Although 'norecovery' mount option was marked as deprecated for a long
time and a warning message was printed during the deprecation window,
it's still actively utilized by several projects that need a safer way
to mount a btrfs without any writes.
Furthermore this 'norecovery' mount option is supported by other major
filesystems, which makes it less clear what's our motivation to remove
it.
Re-introduce the 'norecovery' mount option, and output a message to recommend
'rescue=nologreplay' option.
Link: https://lore.kernel.org/linux-btrfs/ZkxZT0J-z0GYvfy8@gardel-login/#t
Link: https://github.com/systemd/systemd/pull/32892
Link: https://bugzilla.suse.com/show_bug.cgi?id=1222429
Reported-by: Lennart Poettering <lennart@poettering.net>
Reported-by: Jiri Slaby <jslaby@suse.com>
Fixes: a1912f7121 ("btrfs: remove code for inode_cache and recovery mount options")
CC: stable@vger.kernel.org # 6.8+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At lookup_extent_data_ref() we are incorrectly checking if we are at the
last slot of the last leaf in the extent tree. We are returning -ENOENT
if btrfs_next_leaf() returns a value greater than 1, but btrfs_next_leaf()
never returns anything greater than 1:
1) It returns < 0 on error;
2) 0 if there is a next leaf (or a new item was added to the end of the
current leaf after releasing the path);
3) 1 if there are no more leaves (and no new items were added to the last
leaf after releasing the path).
So fix this by checking if the return value is greater than zero instead
of being greater than one.
Fixes: 1618aa3c2e ("btrfs: simplify return variables in lookup_extent_data_ref()")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The following error message is displayed:
../fs/btrfs/scrub.c:2152:9: error: ‘ret’ may be used uninitialized
in this function [-Werror=maybe-uninitialized]"
Compiler version: gcc version: (Debian 10.2.1-6) 10.2.1 20210110
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Lu Yao <yaolu@kylinos.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
While loading a zone's info during creation of a block group, we can race
with a device replace operation and then trigger a use-after-free on the
device that was just replaced (source device of the replace operation).
This happens because at btrfs_load_zone_info() we extract a device from
the chunk map into a local variable and then use the device while not
under the protection of the device replace rwsem. So if there's a device
replace operation happening when we extract the device and that device
is the source of the replace operation, we will trigger a use-after-free
if before we finish using the device the replace operation finishes and
frees the device.
Fix this by enlarging the critical section under the protection of the
device replace rwsem so that all uses of the device are done inside the
critical section.
CC: stable@vger.kernel.org # 6.1.x: 15c12fcc50: btrfs: zoned: introduce a zone_info struct in btrfs_load_block_group_zone_info
CC: stable@vger.kernel.org # 6.1.x: 09a46725cc: btrfs: zoned: factor out per-zone logic from btrfs_load_block_group_zone_info
CC: stable@vger.kernel.org # 6.1.x: 9e0e3e74dc: btrfs: zoned: factor out single bg handling from btrfs_load_block_group_zone_info
CC: stable@vger.kernel.org # 6.1.x: 87463f7e02: btrfs: zoned: factor out DUP bg handling from btrfs_load_block_group_zone_info
CC: stable@vger.kernel.org # 6.1.x
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we delete subvolumes whose ID is the largest in the filesystem, then
unmount and mount again, then btrfs_init_root_free_objectid on the
tree_root will select a subvolid smaller than that one and thus allow
reusing it.
If we are also using qgroups (and particularly squotas) it is possible
to delete the subvol without deleting the qgroup. In that case, we will
be able to create a new subvol whose id already has a level 0 qgroup.
This will result in re-using that qgroup which would then lead to
incorrect accounting.
Fixes: 6ed05643dd ("btrfs: create qgroup earlier in snapshot creation")
CC: stable@vger.kernel.org # 6.7+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
On filesystems without enabled quotas there's still a warning message in
the logs when rescan is called. In that case it's not a problem that
should be reported, rescan can be called unconditionally. Change the
error code to ENOTCONN which is used for 'quotas not enabled' elsewhere.
Remove message (also a warning) when rescan is called during an ongoing
rescan, this brings no useful information and the error code is
sufficient.
Change message levels to debug for now, they can be removed eventually.
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
The "i++" was accidentally left out so it just sets qgids[0] over and
over.
This can lead to unexpected problems, as the groups[1:] would be all 0,
leading to later find_qgroup_rb() unable to find a qgroup and cause
snapshot creation failure.
Fixes: 5343cd9364 ("btrfs: qgroup: simple quota auto hierarchy for nested subvolumes")
CC: stable@vger.kernel.org # 6.7+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently the error status of super block write is tracked in page/folio
status bit Error. For that we need to keep the reference for the whole
duration of write and wait.
Count the number of superblock writeback errors in the btrfs_device.
That means we don't need the folio to stay around until it's waited for,
and can avoid the extra call to folio_get/put.
Also remove a mention of PageError in a comment as it's the last mention
of the page Error state.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Iterate over folios instead of bvecs. Switch the order of unlock and put
to be the usual order; we know this folio can't be put until it's been
waited for, but that's fragile. Remove the calls to ClearPageUptodate /
SetPageUptodate -- if PAGE_SIZE is larger than BTRFS_SUPER_INFO_SIZE,
we'd be marking the entire folio uptodate without having actually
initialised all the bytes in the page.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is a direct conversion from pages to folios, assuming single page
folio. Also removes some calls to obsolete APIs and some hidden calls to
compound_head().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is a direct conversion from pages to folios, assuming single page
folio. Also removes a few calls to compound_head() and calls to
obsolete APIs.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Several modules use __bio_add_page() today and may need to be converted
to bio_add_folio_nofail().
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that we have the lock_extent tightly coupled with
extent_clear_unlock_delalloc we can add a cached state to
extent_clear_unlock_delalloc and benefit from skipping the extra lookup
when we're doing cow.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We don't need to include the time we spend in the allocator under our
extent lock protection, move it after the allocator and make sure we
lock the extent in the error case to ensure we're not clearing these
bits without the extent lock held.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that we've got the extent lock pushed into cow_file_range() we can
push it further down into the allocation loop. This allows us to only
hold the extent lock during the dropping of the extent map range and
inserting the ordered extent.
This makes the error case a little trickier as we'll now have to lock
the range before clearing any of the other extent bits for the range,
but this is the error path so is less performance critical.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
These checks aren't reliant on the extent lock. Move this up into
cow_file_range_inline(), and then update encoded writes to call this
check before calling __cow_file_range_inline(). This will allow us to
skip the extent lock if we're not able to inline the given extent.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that we've pushed the lock_extent() into cow_file_range() we can
push the extent locking into cow_file_range_inline() and move the
lock_extent in cow_file_range() to after we call
cow_file_range_inline().
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that cow_file_range is the only function that is called with the
range locked, push this call into cow_file_range so we can further
narrow the scope.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This is used by zoned but also as the fallback for uncompressed extents
when we fail to compress the ranges. Push the extent lock into
run_dealloc_cow(), and adjust the compression case to take the extent
lock after calling run_delalloc_cow().
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since we immediately unlock the extent range when we enter
run_delalloc_compressed() simply move the lock_extent() down to cover
cow_file_range() and then remove the unlock_extent() from
run_delalloc_compressed.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
run_delalloc_nocow is a little special because we use the file extents
to see if we can nocow a range. We don't actually need the protection
of the extent lock to look at the file extents at this point however.
We are currently holding the page lock for this range, so we are
protected from anybody who would simultaneously be modifying the file
extent items for this range.
* mmap() - we're holding the page lock.
* buffered writes - we're holding the page lock.
* direct writes - we're holding the page lock and direct IO has to flush
page cache before it's able to continue.
* fallocate() - all callers flush the range and wait on ordered extents
while holding the inode lock and the mmap lock, so we are again saved
by the page lock.
We want to use the extent lock to protect
1) The mapping tree for the given range.
2) The ordered extents for the given range.
3) The io_tree for the given range.
Push the extent lock down to cover these operations. In the
fallback_to_cow() case we simply lock before doing anything and rely on
the cow_file_range() helper to handle it's range properly.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have the following pattern
while (1) {
if (cur_offset > end)
break;
}
Which is just
while (cur_offset <= end) {
...
}
so adjust the code to be more clear.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@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>
run_delalloc_nocow is a bit special as it walks through the file extents
for the inode and determines what it can nocow and what it can't. This
is the more complicated area for extent locking, so start with this
function.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We want to limit the scope of the extent lock to be around operations
that can change in flight. Currently we hold the extent lock through
the entire writepage operation, which isn't really necessary.
We want to protect to make sure nobody has updated DELALLOC. In
find_lock_delalloc_range we must lock the range in order to validate the
contents of our io_tree. However once we've done that we're safe to
unlock the range and continue, as we have the page lock already held for
the range.
We are protected from all operations at this point.
* mmap() - we're holding the page lock, thus are protected.
* buffered writes - again, we're protected because we take the page lock
for the first and last page in our range for buffered writes so we
won't create new delalloc ranges in this area.
* direct IO - we invalidate pagecache before attempting to write a new
area, which requires the page lock, so again are protected once we're
holding the page lock on this range.
Additionally this behavior actually already exists for compressed, we
unlock the range as soon as we start to process the async extents, and
re-lock it during compression. So this is completely safe, and makes
the locking more consistent.
Make this simple by just pushing the extent lock into
btrfs_run_delalloc_range. From there followup patches will push the
lock further down into its users.
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We currently don't lock the extent when we're doing a
cow_file_range_inline() for a compressed extent. This isn't a problem
necessarily, but it's inconsistent with the rest of our usage of
cow_file_range_inline(). This also leads to some extra weird logic
around whether the extent is locked or not. Fix this to lock the extent
before calling cow_file_range_inline() in compression to make it
consistent with the rest of the inline users. In future patches this
will be pushed down into the cow_file_range_inline() helper, so we're
fine with the quick and dirty locking here. This patch exists to make
the behavior change obvious.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We duplicate the extent cleanup for cow_file_range_inline() in the cow
and compressed case. The encoded case doesn't need to do cleanup the
same way, so rename cow_file_range_inline to __cow_file_range_inline and
then make cow_file_range_inline handle the extent cleanup appropriately,
and update the callers.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since 4750af3bbe ("btrfs: prevent extent_clear_unlock_delalloc() to
unlock page not locked by __process_pages_contig()") we have been
unlocking the locked page manually instead of via
extent_clear_unlock_delalloc() because of subpage blocksize support.
However we actually disable inline extent creation for subpage blocksize
support, so this behavior isn't necessary. Remove this code and
comment, if at some point the subpage blocksize code grows support for
inline extents this can be re-evaluated.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently we have a lot of duplicated checks of
if (start == 0 && fs_info->sectorsize == PAGE_SIZE)
cow_file_range_inline();
Instead of duplicating this check everywhere, consolidate all of the
inline extent logic into a helper which documents all of the checks and
then use that helper inside of cow_file_range_inline(). With this we
can clean up all of the calls to either unconditionally call
cow_file_range_inline(), or at least reduce the checks we're doing
before we call cow_file_range_inline();
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In the cow path we will clone the reloc csums for relocated data
extents, and if there's an error we already have an ordered extent and
rely on the ordered extent finishing to clean everything up.
There's a problem however, we don't mark the ordered extent with an
error, we pretend like everything was just fine. If we were at the end
of our range we won't actually bubble up this error anywhere, and we
could end up inserting an extent that doesn't have csums where it should
have them.
Fix this by adding a helper to mark the ordered extent with an error,
and then use this when we fail to lookup the csums in
btrfs_reloc_clone_csums. Use this helper in the other place where we
use the same pattern while we're here.
This will prevent us from erroneously inserting the extent that doesn't
have the required checksums.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function create_io_em() is called before we submit an IO, to update
the in-memory extent map for the involved range.
This patch changes the following aspects:
- Does not allow BTRFS_ORDERED_NOCOW type
For real NOCOW (excluding NOCOW writes into preallocated ranges)
writes, we never call create_io_em(), as we does not need to update
the extent map at all.
So remove the sanity check allowing BTRFS_ORDERED_NOCOW type.
- Add extra sanity checks
* PREALLOC
- @block_len == len
For uncompressed writes.
* REGULAR
- @block_len == @orig_block_len == @ram_bytes == @len
We're creating a new uncompressed extent, and referring all of it.
- @orig_start == @start
We haven no offset inside the extent.
* COMPRESSED
- valid @compress_type
- @len <= @ram_bytes
This is to co-operate with encoded writes, which can cause a new
file extent referring only part of a uncompressed extent.
Reviewed-by: Filipe Manana <fdmanana@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>
With the tree-checker ensuring all inline file extents starts at file
offset 0 and has a length no larger than sectorsize, we can simplify the
calculation to assigned those fixes values directly.
Reviewed-by: Filipe Manana <fdmanana@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>
The extent_map structure is very critical to btrfs, as it is involved
for both read and write paths.
Unfortunately the structure is not properly explained, making it pretty
hard to understand nor to do further improvement.
This patch adds extra comments explaining the major members based on my
code reading. Hopefully we can find more members to cleanup in the
future.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
calcu_metadata_size() has a "reserve" argument, but the only caller always
set it to "1". The other usage (reserve = 0) is dropped by a commit
0647bf564f ("Btrfs: improve forever loop when doing balance relocation"),
which is more than 10 years ago. Drop the argument and simplify the code.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@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>
There's another return variable wret that is only passed to ret on
error, we can simply use ret.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
First, drop err instead reuse ret, choose to return the error instead of
goto fail and then return the same error. Do not initialize the ret
until where it has to be initialized. Slight logic change in handling
the btrfs_search_slot() and btrfs_next_leaf() return value.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Rename ret to ret2 compile and then err to ret. Also, new ret2 is found
to be localized within the 'if (trans)' statement, so move its
declaration there.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In quick_update_accounting() err is used as 2nd return value, which could
be achieved just with ret.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Coding style fixes the function relocate_tree_blocks(). After the fix,
ret is the return value variable.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Code style fix in the function build_backref_tree(). Drop the ret
initialization 0, as we don't need it.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Rename the function's local return variables err and werr to ret.
Also, align the variable declarations with the other declarations in
the function for better function space alignment.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Rename the function's local variable werr and err to ret.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In the function btrfs_write_marked_extents() and in __btrfs_wait_marked_extents()
return the actual error if when filemap_fdata<write|wait>_range() fails.
Suggested-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are open coded tests of BTRFS_FS_STATE_DUMMY_FS_INFO and we have a
wrapper for that that's a compile-time constant when self-tests are not
built in. As this is only for development we can save some bytes and
conditions on release configs by using the helper in the remaining
cases.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's no need to initialize the delayed inodes xarray with a GFP_ATOMIC
flag because that actually does nothing on the xarray operations. That was
needed for radix trees, but for xarrays the allocation flags are passed as
the last argument to xa_store() (which we are using correctly).
So initialize the delayed inodes xarray with a simple xa_init().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently try_release_extent_mapping() as an int return type, but we
use it as a boolean. Its only caller, the release folio callback, also
returns a boolean which corresponds to try_release_extent_mapping()'s
return value. So change its return value type to bool as well as its
helper try_release_extent_state().
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At try_release_extent_mapping(), called during the release folio callback
(btrfs_release_folio() callchain), we don't release any extent maps in the
range if the GFP flags don't allow blocking. This behaviour is exaggerated
because:
1) Both searching for extent maps and removing them are not blocking
operations. The only thing that it is the cond_resched() call at the
end of the loop that searches for and removes extent maps;
2) We currently only operate on a single page, so for the case where
block size matches the page size, we can only have one extent map,
and for the case where the block size is smaller than the page size,
we can have at most 16 extent maps.
So it's very unlikely the cond_resched() call will ever block even in the
block size smaller than page size scenario.
So instead of not removing any extent maps at all in case the GFP glags
don't allow blocking, keep removing extent maps while we don't need to
reschedule. This makes it safe for the subpage case and for a future
where we can process folios with a size larger than a page.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently we don't attempt to release extent maps if the inode has an
i_size that is not greater than 16M. This condition was added way back
in 2008 by commit 70dec8079d ("Btrfs: extent_io and extent_state
optimizations"), without any explanation about it. A quick chat with
Chris on slack revealed that the goal was probably to release the extent
maps for small files only when closing the inode. This however can be
harmful in case we have tons of such files being kept open for very long
periods of time, since we will consume more and more pages for extent
maps.
So remove the condition.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nowadays we have the btrfs_get_fs_generation() to get the current
generation of the filesystem, so there's no need anymore to lock the
transaction spinlock to read it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Rename the following variables:
1) "btrfs_inode" to "inode", because it's shorter to type and clear, and
we don't have a VFS inode here as well, so there's no confusion;
2) "tree" to "io_tree", to be clear which tree we are dealing with, since
we use 2 different trees in the function;
3) "map" to "extent_tree" since "map" gives the idea we are dealing with
an extent map for example, but we are dealing with the inode's extent
tree (the tree which stores extent maps).
These also make the next patches simpler.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
