
|
|
|
|
if (btrfs_op(&bbio->bio) == BTRFS_MAP_READ &&
|
|
bio_ctrl->compress_type != BTRFS_COMPRESS_NONE)
|
|
btrfs_submit_compressed_read(bbio, 0);
|
|
else
|
|
btrfs_submit_bio(bbio, 0);
|
|
|
|
/* The bbio is owned by the end_io handler now */
|
|
bio_ctrl->bbio = NULL;
|
|
}
|
|
|
|
/*
|
|
* Submit or fail the current bio in the bio_ctrl structure.
|
|
*/
|
|
static void submit_write_bio(struct btrfs_bio_ctrl *bio_ctrl, int ret)
|
|
{
|
|
struct btrfs_bio *bbio = bio_ctrl->bbio;
|
|
|
|
if (!bbio)
|
|
return;
|
|
|
|
if (ret) {
|
|
ASSERT(ret < 0);
|
|
btrfs_bio_end_io(bbio, errno_to_blk_status(ret));
|
|
/* The bio is owned by the end_io handler now */
|
|
bio_ctrl->bbio = NULL;
|
|
} else {
|
|
submit_one_bio(bio_ctrl);
|
|
}
|
|
}
|
|
|
|
int __init extent_buffer_init_cachep(void)
|
|
{
|
|
extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
|
|
sizeof(struct extent_buffer), 0,
|
|
SLAB_MEM_SPREAD, NULL);
|
|
if (!extent_buffer_cache)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void __cold extent_buffer_free_cachep(void)
|
|
{
|
|
/*
|
|
* Make sure all delayed rcu free are flushed before we
|
|
* destroy caches.
|
|
*/
|
|
rcu_barrier();
|
|
kmem_cache_destroy(extent_buffer_cache);
|
|
}
|
|
|
|
void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
|
|
{
|
|
unsigned long index = start >> PAGE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_SHIFT;
|
|
struct page *page;
|
|
|
|
while (index <= end_index) {
|
|
page = find_get_page(inode->i_mapping, index);
|
|
BUG_ON(!page); /* Pages should be in the extent_io_tree */
|
|
clear_page_dirty_for_io(page);
|
|
put_page(page);
|
|
index++;
|
|
}
|
|
}
|
|
|
|
void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end)
|
|
{
|
|
struct address_space *mapping = inode->i_mapping;
|
|
unsigned long index = start >> PAGE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_SHIFT;
|
|
struct folio *folio;
|
|
|
|
while (index <= end_index) {
|
|
folio = filemap_get_folio(mapping, index);
|
|
filemap_dirty_folio(mapping, folio);
|
|
folio_account_redirty(folio);
|
|
index += folio_nr_pages(folio);
|
|
folio_put(folio);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Process one page for __process_pages_contig().
|
|
*
|
|
* Return >0 if we hit @page == @locked_page.
|
|
* Return 0 if we updated the page status.
|
|
* Return -EGAIN if the we need to try again.
|
|
* (For PAGE_LOCK case but got dirty page or page not belong to mapping)
|
|
*/
|
|
static int process_one_page(struct btrfs_fs_info *fs_info,
|
|
struct address_space *mapping,
|
|
struct page *page, struct page *locked_page,
|
|
unsigned long page_ops, u64 start, u64 end)
|
|
{
|
|
u32 len;
|
|
|
|
ASSERT(end + 1 - start != 0 && end + 1 - start < U32_MAX);
|
|
len = end + 1 - start;
|
|
|
|
if (page_ops & PAGE_SET_ORDERED)
|
|
btrfs_page_clamp_set_ordered(fs_info, page, start, len);
|
|
if (page_ops & PAGE_SET_ERROR)
|
|
btrfs_page_clamp_set_error(fs_info, page, start, len);
|
|
if (page_ops & PAGE_START_WRITEBACK) {
|
|
btrfs_page_clamp_clear_dirty(fs_info, page, start, len);
|
|
btrfs_page_clamp_set_writeback(fs_info, page, start, len);
|
|
}
|
|
if (page_ops & PAGE_END_WRITEBACK)
|
|
btrfs_page_clamp_clear_writeback(fs_info, page, start, len);
|
|
|
|
if (page == locked_page)
|
|
return 1;
|
|
|
|
if (page_ops & PAGE_LOCK) {
|
|
int ret;
|
|
|
|
ret = btrfs_page_start_writer_lock(fs_info, page, start, len);
|
|
if (ret)
|
|
return ret;
|
|
if (!PageDirty(page) || page->mapping != mapping) {
|
|
btrfs_page_end_writer_lock(fs_info, page, start, len);
|
|
return -EAGAIN;
|
|
}
|
|
}
|
|
if (page_ops & PAGE_UNLOCK)
|
|
btrfs_page_end_writer_lock(fs_info, page, start, len);
|
|
return 0;
|
|
}
|
|
|
|
static int __process_pages_contig(struct address_space *mapping,
|
|
struct page *locked_page,
|
|
u64 start, u64 end, unsigned long page_ops,
|
|
u64 *processed_end)
|
|
{
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(mapping->host->i_sb);
|
|
pgoff_t start_index = start >> PAGE_SHIFT;
|
|
pgoff_t end_index = end >> PAGE_SHIFT;
|
|
pgoff_t index = start_index;
|
|
unsigned long pages_processed = 0;
|
|
struct folio_batch fbatch;
|
|
int err = 0;
|
|
int i;
|
|
|
|
if (page_ops & PAGE_LOCK) {
|
|
ASSERT(page_ops == PAGE_LOCK);
|
|
ASSERT(processed_end && *processed_end == start);
|
|
}
|
|
|
|
if ((page_ops & PAGE_SET_ERROR) && start_index <= end_index)
|
|
mapping_set_error(mapping, -EIO);
|
|
|
|
folio_batch_init(&fbatch);
|
|
while (index <= end_index) {
|
|
int found_folios;
|
|
|
|
found_folios = filemap_get_folios_contig(mapping, &index,
|
|
end_index, &fbatch);
|
|
|
|
if (found_folios == 0) {
|
|
/*
|
|
* Only if we're going to lock these pages, we can find
|
|
* nothing at @index.
|
|
*/
|
|
ASSERT(page_ops & PAGE_LOCK);
|
|
err = -EAGAIN;
|
|
goto out;
|
|
}
|
|
|
|
for (i = 0; i < found_folios; i++) {
|
|
int process_ret;
|
|
struct folio *folio = fbatch.folios[i];
|
|
process_ret = process_one_page(fs_info, mapping,
|
|
&folio->page, locked_page, page_ops,
|
|
start, end);
|
|
if (process_ret < 0) {
|
|
err = -EAGAIN;
|
|
folio_batch_release(&fbatch);
|
|
goto out;
|
|
}
|
|
pages_processed += folio_nr_pages(folio);
|
|
}
|
|
folio_batch_release(&fbatch);
|
|
cond_resched();
|
|
}
|
|
out:
|
|
if (err && processed_end) {
|
|
/*
|
|
* Update @processed_end. I know this is awful since it has
|
|
* two different return value patterns (inclusive vs exclusive).
|
|
*
|
|
* But the exclusive pattern is necessary if @start is 0, or we
|
|
* underflow and check against processed_end won't work as
|
|
* expected.
|
|
*/
|
|
if (pages_processed)
|
|
*processed_end = min(end,
|
|
((u64)(start_index + pages_processed) << PAGE_SHIFT) - 1);
|
|
else
|
|
*processed_end = start;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static noinline void __unlock_for_delalloc(struct inode *inode,
|
|
struct page *locked_page,
|
|
u64 start, u64 end)
|
|
{
|
|
unsigned long index = start >> PAGE_SHIFT;
|
|
unsigned long end_index = end >> PAGE_SHIFT;
|
|
|
|
ASSERT(locked_page);
|
|
if (index == locked_page->index && end_index == index)
|
|
return;
|
|
|
|
__process_pages_contig(inode->i_mapping, locked_page, start, end,
|
|
PAGE_UNLOCK, NULL);
|
|
}
|
|
|
|
static noinline int lock_delalloc_pages(struct inode *inode,
|
|
struct page *locked_page,
|
|
u64 delalloc_start,
|
|
u64 delalloc_end)
|
|
{
|
|
unsigned long index = delalloc_start >> PAGE_SHIFT;
|
|
unsigned long end_index = delalloc_end >> PAGE_SHIFT;
|
|
u64 processed_end = delalloc_start;
|
|
int ret;
|
|
|
|
ASSERT(locked_page);
|
|
if (index == locked_page->index && index == end_index)
|
|
return 0;
|
|
|
|
ret = __process_pages_contig(inode->i_mapping, locked_page, delalloc_start,
|
|
delalloc_end, PAGE_LOCK, &processed_end);
|
|
if (ret == -EAGAIN && processed_end > delalloc_start)
|
|
__unlock_for_delalloc(inode, locked_page, delalloc_start,
|
|
processed_end);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Find and lock a contiguous range of bytes in the file marked as delalloc, no
|
|
* more than @max_bytes.
|
|
*
|
|
* @start: The original start bytenr to search.
|
|
* Will store the extent range start bytenr.
|
|
* @end: The original end bytenr of the search range
|
|
* Will store the extent range end bytenr.
|
|
*
|
|
* Return true if we find a delalloc range which starts inside the original
|
|
* range, and @start/@end will store the delalloc range start/end.
|
|
*
|
|
* Return false if we can't find any delalloc range which starts inside the
|
|
* original range, and @start/@end will be the non-delalloc range start/end.
|
|
*/
|
|
EXPORT_FOR_TESTS
|
|
noinline_for_stack bool find_lock_delalloc_range(struct inode *inode,
|
|
struct page *locked_page, u64 *start,
|
|
u64 *end)
|
|
{
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
|
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
|
|
const u64 orig_start = *start;
|
|
const u64 orig_end = *end;
|
|
/* The sanity tests may not set a valid fs_info. */
|
|
u64 max_bytes = fs_info ? fs_info->max_extent_size : BTRFS_MAX_EXTENT_SIZE;
|
|
u64 delalloc_start;
|
|
u64 delalloc_end;
|
|
bool found;
|
|
struct extent_state *cached_state = NULL;
|
|
int ret;
|
|
int loops = 0;
|
|
|
|
/* Caller should pass a valid @end to indicate the search range end */
|
|
ASSERT(orig_end > orig_start);
|
|
|
|
/* The range should at least cover part of the page */
|
|
ASSERT(!(orig_start >= page_offset(locked_page) + PAGE_SIZE ||
|
|
orig_end <= page_offset(locked_page)));
|
|
again:
|
|
/* step one, find a bunch of delalloc bytes starting at start */
|
|
delalloc_start = *start;
|
|
delalloc_end = 0;
|
|
found = btrfs_find_delalloc_range(tree, &delalloc_start, &delalloc_end,
|
|
max_bytes, &cached_state);
|
|
if (!found || delalloc_end <= *start || delalloc_start > orig_end) {
|
|
*start = delalloc_start;
|
|
|
|
/* @delalloc_end can be -1, never go beyond @orig_end */
|
|
*end = min(delalloc_end, orig_end);
|
|
free_extent_state(cached_state);
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* start comes from the offset of locked_page. We have to lock
|
|
* pages in order, so we can't process delalloc bytes before
|
|
* locked_page
|
|
*/
|
|
if (delalloc_start < *start)
|
|
delalloc_start = *start;
|
|
|
|
/*
|
|
* make sure to limit the number of pages we try to lock down
|
|
*/
|
|
if (delalloc_end + 1 - delalloc_start > max_bytes)
|
|
delalloc_end = delalloc_start + max_bytes - 1;
|
|
|
|
/* step two, lock all the pages after the page that has start */
|
|
ret = lock_delalloc_pages(inode, locked_page,
|
|
delalloc_start, delalloc_end);
|
|
ASSERT(!ret || ret == -EAGAIN);
|
|
if (ret == -EAGAIN) {
|
|
/* some of the pages are gone, lets avoid looping by
|
|
* shortening the size of the delalloc range we're searching
|
|
*/
|
|
free_extent_state(cached_state);
|
|
cached_state = NULL;
|
|
if (!loops) {
|
|
max_bytes = PAGE_SIZE;
|
|
loops = 1;
|
|
goto again;
|
|
} else {
|
|
found = false;
|
|
goto out_failed;
|
|
}
|
|
}
|
|
|
|
/* step three, lock the state bits for the whole range */
|
|
lock_extent(tree, delalloc_start, delalloc_end, &cached_state);
|
|
|
|
/* then test to make sure it is all still delalloc */
|
|
ret = test_range_bit(tree, delalloc_start, delalloc_end,
|
|
EXTENT_DELALLOC, 1, cached_state);
|
|
if (!ret) {
|
|
unlock_extent(tree, delalloc_start, delalloc_end,
|
|
&cached_state);
|
|
__unlock_for_delalloc(inode, locked_page,
|
|
delalloc_start, delalloc_end);
|
|
cond_resched();
|
|
goto again;
|
|
}
|
|
free_extent_state(cached_state);
|
|
*start = delalloc_start;
|
|
*end = delalloc_end;
|
|
out_failed:
|
|
return found;
|
|
}
|
|
|
|
void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
|
|
struct page *locked_page,
|
|
u32 clear_bits, unsigned long page_ops)
|
|
{
|
|
clear_extent_bit(&inode->io_tree, start, end, clear_bits, NULL);
|
|
|
|
__process_pages_contig(inode->vfs_inode.i_mapping, locked_page,
|
|
start, end, page_ops, NULL);
|
|
}
|
|
|
|
static bool btrfs_verify_page(struct page *page, u64 start)
|
|
{
|
|
if (!fsverity_active(page->mapping->host) ||
|
|
PageError(page) || PageUptodate(page) ||
|
|
start >= i_size_read(page->mapping->host))
|
|
return true;
|
|
return fsverity_verify_page(page);
|
|
}
|
|
|
|
static void end_page_read(struct page *page, bool uptodate, u64 start, u32 len)
|
|
{
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
|
|
|
|
ASSERT(page_offset(page) <= start &&
|
|
start + len <= page_offset(page) + PAGE_SIZE);
|
|
|
|
if (uptodate && btrfs_verify_page(page, start)) {
|
|
btrfs_page_set_uptodate(fs_info, page, start, len);
|
|
} else {
|
|
btrfs_page_clear_uptodate(fs_info, page, start, len);
|
|
btrfs_page_set_error(fs_info, page, start, len);
|
|
}
|
|
|
|
if (!btrfs_is_subpage(fs_info, page))
|
|
unlock_page(page);
|
|
else
|
|
btrfs_subpage_end_reader(fs_info, page, start, len);
|
|
}
|
|
|
|
/* lots and lots of room for performance fixes in the end_bio funcs */
|
|
|
|
void end_extent_writepage(struct page *page, int err, u64 start, u64 end)
|
|
{
|
|
struct btrfs_inode *inode;
|
|
const bool uptodate = (err == 0);
|
|
int ret = 0;
|
|
|
|
ASSERT(page && page->mapping);
|
|
inode = BTRFS_I(page->mapping->host);
|
|
btrfs_writepage_endio_finish_ordered(inode, page, start, end, uptodate);
|
|
|
|
if (!uptodate) {
|
|
const struct btrfs_fs_info *fs_info = inode->root->fs_info;
|
|
u32 len;
|
|
|
|
ASSERT(end + 1 - start <= U32_MAX);
|
|
len = end + 1 - start;
|
|
|
|
btrfs_page_clear_uptodate(fs_info, page, start, len);
|
|
btrfs_page_set_error(fs_info, page, start, len);
|
|
ret = err < 0 ? err : -EIO;
|
|
mapping_set_error(page->mapping, ret);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* after a writepage IO is done, we need to:
|
|
* clear the uptodate bits on error
|
|
* clear the writeback bits in the extent tree for this IO
|
|
* end_page_writeback if the page has no more pending IO
|
|
*
|
|
* Scheduling is not allowed, so the extent state tree is expected
|
|
* to have one and only one object corresponding to this IO.
|
|
*/
|
|
static void end_bio_extent_writepage(struct btrfs_bio *bbio)
|
|
{
|
|
struct bio *bio = &bbio->bio;
|
|
int error = blk_status_to_errno(bio->bi_status);
|
|
struct bio_vec *bvec;
|
|
u64 start;
|
|
u64 end;
|
|
struct bvec_iter_all iter_all;
|
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED));
|
|
bio_for_each_segment_all(bvec, bio, iter_all) {
|
|
struct page *page = bvec->bv_page;
|
|
struct inode *inode = page->mapping->host;
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
|
const u32 sectorsize = fs_info->sectorsize;
|
|
|
|
/* Our read/write should always be sector aligned. */
|
|
if (!IS_ALIGNED(bvec->bv_offset, sectorsize))
|
|
btrfs_err(fs_info,
|
|
"partial page write in btrfs with offset %u and length %u",
|
|
bvec->bv_offset, bvec->bv_len);
|
|
else if (!IS_ALIGNED(bvec->bv_len, sectorsize))
|
|
btrfs_info(fs_info,
|
|
"incomplete page write with offset %u and length %u",
|
|
bvec->bv_offset, bvec->bv_len);
|
|
|
|
start = page_offset(page) + bvec->bv_offset;
|
|
end = start + bvec->bv_len - 1;
|
|
|
|
end_extent_writepage(page, error, start, end);
|
|
|
|
btrfs_page_clear_writeback(fs_info, page, start, bvec->bv_len);
|
|
}
|
|
|
|
bio_put(bio);
|
|
}
|
|
|
|
/*
|
|
* Record previously processed extent range
|
|
*
|
|
* For endio_readpage_release_extent() to handle a full extent range, reducing
|
|
* the extent io operations.
|
|
*/
|
|
struct processed_extent {
|
|
struct btrfs_inode *inode;
|
|
/* Start of the range in @inode */
|
|
u64 start;
|
|
/* End of the range in @inode */
|
|
u64 end;
|
|
bool uptodate;
|
|
};
|
|
|
|
/*
|
|
* Try to release processed extent range
|
|
*
|
|
* May not release the extent range right now if the current range is
|
|
* contiguous to processed extent.
|
|
*
|
|
* Will release processed extent when any of @inode, @uptodate, the range is
|
|
* no longer contiguous to the processed range.
|
|
*
|
|
* Passing @inode == NULL will force processed extent to be released.
|
|
*/
|
|
static void endio_readpage_release_extent(struct processed_extent *processed,
|
|
struct btrfs_inode *inode, u64 start, u64 end,
|
|
bool uptodate)
|
|
{
|
|
struct extent_state *cached = NULL;
|
|
struct extent_io_tree *tree;
|
|
|
|
/* The first extent, initialize @processed */
|
|
if (!processed->inode)
|
|
goto update;
|
|
|
|
/*
|
|
* Contiguous to processed extent, just uptodate the end.
|
|
*
|
|
* Several things to notice:
|
|
*
|
|
* - bio can be merged as long as on-disk bytenr is contiguous
|
|
* This means we can have page belonging to other inodes, thus need to
|
|
* check if the inode still matches.
|
|
* - bvec can contain range beyond current page for multi-page bvec
|
|
* Thus we need to do processed->end + 1 >= start check
|
|
*/
|
|
if (processed->inode == inode && processed->uptodate == uptodate &&
|
|
processed->end + 1 >= start && end >= processed->end) {
|
|
processed->end = end;
|
|
return;
|
|
}
|
|
|
|
tree = &processed->inode->io_tree;
|
|
/*
|
|
* Now we don't have range contiguous to the processed range, release
|
|
* the processed range now.
|
|
*/
|
|
unlock_extent(tree, processed->start, processed->end, &cached);
|
|
|
|
update:
|
|
/* Update processed to current range */
|
|
processed->inode = inode;
|
|
processed->start = start;
|
|
processed->end = end;
|
|
processed->uptodate = uptodate;
|
|
}
|
|
|
|
static void begin_page_read(struct btrfs_fs_info *fs_info, struct page *page)
|
|
{
|
|
ASSERT(PageLocked(page));
|
|
if (!btrfs_is_subpage(fs_info, page))
|
|
return;
|
|
|
|
ASSERT(PagePrivate(page));
|
|
btrfs_subpage_start_reader(fs_info, page, page_offset(page), PAGE_SIZE);
|
|
}
|
|
|
|
/*
|
|
* Find extent buffer for a givne bytenr.
|
|
*
|
|
* This is for end_bio_extent_readpage(), thus we can't do any unsafe locking
|
|
* in endio context.
|
|
*/
|
|
static struct extent_buffer *find_extent_buffer_readpage(
|
|
struct btrfs_fs_info *fs_info, struct page *page, u64 bytenr)
|
|
{
|
|
struct extent_buffer *eb;
|
|
|
|
/*
|
|
* For regular sectorsize, we can use page->private to grab extent
|
|
* buffer
|
|
*/
|
|
if (fs_info->nodesize >= PAGE_SIZE) {
|
|
ASSERT(PagePrivate(page) && page->private);
|
|
return (struct extent_buffer *)page->private;
|
|
}
|
|
|
|
/* For subpage case, we need to lookup buffer radix tree */
|
|
rcu_read_lock();
|
|
eb = radix_tree_lookup(&fs_info->buffer_radix,
|
|
bytenr >> fs_info->sectorsize_bits);
|
|
rcu_read_unlock();
|
|
ASSERT(eb);
|
|
return eb;
|
|
}
|
|
|
|
/*
|
|
* after a readpage IO is done, we need to:
|
|
* clear the uptodate bits on error
|
|
* set the uptodate bits if things worked
|
|
* set the page up to date if all extents in the tree are uptodate
|
|
* clear the lock bit in the extent tree
|
|
* unlock the page if there are no other extents locked for it
|
|
*
|
|
* Scheduling is not allowed, so the extent state tree is expected
|
|
* to have one and only one object corresponding to this IO.
|
|
*/
|
|
static void end_bio_extent_readpage(struct btrfs_bio *bbio)
|
|
{
|
|
struct bio *bio = &bbio->bio;
|
|
struct bio_vec *bvec;
|
|
struct processed_extent processed = { 0 };
|
|
/*
|
|
* The offset to the beginning of a bio, since one bio can never be
|
|
* larger than UINT_MAX, u32 here is enough.
|
|
*/
|
|
u32 bio_offset = 0;
|
|
int mirror;
|
|
struct bvec_iter_all iter_all;
|
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED));
|
|
bio_for_each_segment_all(bvec, bio, iter_all) {
|
|
bool uptodate = !bio->bi_status;
|
|
struct page *page = bvec->bv_page;
|
|
struct inode *inode = page->mapping->host;
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
|
const u32 sectorsize = fs_info->sectorsize;
|
|
u64 start;
|
|
u64 end;
|
|
u32 len;
|
|
|
|
btrfs_debug(fs_info,
|
|
"end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u",
|
|
bio->bi_iter.bi_sector, bio->bi_status,
|
|
bbio->mirror_num);
|
|
|
|
/*
|
|
* We always issue full-sector reads, but if some block in a
|
|
* page fails to read, blk_update_request() will advance
|
|
* bv_offset and adjust bv_len to compensate. Print a warning
|
|
* for unaligned offsets, and an error if they don't add up to
|
|
* a full sector.
|
|
*/
|
|
if (!IS_ALIGNED(bvec->bv_offset, sectorsize))
|
|
btrfs_err(fs_info,
|
|
"partial page read in btrfs with offset %u and length %u",
|
|
bvec->bv_offset, bvec->bv_len);
|
|
else if (!IS_ALIGNED(bvec->bv_offset + bvec->bv_len,
|
|
sectorsize))
|
|
btrfs_info(fs_info,
|
|
"incomplete page read with offset %u and length %u",
|
|
bvec->bv_offset, bvec->bv_len);
|
|
|
|
start = page_offset(page) + bvec->bv_offset;
|
|
end = start + bvec->bv_len - 1;
|
|
len = bvec->bv_len;
|
|
|
|
mirror = bbio->mirror_num;
|
|
if (uptodate && !is_data_inode(inode) &&
|
|
btrfs_validate_metadata_buffer(bbio, page, start, end, mirror))
|
|
uptodate = false;
|
|
|
|
if (likely(uptodate)) {
|
|
loff_t i_size = i_size_read(inode);
|
|
pgoff_t end_index = i_size >> PAGE_SHIFT;
|
|
|
|
/*
|
|
* Zero out the remaining part if this range straddles
|
|
* i_size.
|
|
*
|
|
* Here we should only zero the range inside the bvec,
|
|
* not touch anything else.
|
|
*
|
|
* NOTE: i_size is exclusive while end is inclusive.
|
|
*/
|
|
if (page->index == end_index && i_size <= end) {
|
|
u32 zero_start = max(offset_in_page(i_size),
|
|
offset_in_page(start));
|
|
|
|
zero_user_segment(page, zero_start,
|
|
offset_in_page(end) + 1);
|
|
}
|
|
} else if (!is_data_inode(inode)) {
|
|
struct extent_buffer *eb;
|
|
|
|
eb = find_extent_buffer_readpage(fs_info, page, start);
|
|
set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
|
|
eb->read_mirror = mirror;
|
|
atomic_dec(&eb->io_pages);
|
|
}
|
|
|
|
/* Update page status and unlock. */
|
|
end_page_read(page, uptodate, start, len);
|
|
endio_readpage_release_extent(&processed, BTRFS_I(inode),
|
|
start, end, PageUptodate(page));
|
|
|
|
ASSERT(bio_offset + len > bio_offset);
|
|
bio_offset += len;
|
|
|
|
}
|
|
/* Release the last extent */
|
|
endio_readpage_release_extent(&processed, NULL, 0, 0, false);
|
|
bio_put(bio);
|
|
}
|
|
|
|
/*
|
|
* Populate every free slot in a provided array with pages.
|
|
*
|
|
* @nr_pages: number of pages to allocate
|
|
* @page_array: the array to fill with pages; any existing non-null entries in
|
|
* the array will be skipped
|
|
*
|
|
* Return: 0 if all pages were able to be allocated;
|
|
* -ENOMEM otherwise, and the caller is responsible for freeing all
|
|
* non-null page pointers in the array.
|
|
*/
|
|
int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array)
|
|
{
|
|
unsigned int allocated;
|
|
|
|
for (allocated = 0; allocated < nr_pages;) {
|
|
unsigned int last = allocated;
|
|
|
|
allocated = alloc_pages_bulk_array(GFP_NOFS, nr_pages, page_array);
|
|
|
|
if (allocated == nr_pages)
|
|
return 0;
|
|
|
|
/*
|
|
* During this iteration, no page could be allocated, even
|
|
* though alloc_pages_bulk_array() falls back to alloc_page()
|
|
* if it could not bulk-allocate. So we must be out of memory.
|
|
*/
|
|
if (allocated == last)
|
|
return -ENOMEM;
|
|
|
|
memalloc_retry_wait(GFP_NOFS);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static bool btrfs_bio_is_contig(struct btrfs_bio_ctrl *bio_ctrl,
|
|
struct page *page, u64 disk_bytenr,
|
|
unsigned int pg_offset)
|
|
{
|
|
struct bio *bio = &bio_ctrl->bbio->bio;
|
|
struct bio_vec *bvec = bio_last_bvec_all(bio);
|
|
const sector_t sector = disk_bytenr >> SECTOR_SHIFT;
|
|
|
|
if (bio_ctrl->compress_type != BTRFS_COMPRESS_NONE) {
|
|
/*
|
|
* For compression, all IO should have its logical bytenr set
|
|
* to the starting bytenr of the compressed extent.
|
|
*/
|
|
return bio->bi_iter.bi_sector == sector;
|
|
}
|
|
|
|
/*
|
|
* The contig check requires the following conditions to be met:
|
|
*
|
|
* 1) The pages are belonging to the same inode
|
|
* This is implied by the call chain.
|
|
*
|
|
* 2) The range has adjacent logical bytenr
|
|
*
|
|
* 3) The range has adjacent file offset
|
|
* This is required for the usage of btrfs_bio->file_offset.
|
|
*/
|
|
return bio_end_sector(bio) == sector &&
|
|
page_offset(bvec->bv_page) + bvec->bv_offset + bvec->bv_len ==
|
|
page_offset(page) + pg_offset;
|
|
}
|
|
|
|
static void alloc_new_bio(struct btrfs_inode *inode,
|
|
struct btrfs_bio_ctrl *bio_ctrl,
|
|
u64 disk_bytenr, u64 file_offset)
|
|
{
|
|
struct btrfs_fs_info *fs_info = inode->root->fs_info;
|
|
struct btrfs_bio *bbio;
|
|
|
|
bbio = btrfs_bio_alloc(BIO_MAX_VECS, bio_ctrl->opf, fs_info,
|
|
bio_ctrl->end_io_func, NULL);
|
|
bbio->bio.bi_iter.bi_sector = disk_bytenr >> SECTOR_SHIFT;
|
|
bbio->inode = inode;
|
|
bbio->file_offset = file_offset;
|
|
bio_ctrl->bbio = bbio;
|
|
bio_ctrl->len_to_oe_boundary = U32_MAX;
|
|
|
|
/*
|
|
* Limit the extent to the ordered boundary for Zone Append.
|
|
* Compressed bios aren't submitted directly, so it doesn't apply to
|
|
* them.
|
|
*/
|
|
if (bio_ctrl->compress_type == BTRFS_COMPRESS_NONE &&
|
|
btrfs_use_zone_append(bbio)) {
|
|
struct btrfs_ordered_extent *ordered;
|
|
|
|
ordered = btrfs_lookup_ordered_extent(inode, file_offset);
|
|
if (ordered) {
|
|
bio_ctrl->len_to_oe_boundary = min_t(u32, U32_MAX,
|
|
ordered->file_offset +
|
|
ordered->disk_num_bytes - file_offset);
|
|
btrfs_put_ordered_extent(ordered);
|
|
}
|
|
}
|
|
|
|
if (bio_ctrl->wbc) {
|
|
/*
|
|
* Pick the last added device to support cgroup writeback. For
|
|
* multi-device file systems this means blk-cgroup policies have
|
|
* to always be set on the last added/replaced device.
|
|
* This is a bit odd but has been like that for a long time.
|
|
*/
|
|
bio_set_dev(&bbio->bio, fs_info->fs_devices->latest_dev->bdev);
|
|
wbc_init_bio(bio_ctrl->wbc, &bbio->bio);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* @disk_bytenr: logical bytenr where the write will be
|
|
* @page: page to add to the bio
|
|
* @size: portion of page that we want to write to
|
|
* @pg_offset: offset of the new bio or to check whether we are adding
|
|
* a contiguous page to the previous one
|
|
*
|
|
* The will either add the page into the existing @bio_ctrl->bbio, or allocate a
|
|
* new one in @bio_ctrl->bbio.
|
|
* The mirror number for this IO should already be initizlied in
|
|
* @bio_ctrl->mirror_num.
|
|
*/
|
|
static void submit_extent_page(struct btrfs_bio_ctrl *bio_ctrl,
|
|
u64 disk_bytenr, struct page *page,
|
|
size_t size, unsigned long pg_offset)
|
|
{
|
|
struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
|
|
|
|
ASSERT(pg_offset + size <= PAGE_SIZE);
|
|
ASSERT(bio_ctrl->end_io_func);
|
|
|
|
if (bio_ctrl->bbio &&
|
|
!btrfs_bio_is_contig(bio_ctrl, page, disk_bytenr, pg_offset))
|
|
submit_one_bio(bio_ctrl);
|
|
|
|
do {
|
|
u32 len = size;
|
|
|
|
/* Allocate new bio if needed */
|
|
if (!bio_ctrl->bbio) {
|
|
alloc_new_bio(inode, bio_ctrl, disk_bytenr,
|
|
page_offset(page) + pg_offset);
|
|
}
|
|
|
|
/* Cap to the current ordered extent boundary if there is one. */
|
|
if (len > bio_ctrl->len_to_oe_boundary) {
|
|
ASSERT(bio_ctrl->compress_type == BTRFS_COMPRESS_NONE);
|
|
ASSERT(is_data_inode(&inode->vfs_inode));
|
|
len = bio_ctrl->len_to_oe_boundary;
|
|
}
|
|
|
|
if (bio_add_page(&bio_ctrl->bbio->bio, page, len, pg_offset) != len) {
|
|
/* bio full: move on to a new one */
|
|
submit_one_bio(bio_ctrl);
|
|
continue;
|
|
}
|
|
|
|
if (bio_ctrl->wbc)
|
|
wbc_account_cgroup_owner(bio_ctrl->wbc, page, len);
|
|
|
|
size -= len;
|
|
pg_offset += len;
|
|
disk_bytenr += len;
|
|
bio_ctrl->len_to_oe_boundary -= len;
|
|
|
|
/* Ordered extent boundary: move on to a new bio. */
|
|
if (bio_ctrl->len_to_oe_boundary == 0)
|
|
submit_one_bio(bio_ctrl);
|
|
} while (size);
|
|
}
|
|
|
|
static int attach_extent_buffer_page(struct extent_buffer *eb,
|
|
struct page *page,
|
|
struct btrfs_subpage *prealloc)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
int ret = 0;
|
|
|
|
/*
|
|
* If the page is mapped to btree inode, we should hold the private
|
|
* lock to prevent race.
|
|
* For cloned or dummy extent buffers, their pages are not mapped and
|
|
* will not race with any other ebs.
|
|
*/
|
|
if (page->mapping)
|
|
lockdep_assert_held(&page->mapping->private_lock);
|
|
|
|
if (fs_info->nodesize >= PAGE_SIZE) {
|
|
if (!PagePrivate(page))
|
|
attach_page_private(page, eb);
|
|
else
|
|
WARN_ON(page->private != (unsigned long)eb);
|
|
return 0;
|
|
}
|
|
|
|
/* Already mapped, just free prealloc */
|
|
if (PagePrivate(page)) {
|
|
btrfs_free_subpage(prealloc);
|
|
return 0;
|
|
}
|
|
|
|
if (prealloc)
|
|
/* Has preallocated memory for subpage */
|
|
attach_page_private(page, prealloc);
|
|
else
|
|
/* Do new allocation to attach subpage */
|
|
ret = btrfs_attach_subpage(fs_info, page,
|
|
BTRFS_SUBPAGE_METADATA);
|
|
return ret;
|
|
}
|
|
|
|
int set_page_extent_mapped(struct page *page)
|
|
{
|
|
struct btrfs_fs_info *fs_info;
|
|
|
|
ASSERT(page->mapping);
|
|
|
|
if (PagePrivate(page))
|
|
return 0;
|
|
|
|
fs_info = btrfs_sb(page->mapping->host->i_sb);
|
|
|
|
if (btrfs_is_subpage(fs_info, page))
|
|
return btrfs_attach_subpage(fs_info, page, BTRFS_SUBPAGE_DATA);
|
|
|
|
attach_page_private(page, (void *)EXTENT_PAGE_PRIVATE);
|
|
return 0;
|
|
}
|
|
|
|
void clear_page_extent_mapped(struct page *page)
|
|
{
|
|
struct btrfs_fs_info *fs_info;
|
|
|
|
ASSERT(page->mapping);
|
|
|
|
if (!PagePrivate(page))
|
|
return;
|
|
|
|
fs_info = btrfs_sb(page->mapping->host->i_sb);
|
|
if (btrfs_is_subpage(fs_info, page))
|
|
return btrfs_detach_subpage(fs_info, page);
|
|
|
|
detach_page_private(page);
|
|
}
|
|
|
|
static struct extent_map *
|
|
__get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
|
|
u64 start, u64 len, struct extent_map **em_cached)
|
|
{
|
|
struct extent_map *em;
|
|
|
|
if (em_cached && *em_cached) {
|
|
em = *em_cached;
|
|
if (extent_map_in_tree(em) && start >= em->start &&
|
|
start < extent_map_end(em)) {
|
|
refcount_inc(&em->refs);
|
|
return em;
|
|
}
|
|
|
|
free_extent_map(em);
|
|
*em_cached = NULL;
|
|
}
|
|
|
|
em = btrfs_get_extent(BTRFS_I(inode), page, pg_offset, start, len);
|
|
if (em_cached && !IS_ERR(em)) {
|
|
BUG_ON(*em_cached);
|
|
refcount_inc(&em->refs);
|
|
*em_cached = em;
|
|
}
|
|
return em;
|
|
}
|
|
/*
|
|
* basic readpage implementation. Locked extent state structs are inserted
|
|
* into the tree that are removed when the IO is done (by the end_io
|
|
* handlers)
|
|
* XXX JDM: This needs looking at to ensure proper page locking
|
|
* return 0 on success, otherwise return error
|
|
*/
|
|
static int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
|
|
struct btrfs_bio_ctrl *bio_ctrl, u64 *prev_em_start)
|
|
{
|
|
struct inode *inode = page->mapping->host;
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
|
u64 start = page_offset(page);
|
|
const u64 end = start + PAGE_SIZE - 1;
|
|
u64 cur = start;
|
|
u64 extent_offset;
|
|
u64 last_byte = i_size_read(inode);
|
|
u64 block_start;
|
|
struct extent_map *em;
|
|
int ret = 0;
|
|
size_t pg_offset = 0;
|
|
size_t iosize;
|
|
size_t blocksize = inode->i_sb->s_blocksize;
|
|
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
|
|
|
|
ret = set_page_extent_mapped(page);
|
|
if (ret < 0) {
|
|
unlock_extent(tree, start, end, NULL);
|
|
btrfs_page_set_error(fs_info, page, start, PAGE_SIZE);
|
|
unlock_page(page);
|
|
return ret;
|
|
}
|
|
|
|
if (page->index == last_byte >> PAGE_SHIFT) {
|
|
size_t zero_offset = offset_in_page(last_byte);
|
|
|
|
if (zero_offset) {
|
|
iosize = PAGE_SIZE - zero_offset;
|
|
memzero_page(page, zero_offset, iosize);
|
|
}
|
|
}
|
|
bio_ctrl->end_io_func = end_bio_extent_readpage;
|
|
begin_page_read(fs_info, page);
|
|
while (cur <= end) {
|
|
enum btrfs_compression_type compress_type = BTRFS_COMPRESS_NONE;
|
|
bool force_bio_submit = false;
|
|
u64 disk_bytenr;
|
|
|
|
ASSERT(IS_ALIGNED(cur, fs_info->sectorsize));
|
|
if (cur >= last_byte) {
|
|
iosize = PAGE_SIZE - pg_offset;
|
|
memzero_page(page, pg_offset, iosize);
|
|
unlock_extent(tree, cur, cur + iosize - 1, NULL);
|
|
end_page_read(page, true, cur, iosize);
|
|
break;
|
|
}
|
|
em = __get_extent_map(inode, page, pg_offset, cur,
|
|
end - cur + 1, em_cached);
|
|
if (IS_ERR(em)) {
|
|
unlock_extent(tree, cur, end, NULL);
|
|
end_page_read(page, false, cur, end + 1 - cur);
|
|
return PTR_ERR(em);
|
|
}
|
|
extent_offset = cur - em->start;
|
|
BUG_ON(extent_map_end(em) <= cur);
|
|
BUG_ON(end < cur);
|
|
|
|
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
|
|
compress_type = em->compress_type;
|
|
|
|
iosize = min(extent_map_end(em) - cur, end - cur + 1);
|
|
iosize = ALIGN(iosize, blocksize);
|
|
if (compress_type != BTRFS_COMPRESS_NONE)
|
|
disk_bytenr = em->block_start;
|
|
else
|
|
disk_bytenr = em->block_start + extent_offset;
|
|
block_start = em->block_start;
|
|
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
|
|
block_start = EXTENT_MAP_HOLE;
|
|
|
|
/*
|
|
* If we have a file range that points to a compressed extent
|
|
* and it's followed by a consecutive file range that points
|
|
* to the same compressed extent (possibly with a different
|
|
* offset and/or length, so it either points to the whole extent
|
|
* or only part of it), we must make sure we do not submit a
|
|
* single bio to populate the pages for the 2 ranges because
|
|
* this makes the compressed extent read zero out the pages
|
|
* belonging to the 2nd range. Imagine the following scenario:
|
|
*
|
|
* File layout
|
|
* [0 - 8K] [8K - 24K]
|
|
* | |
|
|
* | |
|
|
* points to extent X, points to extent X,
|
|
* offset 4K, length of 8K offset 0, length 16K
|
|
*
|
|
* [extent X, compressed length = 4K uncompressed length = 16K]
|
|
*
|
|
* If the bio to read the compressed extent covers both ranges,
|
|
* it will decompress extent X into the pages belonging to the
|
|
* first range and then it will stop, zeroing out the remaining
|
|
* pages that belong to the other range that points to extent X.
|
|
* So here we make sure we submit 2 bios, one for the first
|
|
* range and another one for the third range. Both will target
|
|
* the same physical extent from disk, but we can't currently
|
|
* make the compressed bio endio callback populate the pages
|
|
* for both ranges because each compressed bio is tightly
|
|
* coupled with a single extent map, and each range can have
|
|
* an extent map with a different offset value relative to the
|
|
* uncompressed data of our extent and different lengths. This
|
|
* is a corner case so we prioritize correctness over
|
|
* non-optimal behavior (submitting 2 bios for the same extent).
|
|
*/
|
|
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
|
|
prev_em_start && *prev_em_start != (u64)-1 &&
|
|
*prev_em_start != em->start)
|
|
force_bio_submit = true;
|
|
|
|
if (prev_em_start)
|
|
*prev_em_start = em->start;
|
|
|
|
free_extent_map(em);
|
|
em = NULL;
|
|
|
|
/* we've found a hole, just zero and go on */
|
|
if (block_start == EXTENT_MAP_HOLE) {
|
|
memzero_page(page, pg_offset, iosize);
|
|
|
|
unlock_extent(tree, cur, cur + iosize - 1, NULL);
|
|
end_page_read(page, true, cur, iosize);
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
continue;
|
|
}
|
|
/* the get_extent function already copied into the page */
|
|
if (block_start == EXTENT_MAP_INLINE) {
|
|
unlock_extent(tree, cur, cur + iosize - 1, NULL);
|
|
end_page_read(page, true, cur, iosize);
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
continue;
|
|
}
|
|
|
|
if (bio_ctrl->compress_type != compress_type) {
|
|
submit_one_bio(bio_ctrl);
|
|
bio_ctrl->compress_type = compress_type;
|
|
}
|
|
|
|
if (force_bio_submit)
|
|
submit_one_bio(bio_ctrl);
|
|
submit_extent_page(bio_ctrl, disk_bytenr, page, iosize,
|
|
pg_offset);
|
|
cur = cur + iosize;
|
|
pg_offset += iosize;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int btrfs_read_folio(struct file *file, struct folio *folio)
|
|
{
|
|
struct page *page = &folio->page;
|
|
struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
|
|
u64 start = page_offset(page);
|
|
u64 end = start + PAGE_SIZE - 1;
|
|
struct btrfs_bio_ctrl bio_ctrl = { .opf = REQ_OP_READ };
|
|
int ret;
|
|
|
|
btrfs_lock_and_flush_ordered_range(inode, start, end, NULL);
|
|
|
|
ret = btrfs_do_readpage(page, NULL, &bio_ctrl, NULL);
|
|
/*
|
|
* If btrfs_do_readpage() failed we will want to submit the assembled
|
|
* bio to do the cleanup.
|
|
*/
|
|
submit_one_bio(&bio_ctrl);
|
|
return ret;
|
|
}
|
|
|
|
static inline void contiguous_readpages(struct page *pages[], int nr_pages,
|
|
u64 start, u64 end,
|
|
struct extent_map **em_cached,
|
|
struct btrfs_bio_ctrl *bio_ctrl,
|
|
u64 *prev_em_start)
|
|
{
|
|
struct btrfs_inode *inode = BTRFS_I(pages[0]->mapping->host);
|
|
int index;
|
|
|
|
btrfs_lock_and_flush_ordered_range(inode, start, end, NULL);
|
|
|
|
for (index = 0; index < nr_pages; index++) {
|
|
btrfs_do_readpage(pages[index], em_cached, bio_ctrl,
|
|
prev_em_start);
|
|
put_page(pages[index]);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* helper for __extent_writepage, doing all of the delayed allocation setup.
|
|
*
|
|
* This returns 1 if btrfs_run_delalloc_range function did all the work required
|
|
* to write the page (copy into inline extent). In this case the IO has
|
|
* been started and the page is already unlocked.
|
|
*
|
|
* This returns 0 if all went well (page still locked)
|
|
* This returns < 0 if there were errors (page still locked)
|
|
*/
|
|
static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode,
|
|
struct page *page, struct writeback_control *wbc)
|
|
{
|
|
const u64 page_end = page_offset(page) + PAGE_SIZE - 1;
|
|
u64 delalloc_start = page_offset(page);
|
|
u64 delalloc_to_write = 0;
|
|
/* How many pages are started by btrfs_run_delalloc_range() */
|
|
unsigned long nr_written = 0;
|
|
int ret;
|
|
int page_started = 0;
|
|
|
|
while (delalloc_start < page_end) {
|
|
u64 delalloc_end = page_end;
|
|
bool found;
|
|
|
|
found = find_lock_delalloc_range(&inode->vfs_inode, page,
|
|
&delalloc_start,
|
|
&delalloc_end);
|
|
if (!found) {
|
|
delalloc_start = delalloc_end + 1;
|
|
continue;
|
|
}
|
|
ret = btrfs_run_delalloc_range(inode, page, delalloc_start,
|
|
delalloc_end, &page_started, &nr_written, wbc);
|
|
if (ret) {
|
|
btrfs_page_set_error(inode->root->fs_info, page,
|
|
page_offset(page), PAGE_SIZE);
|
|
return ret;
|
|
}
|
|
/*
|
|
* delalloc_end is already one less than the total length, so
|
|
* we don't subtract one from PAGE_SIZE
|
|
*/
|
|
delalloc_to_write += (delalloc_end - delalloc_start +
|
|
PAGE_SIZE) >> PAGE_SHIFT;
|
|
delalloc_start = delalloc_end + 1;
|
|
}
|
|
if (wbc->nr_to_write < delalloc_to_write) {
|
|
int thresh = 8192;
|
|
|
|
if (delalloc_to_write < thresh * 2)
|
|
thresh = delalloc_to_write;
|
|
wbc->nr_to_write = min_t(u64, delalloc_to_write,
|
|
thresh);
|
|
}
|
|
|
|
/* Did btrfs_run_dealloc_range() already unlock and start the IO? */
|
|
if (page_started) {
|
|
/*
|
|
* We've unlocked the page, so we can't update the mapping's
|
|
* writeback index, just update nr_to_write.
|
|
*/
|
|
wbc->nr_to_write -= nr_written;
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Find the first byte we need to write.
|
|
*
|
|
* For subpage, one page can contain several sectors, and
|
|
* __extent_writepage_io() will just grab all extent maps in the page
|
|
* range and try to submit all non-inline/non-compressed extents.
|
|
*
|
|
* This is a big problem for subpage, we shouldn't re-submit already written
|
|
* data at all.
|
|
* This function will lookup subpage dirty bit to find which range we really
|
|
* need to submit.
|
|
*
|
|
* Return the next dirty range in [@start, @end).
|
|
* If no dirty range is found, @start will be page_offset(page) + PAGE_SIZE.
|
|
*/
|
|
static void find_next_dirty_byte(struct btrfs_fs_info *fs_info,
|
|
struct page *page, u64 *start, u64 *end)
|
|
{
|
|
struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private;
|
|
struct btrfs_subpage_info *spi = fs_info->subpage_info;
|
|
u64 orig_start = *start;
|
|
/* Declare as unsigned long so we can use bitmap ops */
|
|
unsigned long flags;
|
|
int range_start_bit;
|
|
int range_end_bit;
|
|
|
|
/*
|
|
* For regular sector size == page size case, since one page only
|
|
* contains one sector, we return the page offset directly.
|
|
*/
|
|
if (!btrfs_is_subpage(fs_info, page)) {
|
|
*start = page_offset(page);
|
|
*end = page_offset(page) + PAGE_SIZE;
|
|
return;
|
|
}
|
|
|
|
range_start_bit = spi->dirty_offset +
|
|
(offset_in_page(orig_start) >> fs_info->sectorsize_bits);
|
|
|
|
/* We should have the page locked, but just in case */
|
|
spin_lock_irqsave(&subpage->lock, flags);
|
|
bitmap_next_set_region(subpage->bitmaps, &range_start_bit, &range_end_bit,
|
|
spi->dirty_offset + spi->bitmap_nr_bits);
|
|
spin_unlock_irqrestore(&subpage->lock, flags);
|
|
|
|
range_start_bit -= spi->dirty_offset;
|
|
range_end_bit -= spi->dirty_offset;
|
|
|
|
*start = page_offset(page) + range_start_bit * fs_info->sectorsize;
|
|
*end = page_offset(page) + range_end_bit * fs_info->sectorsize;
|
|
}
|
|
|
|
/*
|
|
* helper for __extent_writepage. This calls the writepage start hooks,
|
|
* and does the loop to map the page into extents and bios.
|
|
*
|
|
* We return 1 if the IO is started and the page is unlocked,
|
|
* 0 if all went well (page still locked)
|
|
* < 0 if there were errors (page still locked)
|
|
*/
|
|
static noinline_for_stack int __extent_writepage_io(struct btrfs_inode *inode,
|
|
struct page *page,
|
|
struct btrfs_bio_ctrl *bio_ctrl,
|
|
loff_t i_size,
|
|
int *nr_ret)
|
|
{
|
|
struct btrfs_fs_info *fs_info = inode->root->fs_info;
|
|
u64 cur = page_offset(page);
|
|
u64 end = cur + PAGE_SIZE - 1;
|
|
u64 extent_offset;
|
|
u64 block_start;
|
|
struct extent_map *em;
|
|
int ret = 0;
|
|
int nr = 0;
|
|
bool compressed;
|
|
|
|
ret = btrfs_writepage_cow_fixup(page);
|
|
if (ret) {
|
|
/* Fixup worker will requeue */
|
|
redirty_page_for_writepage(bio_ctrl->wbc, page);
|
|
unlock_page(page);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* we don't want to touch the inode after unlocking the page,
|
|
* so we update the mapping writeback index now
|
|
*/
|
|
bio_ctrl->wbc->nr_to_write--;
|
|
|
|
bio_ctrl->end_io_func = end_bio_extent_writepage;
|
|
while (cur <= end) {
|
|
u64 disk_bytenr;
|
|
u64 em_end;
|
|
u64 dirty_range_start = cur;
|
|
u64 dirty_range_end;
|
|
u32 iosize;
|
|
|
|
if (cur >= i_size) {
|
|
btrfs_writepage_endio_finish_ordered(inode, page, cur,
|
|
end, true);
|
|
/*
|
|
* This range is beyond i_size, thus we don't need to
|
|
* bother writing back.
|
|
* But we still need to clear the dirty subpage bit, or
|
|
* the next time the page gets dirtied, we will try to
|
|
* writeback the sectors with subpage dirty bits,
|
|
* causing writeback without ordered extent.
|
|
*/
|
|
btrfs_page_clear_dirty(fs_info, page, cur, end + 1 - cur);
|
|
break;
|
|
}
|
|
|
|
find_next_dirty_byte(fs_info, page, &dirty_range_start,
|
|
&dirty_range_end);
|
|
if (cur < dirty_range_start) {
|
|
cur = dirty_range_start;
|
|
continue;
|
|
}
|
|
|
|
em = btrfs_get_extent(inode, NULL, 0, cur, end - cur + 1);
|
|
if (IS_ERR(em)) {
|
|
btrfs_page_set_error(fs_info, page, cur, end - cur + 1);
|
|
ret = PTR_ERR_OR_ZERO(em);
|
|
goto out_error;
|
|
}
|
|
|
|
extent_offset = cur - em->start;
|
|
em_end = extent_map_end(em);
|
|
ASSERT(cur <= em_end);
|
|
ASSERT(cur < end);
|
|
ASSERT(IS_ALIGNED(em->start, fs_info->sectorsize));
|
|
ASSERT(IS_ALIGNED(em->len, fs_info->sectorsize));
|
|
block_start = em->block_start;
|
|
compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
|
|
disk_bytenr = em->block_start + extent_offset;
|
|
|
|
/*
|
|
* Note that em_end from extent_map_end() and dirty_range_end from
|
|
* find_next_dirty_byte() are all exclusive
|
|
*/
|
|
iosize = min(min(em_end, end + 1), dirty_range_end) - cur;
|
|
free_extent_map(em);
|
|
em = NULL;
|
|
|
|
/*
|
|
* compressed and inline extents are written through other
|
|
* paths in the FS
|
|
*/
|
|
if (compressed || block_start == EXTENT_MAP_HOLE ||
|
|
block_start == EXTENT_MAP_INLINE) {
|
|
if (compressed)
|
|
nr++;
|
|
else
|
|
btrfs_writepage_endio_finish_ordered(inode,
|
|
page, cur, cur + iosize - 1, true);
|
|
btrfs_page_clear_dirty(fs_info, page, cur, iosize);
|
|
cur += iosize;
|
|
continue;
|
|
}
|
|
|
|
btrfs_set_range_writeback(inode, cur, cur + iosize - 1);
|
|
if (!PageWriteback(page)) {
|
|
btrfs_err(inode->root->fs_info,
|
|
"page %lu not writeback, cur %llu end %llu",
|
|
page->index, cur, end);
|
|
}
|
|
|
|
/*
|
|
* Although the PageDirty bit is cleared before entering this
|
|
* function, subpage dirty bit is not cleared.
|
|
* So clear subpage dirty bit here so next time we won't submit
|
|
* page for range already written to disk.
|
|
*/
|
|
btrfs_page_clear_dirty(fs_info, page, cur, iosize);
|
|
|
|
submit_extent_page(bio_ctrl, disk_bytenr, page, iosize,
|
|
cur - page_offset(page));
|
|
cur += iosize;
|
|
nr++;
|
|
}
|
|
|
|
btrfs_page_assert_not_dirty(fs_info, page);
|
|
*nr_ret = nr;
|
|
return 0;
|
|
|
|
out_error:
|
|
/*
|
|
* If we finish without problem, we should not only clear page dirty,
|
|
* but also empty subpage dirty bits
|
|
*/
|
|
*nr_ret = nr;
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* the writepage semantics are similar to regular writepage. extent
|
|
* records are inserted to lock ranges in the tree, and as dirty areas
|
|
* are found, they are marked writeback. Then the lock bits are removed
|
|
* and the end_io handler clears the writeback ranges
|
|
*
|
|
* Return 0 if everything goes well.
|
|
* Return <0 for error.
|
|
*/
|
|
static int __extent_writepage(struct page *page, struct btrfs_bio_ctrl *bio_ctrl)
|
|
{
|
|
struct folio *folio = page_folio(page);
|
|
struct inode *inode = page->mapping->host;
|
|
const u64 page_start = page_offset(page);
|
|
const u64 page_end = page_start + PAGE_SIZE - 1;
|
|
int ret;
|
|
int nr = 0;
|
|
size_t pg_offset;
|
|
loff_t i_size = i_size_read(inode);
|
|
unsigned long end_index = i_size >> PAGE_SHIFT;
|
|
|
|
trace___extent_writepage(page, inode, bio_ctrl->wbc);
|
|
|
|
WARN_ON(!PageLocked(page));
|
|
|
|
btrfs_page_clear_error(btrfs_sb(inode->i_sb), page,
|
|
page_offset(page), PAGE_SIZE);
|
|
|
|
pg_offset = offset_in_page(i_size);
|
|
if (page->index > end_index ||
|
|
(page->index == end_index && !pg_offset)) {
|
|
folio_invalidate(folio, 0, folio_size(folio));
|
|
folio_unlock(folio);
|
|
return 0;
|
|
}
|
|
|
|
if (page->index == end_index)
|
|
memzero_page(page, pg_offset, PAGE_SIZE - pg_offset);
|
|
|
|
ret = set_page_extent_mapped(page);
|
|
if (ret < 0) {
|
|
SetPageError(page);
|
|
goto done;
|
|
}
|
|
|
|
ret = writepage_delalloc(BTRFS_I(inode), page, bio_ctrl->wbc);
|
|
if (ret == 1)
|
|
return 0;
|
|
if (ret)
|
|
goto done;
|
|
|
|
ret = __extent_writepage_io(BTRFS_I(inode), page, bio_ctrl, i_size, &nr);
|
|
if (ret == 1)
|
|
return 0;
|
|
|
|
done:
|
|
if (nr == 0) {
|
|
/* make sure the mapping tag for page dirty gets cleared */
|
|
set_page_writeback(page);
|
|
end_page_writeback(page);
|
|
}
|
|
if (ret)
|
|
end_extent_writepage(page, ret, page_start, page_end);
|
|
unlock_page(page);
|
|
ASSERT(ret <= 0);
|
|
return ret;
|
|
}
|
|
|
|
void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
|
|
{
|
|
wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
|
|
TASK_UNINTERRUPTIBLE);
|
|
}
|
|
|
|
static void end_extent_buffer_writeback(struct extent_buffer *eb)
|
|
{
|
|
clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
|
|
smp_mb__after_atomic();
|
|
wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK);
|
|
}
|
|
|
|
/*
|
|
* Lock extent buffer status and pages for writeback.
|
|
*
|
|
* Return %false if the extent buffer doesn't need to be submitted (e.g. the
|
|
* extent buffer is not dirty)
|
|
* Return %true is the extent buffer is submitted to bio.
|
|
*/
|
|
static noinline_for_stack bool lock_extent_buffer_for_io(struct extent_buffer *eb,
|
|
struct writeback_control *wbc)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
bool ret = false;
|
|
int i;
|
|
|
|
btrfs_tree_lock(eb);
|
|
while (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
|
|
btrfs_tree_unlock(eb);
|
|
if (wbc->sync_mode != WB_SYNC_ALL)
|
|
return false;
|
|
wait_on_extent_buffer_writeback(eb);
|
|
btrfs_tree_lock(eb);
|
|
}
|
|
|
|
/*
|
|
* We need to do this to prevent races in people who check if the eb is
|
|
* under IO since we can end up having no IO bits set for a short period
|
|
* of time.
|
|
*/
|
|
spin_lock(&eb->refs_lock);
|
|
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
|
|
set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
|
|
spin_unlock(&eb->refs_lock);
|
|
btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
|
|
percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
|
|
-eb->len,
|
|
fs_info->dirty_metadata_batch);
|
|
ret = true;
|
|
} else {
|
|
spin_unlock(&eb->refs_lock);
|
|
}
|
|
|
|
btrfs_tree_unlock(eb);
|
|
|
|
/*
|
|
* Either we don't need to submit any tree block, or we're submitting
|
|
* subpage eb.
|
|
* Subpage metadata doesn't use page locking at all, so we can skip
|
|
* the page locking.
|
|
*/
|
|
if (!ret || fs_info->nodesize < PAGE_SIZE)
|
|
return ret;
|
|
|
|
for (i = 0; i < num_extent_pages(eb); i++)
|
|
lock_page(eb->pages[i]);
|
|
return ret;
|
|
}
|
|
|
|
static void set_btree_ioerr(struct page *page, struct extent_buffer *eb)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
|
|
btrfs_page_set_error(fs_info, page, eb->start, eb->len);
|
|
if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags))
|
|
return;
|
|
|
|
/*
|
|
* A read may stumble upon this buffer later, make sure that it gets an
|
|
* error and knows there was an error.
|
|
*/
|
|
clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
|
|
/*
|
|
* We need to set the mapping with the io error as well because a write
|
|
* error will flip the file system readonly, and then syncfs() will
|
|
* return a 0 because we are readonly if we don't modify the err seq for
|
|
* the superblock.
|
|
*/
|
|
mapping_set_error(page->mapping, -EIO);
|
|
|
|
/*
|
|
* If writeback for a btree extent that doesn't belong to a log tree
|
|
* failed, increment the counter transaction->eb_write_errors.
|
|
* We do this because while the transaction is running and before it's
|
|
* committing (when we call filemap_fdata[write|wait]_range against
|
|
* the btree inode), we might have
|
|
* btree_inode->i_mapping->a_ops->writepages() called by the VM - if it
|
|
* returns an error or an error happens during writeback, when we're
|
|
* committing the transaction we wouldn't know about it, since the pages
|
|
* can be no longer dirty nor marked anymore for writeback (if a
|
|
* subsequent modification to the extent buffer didn't happen before the
|
|
* transaction commit), which makes filemap_fdata[write|wait]_range not
|
|
* able to find the pages tagged with SetPageError at transaction
|
|
* commit time. So if this happens we must abort the transaction,
|
|
* otherwise we commit a super block with btree roots that point to
|
|
* btree nodes/leafs whose content on disk is invalid - either garbage
|
|
* or the content of some node/leaf from a past generation that got
|
|
* cowed or deleted and is no longer valid.
|
|
*
|
|
* Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would
|
|
* not be enough - we need to distinguish between log tree extents vs
|
|
* non-log tree extents, and the next filemap_fdatawait_range() call
|
|
* will catch and clear such errors in the mapping - and that call might
|
|
* be from a log sync and not from a transaction commit. Also, checking
|
|
* for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is
|
|
* not done and would not be reliable - the eb might have been released
|
|
* from memory and reading it back again means that flag would not be
|
|
* set (since it's a runtime flag, not persisted on disk).
|
|
*
|
|
* Using the flags below in the btree inode also makes us achieve the
|
|
* goal of AS_EIO/AS_ENOSPC when writepages() returns success, started
|
|
* writeback for all dirty pages and before filemap_fdatawait_range()
|
|
* is called, the writeback for all dirty pages had already finished
|
|
* with errors - because we were not using AS_EIO/AS_ENOSPC,
|
|
* filemap_fdatawait_range() would return success, as it could not know
|
|
* that writeback errors happened (the pages were no longer tagged for
|
|
* writeback).
|
|
*/
|
|
switch (eb->log_index) {
|
|
case -1:
|
|
set_bit(BTRFS_FS_BTREE_ERR, &fs_info->flags);
|
|
break;
|
|
case 0:
|
|
set_bit(BTRFS_FS_LOG1_ERR, &fs_info->flags);
|
|
break;
|
|
case 1:
|
|
set_bit(BTRFS_FS_LOG2_ERR, &fs_info->flags);
|
|
break;
|
|
default:
|
|
BUG(); /* unexpected, logic error */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The endio specific version which won't touch any unsafe spinlock in endio
|
|
* context.
|
|
*/
|
|
static struct extent_buffer *find_extent_buffer_nolock(
|
|
struct btrfs_fs_info *fs_info, u64 start)
|
|
{
|
|
struct extent_buffer *eb;
|
|
|
|
rcu_read_lock();
|
|
eb = radix_tree_lookup(&fs_info->buffer_radix,
|
|
start >> fs_info->sectorsize_bits);
|
|
if (eb && atomic_inc_not_zero(&eb->refs)) {
|
|
rcu_read_unlock();
|
|
return eb;
|
|
}
|
|
rcu_read_unlock();
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* The endio function for subpage extent buffer write.
|
|
*
|
|
* Unlike end_bio_extent_buffer_writepage(), we only call end_page_writeback()
|
|
* after all extent buffers in the page has finished their writeback.
|
|
*/
|
|
static void end_bio_subpage_eb_writepage(struct btrfs_bio *bbio)
|
|
{
|
|
struct bio *bio = &bbio->bio;
|
|
struct btrfs_fs_info *fs_info;
|
|
struct bio_vec *bvec;
|
|
struct bvec_iter_all iter_all;
|
|
|
|
fs_info = btrfs_sb(bio_first_page_all(bio)->mapping->host->i_sb);
|
|
ASSERT(fs_info->nodesize < PAGE_SIZE);
|
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED));
|
|
bio_for_each_segment_all(bvec, bio, iter_all) {
|
|
struct page *page = bvec->bv_page;
|
|
u64 bvec_start = page_offset(page) + bvec->bv_offset;
|
|
u64 bvec_end = bvec_start + bvec->bv_len - 1;
|
|
u64 cur_bytenr = bvec_start;
|
|
|
|
ASSERT(IS_ALIGNED(bvec->bv_len, fs_info->nodesize));
|
|
|
|
/* Iterate through all extent buffers in the range */
|
|
while (cur_bytenr <= bvec_end) {
|
|
struct extent_buffer *eb;
|
|
int done;
|
|
|
|
/*
|
|
* Here we can't use find_extent_buffer(), as it may
|
|
* try to lock eb->refs_lock, which is not safe in endio
|
|
* context.
|
|
*/
|
|
eb = find_extent_buffer_nolock(fs_info, cur_bytenr);
|
|
ASSERT(eb);
|
|
|
|
cur_bytenr = eb->start + eb->len;
|
|
|
|
ASSERT(test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags));
|
|
done = atomic_dec_and_test(&eb->io_pages);
|
|
ASSERT(done);
|
|
|
|
if (bio->bi_status ||
|
|
test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
|
|
ClearPageUptodate(page);
|
|
set_btree_ioerr(page, eb);
|
|
}
|
|
|
|
btrfs_subpage_clear_writeback(fs_info, page, eb->start,
|
|
eb->len);
|
|
end_extent_buffer_writeback(eb);
|
|
/*
|
|
* free_extent_buffer() will grab spinlock which is not
|
|
* safe in endio context. Thus here we manually dec
|
|
* the ref.
|
|
*/
|
|
atomic_dec(&eb->refs);
|
|
}
|
|
}
|
|
bio_put(bio);
|
|
}
|
|
|
|
static void end_bio_extent_buffer_writepage(struct btrfs_bio *bbio)
|
|
{
|
|
struct bio *bio = &bbio->bio;
|
|
struct bio_vec *bvec;
|
|
struct extent_buffer *eb;
|
|
int done;
|
|
struct bvec_iter_all iter_all;
|
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED));
|
|
bio_for_each_segment_all(bvec, bio, iter_all) {
|
|
struct page *page = bvec->bv_page;
|
|
|
|
eb = (struct extent_buffer *)page->private;
|
|
BUG_ON(!eb);
|
|
done = atomic_dec_and_test(&eb->io_pages);
|
|
|
|
if (bio->bi_status ||
|
|
test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) {
|
|
ClearPageUptodate(page);
|
|
set_btree_ioerr(page, eb);
|
|
}
|
|
|
|
end_page_writeback(page);
|
|
|
|
if (!done)
|
|
continue;
|
|
|
|
end_extent_buffer_writeback(eb);
|
|
}
|
|
|
|
bio_put(bio);
|
|
}
|
|
|
|
static void prepare_eb_write(struct extent_buffer *eb)
|
|
{
|
|
u32 nritems;
|
|
unsigned long start;
|
|
unsigned long end;
|
|
|
|
clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
|
|
atomic_set(&eb->io_pages, num_extent_pages(eb));
|
|
|
|
/* Set btree blocks beyond nritems with 0 to avoid stale content */
|
|
nritems = btrfs_header_nritems(eb);
|
|
if (btrfs_header_level(eb) > 0) {
|
|
end = btrfs_node_key_ptr_offset(eb, nritems);
|
|
memzero_extent_buffer(eb, end, eb->len - end);
|
|
} else {
|
|
/*
|
|
* Leaf:
|
|
* header 0 1 2 .. N ... data_N .. data_2 data_1 data_0
|
|
*/
|
|
start = btrfs_item_nr_offset(eb, nritems);
|
|
end = btrfs_item_nr_offset(eb, 0);
|
|
if (nritems == 0)
|
|
end += BTRFS_LEAF_DATA_SIZE(eb->fs_info);
|
|
else
|
|
end += btrfs_item_offset(eb, nritems - 1);
|
|
memzero_extent_buffer(eb, start, end - start);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Unlike the work in write_one_eb(), we rely completely on extent locking.
|
|
* Page locking is only utilized at minimum to keep the VMM code happy.
|
|
*/
|
|
static void write_one_subpage_eb(struct extent_buffer *eb,
|
|
struct writeback_control *wbc)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
struct page *page = eb->pages[0];
|
|
bool no_dirty_ebs = false;
|
|
struct btrfs_bio_ctrl bio_ctrl = {
|
|
.wbc = wbc,
|
|
.opf = REQ_OP_WRITE | wbc_to_write_flags(wbc),
|
|
.end_io_func = end_bio_subpage_eb_writepage,
|
|
};
|
|
|
|
prepare_eb_write(eb);
|
|
|
|
/* clear_page_dirty_for_io() in subpage helper needs page locked */
|
|
lock_page(page);
|
|
btrfs_subpage_set_writeback(fs_info, page, eb->start, eb->len);
|
|
|
|
/* Check if this is the last dirty bit to update nr_written */
|
|
no_dirty_ebs = btrfs_subpage_clear_and_test_dirty(fs_info, page,
|
|
eb->start, eb->len);
|
|
if (no_dirty_ebs)
|
|
clear_page_dirty_for_io(page);
|
|
|
|
submit_extent_page(&bio_ctrl, eb->start, page, eb->len,
|
|
eb->start - page_offset(page));
|
|
unlock_page(page);
|
|
submit_one_bio(&bio_ctrl);
|
|
/*
|
|
* Submission finished without problem, if no range of the page is
|
|
* dirty anymore, we have submitted a page. Update nr_written in wbc.
|
|
*/
|
|
if (no_dirty_ebs)
|
|
wbc->nr_to_write--;
|
|
}
|
|
|
|
static noinline_for_stack void write_one_eb(struct extent_buffer *eb,
|
|
struct writeback_control *wbc)
|
|
{
|
|
u64 disk_bytenr = eb->start;
|
|
int i, num_pages;
|
|
struct btrfs_bio_ctrl bio_ctrl = {
|
|
.wbc = wbc,
|
|
.opf = REQ_OP_WRITE | wbc_to_write_flags(wbc),
|
|
.end_io_func = end_bio_extent_buffer_writepage,
|
|
};
|
|
|
|
prepare_eb_write(eb);
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *p = eb->pages[i];
|
|
|
|
clear_page_dirty_for_io(p);
|
|
set_page_writeback(p);
|
|
submit_extent_page(&bio_ctrl, disk_bytenr, p, PAGE_SIZE, 0);
|
|
disk_bytenr += PAGE_SIZE;
|
|
wbc->nr_to_write--;
|
|
unlock_page(p);
|
|
}
|
|
submit_one_bio(&bio_ctrl);
|
|
}
|
|
|
|
/*
|
|
* Submit one subpage btree page.
|
|
*
|
|
* The main difference to submit_eb_page() is:
|
|
* - Page locking
|
|
* For subpage, we don't rely on page locking at all.
|
|
*
|
|
* - Flush write bio
|
|
* We only flush bio if we may be unable to fit current extent buffers into
|
|
* current bio.
|
|
*
|
|
* Return >=0 for the number of submitted extent buffers.
|
|
* Return <0 for fatal error.
|
|
*/
|
|
static int submit_eb_subpage(struct page *page, struct writeback_control *wbc)
|
|
{
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
|
|
int submitted = 0;
|
|
u64 page_start = page_offset(page);
|
|
int bit_start = 0;
|
|
int sectors_per_node = fs_info->nodesize >> fs_info->sectorsize_bits;
|
|
|
|
/* Lock and write each dirty extent buffers in the range */
|
|
while (bit_start < fs_info->subpage_info->bitmap_nr_bits) {
|
|
struct btrfs_subpage *subpage = (struct btrfs_subpage *)page->private;
|
|
struct extent_buffer *eb;
|
|
unsigned long flags;
|
|
u64 start;
|
|
|
|
/*
|
|
* Take private lock to ensure the subpage won't be detached
|
|
* in the meantime.
|
|
*/
|
|
spin_lock(&page->mapping->private_lock);
|
|
if (!PagePrivate(page)) {
|
|
spin_unlock(&page->mapping->private_lock);
|
|
break;
|
|
}
|
|
spin_lock_irqsave(&subpage->lock, flags);
|
|
if (!test_bit(bit_start + fs_info->subpage_info->dirty_offset,
|
|
subpage->bitmaps)) {
|
|
spin_unlock_irqrestore(&subpage->lock, flags);
|
|
spin_unlock(&page->mapping->private_lock);
|
|
bit_start++;
|
|
continue;
|
|
}
|
|
|
|
start = page_start + bit_start * fs_info->sectorsize;
|
|
bit_start += sectors_per_node;
|
|
|
|
/*
|
|
* Here we just want to grab the eb without touching extra
|
|
* spin locks, so call find_extent_buffer_nolock().
|
|
*/
|
|
eb = find_extent_buffer_nolock(fs_info, start);
|
|
spin_unlock_irqrestore(&subpage->lock, flags);
|
|
spin_unlock(&page->mapping->private_lock);
|
|
|
|
/*
|
|
* The eb has already reached 0 refs thus find_extent_buffer()
|
|
* doesn't return it. We don't need to write back such eb
|
|
* anyway.
|
|
*/
|
|
if (!eb)
|
|
continue;
|
|
|
|
if (lock_extent_buffer_for_io(eb, wbc)) {
|
|
write_one_subpage_eb(eb, wbc);
|
|
submitted++;
|
|
}
|
|
free_extent_buffer(eb);
|
|
}
|
|
return submitted;
|
|
}
|
|
|
|
/*
|
|
* Submit all page(s) of one extent buffer.
|
|
*
|
|
* @page: the page of one extent buffer
|
|
* @eb_context: to determine if we need to submit this page, if current page
|
|
* belongs to this eb, we don't need to submit
|
|
*
|
|
* The caller should pass each page in their bytenr order, and here we use
|
|
* @eb_context to determine if we have submitted pages of one extent buffer.
|
|
*
|
|
* If we have, we just skip until we hit a new page that doesn't belong to
|
|
* current @eb_context.
|
|
*
|
|
* If not, we submit all the page(s) of the extent buffer.
|
|
*
|
|
* Return >0 if we have submitted the extent buffer successfully.
|
|
* Return 0 if we don't need to submit the page, as it's already submitted by
|
|
* previous call.
|
|
* Return <0 for fatal error.
|
|
*/
|
|
static int submit_eb_page(struct page *page, struct writeback_control *wbc,
|
|
struct extent_buffer **eb_context)
|
|
{
|
|
struct address_space *mapping = page->mapping;
|
|
struct btrfs_block_group *cache = NULL;
|
|
struct extent_buffer *eb;
|
|
int ret;
|
|
|
|
if (!PagePrivate(page))
|
|
return 0;
|
|
|
|
if (btrfs_sb(page->mapping->host->i_sb)->nodesize < PAGE_SIZE)
|
|
return submit_eb_subpage(page, wbc);
|
|
|
|
spin_lock(&mapping->private_lock);
|
|
if (!PagePrivate(page)) {
|
|
spin_unlock(&mapping->private_lock);
|
|
return 0;
|
|
}
|
|
|
|
eb = (struct extent_buffer *)page->private;
|
|
|
|
/*
|
|
* Shouldn't happen and normally this would be a BUG_ON but no point
|
|
* crashing the machine for something we can survive anyway.
|
|
*/
|
|
if (WARN_ON(!eb)) {
|
|
spin_unlock(&mapping->private_lock);
|
|
return 0;
|
|
}
|
|
|
|
if (eb == *eb_context) {
|
|
spin_unlock(&mapping->private_lock);
|
|
return 0;
|
|
}
|
|
ret = atomic_inc_not_zero(&eb->refs);
|
|
spin_unlock(&mapping->private_lock);
|
|
if (!ret)
|
|
return 0;
|
|
|
|
if (!btrfs_check_meta_write_pointer(eb->fs_info, eb, &cache)) {
|
|
/*
|
|
* If for_sync, this hole will be filled with
|
|
* trasnsaction commit.
|
|
*/
|
|
if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync)
|
|
ret = -EAGAIN;
|
|
else
|
|
ret = 0;
|
|
free_extent_buffer(eb);
|
|
return ret;
|
|
}
|
|
|
|
*eb_context = eb;
|
|
|
|
if (!lock_extent_buffer_for_io(eb, wbc)) {
|
|
btrfs_revert_meta_write_pointer(cache, eb);
|
|
if (cache)
|
|
btrfs_put_block_group(cache);
|
|
free_extent_buffer(eb);
|
|
return 0;
|
|
}
|
|
if (cache) {
|
|
/*
|
|
* Implies write in zoned mode. Mark the last eb in a block group.
|
|
*/
|
|
btrfs_schedule_zone_finish_bg(cache, eb);
|
|
btrfs_put_block_group(cache);
|
|
}
|
|
write_one_eb(eb, wbc);
|
|
free_extent_buffer(eb);
|
|
return 1;
|
|
}
|
|
|
|
int btree_write_cache_pages(struct address_space *mapping,
|
|
struct writeback_control *wbc)
|
|
{
|
|
struct extent_buffer *eb_context = NULL;
|
|
struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
|
|
int ret = 0;
|
|
int done = 0;
|
|
int nr_to_write_done = 0;
|
|
struct folio_batch fbatch;
|
|
unsigned int nr_folios;
|
|
pgoff_t index;
|
|
pgoff_t end; /* Inclusive */
|
|
int scanned = 0;
|
|
xa_mark_t tag;
|
|
|
|
folio_batch_init(&fbatch);
|
|
if (wbc->range_cyclic) {
|
|
index = mapping->writeback_index; /* Start from prev offset */
|
|
end = -1;
|
|
/*
|
|
* Start from the beginning does not need to cycle over the
|
|
* range, mark it as scanned.
|
|
*/
|
|
scanned = (index == 0);
|
|
} else {
|
|
index = wbc->range_start >> PAGE_SHIFT;
|
|
end = wbc->range_end >> PAGE_SHIFT;
|
|
scanned = 1;
|
|
}
|
|
if (wbc->sync_mode == WB_SYNC_ALL)
|
|
tag = PAGECACHE_TAG_TOWRITE;
|
|
else
|
|
tag = PAGECACHE_TAG_DIRTY;
|
|
btrfs_zoned_meta_io_lock(fs_info);
|
|
retry:
|
|
if (wbc->sync_mode == WB_SYNC_ALL)
|
|
tag_pages_for_writeback(mapping, index, end);
|
|
while (!done && !nr_to_write_done && (index <= end) &&
|
|
(nr_folios = filemap_get_folios_tag(mapping, &index, end,
|
|
tag, &fbatch))) {
|
|
unsigned i;
|
|
|
|
for (i = 0; i < nr_folios; i++) {
|
|
struct folio *folio = fbatch.folios[i];
|
|
|
|
ret = submit_eb_page(&folio->page, wbc, &eb_context);
|
|
if (ret == 0)
|
|
continue;
|
|
if (ret < 0) {
|
|
done = 1;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* the filesystem may choose to bump up nr_to_write.
|
|
* We have to make sure to honor the new nr_to_write
|
|
* at any time
|
|
*/
|
|
nr_to_write_done = wbc->nr_to_write <= 0;
|
|
}
|
|
folio_batch_release(&fbatch);
|
|
cond_resched();
|
|
}
|
|
if (!scanned && !done) {
|
|
/*
|
|
* We hit the last page and there is more work to be done: wrap
|
|
* back to the start of the file
|
|
*/
|
|
scanned = 1;
|
|
index = 0;
|
|
goto retry;
|
|
}
|
|
/*
|
|
* If something went wrong, don't allow any metadata write bio to be
|
|
* submitted.
|
|
*
|
|
* This would prevent use-after-free if we had dirty pages not
|
|
* cleaned up, which can still happen by fuzzed images.
|
|
*
|
|
* - Bad extent tree
|
|
* Allowing existing tree block to be allocated for other trees.
|
|
*
|
|
* - Log tree operations
|
|
* Exiting tree blocks get allocated to log tree, bumps its
|
|
* generation, then get cleaned in tree re-balance.
|
|
* Such tree block will not be written back, since it's clean,
|
|
* thus no WRITTEN flag set.
|
|
* And after log writes back, this tree block is not traced by
|
|
* any dirty extent_io_tree.
|
|
*
|
|
* - Offending tree block gets re-dirtied from its original owner
|
|
* Since it has bumped generation, no WRITTEN flag, it can be
|
|
* reused without COWing. This tree block will not be traced
|
|
* by btrfs_transaction::dirty_pages.
|
|
*
|
|
* Now such dirty tree block will not be cleaned by any dirty
|
|
* extent io tree. Thus we don't want to submit such wild eb
|
|
* if the fs already has error.
|
|
*
|
|
* We can get ret > 0 from submit_extent_page() indicating how many ebs
|
|
* were submitted. Reset it to 0 to avoid false alerts for the caller.
|
|
*/
|
|
if (ret > 0)
|
|
ret = 0;
|
|
if (!ret && BTRFS_FS_ERROR(fs_info))
|
|
ret = -EROFS;
|
|
btrfs_zoned_meta_io_unlock(fs_info);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Walk the list of dirty pages of the given address space and write all of them.
|
|
*
|
|
* @mapping: address space structure to write
|
|
* @wbc: subtract the number of written pages from *@wbc->nr_to_write
|
|
* @bio_ctrl: holds context for the write, namely the bio
|
|
*
|
|
* If a page is already under I/O, write_cache_pages() skips it, even
|
|
* if it's dirty. This is desirable behaviour for memory-cleaning writeback,
|
|
* but it is INCORRECT for data-integrity system calls such as fsync(). fsync()
|
|
* and msync() need to guarantee that all the data which was dirty at the time
|
|
* the call was made get new I/O started against them. If wbc->sync_mode is
|
|
* WB_SYNC_ALL then we were called for data integrity and we must wait for
|
|
* existing IO to complete.
|
|
*/
|
|
static int extent_write_cache_pages(struct address_space *mapping,
|
|
struct btrfs_bio_ctrl *bio_ctrl)
|
|
{
|
|
struct writeback_control *wbc = bio_ctrl->wbc;
|
|
struct inode *inode = mapping->host;
|
|
int ret = 0;
|
|
int done = 0;
|
|
int nr_to_write_done = 0;
|
|
struct folio_batch fbatch;
|
|
unsigned int nr_folios;
|
|
pgoff_t index;
|
|
pgoff_t end; /* Inclusive */
|
|
pgoff_t done_index;
|
|
int range_whole = 0;
|
|
int scanned = 0;
|
|
xa_mark_t tag;
|
|
|
|
/*
|
|
* We have to hold onto the inode so that ordered extents can do their
|
|
* work when the IO finishes. The alternative to this is failing to add
|
|
* an ordered extent if the igrab() fails there and that is a huge pain
|
|
* to deal with, so instead just hold onto the inode throughout the
|
|
* writepages operation. If it fails here we are freeing up the inode
|
|
* anyway and we'd rather not waste our time writing out stuff that is
|
|
* going to be truncated anyway.
|
|
*/
|
|
if (!igrab(inode))
|
|
return 0;
|
|
|
|
folio_batch_init(&fbatch);
|
|
if (wbc->range_cyclic) {
|
|
index = mapping->writeback_index; /* Start from prev offset */
|
|
end = -1;
|
|
/*
|
|
* Start from the beginning does not need to cycle over the
|
|
* range, mark it as scanned.
|
|
*/
|
|
scanned = (index == 0);
|
|
} else {
|
|
index = wbc->range_start >> PAGE_SHIFT;
|
|
end = wbc->range_end >> PAGE_SHIFT;
|
|
if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
|
|
range_whole = 1;
|
|
scanned = 1;
|
|
}
|
|
|
|
/*
|
|
* We do the tagged writepage as long as the snapshot flush bit is set
|
|
* and we are the first one who do the filemap_flush() on this inode.
|
|
*
|
|
* The nr_to_write == LONG_MAX is needed to make sure other flushers do
|
|
* not race in and drop the bit.
|
|
*/
|
|
if (range_whole && wbc->nr_to_write == LONG_MAX &&
|
|
test_and_clear_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
|
|
&BTRFS_I(inode)->runtime_flags))
|
|
wbc->tagged_writepages = 1;
|
|
|
|
if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
|
|
tag = PAGECACHE_TAG_TOWRITE;
|
|
else
|
|
tag = PAGECACHE_TAG_DIRTY;
|
|
retry:
|
|
if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
|
|
tag_pages_for_writeback(mapping, index, end);
|
|
done_index = index;
|
|
while (!done && !nr_to_write_done && (index <= end) &&
|
|
(nr_folios = filemap_get_folios_tag(mapping, &index,
|
|
end, tag, &fbatch))) {
|
|
unsigned i;
|
|
|
|
for (i = 0; i < nr_folios; i++) {
|
|
struct folio *folio = fbatch.folios[i];
|
|
|
|
done_index = folio->index + folio_nr_pages(folio);
|
|
/*
|
|
* At this point we hold neither the i_pages lock nor
|
|
* the page lock: the page may be truncated or
|
|
* invalidated (changing page->mapping to NULL),
|
|
* or even swizzled back from swapper_space to
|
|
* tmpfs file mapping
|
|
*/
|
|
if (!folio_trylock(folio)) {
|
|
submit_write_bio(bio_ctrl, 0);
|
|
folio_lock(folio);
|
|
}
|
|
|
|
if (unlikely(folio->mapping != mapping)) {
|
|
folio_unlock(folio);
|
|
continue;
|
|
}
|
|
|
|
if (wbc->sync_mode != WB_SYNC_NONE) {
|
|
if (folio_test_writeback(folio))
|
|
submit_write_bio(bio_ctrl, 0);
|
|
folio_wait_writeback(folio);
|
|
}
|
|
|
|
if (folio_test_writeback(folio) ||
|
|
!folio_clear_dirty_for_io(folio)) {
|
|
folio_unlock(folio);
|
|
continue;
|
|
}
|
|
|
|
ret = __extent_writepage(&folio->page, bio_ctrl);
|
|
if (ret < 0) {
|
|
done = 1;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* the filesystem may choose to bump up nr_to_write.
|
|
* We have to make sure to honor the new nr_to_write
|
|
* at any time
|
|
*/
|
|
nr_to_write_done = wbc->nr_to_write <= 0;
|
|
}
|
|
folio_batch_release(&fbatch);
|
|
cond_resched();
|
|
}
|
|
if (!scanned && !done) {
|
|
/*
|
|
* We hit the last page and there is more work to be done: wrap
|
|
* back to the start of the file
|
|
*/
|
|
scanned = 1;
|
|
index = 0;
|
|
|
|
/*
|
|
* If we're looping we could run into a page that is locked by a
|
|
* writer and that writer could be waiting on writeback for a
|
|
* page in our current bio, and thus deadlock, so flush the
|
|
* write bio here.
|
|
*/
|
|
submit_write_bio(bio_ctrl, 0);
|
|
goto retry;
|
|
}
|
|
|
|
if (wbc->range_cyclic || (wbc->nr_to_write > 0 && range_whole))
|
|
mapping->writeback_index = done_index;
|
|
|
|
btrfs_add_delayed_iput(BTRFS_I(inode));
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Submit the pages in the range to bio for call sites which delalloc range has
|
|
* already been ran (aka, ordered extent inserted) and all pages are still
|
|
* locked.
|
|
*/
|
|
int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
|
|
struct writeback_control *wbc)
|
|
{
|
|
bool found_error = false;
|
|
int first_error = 0;
|
|
int ret = 0;
|
|
struct address_space *mapping = inode->i_mapping;
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
|
|
const u32 sectorsize = fs_info->sectorsize;
|
|
loff_t i_size = i_size_read(inode);
|
|
u64 cur = start;
|
|
struct btrfs_bio_ctrl bio_ctrl = {
|
|
.wbc = wbc,
|
|
.opf = REQ_OP_WRITE | wbc_to_write_flags(wbc),
|
|
};
|
|
|
|
if (wbc->no_cgroup_owner)
|
|
bio_ctrl.opf |= REQ_BTRFS_CGROUP_PUNT;
|
|
|
|
ASSERT(IS_ALIGNED(start, sectorsize) && IS_ALIGNED(end + 1, sectorsize));
|
|
|
|
while (cur <= end) {
|
|
u64 cur_end = min(round_down(cur, PAGE_SIZE) + PAGE_SIZE - 1, end);
|
|
struct page *page;
|
|
int nr = 0;
|
|
|
|
page = find_get_page(mapping, cur >> PAGE_SHIFT);
|
|
/*
|
|
* All pages in the range are locked since
|
|
* btrfs_run_delalloc_range(), thus there is no way to clear
|
|
* the page dirty flag.
|
|
*/
|
|
ASSERT(PageLocked(page));
|
|
ASSERT(PageDirty(page));
|
|
clear_page_dirty_for_io(page);
|
|
|
|
ret = __extent_writepage_io(BTRFS_I(inode), page, &bio_ctrl,
|
|
i_size, &nr);
|
|
if (ret == 1)
|
|
goto next_page;
|
|
|
|
/* Make sure the mapping tag for page dirty gets cleared. */
|
|
if (nr == 0) {
|
|
set_page_writeback(page);
|
|
end_page_writeback(page);
|
|
}
|
|
if (ret)
|
|
end_extent_writepage(page, ret, cur, cur_end);
|
|
btrfs_page_unlock_writer(fs_info, page, cur, cur_end + 1 - cur);
|
|
if (ret < 0) {
|
|
found_error = true;
|
|
first_error = ret;
|
|
}
|
|
next_page:
|
|
put_page(page);
|
|
cur = cur_end + 1;
|
|
}
|
|
|
|
submit_write_bio(&bio_ctrl, found_error ? ret : 0);
|
|
|
|
if (found_error)
|
|
return first_error;
|
|
return ret;
|
|
}
|
|
|
|
int extent_writepages(struct address_space *mapping,
|
|
struct writeback_control *wbc)
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
int ret = 0;
|
|
struct btrfs_bio_ctrl bio_ctrl = {
|
|
.wbc = wbc,
|
|
.opf = REQ_OP_WRITE | wbc_to_write_flags(wbc),
|
|
};
|
|
|
|
/*
|
|
* Allow only a single thread to do the reloc work in zoned mode to
|
|
* protect the write pointer updates.
|
|
*/
|
|
btrfs_zoned_data_reloc_lock(BTRFS_I(inode));
|
|
ret = extent_write_cache_pages(mapping, &bio_ctrl);
|
|
submit_write_bio(&bio_ctrl, ret);
|
|
btrfs_zoned_data_reloc_unlock(BTRFS_I(inode));
|
|
return ret;
|
|
}
|
|
|
|
void extent_readahead(struct readahead_control *rac)
|
|
{
|
|
struct btrfs_bio_ctrl bio_ctrl = { .opf = REQ_OP_READ | REQ_RAHEAD };
|
|
struct page *pagepool[16];
|
|
struct extent_map *em_cached = NULL;
|
|
u64 prev_em_start = (u64)-1;
|
|
int nr;
|
|
|
|
while ((nr = readahead_page_batch(rac, pagepool))) {
|
|
u64 contig_start = readahead_pos(rac);
|
|
u64 contig_end = contig_start + readahead_batch_length(rac) - 1;
|
|
|
|
contiguous_readpages(pagepool, nr, contig_start, contig_end,
|
|
&em_cached, &bio_ctrl, &prev_em_start);
|
|
}
|
|
|
|
if (em_cached)
|
|
free_extent_map(em_cached);
|
|
submit_one_bio(&bio_ctrl);
|
|
}
|
|
|
|
/*
|
|
* basic invalidate_folio code, this waits on any locked or writeback
|
|
* ranges corresponding to the folio, and then deletes any extent state
|
|
* records from the tree
|
|
*/
|
|
int extent_invalidate_folio(struct extent_io_tree *tree,
|
|
struct folio *folio, size_t offset)
|
|
{
|
|
struct extent_state *cached_state = NULL;
|
|
u64 start = folio_pos(folio);
|
|
u64 end = start + folio_size(folio) - 1;
|
|
size_t blocksize = folio->mapping->host->i_sb->s_blocksize;
|
|
|
|
/* This function is only called for the btree inode */
|
|
ASSERT(tree->owner == IO_TREE_BTREE_INODE_IO);
|
|
|
|
start += ALIGN(offset, blocksize);
|
|
if (start > end)
|
|
return 0;
|
|
|
|
lock_extent(tree, start, end, &cached_state);
|
|
folio_wait_writeback(folio);
|
|
|
|
/*
|
|
* Currently for btree io tree, only EXTENT_LOCKED is utilized,
|
|
* so here we only need to unlock the extent range to free any
|
|
* existing extent state.
|
|
*/
|
|
unlock_extent(tree, start, end, &cached_state);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* a helper for release_folio, this tests for areas of the page that
|
|
* are locked or under IO and drops the related state bits if it is safe
|
|
* to drop the page.
|
|
*/
|
|
static int try_release_extent_state(struct extent_io_tree *tree,
|
|
struct page *page, gfp_t mask)
|
|
{
|
|
u64 start = page_offset(page);
|
|
u64 end = start + PAGE_SIZE - 1;
|
|
int ret = 1;
|
|
|
|
if (test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL)) {
|
|
ret = 0;
|
|
} else {
|
|
u32 clear_bits = ~(EXTENT_LOCKED | EXTENT_NODATASUM |
|
|
EXTENT_DELALLOC_NEW | EXTENT_CTLBITS);
|
|
|
|
/*
|
|
* At this point we can safely clear everything except the
|
|
* locked bit, the nodatasum bit and the delalloc new bit.
|
|
* The delalloc new bit will be cleared by ordered extent
|
|
* completion.
|
|
*/
|
|
ret = __clear_extent_bit(tree, start, end, clear_bits, NULL,
|
|
mask, NULL);
|
|
|
|
/* if clear_extent_bit failed for enomem reasons,
|
|
* we can't allow the release to continue.
|
|
*/
|
|
if (ret < 0)
|
|
ret = 0;
|
|
else
|
|
ret = 1;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* a helper for release_folio. As long as there are no locked extents
|
|
* in the range corresponding to the page, both state records and extent
|
|
* map records are removed
|
|
*/
|
|
int try_release_extent_mapping(struct page *page, gfp_t mask)
|
|
{
|
|
struct extent_map *em;
|
|
u64 start = page_offset(page);
|
|
u64 end = start + PAGE_SIZE - 1;
|
|
struct btrfs_inode *btrfs_inode = BTRFS_I(page->mapping->host);
|
|
struct extent_io_tree *tree = &btrfs_inode->io_tree;
|
|
struct extent_map_tree *map = &btrfs_inode->extent_tree;
|
|
|
|
if (gfpflags_allow_blocking(mask) &&
|
|
page->mapping->host->i_size > SZ_16M) {
|
|
u64 len;
|
|
while (start <= end) {
|
|
struct btrfs_fs_info *fs_info;
|
|
u64 cur_gen;
|
|
|
|
len = end - start + 1;
|
|
write_lock(&map->lock);
|
|
em = lookup_extent_mapping(map, start, len);
|
|
if (!em) {
|
|
write_unlock(&map->lock);
|
|
break;
|
|
}
|
|
if (test_bit(EXTENT_FLAG_PINNED, &em->flags) ||
|
|
em->start != start) {
|
|
write_unlock(&map->lock);
|
|
free_extent_map(em);
|
|
break;
|
|
}
|
|
if (test_range_bit(tree, em->start,
|
|
extent_map_end(em) - 1,
|
|
EXTENT_LOCKED, 0, NULL))
|
|
goto next;
|
|
/*
|
|
* If it's not in the list of modified extents, used
|
|
* by a fast fsync, we can remove it. If it's being
|
|
* logged we can safely remove it since fsync took an
|
|
* extra reference on the em.
|
|
*/
|
|
if (list_empty(&em->list) ||
|
|
test_bit(EXTENT_FLAG_LOGGING, &em->flags))
|
|
goto remove_em;
|
|
/*
|
|
* If it's in the list of modified extents, remove it
|
|
* only if its generation is older then the current one,
|
|
* in which case we don't need it for a fast fsync.
|
|
* Otherwise don't remove it, we could be racing with an
|
|
* ongoing fast fsync that could miss the new extent.
|
|
*/
|
|
fs_info = btrfs_inode->root->fs_info;
|
|
spin_lock(&fs_info->trans_lock);
|
|
cur_gen = fs_info->generation;
|
|
spin_unlock(&fs_info->trans_lock);
|
|
if (em->generation >= cur_gen)
|
|
goto next;
|
|
remove_em:
|
|
/*
|
|
* We only remove extent maps that are not in the list of
|
|
* modified extents or that are in the list but with a
|
|
* generation lower then the current generation, so there
|
|
* is no need to set the full fsync flag on the inode (it
|
|
* hurts the fsync performance for workloads with a data
|
|
* size that exceeds or is close to the system's memory).
|
|
*/
|
|
remove_extent_mapping(map, em);
|
|
/* once for the rb tree */
|
|
free_extent_map(em);
|
|
next:
|
|
start = extent_map_end(em);
|
|
write_unlock(&map->lock);
|
|
|
|
/* once for us */
|
|
free_extent_map(em);
|
|
|
|
cond_resched(); /* Allow large-extent preemption. */
|
|
}
|
|
}
|
|
return try_release_extent_state(tree, page, mask);
|
|
}
|
|
|
|
/*
|
|
* To cache previous fiemap extent
|
|
*
|
|
* Will be used for merging fiemap extent
|
|
*/
|
|
struct fiemap_cache {
|
|
u64 offset;
|
|
u64 phys;
|
|
u64 len;
|
|
u32 flags;
|
|
bool cached;
|
|
};
|
|
|
|
/*
|
|
* Helper to submit fiemap extent.
|
|
*
|
|
* Will try to merge current fiemap extent specified by @offset, @phys,
|
|
* @len and @flags with cached one.
|
|
* And only when we fails to merge, cached one will be submitted as
|
|
* fiemap extent.
|
|
*
|
|
* Return value is the same as fiemap_fill_next_extent().
|
|
*/
|
|
static int emit_fiemap_extent(struct fiemap_extent_info *fieinfo,
|
|
struct fiemap_cache *cache,
|
|
u64 offset, u64 phys, u64 len, u32 flags)
|
|
{
|
|
int ret = 0;
|
|
|
|
/* Set at the end of extent_fiemap(). */
|
|
ASSERT((flags & FIEMAP_EXTENT_LAST) == 0);
|
|
|
|
if (!cache->cached)
|
|
goto assign;
|
|
|
|
/*
|
|
* Sanity check, extent_fiemap() should have ensured that new
|
|
* fiemap extent won't overlap with cached one.
|
|
* Not recoverable.
|
|
*
|
|
* NOTE: Physical address can overlap, due to compression
|
|
*/
|
|
if (cache->offset + cache->len > offset) {
|
|
WARN_ON(1);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Only merges fiemap extents if
|
|
* 1) Their logical addresses are continuous
|
|
*
|
|
* 2) Their physical addresses are continuous
|
|
* So truly compressed (physical size smaller than logical size)
|
|
* extents won't get merged with each other
|
|
*
|
|
* 3) Share same flags
|
|
*/
|
|
if (cache->offset + cache->len == offset &&
|
|
cache->phys + cache->len == phys &&
|
|
cache->flags == flags) {
|
|
cache->len += len;
|
|
return 0;
|
|
}
|
|
|
|
/* Not mergeable, need to submit cached one */
|
|
ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
|
|
cache->len, cache->flags);
|
|
cache->cached = false;
|
|
if (ret)
|
|
return ret;
|
|
assign:
|
|
cache->cached = true;
|
|
cache->offset = offset;
|
|
cache->phys = phys;
|
|
cache->len = len;
|
|
cache->flags = flags;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Emit last fiemap cache
|
|
*
|
|
* The last fiemap cache may still be cached in the following case:
|
|
* 0 4k 8k
|
|
* |<- Fiemap range ->|
|
|
* |<------------ First extent ----------->|
|
|
*
|
|
* In this case, the first extent range will be cached but not emitted.
|
|
* So we must emit it before ending extent_fiemap().
|
|
*/
|
|
static int emit_last_fiemap_cache(struct fiemap_extent_info *fieinfo,
|
|
struct fiemap_cache *cache)
|
|
{
|
|
int ret;
|
|
|
|
if (!cache->cached)
|
|
return 0;
|
|
|
|
ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
|
|
cache->len, cache->flags);
|
|
cache->cached = false;
|
|
if (ret > 0)
|
|
ret = 0;
|
|
return ret;
|
|
}
|
|
|
|
static int fiemap_next_leaf_item(struct btrfs_inode *inode, struct btrfs_path *path)
|
|
{
|
|
struct extent_buffer *clone;
|
|
struct btrfs_key key;
|
|
int slot;
|
|
int ret;
|
|
|
|
path->slots[0]++;
|
|
if (path->slots[0] < btrfs_header_nritems(path->nodes[0]))
|
|
return 0;
|
|
|
|
ret = btrfs_next_leaf(inode->root, path);
|
|
if (ret != 0)
|
|
return ret;
|
|
|
|
/*
|
|
* Don't bother with cloning if there are no more file extent items for
|
|
* our inode.
|
|
*/
|
|
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
|
|
if (key.objectid != btrfs_ino(inode) || key.type != BTRFS_EXTENT_DATA_KEY)
|
|
return 1;
|
|
|
|
/* See the comment at fiemap_search_slot() about why we clone. */
|
|
clone = btrfs_clone_extent_buffer(path->nodes[0]);
|
|
if (!clone)
|
|
return -ENOMEM;
|
|
|
|
slot = path->slots[0];
|
|
btrfs_release_path(path);
|
|
path->nodes[0] = clone;
|
|
path->slots[0] = slot;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Search for the first file extent item that starts at a given file offset or
|
|
* the one that starts immediately before that offset.
|
|
* Returns: 0 on success, < 0 on error, 1 if not found.
|
|
*/
|
|
static int fiemap_search_slot(struct btrfs_inode *inode, struct btrfs_path *path,
|
|
u64 file_offset)
|
|
{
|
|
const u64 ino = btrfs_ino(inode);
|
|
struct btrfs_root *root = inode->root;
|
|
struct extent_buffer *clone;
|
|
struct btrfs_key key;
|
|
int slot;
|
|
int ret;
|
|
|
|
key.objectid = ino;
|
|
key.type = BTRFS_EXTENT_DATA_KEY;
|
|
key.offset = file_offset;
|
|
|
|
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (ret > 0 && path->slots[0] > 0) {
|
|
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1);
|
|
if (key.objectid == ino && key.type == BTRFS_EXTENT_DATA_KEY)
|
|
path->slots[0]--;
|
|
}
|
|
|
|
if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
|
|
ret = btrfs_next_leaf(root, path);
|
|
if (ret != 0)
|
|
return ret;
|
|
|
|
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
|
|
if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY)
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* We clone the leaf and use it during fiemap. This is because while
|
|
* using the leaf we do expensive things like checking if an extent is
|
|
* shared, which can take a long time. In order to prevent blocking
|
|
* other tasks for too long, we use a clone of the leaf. We have locked
|
|
* the file range in the inode's io tree, so we know none of our file
|
|
* extent items can change. This way we avoid blocking other tasks that
|
|
* want to insert items for other inodes in the same leaf or b+tree
|
|
* rebalance operations (triggered for example when someone is trying
|
|
* to push items into this leaf when trying to insert an item in a
|
|
* neighbour leaf).
|
|
* We also need the private clone because holding a read lock on an
|
|
* extent buffer of the subvolume's b+tree will make lockdep unhappy
|
|
* when we call fiemap_fill_next_extent(), because that may cause a page
|
|
* fault when filling the user space buffer with fiemap data.
|
|
*/
|
|
clone = btrfs_clone_extent_buffer(path->nodes[0]);
|
|
if (!clone)
|
|
return -ENOMEM;
|
|
|
|
slot = path->slots[0];
|
|
btrfs_release_path(path);
|
|
path->nodes[0] = clone;
|
|
path->slots[0] = slot;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Process a range which is a hole or a prealloc extent in the inode's subvolume
|
|
* btree. If @disk_bytenr is 0, we are dealing with a hole, otherwise a prealloc
|
|
* extent. The end offset (@end) is inclusive.
|
|
*/
|
|
static int fiemap_process_hole(struct btrfs_inode *inode,
|
|
struct fiemap_extent_info *fieinfo,
|
|
struct fiemap_cache *cache,
|
|
struct extent_state **delalloc_cached_state,
|
|
struct btrfs_backref_share_check_ctx *backref_ctx,
|
|
u64 disk_bytenr, u64 extent_offset,
|
|
u64 extent_gen,
|
|
u64 start, u64 end)
|
|
{
|
|
const u64 i_size = i_size_read(&inode->vfs_inode);
|
|
u64 cur_offset = start;
|
|
u64 last_delalloc_end = 0;
|
|
u32 prealloc_flags = FIEMAP_EXTENT_UNWRITTEN;
|
|
bool checked_extent_shared = false;
|
|
int ret;
|
|
|
|
/*
|
|
* There can be no delalloc past i_size, so don't waste time looking for
|
|
* it beyond i_size.
|
|
*/
|
|
while (cur_offset < end && cur_offset < i_size) {
|
|
u64 delalloc_start;
|
|
u64 delalloc_end;
|
|
u64 prealloc_start;
|
|
u64 prealloc_len = 0;
|
|
bool delalloc;
|
|
|
|
delalloc = btrfs_find_delalloc_in_range(inode, cur_offset, end,
|
|
delalloc_cached_state,
|
|
&delalloc_start,
|
|
&delalloc_end);
|
|
if (!delalloc)
|
|
break;
|
|
|
|
/*
|
|
* If this is a prealloc extent we have to report every section
|
|
* of it that has no delalloc.
|
|
*/
|
|
if (disk_bytenr != 0) {
|
|
if (last_delalloc_end == 0) {
|
|
prealloc_start = start;
|
|
prealloc_len = delalloc_start - start;
|
|
} else {
|
|
prealloc_start = last_delalloc_end + 1;
|
|
prealloc_len = delalloc_start - prealloc_start;
|
|
}
|
|
}
|
|
|
|
if (prealloc_len > 0) {
|
|
if (!checked_extent_shared && fieinfo->fi_extents_max) {
|
|
ret = btrfs_is_data_extent_shared(inode,
|
|
disk_bytenr,
|
|
extent_gen,
|
|
backref_ctx);
|
|
if (ret < 0)
|
|
return ret;
|
|
else if (ret > 0)
|
|
prealloc_flags |= FIEMAP_EXTENT_SHARED;
|
|
|
|
checked_extent_shared = true;
|
|
}
|
|
ret = emit_fiemap_extent(fieinfo, cache, prealloc_start,
|
|
disk_bytenr + extent_offset,
|
|
prealloc_len, prealloc_flags);
|
|
if (ret)
|
|
return ret;
|
|
extent_offset += prealloc_len;
|
|
}
|
|
|
|
ret = emit_fiemap_extent(fieinfo, cache, delalloc_start, 0,
|
|
delalloc_end + 1 - delalloc_start,
|
|
FIEMAP_EXTENT_DELALLOC |
|
|
FIEMAP_EXTENT_UNKNOWN);
|
|
if (ret)
|
|
return ret;
|
|
|
|
last_delalloc_end = delalloc_end;
|
|
cur_offset = delalloc_end + 1;
|
|
extent_offset += cur_offset - delalloc_start;
|
|
cond_resched();
|
|
}
|
|
|
|
/*
|
|
* Either we found no delalloc for the whole prealloc extent or we have
|
|
* a prealloc extent that spans i_size or starts at or after i_size.
|
|
*/
|
|
if (disk_bytenr != 0 && last_delalloc_end < end) {
|
|
u64 prealloc_start;
|
|
u64 prealloc_len;
|
|
|
|
if (last_delalloc_end == 0) {
|
|
prealloc_start = start;
|
|
prealloc_len = end + 1 - start;
|
|
} else {
|
|
prealloc_start = last_delalloc_end + 1;
|
|
prealloc_len = end + 1 - prealloc_start;
|
|
}
|
|
|
|
if (!checked_extent_shared && fieinfo->fi_extents_max) {
|
|
ret = btrfs_is_data_extent_shared(inode,
|
|
disk_bytenr,
|
|
extent_gen,
|
|
backref_ctx);
|
|
if (ret < 0)
|
|
return ret;
|
|
else if (ret > 0)
|
|
prealloc_flags |= FIEMAP_EXTENT_SHARED;
|
|
}
|
|
ret = emit_fiemap_extent(fieinfo, cache, prealloc_start,
|
|
disk_bytenr + extent_offset,
|
|
prealloc_len, prealloc_flags);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int fiemap_find_last_extent_offset(struct btrfs_inode *inode,
|
|
struct btrfs_path *path,
|
|
u64 *last_extent_end_ret)
|
|
{
|
|
const u64 ino = btrfs_ino(inode);
|
|
struct btrfs_root *root = inode->root;
|
|
struct extent_buffer *leaf;
|
|
struct btrfs_file_extent_item *ei;
|
|
struct btrfs_key key;
|
|
u64 disk_bytenr;
|
|
int ret;
|
|
|
|
/*
|
|
* Lookup the last file extent. We're not using i_size here because
|
|
* there might be preallocation past i_size.
|
|
*/
|
|
ret = btrfs_lookup_file_extent(NULL, root, path, ino, (u64)-1, 0);
|
|
/* There can't be a file extent item at offset (u64)-1 */
|
|
ASSERT(ret != 0);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
/*
|
|
* For a non-existing key, btrfs_search_slot() always leaves us at a
|
|
* slot > 0, except if the btree is empty, which is impossible because
|
|
* at least it has the inode item for this inode and all the items for
|
|
* the root inode 256.
|
|
*/
|
|
ASSERT(path->slots[0] > 0);
|
|
path->slots[0]--;
|
|
leaf = path->nodes[0];
|
|
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
|
|
if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) {
|
|
/* No file extent items in the subvolume tree. */
|
|
*last_extent_end_ret = 0;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* For an inline extent, the disk_bytenr is where inline data starts at,
|
|
* so first check if we have an inline extent item before checking if we
|
|
* have an implicit hole (disk_bytenr == 0).
|
|
*/
|
|
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item);
|
|
if (btrfs_file_extent_type(leaf, ei) == BTRFS_FILE_EXTENT_INLINE) {
|
|
*last_extent_end_ret = btrfs_file_extent_end(path);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Find the last file extent item that is not a hole (when NO_HOLES is
|
|
* not enabled). This should take at most 2 iterations in the worst
|
|
* case: we have one hole file extent item at slot 0 of a leaf and
|
|
* another hole file extent item as the last item in the previous leaf.
|
|
* This is because we merge file extent items that represent holes.
|
|
*/
|
|
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, ei);
|
|
while (disk_bytenr == 0) {
|
|
ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY);
|
|
if (ret < 0) {
|
|
return ret;
|
|
} else if (ret > 0) {
|
|
/* No file extent items that are not holes. */
|
|
*last_extent_end_ret = 0;
|
|
return 0;
|
|
}
|
|
leaf = path->nodes[0];
|
|
ei = btrfs_item_ptr(leaf, path->slots[0],
|
|
struct btrfs_file_extent_item);
|
|
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, ei);
|
|
}
|
|
|
|
*last_extent_end_ret = btrfs_file_extent_end(path);
|
|
return 0;
|
|
}
|
|
|
|
int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
|
|
u64 start, u64 len)
|
|
{
|
|
const u64 ino = btrfs_ino(inode);
|
|
struct extent_state *cached_state = NULL;
|
|
struct extent_state *delalloc_cached_state = NULL;
|
|
struct btrfs_path *path;
|
|
struct fiemap_cache cache = { 0 };
|
|
struct btrfs_backref_share_check_ctx *backref_ctx;
|
|
u64 last_extent_end;
|
|
u64 prev_extent_end;
|
|
u64 lockstart;
|
|
u64 lockend;
|
|
bool stopped = false;
|
|
int ret;
|
|
|
|
backref_ctx = btrfs_alloc_backref_share_check_ctx();
|
|
path = btrfs_alloc_path();
|
|
if (!backref_ctx || !path) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
lockstart = round_down(start, inode->root->fs_info->sectorsize);
|
|
lockend = round_up(start + len, inode->root->fs_info->sectorsize);
|
|
prev_extent_end = lockstart;
|
|
|
|
btrfs_inode_lock(inode, BTRFS_ILOCK_SHARED);
|
|
lock_extent(&inode->io_tree, lockstart, lockend, &cached_state);
|
|
|
|
ret = fiemap_find_last_extent_offset(inode, path, &last_extent_end);
|
|
if (ret < 0)
|
|
goto out_unlock;
|
|
btrfs_release_path(path);
|
|
|
|
path->reada = READA_FORWARD;
|
|
ret = fiemap_search_slot(inode, path, lockstart);
|
|
if (ret < 0) {
|
|
goto out_unlock;
|
|
} else if (ret > 0) {
|
|
/*
|
|
* No file extent item found, but we may have delalloc between
|
|
* the current offset and i_size. So check for that.
|
|
*/
|
|
ret = 0;
|
|
goto check_eof_delalloc;
|
|
}
|
|
|
|
while (prev_extent_end < lockend) {
|
|
struct extent_buffer *leaf = path->nodes[0];
|
|
struct btrfs_file_extent_item *ei;
|
|
struct btrfs_key key;
|
|
u64 extent_end;
|
|
u64 extent_len;
|
|
u64 extent_offset = 0;
|
|
u64 extent_gen;
|
|
u64 disk_bytenr = 0;
|
|
u64 flags = 0;
|
|
int extent_type;
|
|
u8 compression;
|
|
|
|
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
|
|
if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY)
|
|
break;
|
|
|
|
extent_end = btrfs_file_extent_end(path);
|
|
|
|
/*
|
|
* The first iteration can leave us at an extent item that ends
|
|
* before our range's start. Move to the next item.
|
|
*/
|
|
if (extent_end <= lockstart)
|
|
goto next_item;
|
|
|
|
backref_ctx->curr_leaf_bytenr = leaf->start;
|
|
|
|
/* We have in implicit hole (NO_HOLES feature enabled). */
|
|
if (prev_extent_end < key.offset) {
|
|
const u64 range_end = min(key.offset, lockend) - 1;
|
|
|
|
ret = fiemap_process_hole(inode, fieinfo, &cache,
|
|
&delalloc_cached_state,
|
|
backref_ctx, 0, 0, 0,
|
|
prev_extent_end, range_end);
|
|
if (ret < 0) {
|
|
goto out_unlock;
|
|
} else if (ret > 0) {
|
|
/* fiemap_fill_next_extent() told us to stop. */
|
|
stopped = true;
|
|
break;
|
|
}
|
|
|
|
/* We've reached the end of the fiemap range, stop. */
|
|
if (key.offset >= lockend) {
|
|
stopped = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
extent_len = extent_end - key.offset;
|
|
ei = btrfs_item_ptr(leaf, path->slots[0],
|
|
struct btrfs_file_extent_item);
|
|
compression = btrfs_file_extent_compression(leaf, ei);
|
|
extent_type = btrfs_file_extent_type(leaf, ei);
|
|
extent_gen = btrfs_file_extent_generation(leaf, ei);
|
|
|
|
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
|
|
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, ei);
|
|
if (compression == BTRFS_COMPRESS_NONE)
|
|
extent_offset = btrfs_file_extent_offset(leaf, ei);
|
|
}
|
|
|
|
if (compression != BTRFS_COMPRESS_NONE)
|
|
flags |= FIEMAP_EXTENT_ENCODED;
|
|
|
|
if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
|
|
flags |= FIEMAP_EXTENT_DATA_INLINE;
|
|
flags |= FIEMAP_EXTENT_NOT_ALIGNED;
|
|
ret = emit_fiemap_extent(fieinfo, &cache, key.offset, 0,
|
|
extent_len, flags);
|
|
} else if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
|
|
ret = fiemap_process_hole(inode, fieinfo, &cache,
|
|
&delalloc_cached_state,
|
|
backref_ctx,
|
|
disk_bytenr, extent_offset,
|
|
extent_gen, key.offset,
|
|
extent_end - 1);
|
|
} else if (disk_bytenr == 0) {
|
|
/* We have an explicit hole. */
|
|
ret = fiemap_process_hole(inode, fieinfo, &cache,
|
|
&delalloc_cached_state,
|
|
backref_ctx, 0, 0, 0,
|
|
key.offset, extent_end - 1);
|
|
} else {
|
|
/* We have a regular extent. */
|
|
if (fieinfo->fi_extents_max) {
|
|
ret = btrfs_is_data_extent_shared(inode,
|
|
disk_bytenr,
|
|
extent_gen,
|
|
backref_ctx);
|
|
if (ret < 0)
|
|
goto out_unlock;
|
|
else if (ret > 0)
|
|
flags |= FIEMAP_EXTENT_SHARED;
|
|
}
|
|
|
|
ret = emit_fiemap_extent(fieinfo, &cache, key.offset,
|
|
disk_bytenr + extent_offset,
|
|
extent_len, flags);
|
|
}
|
|
|
|
if (ret < 0) {
|
|
goto out_unlock;
|
|
} else if (ret > 0) {
|
|
/* fiemap_fill_next_extent() told us to stop. */
|
|
stopped = true;
|
|
break;
|
|
}
|
|
|
|
prev_extent_end = extent_end;
|
|
next_item:
|
|
if (fatal_signal_pending(current)) {
|
|
ret = -EINTR;
|
|
goto out_unlock;
|
|
}
|
|
|
|
ret = fiemap_next_leaf_item(inode, path);
|
|
if (ret < 0) {
|
|
goto out_unlock;
|
|
} else if (ret > 0) {
|
|
/* No more file extent items for this inode. */
|
|
break;
|
|
}
|
|
cond_resched();
|
|
}
|
|
|
|
check_eof_delalloc:
|
|
/*
|
|
* Release (and free) the path before emitting any final entries to
|
|
* fiemap_fill_next_extent() to keep lockdep happy. This is because
|
|
* once we find no more file extent items exist, we may have a
|
|
* non-cloned leaf, and fiemap_fill_next_extent() can trigger page
|
|
* faults when copying data to the user space buffer.
|
|
*/
|
|
btrfs_free_path(path);
|
|
path = NULL;
|
|
|
|
if (!stopped && prev_extent_end < lockend) {
|
|
ret = fiemap_process_hole(inode, fieinfo, &cache,
|
|
&delalloc_cached_state, backref_ctx,
|
|
0, 0, 0, prev_extent_end, lockend - 1);
|
|
if (ret < 0)
|
|
goto out_unlock;
|
|
prev_extent_end = lockend;
|
|
}
|
|
|
|
if (cache.cached && cache.offset + cache.len >= last_extent_end) {
|
|
const u64 i_size = i_size_read(&inode->vfs_inode);
|
|
|
|
if (prev_extent_end < i_size) {
|
|
u64 delalloc_start;
|
|
u64 delalloc_end;
|
|
bool delalloc;
|
|
|
|
delalloc = btrfs_find_delalloc_in_range(inode,
|
|
prev_extent_end,
|
|
i_size - 1,
|
|
&delalloc_cached_state,
|
|
&delalloc_start,
|
|
&delalloc_end);
|
|
if (!delalloc)
|
|
cache.flags |= FIEMAP_EXTENT_LAST;
|
|
} else {
|
|
cache.flags |= FIEMAP_EXTENT_LAST;
|
|
}
|
|
}
|
|
|
|
ret = emit_last_fiemap_cache(fieinfo, &cache);
|
|
|
|
out_unlock:
|
|
unlock_extent(&inode->io_tree, lockstart, lockend, &cached_state);
|
|
btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
|
|
out:
|
|
free_extent_state(delalloc_cached_state);
|
|
btrfs_free_backref_share_ctx(backref_ctx);
|
|
btrfs_free_path(path);
|
|
return ret;
|
|
}
|
|
|
|
static void __free_extent_buffer(struct extent_buffer *eb)
|
|
{
|
|
kmem_cache_free(extent_buffer_cache, eb);
|
|
}
|
|
|
|
int extent_buffer_under_io(const struct extent_buffer *eb)
|
|
{
|
|
return (atomic_read(&eb->io_pages) ||
|
|
test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
|
|
test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
|
|
}
|
|
|
|
static bool page_range_has_eb(struct btrfs_fs_info *fs_info, struct page *page)
|
|
{
|
|
struct btrfs_subpage *subpage;
|
|
|
|
lockdep_assert_held(&page->mapping->private_lock);
|
|
|
|
if (PagePrivate(page)) {
|
|
subpage = (struct btrfs_subpage *)page->private;
|
|
if (atomic_read(&subpage->eb_refs))
|
|
return true;
|
|
/*
|
|
* Even there is no eb refs here, we may still have
|
|
* end_page_read() call relying on page::private.
|
|
*/
|
|
if (atomic_read(&subpage->readers))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static void detach_extent_buffer_page(struct extent_buffer *eb, struct page *page)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
const bool mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
|
|
|
|
/*
|
|
* For mapped eb, we're going to change the page private, which should
|
|
* be done under the private_lock.
|
|
*/
|
|
if (mapped)
|
|
spin_lock(&page->mapping->private_lock);
|
|
|
|
if (!PagePrivate(page)) {
|
|
if (mapped)
|
|
spin_unlock(&page->mapping->private_lock);
|
|
return;
|
|
}
|
|
|
|
if (fs_info->nodesize >= PAGE_SIZE) {
|
|
/*
|
|
* We do this since we'll remove the pages after we've
|
|
* removed the eb from the radix tree, so we could race
|
|
* and have this page now attached to the new eb. So
|
|
* only clear page_private if it's still connected to
|
|
* this eb.
|
|
*/
|
|
if (PagePrivate(page) &&
|
|
page->private == (unsigned long)eb) {
|
|
BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags));
|
|
BUG_ON(PageDirty(page));
|
|
BUG_ON(PageWriteback(page));
|
|
/*
|
|
* We need to make sure we haven't be attached
|
|
* to a new eb.
|
|
*/
|
|
detach_page_private(page);
|
|
}
|
|
if (mapped)
|
|
spin_unlock(&page->mapping->private_lock);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* For subpage, we can have dummy eb with page private. In this case,
|
|
* we can directly detach the private as such page is only attached to
|
|
* one dummy eb, no sharing.
|
|
*/
|
|
if (!mapped) {
|
|
btrfs_detach_subpage(fs_info, page);
|
|
return;
|
|
}
|
|
|
|
btrfs_page_dec_eb_refs(fs_info, page);
|
|
|
|
/*
|
|
* We can only detach the page private if there are no other ebs in the
|
|
* page range and no unfinished IO.
|
|
*/
|
|
if (!page_range_has_eb(fs_info, page))
|
|
btrfs_detach_subpage(fs_info, page);
|
|
|
|
spin_unlock(&page->mapping->private_lock);
|
|
}
|
|
|
|
/* Release all pages attached to the extent buffer */
|
|
static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb)
|
|
{
|
|
int i;
|
|
int num_pages;
|
|
|
|
ASSERT(!extent_buffer_under_io(eb));
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *page = eb->pages[i];
|
|
|
|
if (!page)
|
|
continue;
|
|
|
|
detach_extent_buffer_page(eb, page);
|
|
|
|
/* One for when we allocated the page */
|
|
put_page(page);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Helper for releasing the extent buffer.
|
|
*/
|
|
static inline void btrfs_release_extent_buffer(struct extent_buffer *eb)
|
|
{
|
|
btrfs_release_extent_buffer_pages(eb);
|
|
btrfs_leak_debug_del_eb(eb);
|
|
__free_extent_buffer(eb);
|
|
}
|
|
|
|
static struct extent_buffer *
|
|
__alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
|
|
unsigned long len)
|
|
{
|
|
struct extent_buffer *eb = NULL;
|
|
|
|
eb = kmem_cache_zalloc(extent_buffer_cache, GFP_NOFS|__GFP_NOFAIL);
|
|
eb->start = start;
|
|
eb->len = len;
|
|
eb->fs_info = fs_info;
|
|
init_rwsem(&eb->lock);
|
|
|
|
btrfs_leak_debug_add_eb(eb);
|
|
INIT_LIST_HEAD(&eb->release_list);
|
|
|
|
spin_lock_init(&eb->refs_lock);
|
|
atomic_set(&eb->refs, 1);
|
|
atomic_set(&eb->io_pages, 0);
|
|
|
|
ASSERT(len <= BTRFS_MAX_METADATA_BLOCKSIZE);
|
|
|
|
return eb;
|
|
}
|
|
|
|
struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src)
|
|
{
|
|
int i;
|
|
struct extent_buffer *new;
|
|
int num_pages = num_extent_pages(src);
|
|
int ret;
|
|
|
|
new = __alloc_extent_buffer(src->fs_info, src->start, src->len);
|
|
if (new == NULL)
|
|
return NULL;
|
|
|
|
/*
|
|
* Set UNMAPPED before calling btrfs_release_extent_buffer(), as
|
|
* btrfs_release_extent_buffer() have different behavior for
|
|
* UNMAPPED subpage extent buffer.
|
|
*/
|
|
set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags);
|
|
|
|
ret = btrfs_alloc_page_array(num_pages, new->pages);
|
|
if (ret) {
|
|
btrfs_release_extent_buffer(new);
|
|
return NULL;
|
|
}
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
int ret;
|
|
struct page *p = new->pages[i];
|
|
|
|
ret = attach_extent_buffer_page(new, p, NULL);
|
|
if (ret < 0) {
|
|
btrfs_release_extent_buffer(new);
|
|
return NULL;
|
|
}
|
|
WARN_ON(PageDirty(p));
|
|
copy_page(page_address(p), page_address(src->pages[i]));
|
|
}
|
|
set_extent_buffer_uptodate(new);
|
|
|
|
return new;
|
|
}
|
|
|
|
struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
|
|
u64 start, unsigned long len)
|
|
{
|
|
struct extent_buffer *eb;
|
|
int num_pages;
|
|
int i;
|
|
int ret;
|
|
|
|
eb = __alloc_extent_buffer(fs_info, start, len);
|
|
if (!eb)
|
|
return NULL;
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
ret = btrfs_alloc_page_array(num_pages, eb->pages);
|
|
if (ret)
|
|
goto err;
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *p = eb->pages[i];
|
|
|
|
ret = attach_extent_buffer_page(eb, p, NULL);
|
|
if (ret < 0)
|
|
goto err;
|
|
}
|
|
|
|
set_extent_buffer_uptodate(eb);
|
|
btrfs_set_header_nritems(eb, 0);
|
|
set_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
|
|
|
|
return eb;
|
|
err:
|
|
for (i = 0; i < num_pages; i++) {
|
|
if (eb->pages[i]) {
|
|
detach_extent_buffer_page(eb, eb->pages[i]);
|
|
__free_page(eb->pages[i]);
|
|
}
|
|
}
|
|
__free_extent_buffer(eb);
|
|
return NULL;
|
|
}
|
|
|
|
struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
|
|
u64 start)
|
|
{
|
|
return __alloc_dummy_extent_buffer(fs_info, start, fs_info->nodesize);
|
|
}
|
|
|
|
static void check_buffer_tree_ref(struct extent_buffer *eb)
|
|
{
|
|
int refs;
|
|
/*
|
|
* The TREE_REF bit is first set when the extent_buffer is added
|
|
* to the radix tree. It is also reset, if unset, when a new reference
|
|
* is created by find_extent_buffer.
|
|
*
|
|
* It is only cleared in two cases: freeing the last non-tree
|
|
* reference to the extent_buffer when its STALE bit is set or
|
|
* calling release_folio when the tree reference is the only reference.
|
|
*
|
|
* In both cases, care is taken to ensure that the extent_buffer's
|
|
* pages are not under io. However, release_folio can be concurrently
|
|
* called with creating new references, which is prone to race
|
|
* conditions between the calls to check_buffer_tree_ref in those
|
|
* codepaths and clearing TREE_REF in try_release_extent_buffer.
|
|
*
|
|
* The actual lifetime of the extent_buffer in the radix tree is
|
|
* adequately protected by the refcount, but the TREE_REF bit and
|
|
* its corresponding reference are not. To protect against this
|
|
* class of races, we call check_buffer_tree_ref from the codepaths
|
|
* which trigger io after they set eb->io_pages. Note that once io is
|
|
* initiated, TREE_REF can no longer be cleared, so that is the
|
|
* moment at which any such race is best fixed.
|
|
*/
|
|
refs = atomic_read(&eb->refs);
|
|
if (refs >= 2 && test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
|
|
return;
|
|
|
|
spin_lock(&eb->refs_lock);
|
|
if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
|
|
atomic_inc(&eb->refs);
|
|
spin_unlock(&eb->refs_lock);
|
|
}
|
|
|
|
static void mark_extent_buffer_accessed(struct extent_buffer *eb,
|
|
struct page *accessed)
|
|
{
|
|
int num_pages, i;
|
|
|
|
check_buffer_tree_ref(eb);
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++) {
|
|
struct page *p = eb->pages[i];
|
|
|
|
if (p != accessed)
|
|
mark_page_accessed(p);
|
|
}
|
|
}
|
|
|
|
struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
|
|
u64 start)
|
|
{
|
|
struct extent_buffer *eb;
|
|
|
|
eb = find_extent_buffer_nolock(fs_info, start);
|
|
if (!eb)
|
|
return NULL;
|
|
/*
|
|
* Lock our eb's refs_lock to avoid races with free_extent_buffer().
|
|
* When we get our eb it might be flagged with EXTENT_BUFFER_STALE and
|
|
* another task running free_extent_buffer() might have seen that flag
|
|
* set, eb->refs == 2, that the buffer isn't under IO (dirty and
|
|
* writeback flags not set) and it's still in the tree (flag
|
|
* EXTENT_BUFFER_TREE_REF set), therefore being in the process of
|
|
* decrementing the extent buffer's reference count twice. So here we
|
|
* could race and increment the eb's reference count, clear its stale
|
|
* flag, mark it as dirty and drop our reference before the other task
|
|
* finishes executing free_extent_buffer, which would later result in
|
|
* an attempt to free an extent buffer that is dirty.
|
|
*/
|
|
if (test_bit(EXTENT_BUFFER_STALE, &eb->bflags)) {
|
|
spin_lock(&eb->refs_lock);
|
|
spin_unlock(&eb->refs_lock);
|
|
}
|
|
mark_extent_buffer_accessed(eb, NULL);
|
|
return eb;
|
|
}
|
|
|
|
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
|
|
struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
|
|
u64 start)
|
|
{
|
|
struct extent_buffer *eb, *exists = NULL;
|
|
int ret;
|
|
|
|
eb = find_extent_buffer(fs_info, start);
|
|
if (eb)
|
|
return eb;
|
|
eb = alloc_dummy_extent_buffer(fs_info, start);
|
|
if (!eb)
|
|
return ERR_PTR(-ENOMEM);
|
|
eb->fs_info = fs_info;
|
|
again:
|
|
ret = radix_tree_preload(GFP_NOFS);
|
|
if (ret) {
|
|
exists = ERR_PTR(ret);
|
|
goto free_eb;
|
|
}
|
|
spin_lock(&fs_info->buffer_lock);
|
|
ret = radix_tree_insert(&fs_info->buffer_radix,
|
|
start >> fs_info->sectorsize_bits, eb);
|
|
spin_unlock(&fs_info->buffer_lock);
|
|
radix_tree_preload_end();
|
|
if (ret == -EEXIST) {
|
|
exists = find_extent_buffer(fs_info, start);
|
|
if (exists)
|
|
goto free_eb;
|
|
else
|
|
goto again;
|
|
}
|
|
check_buffer_tree_ref(eb);
|
|
set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
|
|
|
|
return eb;
|
|
free_eb:
|
|
btrfs_release_extent_buffer(eb);
|
|
return exists;
|
|
}
|
|
#endif
|
|
|
|
static struct extent_buffer *grab_extent_buffer(
|
|
struct btrfs_fs_info *fs_info, struct page *page)
|
|
{
|
|
struct extent_buffer *exists;
|
|
|
|
/*
|
|
* For subpage case, we completely rely on radix tree to ensure we
|
|
* don't try to insert two ebs for the same bytenr. So here we always
|
|
* return NULL and just continue.
|
|
*/
|
|
if (fs_info->nodesize < PAGE_SIZE)
|
|
return NULL;
|
|
|
|
/* Page not yet attached to an extent buffer */
|
|
if (!PagePrivate(page))
|
|
return NULL;
|
|
|
|
/*
|
|
* We could have already allocated an eb for this page and attached one
|
|
* so lets see if we can get a ref on the existing eb, and if we can we
|
|
* know it's good and we can just return that one, else we know we can
|
|
* just overwrite page->private.
|
|
*/
|
|
exists = (struct extent_buffer *)page->private;
|
|
if (atomic_inc_not_zero(&exists->refs))
|
|
return exists;
|
|
|
|
WARN_ON(PageDirty(page));
|
|
detach_page_private(page);
|
|
return NULL;
|
|
}
|
|
|
|
static int check_eb_alignment(struct btrfs_fs_info *fs_info, u64 start)
|
|
{
|
|
if (!IS_ALIGNED(start, fs_info->sectorsize)) {
|
|
btrfs_err(fs_info, "bad tree block start %llu", start);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (fs_info->nodesize < PAGE_SIZE &&
|
|
offset_in_page(start) + fs_info->nodesize > PAGE_SIZE) {
|
|
btrfs_err(fs_info,
|
|
"tree block crosses page boundary, start %llu nodesize %u",
|
|
start, fs_info->nodesize);
|
|
return -EINVAL;
|
|
}
|
|
if (fs_info->nodesize >= PAGE_SIZE &&
|
|
!PAGE_ALIGNED(start)) {
|
|
btrfs_err(fs_info,
|
|
"tree block is not page aligned, start %llu nodesize %u",
|
|
start, fs_info->nodesize);
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
|
|
u64 start, u64 owner_root, int level)
|
|
{
|
|
unsigned long len = fs_info->nodesize;
|
|
int num_pages;
|
|
int i;
|
|
unsigned long index = start >> PAGE_SHIFT;
|
|
struct extent_buffer *eb;
|
|
struct extent_buffer *exists = NULL;
|
|
struct page *p;
|
|
struct address_space *mapping = fs_info->btree_inode->i_mapping;
|
|
u64 lockdep_owner = owner_root;
|
|
int uptodate = 1;
|
|
int ret;
|
|
|
|
if (check_eb_alignment(fs_info, start))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
#if BITS_PER_LONG == 32
|
|
if (start >= MAX_LFS_FILESIZE) {
|
|
btrfs_err_rl(fs_info,
|
|
"extent buffer %llu is beyond 32bit page cache limit", start);
|
|
btrfs_err_32bit_limit(fs_info);
|
|
return ERR_PTR(-EOVERFLOW);
|
|
}
|
|
if (start >= BTRFS_32BIT_EARLY_WARN_THRESHOLD)
|
|
btrfs_warn_32bit_limit(fs_info);
|
|
#endif
|
|
|
|
eb = find_extent_buffer(fs_info, start);
|
|
if (eb)
|
|
return eb;
|
|
|
|
eb = __alloc_extent_buffer(fs_info, start, len);
|
|
if (!eb)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
/*
|
|
* The reloc trees are just snapshots, so we need them to appear to be
|
|
* just like any other fs tree WRT lockdep.
|
|
*/
|
|
if (lockdep_owner == BTRFS_TREE_RELOC_OBJECTID)
|
|
lockdep_owner = BTRFS_FS_TREE_OBJECTID;
|
|
|
|
btrfs_set_buffer_lockdep_class(lockdep_owner, eb, level);
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++, index++) {
|
|
struct btrfs_subpage *prealloc = NULL;
|
|
|
|
p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
|
|
if (!p) {
|
|
exists = ERR_PTR(-ENOMEM);
|
|
goto free_eb;
|
|
}
|
|
|
|
/*
|
|
* Preallocate page->private for subpage case, so that we won't
|
|
* allocate memory with private_lock hold. The memory will be
|
|
* freed by attach_extent_buffer_page() or freed manually if
|
|
* we exit earlier.
|
|
*
|
|
* Although we have ensured one subpage eb can only have one
|
|
* page, but it may change in the future for 16K page size
|
|
* support, so we still preallocate the memory in the loop.
|
|
*/
|
|
if (fs_info->nodesize < PAGE_SIZE) {
|
|
prealloc = btrfs_alloc_subpage(fs_info, BTRFS_SUBPAGE_METADATA);
|
|
if (IS_ERR(prealloc)) {
|
|
ret = PTR_ERR(prealloc);
|
|
unlock_page(p);
|
|
put_page(p);
|
|
exists = ERR_PTR(ret);
|
|
goto free_eb;
|
|
}
|
|
}
|
|
|
|
spin_lock(&mapping->private_lock);
|
|
exists = grab_extent_buffer(fs_info, p);
|
|
if (exists) {
|
|
spin_unlock(&mapping->private_lock);
|
|
unlock_page(p);
|
|
put_page(p);
|
|
mark_extent_buffer_accessed(exists, p);
|
|
btrfs_free_subpage(prealloc);
|
|
goto free_eb;
|
|
}
|
|
/* Should not fail, as we have preallocated the memory */
|
|
ret = attach_extent_buffer_page(eb, p, prealloc);
|
|
ASSERT(!ret);
|
|
/*
|
|
* To inform we have extra eb under allocation, so that
|
|
* detach_extent_buffer_page() won't release the page private
|
|
* when the eb hasn't yet been inserted into radix tree.
|
|
*
|
|
* The ref will be decreased when the eb released the page, in
|
|
* detach_extent_buffer_page().
|
|
* Thus needs no special handling in error path.
|
|
*/
|
|
btrfs_page_inc_eb_refs(fs_info, p);
|
|
spin_unlock(&mapping->private_lock);
|
|
|
|
WARN_ON(btrfs_page_test_dirty(fs_info, p, eb->start, eb->len));
|
|
eb->pages[i] = p;
|
|
if (!PageUptodate(p))
|
|
uptodate = 0;
|
|
|
|
/*
|
|
* We can't unlock the pages just yet since the extent buffer
|
|
* hasn't been properly inserted in the radix tree, this
|
|
* opens a race with btree_release_folio which can free a page
|
|
* while we are still filling in all pages for the buffer and
|
|
* we could crash.
|
|
*/
|
|
}
|
|
if (uptodate)
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
again:
|
|
ret = radix_tree_preload(GFP_NOFS);
|
|
if (ret) {
|
|
exists = ERR_PTR(ret);
|
|
goto free_eb;
|
|
}
|
|
|
|
spin_lock(&fs_info->buffer_lock);
|
|
ret = radix_tree_insert(&fs_info->buffer_radix,
|
|
start >> fs_info->sectorsize_bits, eb);
|
|
spin_unlock(&fs_info->buffer_lock);
|
|
radix_tree_preload_end();
|
|
if (ret == -EEXIST) {
|
|
exists = find_extent_buffer(fs_info, start);
|
|
if (exists)
|
|
goto free_eb;
|
|
else
|
|
goto again;
|
|
}
|
|
/* add one reference for the tree */
|
|
check_buffer_tree_ref(eb);
|
|
set_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags);
|
|
|
|
/*
|
|
* Now it's safe to unlock the pages because any calls to
|
|
* btree_release_folio will correctly detect that a page belongs to a
|
|
* live buffer and won't free them prematurely.
|
|
*/
|
|
for (i = 0; i < num_pages; i++)
|
|
unlock_page(eb->pages[i]);
|
|
return eb;
|
|
|
|
free_eb:
|
|
WARN_ON(!atomic_dec_and_test(&eb->refs));
|
|
for (i = 0; i < num_pages; i++) {
|
|
if (eb->pages[i])
|
|
unlock_page(eb->pages[i]);
|
|
}
|
|
|
|
btrfs_release_extent_buffer(eb);
|
|
return exists;
|
|
}
|
|
|
|
static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
|
|
{
|
|
struct extent_buffer *eb =
|
|
container_of(head, struct extent_buffer, rcu_head);
|
|
|
|
__free_extent_buffer(eb);
|
|
}
|
|
|
|
static int release_extent_buffer(struct extent_buffer *eb)
|
|
__releases(&eb->refs_lock)
|
|
{
|
|
lockdep_assert_held(&eb->refs_lock);
|
|
|
|
WARN_ON(atomic_read(&eb->refs) == 0);
|
|
if (atomic_dec_and_test(&eb->refs)) {
|
|
if (test_and_clear_bit(EXTENT_BUFFER_IN_TREE, &eb->bflags)) {
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
|
|
spin_unlock(&eb->refs_lock);
|
|
|
|
spin_lock(&fs_info->buffer_lock);
|
|
radix_tree_delete(&fs_info->buffer_radix,
|
|
eb->start >> fs_info->sectorsize_bits);
|
|
spin_unlock(&fs_info->buffer_lock);
|
|
} else {
|
|
spin_unlock(&eb->refs_lock);
|
|
}
|
|
|
|
btrfs_leak_debug_del_eb(eb);
|
|
/* Should be safe to release our pages at this point */
|
|
btrfs_release_extent_buffer_pages(eb);
|
|
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
|
|
if (unlikely(test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags))) {
|
|
__free_extent_buffer(eb);
|
|
return 1;
|
|
}
|
|
#endif
|
|
call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
|
|
return 1;
|
|
}
|
|
spin_unlock(&eb->refs_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void free_extent_buffer(struct extent_buffer *eb)
|
|
{
|
|
int refs;
|
|
if (!eb)
|
|
return;
|
|
|
|
refs = atomic_read(&eb->refs);
|
|
while (1) {
|
|
if ((!test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) && refs <= 3)
|
|
|| (test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags) &&
|
|
refs == 1))
|
|
break;
|
|
if (atomic_try_cmpxchg(&eb->refs, &refs, refs - 1))
|
|
return;
|
|
}
|
|
|
|
spin_lock(&eb->refs_lock);
|
|
if (atomic_read(&eb->refs) == 2 &&
|
|
test_bit(EXTENT_BUFFER_STALE, &eb->bflags) &&
|
|
!extent_buffer_under_io(eb) &&
|
|
test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
|
|
atomic_dec(&eb->refs);
|
|
|
|
/*
|
|
* I know this is terrible, but it's temporary until we stop tracking
|
|
* the uptodate bits and such for the extent buffers.
|
|
*/
|
|
release_extent_buffer(eb);
|
|
}
|
|
|
|
void free_extent_buffer_stale(struct extent_buffer *eb)
|
|
{
|
|
if (!eb)
|
|
return;
|
|
|
|
spin_lock(&eb->refs_lock);
|
|
set_bit(EXTENT_BUFFER_STALE, &eb->bflags);
|
|
|
|
if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) &&
|
|
test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
|
|
atomic_dec(&eb->refs);
|
|
release_extent_buffer(eb);
|
|
}
|
|
|
|
static void btree_clear_page_dirty(struct page *page)
|
|
{
|
|
ASSERT(PageDirty(page));
|
|
ASSERT(PageLocked(page));
|
|
clear_page_dirty_for_io(page);
|
|
xa_lock_irq(&page->mapping->i_pages);
|
|
if (!PageDirty(page))
|
|
__xa_clear_mark(&page->mapping->i_pages,
|
|
page_index(page), PAGECACHE_TAG_DIRTY);
|
|
xa_unlock_irq(&page->mapping->i_pages);
|
|
}
|
|
|
|
static void clear_subpage_extent_buffer_dirty(const struct extent_buffer *eb)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
struct page *page = eb->pages[0];
|
|
bool last;
|
|
|
|
/* btree_clear_page_dirty() needs page locked */
|
|
lock_page(page);
|
|
last = btrfs_subpage_clear_and_test_dirty(fs_info, page, eb->start,
|
|
eb->len);
|
|
if (last)
|
|
btree_clear_page_dirty(page);
|
|
unlock_page(page);
|
|
WARN_ON(atomic_read(&eb->refs) == 0);
|
|
}
|
|
|
|
void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans,
|
|
struct extent_buffer *eb)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
int i;
|
|
int num_pages;
|
|
struct page *page;
|
|
|
|
btrfs_assert_tree_write_locked(eb);
|
|
|
|
if (trans && btrfs_header_generation(eb) != trans->transid)
|
|
return;
|
|
|
|
if (!test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags))
|
|
return;
|
|
|
|
percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, -eb->len,
|
|
fs_info->dirty_metadata_batch);
|
|
|
|
if (eb->fs_info->nodesize < PAGE_SIZE)
|
|
return clear_subpage_extent_buffer_dirty(eb);
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
if (!PageDirty(page))
|
|
continue;
|
|
lock_page(page);
|
|
btree_clear_page_dirty(page);
|
|
ClearPageError(page);
|
|
unlock_page(page);
|
|
}
|
|
WARN_ON(atomic_read(&eb->refs) == 0);
|
|
}
|
|
|
|
void set_extent_buffer_dirty(struct extent_buffer *eb)
|
|
{
|
|
int i;
|
|
int num_pages;
|
|
bool was_dirty;
|
|
|
|
check_buffer_tree_ref(eb);
|
|
|
|
was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
WARN_ON(atomic_read(&eb->refs) == 0);
|
|
WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));
|
|
|
|
if (!was_dirty) {
|
|
bool subpage = eb->fs_info->nodesize < PAGE_SIZE;
|
|
|
|
/*
|
|
* For subpage case, we can have other extent buffers in the
|
|
* same page, and in clear_subpage_extent_buffer_dirty() we
|
|
* have to clear page dirty without subpage lock held.
|
|
* This can cause race where our page gets dirty cleared after
|
|
* we just set it.
|
|
*
|
|
* Thankfully, clear_subpage_extent_buffer_dirty() has locked
|
|
* its page for other reasons, we can use page lock to prevent
|
|
* the above race.
|
|
*/
|
|
if (subpage)
|
|
lock_page(eb->pages[0]);
|
|
for (i = 0; i < num_pages; i++)
|
|
btrfs_page_set_dirty(eb->fs_info, eb->pages[i],
|
|
eb->start, eb->len);
|
|
if (subpage)
|
|
unlock_page(eb->pages[0]);
|
|
percpu_counter_add_batch(&eb->fs_info->dirty_metadata_bytes,
|
|
eb->len,
|
|
eb->fs_info->dirty_metadata_batch);
|
|
}
|
|
#ifdef CONFIG_BTRFS_DEBUG
|
|
for (i = 0; i < num_pages; i++)
|
|
ASSERT(PageDirty(eb->pages[i]));
|
|
#endif
|
|
}
|
|
|
|
void clear_extent_buffer_uptodate(struct extent_buffer *eb)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
struct page *page;
|
|
int num_pages;
|
|
int i;
|
|
|
|
clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
if (!page)
|
|
continue;
|
|
|
|
/*
|
|
* This is special handling for metadata subpage, as regular
|
|
* btrfs_is_subpage() can not handle cloned/dummy metadata.
|
|
*/
|
|
if (fs_info->nodesize >= PAGE_SIZE)
|
|
ClearPageUptodate(page);
|
|
else
|
|
btrfs_subpage_clear_uptodate(fs_info, page, eb->start,
|
|
eb->len);
|
|
}
|
|
}
|
|
|
|
void set_extent_buffer_uptodate(struct extent_buffer *eb)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
struct page *page;
|
|
int num_pages;
|
|
int i;
|
|
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
|
|
/*
|
|
* This is special handling for metadata subpage, as regular
|
|
* btrfs_is_subpage() can not handle cloned/dummy metadata.
|
|
*/
|
|
if (fs_info->nodesize >= PAGE_SIZE)
|
|
SetPageUptodate(page);
|
|
else
|
|
btrfs_subpage_set_uptodate(fs_info, page, eb->start,
|
|
eb->len);
|
|
}
|
|
}
|
|
|
|
static void __read_extent_buffer_pages(struct extent_buffer *eb, int mirror_num,
|
|
struct btrfs_tree_parent_check *check)
|
|
{
|
|
int num_pages = num_extent_pages(eb), i;
|
|
struct btrfs_bio *bbio;
|
|
|
|
clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags);
|
|
eb->read_mirror = 0;
|
|
atomic_set(&eb->io_pages, num_pages);
|
|
check_buffer_tree_ref(eb);
|
|
|
|
bbio = btrfs_bio_alloc(INLINE_EXTENT_BUFFER_PAGES,
|
|
REQ_OP_READ | REQ_META, eb->fs_info,
|
|
end_bio_extent_readpage, NULL);
|
|
bbio->bio.bi_iter.bi_sector = eb->start >> SECTOR_SHIFT;
|
|
bbio->inode = BTRFS_I(eb->fs_info->btree_inode);
|
|
bbio->file_offset = eb->start;
|
|
memcpy(&bbio->parent_check, check, sizeof(*check));
|
|
if (eb->fs_info->nodesize < PAGE_SIZE) {
|
|
__bio_add_page(&bbio->bio, eb->pages[0], eb->len,
|
|
eb->start - page_offset(eb->pages[0]));
|
|
} else {
|
|
for (i = 0; i < num_pages; i++) {
|
|
ClearPageError(eb->pages[i]);
|
|
__bio_add_page(&bbio->bio, eb->pages[i], PAGE_SIZE, 0);
|
|
}
|
|
}
|
|
btrfs_submit_bio(bbio, mirror_num);
|
|
}
|
|
|
|
static int read_extent_buffer_subpage(struct extent_buffer *eb, int wait,
|
|
int mirror_num,
|
|
struct btrfs_tree_parent_check *check)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
struct extent_io_tree *io_tree;
|
|
struct page *page = eb->pages[0];
|
|
struct extent_state *cached_state = NULL;
|
|
int ret;
|
|
|
|
ASSERT(!test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags));
|
|
ASSERT(PagePrivate(page));
|
|
ASSERT(check);
|
|
io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
|
|
|
|
if (wait == WAIT_NONE) {
|
|
if (!try_lock_extent(io_tree, eb->start, eb->start + eb->len - 1,
|
|
&cached_state))
|
|
return -EAGAIN;
|
|
} else {
|
|
ret = lock_extent(io_tree, eb->start, eb->start + eb->len - 1,
|
|
&cached_state);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags) ||
|
|
PageUptodate(page) ||
|
|
btrfs_subpage_test_uptodate(fs_info, page, eb->start, eb->len)) {
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
unlock_extent(io_tree, eb->start, eb->start + eb->len - 1,
|
|
&cached_state);
|
|
return 0;
|
|
}
|
|
|
|
btrfs_subpage_clear_error(fs_info, page, eb->start, eb->len);
|
|
btrfs_subpage_start_reader(fs_info, page, eb->start, eb->len);
|
|
|
|
__read_extent_buffer_pages(eb, mirror_num, check);
|
|
if (wait != WAIT_COMPLETE) {
|
|
free_extent_state(cached_state);
|
|
return 0;
|
|
}
|
|
|
|
wait_extent_bit(io_tree, eb->start, eb->start + eb->len - 1,
|
|
EXTENT_LOCKED, &cached_state);
|
|
if (!test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
|
|
return -EIO;
|
|
return 0;
|
|
}
|
|
|
|
int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num,
|
|
struct btrfs_tree_parent_check *check)
|
|
{
|
|
int i;
|
|
struct page *page;
|
|
int locked_pages = 0;
|
|
int all_uptodate = 1;
|
|
int num_pages;
|
|
|
|
if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
|
|
return 0;
|
|
|
|
/*
|
|
* We could have had EXTENT_BUFFER_UPTODATE cleared by the write
|
|
* operation, which could potentially still be in flight. In this case
|
|
* we simply want to return an error.
|
|
*/
|
|
if (unlikely(test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)))
|
|
return -EIO;
|
|
|
|
if (eb->fs_info->nodesize < PAGE_SIZE)
|
|
return read_extent_buffer_subpage(eb, wait, mirror_num, check);
|
|
|
|
num_pages = num_extent_pages(eb);
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
if (wait == WAIT_NONE) {
|
|
/*
|
|
* WAIT_NONE is only utilized by readahead. If we can't
|
|
* acquire the lock atomically it means either the eb
|
|
* is being read out or under modification.
|
|
* Either way the eb will be or has been cached,
|
|
* readahead can exit safely.
|
|
*/
|
|
if (!trylock_page(page))
|
|
goto unlock_exit;
|
|
} else {
|
|
lock_page(page);
|
|
}
|
|
locked_pages++;
|
|
}
|
|
/*
|
|
* We need to firstly lock all pages to make sure that
|
|
* the uptodate bit of our pages won't be affected by
|
|
* clear_extent_buffer_uptodate().
|
|
*/
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
if (!PageUptodate(page))
|
|
all_uptodate = 0;
|
|
}
|
|
|
|
if (all_uptodate) {
|
|
set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
|
|
goto unlock_exit;
|
|
}
|
|
|
|
__read_extent_buffer_pages(eb, mirror_num, check);
|
|
|
|
if (wait != WAIT_COMPLETE)
|
|
return 0;
|
|
|
|
for (i = 0; i < num_pages; i++) {
|
|
page = eb->pages[i];
|
|
wait_on_page_locked(page);
|
|
if (!PageUptodate(page))
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
|
|
unlock_exit:
|
|
while (locked_pages > 0) {
|
|
locked_pages--;
|
|
page = eb->pages[locked_pages];
|
|
unlock_page(page);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static bool report_eb_range(const struct extent_buffer *eb, unsigned long start,
|
|
unsigned long len)
|
|
{
|
|
btrfs_warn(eb->fs_info,
|
|
"access to eb bytenr %llu len %lu out of range start %lu len %lu",
|
|
eb->start, eb->len, start, len);
|
|
WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG));
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Check if the [start, start + len) range is valid before reading/writing
|
|
* the eb.
|
|
* NOTE: @start and @len are offset inside the eb, not logical address.
|
|
*
|
|
* Caller should not touch the dst/src memory if this function returns error.
|
|
*/
|
|
static inline int check_eb_range(const struct extent_buffer *eb,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
unsigned long offset;
|
|
|
|
/* start, start + len should not go beyond eb->len nor overflow */
|
|
if (unlikely(check_add_overflow(start, len, &offset) || offset > eb->len))
|
|
return report_eb_range(eb, start, len);
|
|
|
|
return false;
|
|
}
|
|
|
|
void read_extent_buffer(const struct extent_buffer *eb, void *dstv,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
char *dst = (char *)dstv;
|
|
unsigned long i = get_eb_page_index(start);
|
|
|
|
if (check_eb_range(eb, start, len))
|
|
return;
|
|
|
|
offset = get_eb_offset_in_page(eb, start);
|
|
|
|
while (len > 0) {
|
|
page = eb->pages[i];
|
|
|
|
cur = min(len, (PAGE_SIZE - offset));
|
|
kaddr = page_address(page);
|
|
memcpy(dst, kaddr + offset, cur);
|
|
|
|
dst += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
int read_extent_buffer_to_user_nofault(const struct extent_buffer *eb,
|
|
void __user *dstv,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
char __user *dst = (char __user *)dstv;
|
|
unsigned long i = get_eb_page_index(start);
|
|
int ret = 0;
|
|
|
|
WARN_ON(start > eb->len);
|
|
WARN_ON(start + len > eb->start + eb->len);
|
|
|
|
offset = get_eb_offset_in_page(eb, start);
|
|
|
|
while (len > 0) {
|
|
page = eb->pages[i];
|
|
|
|
cur = min(len, (PAGE_SIZE - offset));
|
|
kaddr = page_address(page);
|
|
if (copy_to_user_nofault(dst, kaddr + offset, cur)) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
dst += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
char *ptr = (char *)ptrv;
|
|
unsigned long i = get_eb_page_index(start);
|
|
int ret = 0;
|
|
|
|
if (check_eb_range(eb, start, len))
|
|
return -EINVAL;
|
|
|
|
offset = get_eb_offset_in_page(eb, start);
|
|
|
|
while (len > 0) {
|
|
page = eb->pages[i];
|
|
|
|
cur = min(len, (PAGE_SIZE - offset));
|
|
|
|
kaddr = page_address(page);
|
|
ret = memcmp(ptr, kaddr + offset, cur);
|
|
if (ret)
|
|
break;
|
|
|
|
ptr += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Check that the extent buffer is uptodate.
|
|
*
|
|
* For regular sector size == PAGE_SIZE case, check if @page is uptodate.
|
|
* For subpage case, check if the range covered by the eb has EXTENT_UPTODATE.
|
|
*/
|
|
static void assert_eb_page_uptodate(const struct extent_buffer *eb,
|
|
struct page *page)
|
|
{
|
|
struct btrfs_fs_info *fs_info = eb->fs_info;
|
|
|
|
/*
|
|
* If we are using the commit root we could potentially clear a page
|
|
* Uptodate while we're using the extent buffer that we've previously
|
|
* looked up. We don't want to complain in this case, as the page was
|
|
* valid before, we just didn't write it out. Instead we want to catch
|
|
* the case where we didn't actually read the block properly, which
|
|
* would have !PageUptodate && !PageError, as we clear PageError before
|
|
* reading.
|
|
*/
|
|
if (fs_info->nodesize < PAGE_SIZE) {
|
|
bool uptodate, error;
|
|
|
|
uptodate = btrfs_subpage_test_uptodate(fs_info, page,
|
|
eb->start, eb->len);
|
|
error = btrfs_subpage_test_error(fs_info, page, eb->start, eb->len);
|
|
WARN_ON(!uptodate && !error);
|
|
} else {
|
|
WARN_ON(!PageUptodate(page) && !PageError(page));
|
|
}
|
|
}
|
|
|
|
void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb,
|
|
const void *srcv)
|
|
{
|
|
char *kaddr;
|
|
|
|
assert_eb_page_uptodate(eb, eb->pages[0]);
|
|
kaddr = page_address(eb->pages[0]) +
|
|
get_eb_offset_in_page(eb, offsetof(struct btrfs_header,
|
|
chunk_tree_uuid));
|
|
memcpy(kaddr, srcv, BTRFS_FSID_SIZE);
|
|
}
|
|
|
|
void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *srcv)
|
|
{
|
|
char *kaddr;
|
|
|
|
assert_eb_page_uptodate(eb, eb->pages[0]);
|
|
kaddr = page_address(eb->pages[0]) +
|
|
get_eb_offset_in_page(eb, offsetof(struct btrfs_header, fsid));
|
|
memcpy(kaddr, srcv, BTRFS_FSID_SIZE);
|
|
}
|
|
|
|
void write_extent_buffer(const struct extent_buffer *eb, const void *srcv,
|
|
unsigned long start, unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
char *src = (char *)srcv;
|
|
unsigned long i = get_eb_page_index(start);
|
|
|
|
WARN_ON(test_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags));
|
|
|
|
if (check_eb_range(eb, start, len))
|
|
return;
|
|
|
|
offset = get_eb_offset_in_page(eb, start);
|
|
|
|
while (len > 0) {
|
|
page = eb->pages[i];
|
|
assert_eb_page_uptodate(eb, page);
|
|
|
|
cur = min(len, PAGE_SIZE - offset);
|
|
kaddr = page_address(page);
|
|
memcpy(kaddr + offset, src, cur);
|
|
|
|
src += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
|
|
unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
unsigned long i = get_eb_page_index(start);
|
|
|
|
if (check_eb_range(eb, start, len))
|
|
return;
|
|
|
|
offset = get_eb_offset_in_page(eb, start);
|
|
|
|
while (len > 0) {
|
|
page = eb->pages[i];
|
|
assert_eb_page_uptodate(eb, page);
|
|
|
|
cur = min(len, PAGE_SIZE - offset);
|
|
kaddr = page_address(page);
|
|
memset(kaddr + offset, 0, cur);
|
|
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
void copy_extent_buffer_full(const struct extent_buffer *dst,
|
|
const struct extent_buffer *src)
|
|
{
|
|
int i;
|
|
int num_pages;
|
|
|
|
ASSERT(dst->len == src->len);
|
|
|
|
if (dst->fs_info->nodesize >= PAGE_SIZE) {
|
|
num_pages = num_extent_pages(dst);
|
|
for (i = 0; i < num_pages; i++)
|
|
copy_page(page_address(dst->pages[i]),
|
|
page_address(src->pages[i]));
|
|
} else {
|
|
size_t src_offset = get_eb_offset_in_page(src, 0);
|
|
size_t dst_offset = get_eb_offset_in_page(dst, 0);
|
|
|
|
ASSERT(src->fs_info->nodesize < PAGE_SIZE);
|
|
memcpy(page_address(dst->pages[0]) + dst_offset,
|
|
page_address(src->pages[0]) + src_offset,
|
|
src->len);
|
|
}
|
|
}
|
|
|
|
void copy_extent_buffer(const struct extent_buffer *dst,
|
|
const struct extent_buffer *src,
|
|
unsigned long dst_offset, unsigned long src_offset,
|
|
unsigned long len)
|
|
{
|
|
u64 dst_len = dst->len;
|
|
size_t cur;
|
|
size_t offset;
|
|
struct page *page;
|
|
char *kaddr;
|
|
unsigned long i = get_eb_page_index(dst_offset);
|
|
|
|
if (check_eb_range(dst, dst_offset, len) ||
|
|
check_eb_range(src, src_offset, len))
|
|
return;
|
|
|
|
WARN_ON(src->len != dst_len);
|
|
|
|
offset = get_eb_offset_in_page(dst, dst_offset);
|
|
|
|
while (len > 0) {
|
|
page = dst->pages[i];
|
|
assert_eb_page_uptodate(dst, page);
|
|
|
|
cur = min(len, (unsigned long)(PAGE_SIZE - offset));
|
|
|
|
kaddr = page_address(page);
|
|
read_extent_buffer(src, kaddr + offset, src_offset, cur);
|
|
|
|
src_offset += cur;
|
|
len -= cur;
|
|
offset = 0;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* eb_bitmap_offset() - calculate the page and offset of the byte containing the
|
|
* given bit number
|
|
* @eb: the extent buffer
|
|
* @start: offset of the bitmap item in the extent buffer
|
|
* @nr: bit number
|
|
* @page_index: return index of the page in the extent buffer that contains the
|
|
* given bit number
|
|
* @page_offset: return offset into the page given by page_index
|
|
*
|
|
* This helper hides the ugliness of finding the byte in an extent buffer which
|
|
* contains a given bit.
|
|
*/
|
|
static inline void eb_bitmap_offset(const struct extent_buffer *eb,
|
|
unsigned long start, unsigned long nr,
|
|
unsigned long *page_index,
|
|
size_t *page_offset)
|
|
{
|
|
size_t byte_offset = BIT_BYTE(nr);
|
|
size_t offset;
|
|
|
|
/*
|
|
* The byte we want is the offset of the extent buffer + the offset of
|
|
* the bitmap item in the extent buffer + the offset of the byte in the
|
|
* bitmap item.
|
|
*/
|
|
offset = start + offset_in_page(eb->start) + byte_offset;
|
|
|
|
*page_index = offset >> PAGE_SHIFT;
|
|
*page_offset = offset_in_page(offset);
|
|
}
|
|
|
|
/*
|
|
* Determine whether a bit in a bitmap item is set.
|
|
*
|
|
* @eb: the extent buffer
|
|
* @start: offset of the bitmap item in the extent buffer
|
|
* @nr: bit number to test
|
|
*/
|
|
int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
|
|
unsigned long nr)
|
|
{
|
|
u8 *kaddr;
|
|
struct page *page;
|
|
unsigned long i;
|
|
size_t offset;
|
|
|
|
eb_bitmap_offset(eb, start, nr, &i, &offset);
|
|
page = eb->pages[i];
|
|
assert_eb_page_uptodate(eb, page);
|
|
kaddr = page_address(page);
|
|
return 1U & (kaddr[offset] >> (nr & (BITS_PER_BYTE - 1)));
|
|
}
|
|
|
|
/*
|
|
* Set an area of a bitmap to 1.
|
|
*
|
|
* @eb: the extent buffer
|
|
* @start: offset of the bitmap item in the extent buffer
|
|
* @pos: bit number of the first bit
|
|
* @len: number of bits to set
|
|
*/
|
|
void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
|
|
unsigned long pos, unsigned long len)
|
|
{
|
|
u8 *kaddr;
|
|
struct page *page;
|
|
unsigned long i;
|
|
size_t offset;
|
|
const unsigned int size = pos + len;
|
|
int bits_to_set = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
|
|
u8 mask_to_set = BITMAP_FIRST_BYTE_MASK(pos);
|
|
|
|
eb_bitmap_offset(eb, start, pos, &i, &offset);
|
|
page = eb->pages[i];
|
|
assert_eb_page_uptodate(eb, page);
|
|
kaddr = page_address(page);
|
|
|
|
while (len >= bits_to_set) {
|
|
kaddr[offset] |= mask_to_set;
|
|
len -= bits_to_set;
|
|
bits_to_set = BITS_PER_BYTE;
|
|
mask_to_set = ~0;
|
|
if (++offset >= PAGE_SIZE && len > 0) {
|
|
offset = 0;
|
|
page = eb->pages[++i];
|
|
assert_eb_page_uptodate(eb, page);
|
|
kaddr = page_address(page);
|
|
}
|
|
}
|
|
if (len) {
|
|
mask_to_set &= BITMAP_LAST_BYTE_MASK(size);
|
|
kaddr[offset] |= mask_to_set;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Clear an area of a bitmap.
|
|
*
|
|
* @eb: the extent buffer
|
|
* @start: offset of the bitmap item in the extent buffer
|
|
* @pos: bit number of the first bit
|
|
* @len: number of bits to clear
|
|
*/
|
|
void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
|
|
unsigned long start, unsigned long pos,
|
|
unsigned long len)
|
|
{
|
|
u8 *kaddr;
|
|
struct page *page;
|
|
unsigned long i;
|
|
size_t offset;
|
|
const unsigned int size = pos + len;
|
|
int bits_to_clear = BITS_PER_BYTE - (pos % BITS_PER_BYTE);
|
|
u8 mask_to_clear = BITMAP_FIRST_BYTE_MASK(pos);
|
|
|
|
eb_bitmap_offset(eb, start, pos, &i, &offset);
|
|
page = eb->pages[i];
|
|
assert_eb_page_uptodate(eb, page);
|
|
kaddr = page_address(page);
|
|
|
|
while (len >= bits_to_clear) {
|
|
kaddr[offset] &= ~mask_to_clear;
|
|
len -= bits_to_clear;
|
|
bits_to_clear = BITS_PER_BYTE;
|
|
mask_to_clear = ~0;
|
|
if (++offset >= PAGE_SIZE && len > 0) {
|
|
offset = 0;
|
|
page = eb->pages[++i];
|
|
assert_eb_page_uptodate(eb, page);
|
|
kaddr = page_address(page);
|
|
}
|
|
}
|
|
if (len) {
|
|
mask_to_clear &= BITMAP_LAST_BYTE_MASK(size);
|
|
kaddr[offset] &= ~mask_to_clear;
|
|
}
|
|
}
|
|
|
|
static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
|
|
{
|
|
unsigned long distance = (src > dst) ? src - dst : dst - src;
|
|
return distance < len;
|
|
}
|
|
|
|
static void copy_pages(struct page *dst_page, struct page *src_page,
|
|
unsigned long dst_off, unsigned long src_off,
|
|
unsigned long len)
|
|
{
|
|
char *dst_kaddr = page_address(dst_page);
|
|
char *src_kaddr;
|
|
int must_memmove = 0;
|
|
|
|
if (dst_page != src_page) {
|
|
src_kaddr = page_address(src_page);
|
|
} else {
|
|
src_kaddr = dst_kaddr;
|
|
if (areas_overlap(src_off, dst_off, len))
|
|
must_memmove = 1;
|
|
}
|
|
|
|
if (must_memmove)
|
|
memmove(dst_kaddr + dst_off, src_kaddr + src_off, len);
|
|
else
|
|
memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
|
|
}
|
|
|
|
void memcpy_extent_buffer(const struct extent_buffer *dst,
|
|
unsigned long dst_offset, unsigned long src_offset,
|
|
unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t dst_off_in_page;
|
|
size_t src_off_in_page;
|
|
unsigned long dst_i;
|
|
unsigned long src_i;
|
|
|
|
if (check_eb_range(dst, dst_offset, len) ||
|
|
check_eb_range(dst, src_offset, len))
|
|
return;
|
|
|
|
while (len > 0) {
|
|
dst_off_in_page = get_eb_offset_in_page(dst, dst_offset);
|
|
src_off_in_page = get_eb_offset_in_page(dst, src_offset);
|
|
|
|
dst_i = get_eb_page_index(dst_offset);
|
|
src_i = get_eb_page_index(src_offset);
|
|
|
|
cur = min(len, (unsigned long)(PAGE_SIZE -
|
|
src_off_in_page));
|
|
cur = min_t(unsigned long, cur,
|
|
(unsigned long)(PAGE_SIZE - dst_off_in_page));
|
|
|
|
copy_pages(dst->pages[dst_i], dst->pages[src_i],
|
|
dst_off_in_page, src_off_in_page, cur);
|
|
|
|
src_offset += cur;
|
|
dst_offset += cur;
|
|
len -= cur;
|
|
}
|
|
}
|
|
|
|
void memmove_extent_buffer(const struct extent_buffer *dst,
|
|
unsigned long dst_offset, unsigned long src_offset,
|
|
unsigned long len)
|
|
{
|
|
size_t cur;
|
|
size_t dst_off_in_page;
|
|
size_t src_off_in_page;
|
|
unsigned long dst_end = dst_offset + len - 1;
|
|
unsigned long src_end = src_offset + len - 1;
|
|
unsigned long dst_i;
|
|
unsigned long src_i;
|
|
|
|
if (check_eb_range(dst, dst_offset, len) ||
|
|
check_eb_range(dst, src_offset, len))
|
|
return;
|
|
if (dst_offset < src_offset) {
|
|
memcpy_extent_buffer(dst, dst_offset, src_offset, len);
|
|
return;
|
|
}
|
|
while (len > 0) {
|
|
dst_i = get_eb_page_index(dst_end);
|
|
src_i = get_eb_page_index(src_end);
|
|
|
|
dst_off_in_page = get_eb_offset_in_page(dst, dst_end);
|
|
src_off_in_page = get_eb_offset_in_page(dst, src_end);
|
|
|
|
cur = min_t(unsigned long, len, src_off_in_page + 1);
|
|
cur = min(cur, dst_off_in_page + 1);
|
|
copy_pages(dst->pages[dst_i], dst->pages[src_i],
|
|
dst_off_in_page - cur + 1,
|
|
src_off_in_page - cur + 1, cur);
|
|
|
|
dst_end -= cur;
|
|
src_end -= cur;
|
|
len -= cur;
|
|
}
|
|
}
|
|
|
|
#define GANG_LOOKUP_SIZE 16
|
|
static struct extent_buffer *get_next_extent_buffer(
|
|
struct btrfs_fs_info *fs_info, struct page *page, u64 bytenr)
|
|
{
|
|
struct extent_buffer *gang[GANG_LOOKUP_SIZE];
|
|
struct extent_buffer *found = NULL;
|
|
u64 page_start = page_offset(page);
|
|
u64 cur = page_start;
|
|
|
|
ASSERT(in_range(bytenr, page_start, PAGE_SIZE));
|
|
lockdep_assert_held(&fs_info->buffer_lock);
|
|
|
|
while (cur < page_start + PAGE_SIZE) {
|
|
int ret;
|
|
int i;
|
|
|
|
ret = radix_tree_gang_lookup(&fs_info->buffer_radix,
|
|
(void **)gang, cur >> fs_info->sectorsize_bits,
|
|
min_t(unsigned int, GANG_LOOKUP_SIZE,
|
|
PAGE_SIZE / fs_info->nodesize));
|
|
if (ret == 0)
|
|
goto out;
|
|
for (i = 0; i < ret; i++) {
|
|
/* Already beyond page end */
|
|
if (gang[i]->start >= page_start + PAGE_SIZE)
|
|
goto out;
|
|
/* Found one */
|
|
if (gang[i]->start >= bytenr) {
|
|
found = gang[i];
|
|
goto out;
|
|
}
|
|
}
|
|
cur = gang[ret - 1]->start + gang[ret - 1]->len;
|
|
}
|
|
out:
|
|
return found;
|
|
}
|
|
|
|
static int try_release_subpage_extent_buffer(struct page *page)
|
|
{
|
|
struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
|
|
u64 cur = page_offset(page);
|
|
const u64 end = page_offset(page) + PAGE_SIZE;
|
|
int ret;
|
|
|
|
while (cur < end) {
|
|
struct extent_buffer *eb = NULL;
|
|
|
|
/*
|
|
* Unlike try_release_extent_buffer() which uses page->private
|
|
* to grab buffer, for subpage case we rely on radix tree, thus
|
|
* we need to ensure radix tree consistency.
|
|
*
|
|
* We also want an atomic snapshot of the radix tree, thus go
|
|
* with spinlock rather than RCU.
|
|
*/
|
|
spin_lock(&fs_info->buffer_lock);
|
|
eb = get_next_extent_buffer(fs_info, page, cur);
|
|
if (!eb) {
|
|
/* No more eb in the page range after or at cur */
|
|
spin_unlock(&fs_info->buffer_lock);
|
|
break;
|
|
}
|
|
cur = eb->start + eb->len;
|
|
|
|
/*
|
|
* The same as try_release_extent_buffer(), to ensure the eb
|
|
* won't disappear out from under us.
|
|
*/
|
|
spin_lock(&eb->refs_lock);
|
|
if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
|
|
spin_unlock(&eb->refs_lock);
|
|
spin_unlock(&fs_info->buffer_lock);
|
|
break;
|
|
}
|
|
spin_unlock(&fs_info->buffer_lock);
|
|
|
|
/*
|
|
* If tree ref isn't set then we know the ref on this eb is a
|
|
* real ref, so just return, this eb will likely be freed soon
|
|
* anyway.
|
|
*/
|
|
if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
|
|
spin_unlock(&eb->refs_lock);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Here we don't care about the return value, we will always
|
|
* check the page private at the end. And
|
|
* release_extent_buffer() will release the refs_lock.
|
|
*/
|
|
release_extent_buffer(eb);
|
|
}
|
|
/*
|
|
* Finally to check if we have cleared page private, as if we have
|
|
* released all ebs in the page, the page private should be cleared now.
|
|
*/
|
|
spin_lock(&page->mapping->private_lock);
|
|
if (!PagePrivate(page))
|
|
ret = 1;
|
|
else
|
|
ret = 0;
|
|
spin_unlock(&page->mapping->private_lock);
|
|
return ret;
|
|
|
|
}
|
|
|
|
int try_release_extent_buffer(struct page *page)
|
|
{
|
|
struct extent_buffer *eb;
|
|
|
|
if (btrfs_sb(page->mapping->host->i_sb)->nodesize < PAGE_SIZE)
|
|
return try_release_subpage_extent_buffer(page);
|
|
|
|
/*
|
|
* We need to make sure nobody is changing page->private, as we rely on
|
|
* page->private as the pointer to extent buffer.
|
|
*/
|
|
spin_lock(&page->mapping->private_lock);
|
|
if (!PagePrivate(page)) {
|
|
spin_unlock(&page->mapping->private_lock);
|
|
return 1;
|
|
}
|
|
|
|
eb = (struct extent_buffer *)page->private;
|
|
BUG_ON(!eb);
|
|
|
|
/*
|
|
* This is a little awful but should be ok, we need to make sure that
|
|
* the eb doesn't disappear out from under us while we're looking at
|
|
* this page.
|
|
*/
|
|
spin_lock(&eb->refs_lock);
|
|
if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) {
|
|
spin_unlock(&eb->refs_lock);
|
|
spin_unlock(&page->mapping->private_lock);
|
|
return 0;
|
|
}
|
|
spin_unlock(&page->mapping->private_lock);
|
|
|
|
/*
|
|
* If tree ref isn't set then we know the ref on this eb is a real ref,
|
|
* so just return, this page will likely be freed soon anyway.
|
|
*/
|
|
if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
|
|
spin_unlock(&eb->refs_lock);
|
|
return 0;
|
|
}
|
|
|
|
return release_extent_buffer(eb);
|
|
}
|
|
|
|
/*
|
|
* btrfs_readahead_tree_block - attempt to readahead a child block
|
|
* @fs_info: the fs_info
|
|
* @bytenr: bytenr to read
|
|
* @owner_root: objectid of the root that owns this eb
|
|
* @gen: generation for the uptodate check, can be 0
|
|
* @level: level for the eb
|
|
*
|
|
* Attempt to readahead a tree block at @bytenr. If @gen is 0 then we do a
|
|
* normal uptodate check of the eb, without checking the generation. If we have
|
|
* to read the block we will not block on anything.
|
|
*/
|
|
void btrfs_readahead_tree_block(struct btrfs_fs_info *fs_info,
|
|
u64 bytenr, u64 owner_root, u64 gen, int level)
|
|
{
|
|
struct btrfs_tree_parent_check check = {
|
|
.has_first_key = 0,
|
|
.level = level,
|
|
.transid = gen
|
|
};
|
|
struct extent_buffer *eb;
|
|
int ret;
|
|
|
|
eb = btrfs_find_create_tree_block(fs_info, bytenr, owner_root, level);
|
|
if (IS_ERR(eb))
|
|
return;
|
|
|
|
if (btrfs_buffer_uptodate(eb, gen, 1)) {
|
|
free_extent_buffer(eb);
|
|
return;
|
|
}
|
|
|
|
ret = read_extent_buffer_pages(eb, WAIT_NONE, 0, &check);
|
|
if (ret < 0)
|
|
free_extent_buffer_stale(eb);
|
|
else
|
|
free_extent_buffer(eb);
|
|
}
|
|
|
|
/*
|
|
* btrfs_readahead_node_child - readahead a node's child block
|
|
* @node: parent node we're reading from
|
|
* @slot: slot in the parent node for the child we want to read
|
|
*
|
|
* A helper for btrfs_readahead_tree_block, we simply read the bytenr pointed at
|
|
* the slot in the node provided.
|
|
*/
|
|
void btrfs_readahead_node_child(struct extent_buffer *node, int slot)
|
|
{
|
|
btrfs_readahead_tree_block(node->fs_info,
|
|
btrfs_node_blockptr(node, slot),
|
|
btrfs_header_owner(node),
|
|
btrfs_node_ptr_generation(node, slot),
|
|
btrfs_header_level(node) - 1);
|
|
}
|