There are several cleanups for extent_write_locked_range(), most of them
are pure cleanups, but with some preparation for future subpage support.
- Add a proper comment for which call sites are suitable
Unlike regular synchronized extent write back, if async COW or zoned
COW happens, we have all pages in the range still locked.
Thus for those (only) two call sites, we need this function to submit
page content into bios and submit them.
- Remove @mode parameter
All the existing two call sites pass WB_SYNC_ALL. No need for @mode
parameter.
- Better error handling
Currently if we hit an error during the page iteration loop, we
overwrite @ret, causing only the last error can be recorded.
Here we add @found_error and @first_error variable to record if we hit
any error, and the first error we hit.
So the first error won't get lost.
- Don't reuse @start as the cursor
We reuse the parameter @start as the cursor to iterate the range, not
a big problem, but since we're here, introduce a proper @cur as the
cursor.
- Remove impossible branch
Since all pages are still locked after the ordered extent is inserted,
there is no way that pages can get its dirty bit cleared.
Remove the branch where page is not dirty and replace it with an
ASSERT().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Previously we had "struct btrfs_bio", which records IO context for
mirrored IO and RAID56, and "strcut btrfs_io_bio", which records extra
btrfs specific info for logical bytenr bio.
With "btrfs_bio" renamed to "btrfs_io_context", we are safe to rename
"btrfs_io_bio" to "btrfs_bio" which is a more suitable name now.
The struct btrfs_bio changes meaning by this commit. There was a
suggested name like btrfs_logical_bio but it's a bit long and we'd
prefer to use a shorter name.
This could be a concern for backports to older kernels where the
different meaning could possibly cause confusion or bugs. Comparing the
new and old structures, there's no overlap among the struct members so a
build would break in case of incorrect backport.
We haven't had many backports to bio code anyway so this is more of a
theoretical cause of bugs and a matter of precaution but we'll need to
keep the semantic change in mind.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helper btrfs_bio_alloc() is almost the same as btrfs_io_bio_alloc(),
except it's allocating using BIO_MAX_VECS as @nr_iovecs, and initializes
bio->bi_iter.bi_sector.
However the naming itself is not using "btrfs_io_bio" to indicate its
parameter is "strcut btrfs_io_bio" and can be easily confused with
"struct btrfs_bio".
Considering assigned bio->bi_iter.bi_sector is such a simple work and
there are already tons of call sites doing that manually, there is no
need to do that in a helper.
Remove btrfs_bio_alloc() helper, and enhance btrfs_io_bio_alloc()
function to provide a fail-safe value for its @nr_iovecs.
And then replace all btrfs_bio_alloc() callers with
btrfs_io_bio_alloc().
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Function repair_io_failure() is no longer used out of extent_io.c since
commit 8b9b6f2554 ("btrfs: scrub: cleanup the remaining nodatasum
fixup code"), which removes the last external caller.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we have written to the zone capacity, the device automatically
deactivates the zone. Sync up block group side (the active BG list and
zone_is_active flag) with it.
We need to do it both on data BGs and metadata BGs. On data side, we add a
hook to btrfs_finish_ordered_io(). On metadata side, we use
end_extent_buffer_writeback().
To reduce excess lookup of a block group, we mark the last extent buffer in
a block group with EXTENT_BUFFER_ZONE_FINISH flag. This cannot be done for
data (ordered_extent), because the address may change due to
REQ_OP_ZONE_APPEND.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The offset and can never be negative use unsigned int instead of int
type for them.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Inside btrfs we use Private2 page status to indicate we have an ordered
extent with pending IO for the sector.
But the page status name, Private2, tells us nothing about the bit
itself, so this patch will rename it to Ordered.
And with extra comment about the bit added, so reader who is still
uncertain about the page Ordered status, will find the comment pretty
easily.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is a lot of code inside extent_io.c needs both "struct bio
**bio_ret" and "unsigned long prev_bio_flags", along with some
parameters like "unsigned long bio_flags".
Such strange parameters are here for bio assembly.
For example, we have such inode page layout:
0 4K 8K 12K
|<-- Extent A-->|<- EB->|
Then what we do is:
- Page [0, 4K)
*bio_ret = NULL
So we allocate a new bio to bio_ret,
Add page [0, 4K) to *bio_ret.
- Page [4K, 8K)
*bio_ret != NULL
We found this page is continuous to *bio_ret,
and if we're not at stripe boundary, we
add page [4K, 8K) to *bio_ret.
- Page [8K, 12K)
*bio_ret != NULL
But we found this page is not continuous, so
we submit *bio_ret, then allocate a new bio,
and add page [8K, 12K) to the new bio.
This means we need to record both the bio and its bio_flag, but we
record them manually using those strange parameter list, other than
encapsulating them into their own structure.
So this patch will introduce a new structure, btrfs_bio_ctrl, to record
both the bio, and its bio_flags.
Also, in above case, for all pages added to the bio, we need to check if
the new page crosses stripe boundary. This check itself can be time
consuming, and we don't really need to do that for each page.
This patch also integrates the stripe boundary check into btrfs_bio_ctrl.
When a new bio is allocated, the stripe and ordered extent boundary is
also calculated, so no matter how large the bio will be, we only
calculate the boundaries once, to save some CPU time.
The following functions/structures are affected:
- struct extent_page_data
Replace its bio pointer with structure btrfs_bio_ctrl (embedded
structure, not pointer)
- end_write_bio()
- flush_write_bio()
Just change how bio is fetched
- btrfs_bio_add_page()
Use pre-calculated boundaries instead of re-calculating them.
And use @bio_ctrl to replace @bio and @prev_bio_flags.
- calc_bio_boundaries()
New function
- submit_extent_page() callers
- btrfs_do_readpage() callers
- contiguous_readpages() callers
To Use @bio_ctrl to replace @bio and @prev_bio_flags, and how to grab
bio.
- btrfs_bio_fits_in_ordered_extent()
Removed, as now the ordered extent size limit is done at bio
allocation time, no need to check for each page range.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The io_failure_record::in_validation was introduced to handle failed bio
which cross several sectors. In such case, we still need to verify
which sectors are corrupted.
But since we've changed the way how we handle corrupted sectors, by only
submitting repair for each corrupted sector, there is no need for extra
validation any more.
This patch will cleanup all io_failure_record::in_validation related
code.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently btrfs_submit_read_repair() has some extra check on whether the
failed bio needs extra validation for repair. But we can avoid all
these extra mechanisms if we submit the repair for each sector.
By this, each read repair can be easily handled without the need to
verify which sector is corrupted.
This will also benefit subpage, as one subpage bvec can contain several
sectors, making the extra verification more complex.
So this patch will:
- Introduce repair_one_sector()
The main code submitting repair, which is more or less the same as old
btrfs_submit_read_repair().
But this time, it only repairs one sector.
- Make btrfs_submit_read_repair() to handle sectors differently
There are 3 different cases:
* Good sector
We need to release the page and extent, set the range uptodate.
* Bad sector and failed to submit repair bio
We need to release the page and extent, but not set the range
uptodate.
* Bad sector but repair bio submitted
The page and extent release will be handled by the submitted repair
bio. Nothing needs to be done.
Since btrfs_submit_read_repair() will handle the page and extent
release now, we need to skip to next bvec even we hit some error.
- Change the lifespan of @uptodate in end_bio_extent_readpage()
Since now btrfs_submit_read_repair() will handle the full bvec
which contains any corruption, we don't need to bother updating
@uptodate bit anymore.
Just let @uptodate to be local variable inside the main loop,
so that any error from one bvec won't affect later bvec.
- Only export btrfs_repair_one_sector(), unexport
btrfs_submit_read_repair()
The only outside caller for read repair is DIO, which already submits
its repair for just one sector.
Only export btrfs_repair_one_sector() for DIO.
This patch will focus on the change on the repair path, the extra
validation code is still kept as is, and will be cleaned up later.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are two forward declarations deep in extent_io.h, move them
to the beginning and remove the duplicate one.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Tree manipulating operations like merging nodes often release
once-allocated tree nodes. Such nodes are cleaned so that pages in the
node are not uselessly written out. On zoned volumes, however, such
optimization blocks the following IOs as the cancellation of the write
out of the freed blocks breaks the sequential write sequence expected by
the device.
Introduce a list of clean and unwritten extent buffers that have been
released in a transaction. Redirty the buffers so that
btree_write_cache_pages() can send proper bios to the devices.
Besides it clears the entire content of the extent buffer not to confuse
raw block scanners e.g. 'btrfs check'. By clearing the content,
csum_dirty_buffer() complains about bytenr mismatch, so avoid the
checking and checksum using newly introduced buffer flag
EXTENT_BUFFER_NO_CHECK.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
To support subpage sector size, data also need extra info to make sure
which sectors in a page are uptodate/dirty/...
This patch will make pages for data inodes get btrfs_subpage structure
attached, and detached when the page is freed.
This patch also slightly changes the timing when
set_page_extent_mapped() is called to make sure:
- We have page->mapping set
page->mapping->host is used to grab btrfs_fs_info, thus we can only
call this function after page is mapped to an inode.
One call site attaches pages to inode manually, thus we have to modify
the timing of set_page_extent_mapped() a bit.
- As soon as possible, before other operations
Since memory allocation can fail, we have to do extra error handling.
Calling set_page_extent_mapped() as soon as possible can simply the
error handling for several call sites.
The idea is pretty much the same as iomap_page, but with more bitmaps
for btrfs specific cases.
Currently the plan is to switch iomap if iomap can provide sector
aligned write back (only write back dirty sectors, but not the full
page, data balance require this feature).
So we will stick to btrfs specific bitmap for now.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
PAGE_CLEAR_DIRTY and PAGE_SET_WRITEBACK are two defines used in
__process_pages_contig(), to let the function know to clear page dirty
bit and then set page writeback.
However page writeback and dirty bits are conflicting (at least for
sector size == PAGE_SIZE case), this means these two have to be always
updated together.
This means we can merge PAGE_CLEAR_DIRTY and PAGE_SET_WRITEBACK to
PAGE_START_WRITEBACK.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
For subpage sized extent buffer, we have ensured no extent buffer will
cross page boundary, thus we would only need one page for any extent
buffer.
Update function num_extent_pages to handle such case. Now
num_extent_pages() returns 1 for subpage sized extent buffer.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Btrfs only support 64K as maximum node size, thus for 4K page system, we
would have at most 16 pages for one extent buffer.
For a system using 64K page size, we would really have just one page.
While we always use 16 pages for extent_buffer::pages, this means for
systems using 64K pages, we are wasting memory for 15 page pointers
which will never be used.
Calculate the array size based on page size and the node size maximum.
- for systems using 4K page size, it will stay 16 pages
- for systems using 64K page size, it will be 1 page
Move the definition of BTRFS_MAX_METADATA_BLOCKSIZE to btrfs_tree.h, to
avoid circular inclusion of ctree.h.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Parameter icsum for check_data_csum() is a little hard to understand.
So is the phy_offset for btrfs_verify_data_csum().
Both parameters are calculated values for csum lookup.
Instead of some calculated value, just pass bio_offset and let the
final and only user, check_data_csum(), calculate whatever it needs.
Since we are here, also make the bio_offset parameter and some related
variables to be u32 (unsigned int).
As bio size is limited by its bi_size, which is unsigned int, and has
extra size limit check during various bio operations.
Thus we are ensured that bio_offset won't overflow u32.
Thus for all involved functions, not only rename the parameter from
@phy_offset to @bio_offset, but also reduce its width to u32, so we
won't have suspicious "u32 = u64 >> sector_bits;" lines anymore.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The parameter bio_offset of extent_submit_bio_start_t is very confusing.
If it's really bio_offset (offset to bio), then it should be u32. But
in fact, it's only utilized by dio read, and that member is used as file
offset, which must be u64.
Rename it to dio_file_offset since the only user uses it as file offset,
and add comment for who is using it.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently the type is unsigned int which could change its width
depending on the architecture. We need up to 32 bits so make it
explicit.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It is unused everywhere now, it can be removed.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that we've plumbed all of the callers to have the owner root and the
level, plumb it down into alloc_extent_buffer().
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We're going to pass around more information when we allocate extent
buffers, in order to make that cleaner how we do readahead. Most of the
callers have the parent node that we're getting our blockptr from, with
the sole exception of relocation which simply has the bytenr it wants to
read.
Add a helper that takes the current arguments that we need (bytenr and
gen), and add another helper for simply reading the slot out of a node.
In followup patches the helper that takes all the extra arguments will
be expanded, and the simpler helper won't need to have it's arguments
adjusted.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
All callers of btrfs_wq_submit_bio() pass struct inode as @private_data,
so there is no need for it to be (void *), replace it with "struct inode
*inode".
While we can extract fs_info from struct inode, also remove the @fs_info
parameter.
Since we're here, also replace all the (void *private_data) into (struct
inode *inode).
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Historically we've implemented our own locking because we wanted to be
able to selectively spin or sleep based on what we were doing in the
tree. For instance, if all of our nodes were in cache then there's
rarely a reason to need to sleep waiting for node locks, as they'll
likely become available soon. At the time this code was written the
rw_semaphore didn't do adaptive spinning, and thus was orders of
magnitude slower than our home grown locking.
However now the opposite is the case. There are a few problems with how
we implement blocking locks, namely that we use a normal waitqueue and
simply wake everybody up in reverse sleep order. This leads to some
suboptimal performance behavior, and a lot of context switches in highly
contended cases. The rw_semaphores actually do this properly, and also
have adaptive spinning that works relatively well.
The locking code is also a bit of a bear to understand, and we lose the
benefit of lockdep for the most part because the blocking states of the
lock are simply ad-hoc and not mapped into lockdep.
So rework the locking code to drop all of this custom locking stuff, and
simply use a rw_semaphore for everything. This makes the locking much
simpler for everything, as we can now drop a lot of cruft and blocking
transitions. The performance numbers vary depending on the workload,
because generally speaking there doesn't tend to be a lot of contention
on the btree. However, on my test system which is an 80 core single
socket system with 256GiB of RAM and a 2TiB NVMe drive I get the
following results (with all debug options off):
dbench 200 baseline
Throughput 216.056 MB/sec 200 clients 200 procs max_latency=1471.197 ms
dbench 200 with patch
Throughput 737.188 MB/sec 200 clients 200 procs max_latency=714.346 ms
Previously we also used fs_mark to test this sort of contention, and
those results are far less impressive, mostly because there's not enough
tasks to really stress the locking
fs_mark -d /d[0-15] -S 0 -L 20 -n 100000 -s 0 -t 16
baseline
Average Files/sec: 160166.7
p50 Files/sec: 165832
p90 Files/sec: 123886
p99 Files/sec: 123495
real 3m26.527s
user 2m19.223s
sys 48m21.856s
patched
Average Files/sec: 164135.7
p50 Files/sec: 171095
p90 Files/sec: 122889
p99 Files/sec: 113819
real 3m29.660s
user 2m19.990s
sys 44m12.259s
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's no longer used just remove the function and any related code which
was initialising it for inodes. No functional changes.
Removing 8 bytes from extent_io_tree in turn reduces size of other
structures where it is embedded, notably btrfs_inode where it reduces
size by 24 bytes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's no longer used so let's remove it.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This makes reading the code a tad easier by decreasing the level of
indirection by one.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's always set to 0 by its sole caller - btrfs_readpage. Simply remove
it.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's always set to 0 from the sole caller - btrfs_readpage.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that btrfs_readpage is the only caller of extent_read_full_page the
latter can be open coded in the former. Use the occassion to rename
__extent_read_full_page to extent_read_full_page. To facillitate this
change submit_one_bio has to be exported as well.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It's called only from btrfs_readpage which always passes 0 so just sink
the argument into extent_read_full_page.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that this function is only responsible for reading data pages it's
no longer necessary to pass get_extent_t parameter across several
layers of functions. This patch removes this parameter from multiple
functions: __get_extent_map/__do_readpage/__extent_read_full_page/
extent_read_full_page and simply calls btrfs_get_extent directly in
__get_extent_map.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nested locking with lockdep and everything else refers to lock hierarchy
within the same lock map. This is how we indicate the same locks for
different objects are ok to take in a specific order, for our use case
that would be to take the lock on a leaf and then take a lock on an
adjacent leaf.
What ->lock_nested _actually_ refers to is if we happen to already be
holding the write lock on the extent buffer and we're allowing a read
lock to be taken on that extent buffer, which is recursion. Rename this
so we don't get confused when we switch to a rwsem and have to start
using the _nested helpers.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
With the conversion of the tree locks to rwsem I got the following
lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
5.8.0-rc7-00165-g04ec4da5f45f-dirty #922 Not tainted
------------------------------------------------------
compsize/11122 is trying to acquire lock:
ffff889fabca8768 (&mm->mmap_lock#2){++++}-{3:3}, at: __might_fault+0x3e/0x90
but task is already holding lock:
ffff889fe720fe40 (btrfs-fs-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (btrfs-fs-00){++++}-{3:3}:
down_write_nested+0x3b/0x70
__btrfs_tree_lock+0x24/0x120
btrfs_search_slot+0x756/0x990
btrfs_lookup_inode+0x3a/0xb4
__btrfs_update_delayed_inode+0x93/0x270
btrfs_async_run_delayed_root+0x168/0x230
btrfs_work_helper+0xd4/0x570
process_one_work+0x2ad/0x5f0
worker_thread+0x3a/0x3d0
kthread+0x133/0x150
ret_from_fork+0x1f/0x30
-> #1 (&delayed_node->mutex){+.+.}-{3:3}:
__mutex_lock+0x9f/0x930
btrfs_delayed_update_inode+0x50/0x440
btrfs_update_inode+0x8a/0xf0
btrfs_dirty_inode+0x5b/0xd0
touch_atime+0xa1/0xd0
btrfs_file_mmap+0x3f/0x60
mmap_region+0x3a4/0x640
do_mmap+0x376/0x580
vm_mmap_pgoff+0xd5/0x120
ksys_mmap_pgoff+0x193/0x230
do_syscall_64+0x50/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
-> #0 (&mm->mmap_lock#2){++++}-{3:3}:
__lock_acquire+0x1272/0x2310
lock_acquire+0x9e/0x360
__might_fault+0x68/0x90
_copy_to_user+0x1e/0x80
copy_to_sk.isra.32+0x121/0x300
search_ioctl+0x106/0x200
btrfs_ioctl_tree_search_v2+0x7b/0xf0
btrfs_ioctl+0x106f/0x30a0
ksys_ioctl+0x83/0xc0
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x50/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
other info that might help us debug this:
Chain exists of:
&mm->mmap_lock#2 --> &delayed_node->mutex --> btrfs-fs-00
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(btrfs-fs-00);
lock(&delayed_node->mutex);
lock(btrfs-fs-00);
lock(&mm->mmap_lock#2);
*** DEADLOCK ***
1 lock held by compsize/11122:
#0: ffff889fe720fe40 (btrfs-fs-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180
stack backtrace:
CPU: 17 PID: 11122 Comm: compsize Kdump: loaded Not tainted 5.8.0-rc7-00165-g04ec4da5f45f-dirty #922
Hardware name: Quanta Tioga Pass Single Side 01-0030993006/Tioga Pass Single Side, BIOS F08_3A18 12/20/2018
Call Trace:
dump_stack+0x78/0xa0
check_noncircular+0x165/0x180
__lock_acquire+0x1272/0x2310
lock_acquire+0x9e/0x360
? __might_fault+0x3e/0x90
? find_held_lock+0x72/0x90
__might_fault+0x68/0x90
? __might_fault+0x3e/0x90
_copy_to_user+0x1e/0x80
copy_to_sk.isra.32+0x121/0x300
? btrfs_search_forward+0x2a6/0x360
search_ioctl+0x106/0x200
btrfs_ioctl_tree_search_v2+0x7b/0xf0
btrfs_ioctl+0x106f/0x30a0
? __do_sys_newfstat+0x5a/0x70
? ksys_ioctl+0x83/0xc0
ksys_ioctl+0x83/0xc0
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x50/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The problem is we're doing a copy_to_user() while holding tree locks,
which can deadlock if we have to do a page fault for the copy_to_user().
This exists even without my locking changes, so it needs to be fixed.
Rework the search ioctl to do the pre-fault and then
copy_to_user_nofault for the copying.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The fiemap callback is not part of UAPI interface and the prototypes
don't have the __u64 types either.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It has one VFS and 1 btrfs inode usages but converting it to btrfs_inode
interface will allow seamless conversion of its callers.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
* Fix performance problems found in dioread_nolock now that it is the
default, caused by transaction leaks.
* Clean up fiemap handling in ext4
* Clean up and refactor multiple block allocator (mballoc) code
* Fix a problem with mballoc with a smaller file systems running out
of blocks because they couldn't properly use blocks that had been
reserved by inode preallocation.
* Fixed a race in ext4_sync_parent() versus rename()
* Simplify the error handling in the extent manipulation code
* Make sure all metadata I/O errors are felected to ext4_ext_dirty()'s and
ext4_make_inode_dirty()'s callers.
* Avoid passing an error pointer to brelse in ext4_xattr_set()
* Fix race which could result to freeing an inode on the dirty last
in data=journal mode.
* Fix refcount handling if ext4_iget() fails
* Fix a crash in generic/019 caused by a corrupted extent node
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"A lot of bug fixes and cleanups for ext4, including:
- Fix performance problems found in dioread_nolock now that it is the
default, caused by transaction leaks.
- Clean up fiemap handling in ext4
- Clean up and refactor multiple block allocator (mballoc) code
- Fix a problem with mballoc with a smaller file systems running out
of blocks because they couldn't properly use blocks that had been
reserved by inode preallocation.
- Fixed a race in ext4_sync_parent() versus rename()
- Simplify the error handling in the extent manipulation code
- Make sure all metadata I/O errors are felected to
ext4_ext_dirty()'s and ext4_make_inode_dirty()'s callers.
- Avoid passing an error pointer to brelse in ext4_xattr_set()
- Fix race which could result to freeing an inode on the dirty last
in data=journal mode.
- Fix refcount handling if ext4_iget() fails
- Fix a crash in generic/019 caused by a corrupted extent node"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (58 commits)
ext4: avoid unnecessary transaction starts during writeback
ext4: don't block for O_DIRECT if IOCB_NOWAIT is set
ext4: remove the access_ok() check in ext4_ioctl_get_es_cache
fs: remove the access_ok() check in ioctl_fiemap
fs: handle FIEMAP_FLAG_SYNC in fiemap_prep
fs: move fiemap range validation into the file systems instances
iomap: fix the iomap_fiemap prototype
fs: move the fiemap definitions out of fs.h
fs: mark __generic_block_fiemap static
ext4: remove the call to fiemap_check_flags in ext4_fiemap
ext4: split _ext4_fiemap
ext4: fix fiemap size checks for bitmap files
ext4: fix EXT4_MAX_LOGICAL_BLOCK macro
add comment for ext4_dir_entry_2 file_type member
jbd2: avoid leaking transaction credits when unreserving handle
ext4: drop ext4_journal_free_reserved()
ext4: mballoc: use lock for checking free blocks while retrying
ext4: mballoc: refactor ext4_mb_good_group()
ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling
ext4: mballoc: refactor ext4_mb_discard_preallocations()
...
No need to pull the fiemap definitions into almost every file in the
kernel build.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Link: https://lore.kernel.org/r/20200523073016.2944131-5-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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Merge tag 'for-5.8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
"Highlights:
- speedup dead root detection during orphan cleanup, eg. when there
are many deleted subvolumes waiting to be cleaned, the trees are
now looked up in radix tree instead of a O(N^2) search
- snapshot creation with inherited qgroup will mark the qgroup
inconsistent, requires a rescan
- send will emit file capabilities after chown, this produces a
stream that does not need postprocessing to set the capabilities
again
- direct io ported to iomap infrastructure, cleaned up and simplified
code, notably removing last use of struct buffer_head in btrfs code
Core changes:
- factor out backreference iteration, to be used by ordinary
backreferences and relocation code
- improved global block reserve utilization
* better logic to serialize requests
* increased maximum available for unlink
* improved handling on large pages (64K)
- direct io cleanups and fixes
* simplify layering, where cloned bios were unnecessarily created
for some cases
* error handling fixes (submit, endio)
* remove repair worker thread, used to avoid deadlocks during
repair
- refactored block group reading code, preparatory work for new type
of block group storage that should improve mount time on large
filesystems
Cleanups:
- cleaned up (and slightly sped up) set/get helpers for metadata data
structure members
- root bit REF_COWS got renamed to SHAREABLE to reflect the that the
blocks of the tree get shared either among subvolumes or with the
relocation trees
Fixes:
- when subvolume deletion fails due to ENOSPC, the filesystem is not
turned read-only
- device scan deals with devices from other filesystems that changed
ownership due to overwrite (mkfs)
- fix a race between scrub and block group removal/allocation
- fix long standing bug of a runaway balance operation, printing the
same line to the syslog, caused by a stale status bit on a reloc
tree that prevented progress
- fix corrupt log due to concurrent fsync of inodes with shared
extents
- fix space underflow for NODATACOW and buffered writes when it for
some reason needs to fallback to COW mode"
* tag 'for-5.8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (133 commits)
btrfs: fix space_info bytes_may_use underflow during space cache writeout
btrfs: fix space_info bytes_may_use underflow after nocow buffered write
btrfs: fix wrong file range cleanup after an error filling dealloc range
btrfs: remove redundant local variable in read_block_for_search
btrfs: open code key_search
btrfs: split btrfs_direct_IO to read and write part
btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK
fs: remove dio_end_io()
btrfs: switch to iomap_dio_rw() for dio
iomap: remove lockdep_assert_held()
iomap: add a filesystem hook for direct I/O bio submission
fs: export generic_file_buffered_read()
btrfs: turn space cache writeout failure messages into debug messages
btrfs: include error on messages about failure to write space/inode caches
btrfs: remove useless 'fail_unlock' label from btrfs_csum_file_blocks()
btrfs: do not ignore error from btrfs_next_leaf() when inserting checksums
btrfs: make checksum item extension more efficient
btrfs: fix corrupt log due to concurrent fsync of inodes with shared extents
btrfs: unexport btrfs_compress_set_level()
btrfs: simplify iget helpers
...
Implement the new readahead method in btrfs using the new
readahead_page_batch() function.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-18-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are many helpers around extent buffers, found in extent_io.h and
ctree.h. Most of them can be converted to take constified eb as there
are no changes to the extent buffer structure itself but rather the
pages.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
All uses of map_private_extent_buffer have been replaced by more
effective way. The set/get helpers have their own bounds checker.
The function name was confusing since the non-private helper was removed
in a65917156e ("Btrfs: stop using highmem for extent_buffers") many
years ago.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently, direct I/O has its own versions of bio_readpage_error() and
btrfs_check_repairable() (dio_read_error() and
btrfs_check_dio_repairable(), respectively). The main difference is that
the direct I/O version doesn't do read validation. The rework of direct
I/O repair makes it possible to do validation, so we can get rid of
btrfs_check_dio_repairable() and combine bio_readpage_error() and
dio_read_error() into a new helper, btrfs_submit_read_repair().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since its introduction in commit 2fe6303e7c ("Btrfs: split
bio_readpage_error into several functions"), btrfs_check_repairable()
has only been used from extent_io.c where it is defined.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Read repair does two things: it finds a good copy of data to return to
the reader, and it corrects the bad copy on disk. If a read of multiple
sectors has an I/O error, repair does an extra "validation" step that
issues a separate read for each sector. This allows us to find the exact
failing sectors and only rewrite those.
This heuristic is implemented in
bio_readpage_error()/btrfs_check_repairable() as:
failed_bio_pages = failed_bio->bi_iter.bi_size >> PAGE_SHIFT;
if (failed_bio_pages > 1)
do validation
However, at this point, bi_iter may have already been advanced. This
means that we'll skip the validation step and rewrite the entire failed
read.
Fix it by getting the actual size from the biovec (which we can do
because this is only called for non-cloned bios, although that will
change in a later commit).
Fixes: 8a2ee44a37 ("btrfs: look at bi_size for repair decisions")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
I'm going to make the entire destruction of btrfs_root's controlled by
their refcount, so it will be helpful to notice if we're leaking their
eb's on umount.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The tree pointer can be safely read from the page's inode, use it and
drop the redundant argument.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We only pass this as 1 from __extent_writepage_io(). The parameter
basically means "pretend I didn't pass in a page". This is silly since
we can simply not pass in the page. Get rid of the parameter from
btrfs_get_extent(), and since it's used as a get_extent_t callback,
remove it from get_extent_t and btree_get_extent(), neither of which
need it.
While we're here, let's document btrfs_get_extent().
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
