mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
1447 lines
36 KiB
C
1447 lines
36 KiB
C
/*
|
|
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
|
|
* All Rights Reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it would be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write the Free Software Foundation,
|
|
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
#include "xfs.h"
|
|
#include "xfs_fs.h"
|
|
#include "xfs_log.h"
|
|
#include "xfs_sb.h"
|
|
#include "xfs_ag.h"
|
|
#include "xfs_trans.h"
|
|
#include "xfs_mount.h"
|
|
#include "xfs_bmap_btree.h"
|
|
#include "xfs_alloc.h"
|
|
#include "xfs_dinode.h"
|
|
#include "xfs_inode.h"
|
|
#include "xfs_inode_item.h"
|
|
#include "xfs_bmap.h"
|
|
#include "xfs_error.h"
|
|
#include "xfs_vnodeops.h"
|
|
#include "xfs_da_btree.h"
|
|
#include "xfs_dir2_format.h"
|
|
#include "xfs_dir2_priv.h"
|
|
#include "xfs_ioctl.h"
|
|
#include "xfs_trace.h"
|
|
|
|
#include <linux/dcache.h>
|
|
#include <linux/falloc.h>
|
|
#include <linux/pagevec.h>
|
|
|
|
static const struct vm_operations_struct xfs_file_vm_ops;
|
|
|
|
/*
|
|
* Locking primitives for read and write IO paths to ensure we consistently use
|
|
* and order the inode->i_mutex, ip->i_lock and ip->i_iolock.
|
|
*/
|
|
static inline void
|
|
xfs_rw_ilock(
|
|
struct xfs_inode *ip,
|
|
int type)
|
|
{
|
|
if (type & XFS_IOLOCK_EXCL)
|
|
mutex_lock(&VFS_I(ip)->i_mutex);
|
|
xfs_ilock(ip, type);
|
|
}
|
|
|
|
static inline void
|
|
xfs_rw_iunlock(
|
|
struct xfs_inode *ip,
|
|
int type)
|
|
{
|
|
xfs_iunlock(ip, type);
|
|
if (type & XFS_IOLOCK_EXCL)
|
|
mutex_unlock(&VFS_I(ip)->i_mutex);
|
|
}
|
|
|
|
static inline void
|
|
xfs_rw_ilock_demote(
|
|
struct xfs_inode *ip,
|
|
int type)
|
|
{
|
|
xfs_ilock_demote(ip, type);
|
|
if (type & XFS_IOLOCK_EXCL)
|
|
mutex_unlock(&VFS_I(ip)->i_mutex);
|
|
}
|
|
|
|
/*
|
|
* xfs_iozero
|
|
*
|
|
* xfs_iozero clears the specified range of buffer supplied,
|
|
* and marks all the affected blocks as valid and modified. If
|
|
* an affected block is not allocated, it will be allocated. If
|
|
* an affected block is not completely overwritten, and is not
|
|
* valid before the operation, it will be read from disk before
|
|
* being partially zeroed.
|
|
*/
|
|
int
|
|
xfs_iozero(
|
|
struct xfs_inode *ip, /* inode */
|
|
loff_t pos, /* offset in file */
|
|
size_t count) /* size of data to zero */
|
|
{
|
|
struct page *page;
|
|
struct address_space *mapping;
|
|
int status;
|
|
|
|
mapping = VFS_I(ip)->i_mapping;
|
|
do {
|
|
unsigned offset, bytes;
|
|
void *fsdata;
|
|
|
|
offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
|
|
bytes = PAGE_CACHE_SIZE - offset;
|
|
if (bytes > count)
|
|
bytes = count;
|
|
|
|
status = pagecache_write_begin(NULL, mapping, pos, bytes,
|
|
AOP_FLAG_UNINTERRUPTIBLE,
|
|
&page, &fsdata);
|
|
if (status)
|
|
break;
|
|
|
|
zero_user(page, offset, bytes);
|
|
|
|
status = pagecache_write_end(NULL, mapping, pos, bytes, bytes,
|
|
page, fsdata);
|
|
WARN_ON(status <= 0); /* can't return less than zero! */
|
|
pos += bytes;
|
|
count -= bytes;
|
|
status = 0;
|
|
} while (count);
|
|
|
|
return (-status);
|
|
}
|
|
|
|
/*
|
|
* Fsync operations on directories are much simpler than on regular files,
|
|
* as there is no file data to flush, and thus also no need for explicit
|
|
* cache flush operations, and there are no non-transaction metadata updates
|
|
* on directories either.
|
|
*/
|
|
STATIC int
|
|
xfs_dir_fsync(
|
|
struct file *file,
|
|
loff_t start,
|
|
loff_t end,
|
|
int datasync)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(file->f_mapping->host);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
xfs_lsn_t lsn = 0;
|
|
|
|
trace_xfs_dir_fsync(ip);
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_SHARED);
|
|
if (xfs_ipincount(ip))
|
|
lsn = ip->i_itemp->ili_last_lsn;
|
|
xfs_iunlock(ip, XFS_ILOCK_SHARED);
|
|
|
|
if (!lsn)
|
|
return 0;
|
|
return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
|
|
}
|
|
|
|
STATIC int
|
|
xfs_file_fsync(
|
|
struct file *file,
|
|
loff_t start,
|
|
loff_t end,
|
|
int datasync)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
int error = 0;
|
|
int log_flushed = 0;
|
|
xfs_lsn_t lsn = 0;
|
|
|
|
trace_xfs_file_fsync(ip);
|
|
|
|
error = filemap_write_and_wait_range(inode->i_mapping, start, end);
|
|
if (error)
|
|
return error;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(mp))
|
|
return -XFS_ERROR(EIO);
|
|
|
|
xfs_iflags_clear(ip, XFS_ITRUNCATED);
|
|
|
|
if (mp->m_flags & XFS_MOUNT_BARRIER) {
|
|
/*
|
|
* If we have an RT and/or log subvolume we need to make sure
|
|
* to flush the write cache the device used for file data
|
|
* first. This is to ensure newly written file data make
|
|
* it to disk before logging the new inode size in case of
|
|
* an extending write.
|
|
*/
|
|
if (XFS_IS_REALTIME_INODE(ip))
|
|
xfs_blkdev_issue_flush(mp->m_rtdev_targp);
|
|
else if (mp->m_logdev_targp != mp->m_ddev_targp)
|
|
xfs_blkdev_issue_flush(mp->m_ddev_targp);
|
|
}
|
|
|
|
/*
|
|
* All metadata updates are logged, which means that we just have
|
|
* to flush the log up to the latest LSN that touched the inode.
|
|
*/
|
|
xfs_ilock(ip, XFS_ILOCK_SHARED);
|
|
if (xfs_ipincount(ip)) {
|
|
if (!datasync ||
|
|
(ip->i_itemp->ili_fields & ~XFS_ILOG_TIMESTAMP))
|
|
lsn = ip->i_itemp->ili_last_lsn;
|
|
}
|
|
xfs_iunlock(ip, XFS_ILOCK_SHARED);
|
|
|
|
if (lsn)
|
|
error = _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed);
|
|
|
|
/*
|
|
* If we only have a single device, and the log force about was
|
|
* a no-op we might have to flush the data device cache here.
|
|
* This can only happen for fdatasync/O_DSYNC if we were overwriting
|
|
* an already allocated file and thus do not have any metadata to
|
|
* commit.
|
|
*/
|
|
if ((mp->m_flags & XFS_MOUNT_BARRIER) &&
|
|
mp->m_logdev_targp == mp->m_ddev_targp &&
|
|
!XFS_IS_REALTIME_INODE(ip) &&
|
|
!log_flushed)
|
|
xfs_blkdev_issue_flush(mp->m_ddev_targp);
|
|
|
|
return -error;
|
|
}
|
|
|
|
STATIC ssize_t
|
|
xfs_file_aio_read(
|
|
struct kiocb *iocb,
|
|
const struct iovec *iovp,
|
|
unsigned long nr_segs,
|
|
loff_t pos)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
size_t size = 0;
|
|
ssize_t ret = 0;
|
|
int ioflags = 0;
|
|
xfs_fsize_t n;
|
|
|
|
XFS_STATS_INC(xs_read_calls);
|
|
|
|
BUG_ON(iocb->ki_pos != pos);
|
|
|
|
if (unlikely(file->f_flags & O_DIRECT))
|
|
ioflags |= IO_ISDIRECT;
|
|
if (file->f_mode & FMODE_NOCMTIME)
|
|
ioflags |= IO_INVIS;
|
|
|
|
ret = generic_segment_checks(iovp, &nr_segs, &size, VERIFY_WRITE);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (unlikely(ioflags & IO_ISDIRECT)) {
|
|
xfs_buftarg_t *target =
|
|
XFS_IS_REALTIME_INODE(ip) ?
|
|
mp->m_rtdev_targp : mp->m_ddev_targp;
|
|
if ((pos & target->bt_smask) || (size & target->bt_smask)) {
|
|
if (pos == i_size_read(inode))
|
|
return 0;
|
|
return -XFS_ERROR(EINVAL);
|
|
}
|
|
}
|
|
|
|
n = mp->m_super->s_maxbytes - pos;
|
|
if (n <= 0 || size == 0)
|
|
return 0;
|
|
|
|
if (n < size)
|
|
size = n;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(mp))
|
|
return -EIO;
|
|
|
|
/*
|
|
* Locking is a bit tricky here. If we take an exclusive lock
|
|
* for direct IO, we effectively serialise all new concurrent
|
|
* read IO to this file and block it behind IO that is currently in
|
|
* progress because IO in progress holds the IO lock shared. We only
|
|
* need to hold the lock exclusive to blow away the page cache, so
|
|
* only take lock exclusively if the page cache needs invalidation.
|
|
* This allows the normal direct IO case of no page cache pages to
|
|
* proceeed concurrently without serialisation.
|
|
*/
|
|
xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
|
|
if ((ioflags & IO_ISDIRECT) && inode->i_mapping->nrpages) {
|
|
xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
|
|
xfs_rw_ilock(ip, XFS_IOLOCK_EXCL);
|
|
|
|
if (inode->i_mapping->nrpages) {
|
|
ret = -filemap_write_and_wait_range(
|
|
VFS_I(ip)->i_mapping,
|
|
pos, -1);
|
|
if (ret) {
|
|
xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL);
|
|
return ret;
|
|
}
|
|
truncate_pagecache_range(VFS_I(ip), pos, -1);
|
|
}
|
|
xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
|
|
}
|
|
|
|
trace_xfs_file_read(ip, size, pos, ioflags);
|
|
|
|
ret = generic_file_aio_read(iocb, iovp, nr_segs, pos);
|
|
if (ret > 0)
|
|
XFS_STATS_ADD(xs_read_bytes, ret);
|
|
|
|
xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
|
|
return ret;
|
|
}
|
|
|
|
STATIC ssize_t
|
|
xfs_file_splice_read(
|
|
struct file *infilp,
|
|
loff_t *ppos,
|
|
struct pipe_inode_info *pipe,
|
|
size_t count,
|
|
unsigned int flags)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(infilp->f_mapping->host);
|
|
int ioflags = 0;
|
|
ssize_t ret;
|
|
|
|
XFS_STATS_INC(xs_read_calls);
|
|
|
|
if (infilp->f_mode & FMODE_NOCMTIME)
|
|
ioflags |= IO_INVIS;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
|
|
return -EIO;
|
|
|
|
xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
|
|
|
|
trace_xfs_file_splice_read(ip, count, *ppos, ioflags);
|
|
|
|
ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
|
|
if (ret > 0)
|
|
XFS_STATS_ADD(xs_read_bytes, ret);
|
|
|
|
xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* xfs_file_splice_write() does not use xfs_rw_ilock() because
|
|
* generic_file_splice_write() takes the i_mutex itself. This, in theory,
|
|
* couuld cause lock inversions between the aio_write path and the splice path
|
|
* if someone is doing concurrent splice(2) based writes and write(2) based
|
|
* writes to the same inode. The only real way to fix this is to re-implement
|
|
* the generic code here with correct locking orders.
|
|
*/
|
|
STATIC ssize_t
|
|
xfs_file_splice_write(
|
|
struct pipe_inode_info *pipe,
|
|
struct file *outfilp,
|
|
loff_t *ppos,
|
|
size_t count,
|
|
unsigned int flags)
|
|
{
|
|
struct inode *inode = outfilp->f_mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
int ioflags = 0;
|
|
ssize_t ret;
|
|
|
|
XFS_STATS_INC(xs_write_calls);
|
|
|
|
if (outfilp->f_mode & FMODE_NOCMTIME)
|
|
ioflags |= IO_INVIS;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
|
|
return -EIO;
|
|
|
|
xfs_ilock(ip, XFS_IOLOCK_EXCL);
|
|
|
|
trace_xfs_file_splice_write(ip, count, *ppos, ioflags);
|
|
|
|
ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
|
|
if (ret > 0)
|
|
XFS_STATS_ADD(xs_write_bytes, ret);
|
|
|
|
xfs_iunlock(ip, XFS_IOLOCK_EXCL);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* This routine is called to handle zeroing any space in the last block of the
|
|
* file that is beyond the EOF. We do this since the size is being increased
|
|
* without writing anything to that block and we don't want to read the
|
|
* garbage on the disk.
|
|
*/
|
|
STATIC int /* error (positive) */
|
|
xfs_zero_last_block(
|
|
struct xfs_inode *ip,
|
|
xfs_fsize_t offset,
|
|
xfs_fsize_t isize)
|
|
{
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
xfs_fileoff_t last_fsb = XFS_B_TO_FSBT(mp, isize);
|
|
int zero_offset = XFS_B_FSB_OFFSET(mp, isize);
|
|
int zero_len;
|
|
int nimaps = 1;
|
|
int error = 0;
|
|
struct xfs_bmbt_irec imap;
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
error = xfs_bmapi_read(ip, last_fsb, 1, &imap, &nimaps, 0);
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
if (error)
|
|
return error;
|
|
|
|
ASSERT(nimaps > 0);
|
|
|
|
/*
|
|
* If the block underlying isize is just a hole, then there
|
|
* is nothing to zero.
|
|
*/
|
|
if (imap.br_startblock == HOLESTARTBLOCK)
|
|
return 0;
|
|
|
|
zero_len = mp->m_sb.sb_blocksize - zero_offset;
|
|
if (isize + zero_len > offset)
|
|
zero_len = offset - isize;
|
|
return xfs_iozero(ip, isize, zero_len);
|
|
}
|
|
|
|
/*
|
|
* Zero any on disk space between the current EOF and the new, larger EOF.
|
|
*
|
|
* This handles the normal case of zeroing the remainder of the last block in
|
|
* the file and the unusual case of zeroing blocks out beyond the size of the
|
|
* file. This second case only happens with fixed size extents and when the
|
|
* system crashes before the inode size was updated but after blocks were
|
|
* allocated.
|
|
*
|
|
* Expects the iolock to be held exclusive, and will take the ilock internally.
|
|
*/
|
|
int /* error (positive) */
|
|
xfs_zero_eof(
|
|
struct xfs_inode *ip,
|
|
xfs_off_t offset, /* starting I/O offset */
|
|
xfs_fsize_t isize) /* current inode size */
|
|
{
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
xfs_fileoff_t start_zero_fsb;
|
|
xfs_fileoff_t end_zero_fsb;
|
|
xfs_fileoff_t zero_count_fsb;
|
|
xfs_fileoff_t last_fsb;
|
|
xfs_fileoff_t zero_off;
|
|
xfs_fsize_t zero_len;
|
|
int nimaps;
|
|
int error = 0;
|
|
struct xfs_bmbt_irec imap;
|
|
|
|
ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
|
|
ASSERT(offset > isize);
|
|
|
|
/*
|
|
* First handle zeroing the block on which isize resides.
|
|
*
|
|
* We only zero a part of that block so it is handled specially.
|
|
*/
|
|
if (XFS_B_FSB_OFFSET(mp, isize) != 0) {
|
|
error = xfs_zero_last_block(ip, offset, isize);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Calculate the range between the new size and the old where blocks
|
|
* needing to be zeroed may exist.
|
|
*
|
|
* To get the block where the last byte in the file currently resides,
|
|
* we need to subtract one from the size and truncate back to a block
|
|
* boundary. We subtract 1 in case the size is exactly on a block
|
|
* boundary.
|
|
*/
|
|
last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
|
|
start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
|
|
end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
|
|
ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
|
|
if (last_fsb == end_zero_fsb) {
|
|
/*
|
|
* The size was only incremented on its last block.
|
|
* We took care of that above, so just return.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
ASSERT(start_zero_fsb <= end_zero_fsb);
|
|
while (start_zero_fsb <= end_zero_fsb) {
|
|
nimaps = 1;
|
|
zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
error = xfs_bmapi_read(ip, start_zero_fsb, zero_count_fsb,
|
|
&imap, &nimaps, 0);
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
if (error)
|
|
return error;
|
|
|
|
ASSERT(nimaps > 0);
|
|
|
|
if (imap.br_state == XFS_EXT_UNWRITTEN ||
|
|
imap.br_startblock == HOLESTARTBLOCK) {
|
|
start_zero_fsb = imap.br_startoff + imap.br_blockcount;
|
|
ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* There are blocks we need to zero.
|
|
*/
|
|
zero_off = XFS_FSB_TO_B(mp, start_zero_fsb);
|
|
zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount);
|
|
|
|
if ((zero_off + zero_len) > offset)
|
|
zero_len = offset - zero_off;
|
|
|
|
error = xfs_iozero(ip, zero_off, zero_len);
|
|
if (error)
|
|
return error;
|
|
|
|
start_zero_fsb = imap.br_startoff + imap.br_blockcount;
|
|
ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Common pre-write limit and setup checks.
|
|
*
|
|
* Called with the iolocked held either shared and exclusive according to
|
|
* @iolock, and returns with it held. Might upgrade the iolock to exclusive
|
|
* if called for a direct write beyond i_size.
|
|
*/
|
|
STATIC ssize_t
|
|
xfs_file_aio_write_checks(
|
|
struct file *file,
|
|
loff_t *pos,
|
|
size_t *count,
|
|
int *iolock)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
int error = 0;
|
|
|
|
restart:
|
|
error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode));
|
|
if (error)
|
|
return error;
|
|
|
|
/*
|
|
* If the offset is beyond the size of the file, we need to zero any
|
|
* blocks that fall between the existing EOF and the start of this
|
|
* write. If zeroing is needed and we are currently holding the
|
|
* iolock shared, we need to update it to exclusive which implies
|
|
* having to redo all checks before.
|
|
*/
|
|
if (*pos > i_size_read(inode)) {
|
|
if (*iolock == XFS_IOLOCK_SHARED) {
|
|
xfs_rw_iunlock(ip, *iolock);
|
|
*iolock = XFS_IOLOCK_EXCL;
|
|
xfs_rw_ilock(ip, *iolock);
|
|
goto restart;
|
|
}
|
|
error = -xfs_zero_eof(ip, *pos, i_size_read(inode));
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Updating the timestamps will grab the ilock again from
|
|
* xfs_fs_dirty_inode, so we have to call it after dropping the
|
|
* lock above. Eventually we should look into a way to avoid
|
|
* the pointless lock roundtrip.
|
|
*/
|
|
if (likely(!(file->f_mode & FMODE_NOCMTIME))) {
|
|
error = file_update_time(file);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* If we're writing the file then make sure to clear the setuid and
|
|
* setgid bits if the process is not being run by root. This keeps
|
|
* people from modifying setuid and setgid binaries.
|
|
*/
|
|
return file_remove_suid(file);
|
|
}
|
|
|
|
/*
|
|
* xfs_file_dio_aio_write - handle direct IO writes
|
|
*
|
|
* Lock the inode appropriately to prepare for and issue a direct IO write.
|
|
* By separating it from the buffered write path we remove all the tricky to
|
|
* follow locking changes and looping.
|
|
*
|
|
* If there are cached pages or we're extending the file, we need IOLOCK_EXCL
|
|
* until we're sure the bytes at the new EOF have been zeroed and/or the cached
|
|
* pages are flushed out.
|
|
*
|
|
* In most cases the direct IO writes will be done holding IOLOCK_SHARED
|
|
* allowing them to be done in parallel with reads and other direct IO writes.
|
|
* However, if the IO is not aligned to filesystem blocks, the direct IO layer
|
|
* needs to do sub-block zeroing and that requires serialisation against other
|
|
* direct IOs to the same block. In this case we need to serialise the
|
|
* submission of the unaligned IOs so that we don't get racing block zeroing in
|
|
* the dio layer. To avoid the problem with aio, we also need to wait for
|
|
* outstanding IOs to complete so that unwritten extent conversion is completed
|
|
* before we try to map the overlapping block. This is currently implemented by
|
|
* hitting it with a big hammer (i.e. inode_dio_wait()).
|
|
*
|
|
* Returns with locks held indicated by @iolock and errors indicated by
|
|
* negative return values.
|
|
*/
|
|
STATIC ssize_t
|
|
xfs_file_dio_aio_write(
|
|
struct kiocb *iocb,
|
|
const struct iovec *iovp,
|
|
unsigned long nr_segs,
|
|
loff_t pos,
|
|
size_t ocount)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct address_space *mapping = file->f_mapping;
|
|
struct inode *inode = mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
ssize_t ret = 0;
|
|
size_t count = ocount;
|
|
int unaligned_io = 0;
|
|
int iolock;
|
|
struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
|
|
mp->m_rtdev_targp : mp->m_ddev_targp;
|
|
|
|
if ((pos & target->bt_smask) || (count & target->bt_smask))
|
|
return -XFS_ERROR(EINVAL);
|
|
|
|
if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask))
|
|
unaligned_io = 1;
|
|
|
|
/*
|
|
* We don't need to take an exclusive lock unless there page cache needs
|
|
* to be invalidated or unaligned IO is being executed. We don't need to
|
|
* consider the EOF extension case here because
|
|
* xfs_file_aio_write_checks() will relock the inode as necessary for
|
|
* EOF zeroing cases and fill out the new inode size as appropriate.
|
|
*/
|
|
if (unaligned_io || mapping->nrpages)
|
|
iolock = XFS_IOLOCK_EXCL;
|
|
else
|
|
iolock = XFS_IOLOCK_SHARED;
|
|
xfs_rw_ilock(ip, iolock);
|
|
|
|
/*
|
|
* Recheck if there are cached pages that need invalidate after we got
|
|
* the iolock to protect against other threads adding new pages while
|
|
* we were waiting for the iolock.
|
|
*/
|
|
if (mapping->nrpages && iolock == XFS_IOLOCK_SHARED) {
|
|
xfs_rw_iunlock(ip, iolock);
|
|
iolock = XFS_IOLOCK_EXCL;
|
|
xfs_rw_ilock(ip, iolock);
|
|
}
|
|
|
|
ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (mapping->nrpages) {
|
|
ret = -filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
|
|
pos, -1);
|
|
if (ret)
|
|
goto out;
|
|
truncate_pagecache_range(VFS_I(ip), pos, -1);
|
|
}
|
|
|
|
/*
|
|
* If we are doing unaligned IO, wait for all other IO to drain,
|
|
* otherwise demote the lock if we had to flush cached pages
|
|
*/
|
|
if (unaligned_io)
|
|
inode_dio_wait(inode);
|
|
else if (iolock == XFS_IOLOCK_EXCL) {
|
|
xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
|
|
iolock = XFS_IOLOCK_SHARED;
|
|
}
|
|
|
|
trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
|
|
ret = generic_file_direct_write(iocb, iovp,
|
|
&nr_segs, pos, &iocb->ki_pos, count, ocount);
|
|
|
|
out:
|
|
xfs_rw_iunlock(ip, iolock);
|
|
|
|
/* No fallback to buffered IO on errors for XFS. */
|
|
ASSERT(ret < 0 || ret == count);
|
|
return ret;
|
|
}
|
|
|
|
STATIC ssize_t
|
|
xfs_file_buffered_aio_write(
|
|
struct kiocb *iocb,
|
|
const struct iovec *iovp,
|
|
unsigned long nr_segs,
|
|
loff_t pos,
|
|
size_t ocount)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct address_space *mapping = file->f_mapping;
|
|
struct inode *inode = mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
ssize_t ret;
|
|
int enospc = 0;
|
|
int iolock = XFS_IOLOCK_EXCL;
|
|
size_t count = ocount;
|
|
|
|
xfs_rw_ilock(ip, iolock);
|
|
|
|
ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/* We can write back this queue in page reclaim */
|
|
current->backing_dev_info = mapping->backing_dev_info;
|
|
|
|
write_retry:
|
|
trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, 0);
|
|
ret = generic_file_buffered_write(iocb, iovp, nr_segs,
|
|
pos, &iocb->ki_pos, count, 0);
|
|
|
|
/*
|
|
* If we just got an ENOSPC, try to write back all dirty inodes to
|
|
* convert delalloc space to free up some of the excess reserved
|
|
* metadata space.
|
|
*/
|
|
if (ret == -ENOSPC && !enospc) {
|
|
enospc = 1;
|
|
xfs_flush_inodes(ip->i_mount);
|
|
goto write_retry;
|
|
}
|
|
|
|
current->backing_dev_info = NULL;
|
|
out:
|
|
xfs_rw_iunlock(ip, iolock);
|
|
return ret;
|
|
}
|
|
|
|
STATIC ssize_t
|
|
xfs_file_aio_write(
|
|
struct kiocb *iocb,
|
|
const struct iovec *iovp,
|
|
unsigned long nr_segs,
|
|
loff_t pos)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct address_space *mapping = file->f_mapping;
|
|
struct inode *inode = mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
ssize_t ret;
|
|
size_t ocount = 0;
|
|
|
|
XFS_STATS_INC(xs_write_calls);
|
|
|
|
BUG_ON(iocb->ki_pos != pos);
|
|
|
|
ret = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (ocount == 0)
|
|
return 0;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
|
|
if (unlikely(file->f_flags & O_DIRECT))
|
|
ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos, ocount);
|
|
else
|
|
ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos,
|
|
ocount);
|
|
|
|
if (ret > 0) {
|
|
ssize_t err;
|
|
|
|
XFS_STATS_ADD(xs_write_bytes, ret);
|
|
|
|
/* Handle various SYNC-type writes */
|
|
err = generic_write_sync(file, pos, ret);
|
|
if (err < 0)
|
|
ret = err;
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
STATIC long
|
|
xfs_file_fallocate(
|
|
struct file *file,
|
|
int mode,
|
|
loff_t offset,
|
|
loff_t len)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
long error;
|
|
loff_t new_size = 0;
|
|
xfs_flock64_t bf;
|
|
xfs_inode_t *ip = XFS_I(inode);
|
|
int cmd = XFS_IOC_RESVSP;
|
|
int attr_flags = XFS_ATTR_NOLOCK;
|
|
|
|
if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
|
|
return -EOPNOTSUPP;
|
|
|
|
bf.l_whence = 0;
|
|
bf.l_start = offset;
|
|
bf.l_len = len;
|
|
|
|
xfs_ilock(ip, XFS_IOLOCK_EXCL);
|
|
|
|
if (mode & FALLOC_FL_PUNCH_HOLE)
|
|
cmd = XFS_IOC_UNRESVSP;
|
|
|
|
/* check the new inode size is valid before allocating */
|
|
if (!(mode & FALLOC_FL_KEEP_SIZE) &&
|
|
offset + len > i_size_read(inode)) {
|
|
new_size = offset + len;
|
|
error = inode_newsize_ok(inode, new_size);
|
|
if (error)
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (file->f_flags & O_DSYNC)
|
|
attr_flags |= XFS_ATTR_SYNC;
|
|
|
|
error = -xfs_change_file_space(ip, cmd, &bf, 0, attr_flags);
|
|
if (error)
|
|
goto out_unlock;
|
|
|
|
/* Change file size if needed */
|
|
if (new_size) {
|
|
struct iattr iattr;
|
|
|
|
iattr.ia_valid = ATTR_SIZE;
|
|
iattr.ia_size = new_size;
|
|
error = -xfs_setattr_size(ip, &iattr, XFS_ATTR_NOLOCK);
|
|
}
|
|
|
|
out_unlock:
|
|
xfs_iunlock(ip, XFS_IOLOCK_EXCL);
|
|
return error;
|
|
}
|
|
|
|
|
|
STATIC int
|
|
xfs_file_open(
|
|
struct inode *inode,
|
|
struct file *file)
|
|
{
|
|
if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
|
|
return -EFBIG;
|
|
if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
|
|
return -EIO;
|
|
return 0;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_dir_open(
|
|
struct inode *inode,
|
|
struct file *file)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
int mode;
|
|
int error;
|
|
|
|
error = xfs_file_open(inode, file);
|
|
if (error)
|
|
return error;
|
|
|
|
/*
|
|
* If there are any blocks, read-ahead block 0 as we're almost
|
|
* certain to have the next operation be a read there.
|
|
*/
|
|
mode = xfs_ilock_map_shared(ip);
|
|
if (ip->i_d.di_nextents > 0)
|
|
xfs_dir2_data_readahead(NULL, ip, 0, -1);
|
|
xfs_iunlock(ip, mode);
|
|
return 0;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_file_release(
|
|
struct inode *inode,
|
|
struct file *filp)
|
|
{
|
|
return -xfs_release(XFS_I(inode));
|
|
}
|
|
|
|
STATIC int
|
|
xfs_file_readdir(
|
|
struct file *filp,
|
|
void *dirent,
|
|
filldir_t filldir)
|
|
{
|
|
struct inode *inode = file_inode(filp);
|
|
xfs_inode_t *ip = XFS_I(inode);
|
|
int error;
|
|
size_t bufsize;
|
|
|
|
/*
|
|
* The Linux API doesn't pass down the total size of the buffer
|
|
* we read into down to the filesystem. With the filldir concept
|
|
* it's not needed for correct information, but the XFS dir2 leaf
|
|
* code wants an estimate of the buffer size to calculate it's
|
|
* readahead window and size the buffers used for mapping to
|
|
* physical blocks.
|
|
*
|
|
* Try to give it an estimate that's good enough, maybe at some
|
|
* point we can change the ->readdir prototype to include the
|
|
* buffer size. For now we use the current glibc buffer size.
|
|
*/
|
|
bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size);
|
|
|
|
error = xfs_readdir(ip, dirent, bufsize,
|
|
(xfs_off_t *)&filp->f_pos, filldir);
|
|
if (error)
|
|
return -error;
|
|
return 0;
|
|
}
|
|
|
|
STATIC int
|
|
xfs_file_mmap(
|
|
struct file *filp,
|
|
struct vm_area_struct *vma)
|
|
{
|
|
vma->vm_ops = &xfs_file_vm_ops;
|
|
|
|
file_accessed(filp);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* mmap()d file has taken write protection fault and is being made
|
|
* writable. We can set the page state up correctly for a writable
|
|
* page, which means we can do correct delalloc accounting (ENOSPC
|
|
* checking!) and unwritten extent mapping.
|
|
*/
|
|
STATIC int
|
|
xfs_vm_page_mkwrite(
|
|
struct vm_area_struct *vma,
|
|
struct vm_fault *vmf)
|
|
{
|
|
return block_page_mkwrite(vma, vmf, xfs_get_blocks);
|
|
}
|
|
|
|
/*
|
|
* This type is designed to indicate the type of offset we would like
|
|
* to search from page cache for either xfs_seek_data() or xfs_seek_hole().
|
|
*/
|
|
enum {
|
|
HOLE_OFF = 0,
|
|
DATA_OFF,
|
|
};
|
|
|
|
/*
|
|
* Lookup the desired type of offset from the given page.
|
|
*
|
|
* On success, return true and the offset argument will point to the
|
|
* start of the region that was found. Otherwise this function will
|
|
* return false and keep the offset argument unchanged.
|
|
*/
|
|
STATIC bool
|
|
xfs_lookup_buffer_offset(
|
|
struct page *page,
|
|
loff_t *offset,
|
|
unsigned int type)
|
|
{
|
|
loff_t lastoff = page_offset(page);
|
|
bool found = false;
|
|
struct buffer_head *bh, *head;
|
|
|
|
bh = head = page_buffers(page);
|
|
do {
|
|
/*
|
|
* Unwritten extents that have data in the page
|
|
* cache covering them can be identified by the
|
|
* BH_Unwritten state flag. Pages with multiple
|
|
* buffers might have a mix of holes, data and
|
|
* unwritten extents - any buffer with valid
|
|
* data in it should have BH_Uptodate flag set
|
|
* on it.
|
|
*/
|
|
if (buffer_unwritten(bh) ||
|
|
buffer_uptodate(bh)) {
|
|
if (type == DATA_OFF)
|
|
found = true;
|
|
} else {
|
|
if (type == HOLE_OFF)
|
|
found = true;
|
|
}
|
|
|
|
if (found) {
|
|
*offset = lastoff;
|
|
break;
|
|
}
|
|
lastoff += bh->b_size;
|
|
} while ((bh = bh->b_this_page) != head);
|
|
|
|
return found;
|
|
}
|
|
|
|
/*
|
|
* This routine is called to find out and return a data or hole offset
|
|
* from the page cache for unwritten extents according to the desired
|
|
* type for xfs_seek_data() or xfs_seek_hole().
|
|
*
|
|
* The argument offset is used to tell where we start to search from the
|
|
* page cache. Map is used to figure out the end points of the range to
|
|
* lookup pages.
|
|
*
|
|
* Return true if the desired type of offset was found, and the argument
|
|
* offset is filled with that address. Otherwise, return false and keep
|
|
* offset unchanged.
|
|
*/
|
|
STATIC bool
|
|
xfs_find_get_desired_pgoff(
|
|
struct inode *inode,
|
|
struct xfs_bmbt_irec *map,
|
|
unsigned int type,
|
|
loff_t *offset)
|
|
{
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
struct pagevec pvec;
|
|
pgoff_t index;
|
|
pgoff_t end;
|
|
loff_t endoff;
|
|
loff_t startoff = *offset;
|
|
loff_t lastoff = startoff;
|
|
bool found = false;
|
|
|
|
pagevec_init(&pvec, 0);
|
|
|
|
index = startoff >> PAGE_CACHE_SHIFT;
|
|
endoff = XFS_FSB_TO_B(mp, map->br_startoff + map->br_blockcount);
|
|
end = endoff >> PAGE_CACHE_SHIFT;
|
|
do {
|
|
int want;
|
|
unsigned nr_pages;
|
|
unsigned int i;
|
|
|
|
want = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
|
|
nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
|
|
want);
|
|
/*
|
|
* No page mapped into given range. If we are searching holes
|
|
* and if this is the first time we got into the loop, it means
|
|
* that the given offset is landed in a hole, return it.
|
|
*
|
|
* If we have already stepped through some block buffers to find
|
|
* holes but they all contains data. In this case, the last
|
|
* offset is already updated and pointed to the end of the last
|
|
* mapped page, if it does not reach the endpoint to search,
|
|
* that means there should be a hole between them.
|
|
*/
|
|
if (nr_pages == 0) {
|
|
/* Data search found nothing */
|
|
if (type == DATA_OFF)
|
|
break;
|
|
|
|
ASSERT(type == HOLE_OFF);
|
|
if (lastoff == startoff || lastoff < endoff) {
|
|
found = true;
|
|
*offset = lastoff;
|
|
}
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* At lease we found one page. If this is the first time we
|
|
* step into the loop, and if the first page index offset is
|
|
* greater than the given search offset, a hole was found.
|
|
*/
|
|
if (type == HOLE_OFF && lastoff == startoff &&
|
|
lastoff < page_offset(pvec.pages[0])) {
|
|
found = true;
|
|
break;
|
|
}
|
|
|
|
for (i = 0; i < nr_pages; i++) {
|
|
struct page *page = pvec.pages[i];
|
|
loff_t b_offset;
|
|
|
|
/*
|
|
* At this point, the page may be truncated or
|
|
* invalidated (changing page->mapping to NULL),
|
|
* or even swizzled back from swapper_space to tmpfs
|
|
* file mapping. However, page->index will not change
|
|
* because we have a reference on the page.
|
|
*
|
|
* Searching done if the page index is out of range.
|
|
* If the current offset is not reaches the end of
|
|
* the specified search range, there should be a hole
|
|
* between them.
|
|
*/
|
|
if (page->index > end) {
|
|
if (type == HOLE_OFF && lastoff < endoff) {
|
|
*offset = lastoff;
|
|
found = true;
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
lock_page(page);
|
|
/*
|
|
* Page truncated or invalidated(page->mapping == NULL).
|
|
* We can freely skip it and proceed to check the next
|
|
* page.
|
|
*/
|
|
if (unlikely(page->mapping != inode->i_mapping)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
if (!page_has_buffers(page)) {
|
|
unlock_page(page);
|
|
continue;
|
|
}
|
|
|
|
found = xfs_lookup_buffer_offset(page, &b_offset, type);
|
|
if (found) {
|
|
/*
|
|
* The found offset may be less than the start
|
|
* point to search if this is the first time to
|
|
* come here.
|
|
*/
|
|
*offset = max_t(loff_t, startoff, b_offset);
|
|
unlock_page(page);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* We either searching data but nothing was found, or
|
|
* searching hole but found a data buffer. In either
|
|
* case, probably the next page contains the desired
|
|
* things, update the last offset to it so.
|
|
*/
|
|
lastoff = page_offset(page) + PAGE_SIZE;
|
|
unlock_page(page);
|
|
}
|
|
|
|
/*
|
|
* The number of returned pages less than our desired, search
|
|
* done. In this case, nothing was found for searching data,
|
|
* but we found a hole behind the last offset.
|
|
*/
|
|
if (nr_pages < want) {
|
|
if (type == HOLE_OFF) {
|
|
*offset = lastoff;
|
|
found = true;
|
|
}
|
|
break;
|
|
}
|
|
|
|
index = pvec.pages[i - 1]->index + 1;
|
|
pagevec_release(&pvec);
|
|
} while (index <= end);
|
|
|
|
out:
|
|
pagevec_release(&pvec);
|
|
return found;
|
|
}
|
|
|
|
STATIC loff_t
|
|
xfs_seek_data(
|
|
struct file *file,
|
|
loff_t start)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
loff_t uninitialized_var(offset);
|
|
xfs_fsize_t isize;
|
|
xfs_fileoff_t fsbno;
|
|
xfs_filblks_t end;
|
|
uint lock;
|
|
int error;
|
|
|
|
lock = xfs_ilock_map_shared(ip);
|
|
|
|
isize = i_size_read(inode);
|
|
if (start >= isize) {
|
|
error = ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
/*
|
|
* Try to read extents from the first block indicated
|
|
* by fsbno to the end block of the file.
|
|
*/
|
|
fsbno = XFS_B_TO_FSBT(mp, start);
|
|
end = XFS_B_TO_FSB(mp, isize);
|
|
for (;;) {
|
|
struct xfs_bmbt_irec map[2];
|
|
int nmap = 2;
|
|
unsigned int i;
|
|
|
|
error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
|
|
XFS_BMAPI_ENTIRE);
|
|
if (error)
|
|
goto out_unlock;
|
|
|
|
/* No extents at given offset, must be beyond EOF */
|
|
if (nmap == 0) {
|
|
error = ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
for (i = 0; i < nmap; i++) {
|
|
offset = max_t(loff_t, start,
|
|
XFS_FSB_TO_B(mp, map[i].br_startoff));
|
|
|
|
/* Landed in a data extent */
|
|
if (map[i].br_startblock == DELAYSTARTBLOCK ||
|
|
(map[i].br_state == XFS_EXT_NORM &&
|
|
!isnullstartblock(map[i].br_startblock)))
|
|
goto out;
|
|
|
|
/*
|
|
* Landed in an unwritten extent, try to search data
|
|
* from page cache.
|
|
*/
|
|
if (map[i].br_state == XFS_EXT_UNWRITTEN) {
|
|
if (xfs_find_get_desired_pgoff(inode, &map[i],
|
|
DATA_OFF, &offset))
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* map[0] is hole or its an unwritten extent but
|
|
* without data in page cache. Probably means that
|
|
* we are reading after EOF if nothing in map[1].
|
|
*/
|
|
if (nmap == 1) {
|
|
error = ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
ASSERT(i > 1);
|
|
|
|
/*
|
|
* Nothing was found, proceed to the next round of search
|
|
* if reading offset not beyond or hit EOF.
|
|
*/
|
|
fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
|
|
start = XFS_FSB_TO_B(mp, fsbno);
|
|
if (start >= isize) {
|
|
error = ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
}
|
|
|
|
out:
|
|
if (offset != file->f_pos)
|
|
file->f_pos = offset;
|
|
|
|
out_unlock:
|
|
xfs_iunlock_map_shared(ip, lock);
|
|
|
|
if (error)
|
|
return -error;
|
|
return offset;
|
|
}
|
|
|
|
STATIC loff_t
|
|
xfs_seek_hole(
|
|
struct file *file,
|
|
loff_t start)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct xfs_inode *ip = XFS_I(inode);
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
loff_t uninitialized_var(offset);
|
|
xfs_fsize_t isize;
|
|
xfs_fileoff_t fsbno;
|
|
xfs_filblks_t end;
|
|
uint lock;
|
|
int error;
|
|
|
|
if (XFS_FORCED_SHUTDOWN(mp))
|
|
return -XFS_ERROR(EIO);
|
|
|
|
lock = xfs_ilock_map_shared(ip);
|
|
|
|
isize = i_size_read(inode);
|
|
if (start >= isize) {
|
|
error = ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
fsbno = XFS_B_TO_FSBT(mp, start);
|
|
end = XFS_B_TO_FSB(mp, isize);
|
|
|
|
for (;;) {
|
|
struct xfs_bmbt_irec map[2];
|
|
int nmap = 2;
|
|
unsigned int i;
|
|
|
|
error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
|
|
XFS_BMAPI_ENTIRE);
|
|
if (error)
|
|
goto out_unlock;
|
|
|
|
/* No extents at given offset, must be beyond EOF */
|
|
if (nmap == 0) {
|
|
error = ENXIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
for (i = 0; i < nmap; i++) {
|
|
offset = max_t(loff_t, start,
|
|
XFS_FSB_TO_B(mp, map[i].br_startoff));
|
|
|
|
/* Landed in a hole */
|
|
if (map[i].br_startblock == HOLESTARTBLOCK)
|
|
goto out;
|
|
|
|
/*
|
|
* Landed in an unwritten extent, try to search hole
|
|
* from page cache.
|
|
*/
|
|
if (map[i].br_state == XFS_EXT_UNWRITTEN) {
|
|
if (xfs_find_get_desired_pgoff(inode, &map[i],
|
|
HOLE_OFF, &offset))
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* map[0] contains data or its unwritten but contains
|
|
* data in page cache, probably means that we are
|
|
* reading after EOF. We should fix offset to point
|
|
* to the end of the file(i.e., there is an implicit
|
|
* hole at the end of any file).
|
|
*/
|
|
if (nmap == 1) {
|
|
offset = isize;
|
|
break;
|
|
}
|
|
|
|
ASSERT(i > 1);
|
|
|
|
/*
|
|
* Both mappings contains data, proceed to the next round of
|
|
* search if the current reading offset not beyond or hit EOF.
|
|
*/
|
|
fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
|
|
start = XFS_FSB_TO_B(mp, fsbno);
|
|
if (start >= isize) {
|
|
offset = isize;
|
|
break;
|
|
}
|
|
}
|
|
|
|
out:
|
|
/*
|
|
* At this point, we must have found a hole. However, the returned
|
|
* offset may be bigger than the file size as it may be aligned to
|
|
* page boundary for unwritten extents, we need to deal with this
|
|
* situation in particular.
|
|
*/
|
|
offset = min_t(loff_t, offset, isize);
|
|
if (offset != file->f_pos)
|
|
file->f_pos = offset;
|
|
|
|
out_unlock:
|
|
xfs_iunlock_map_shared(ip, lock);
|
|
|
|
if (error)
|
|
return -error;
|
|
return offset;
|
|
}
|
|
|
|
STATIC loff_t
|
|
xfs_file_llseek(
|
|
struct file *file,
|
|
loff_t offset,
|
|
int origin)
|
|
{
|
|
switch (origin) {
|
|
case SEEK_END:
|
|
case SEEK_CUR:
|
|
case SEEK_SET:
|
|
return generic_file_llseek(file, offset, origin);
|
|
case SEEK_DATA:
|
|
return xfs_seek_data(file, offset);
|
|
case SEEK_HOLE:
|
|
return xfs_seek_hole(file, offset);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
const struct file_operations xfs_file_operations = {
|
|
.llseek = xfs_file_llseek,
|
|
.read = do_sync_read,
|
|
.write = do_sync_write,
|
|
.aio_read = xfs_file_aio_read,
|
|
.aio_write = xfs_file_aio_write,
|
|
.splice_read = xfs_file_splice_read,
|
|
.splice_write = xfs_file_splice_write,
|
|
.unlocked_ioctl = xfs_file_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = xfs_file_compat_ioctl,
|
|
#endif
|
|
.mmap = xfs_file_mmap,
|
|
.open = xfs_file_open,
|
|
.release = xfs_file_release,
|
|
.fsync = xfs_file_fsync,
|
|
.fallocate = xfs_file_fallocate,
|
|
};
|
|
|
|
const struct file_operations xfs_dir_file_operations = {
|
|
.open = xfs_dir_open,
|
|
.read = generic_read_dir,
|
|
.readdir = xfs_file_readdir,
|
|
.llseek = generic_file_llseek,
|
|
.unlocked_ioctl = xfs_file_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = xfs_file_compat_ioctl,
|
|
#endif
|
|
.fsync = xfs_dir_fsync,
|
|
};
|
|
|
|
static const struct vm_operations_struct xfs_file_vm_ops = {
|
|
.fault = filemap_fault,
|
|
.page_mkwrite = xfs_vm_page_mkwrite,
|
|
.remap_pages = generic_file_remap_pages,
|
|
};
|