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2025-11-24btrfs: remove pointless data_end assignment in btrfs_extent_item()Filipe Manana
There's no point in setting 'data_end' to 'old_data' as we don't use it afterwards. So remove the redundant assignment which was never needed and added when the function was first added in commit 6567e837df07 ("Btrfs: early work to file_write in big extents"). Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: use the key format macros when printing keysFilipe Manana
Change all locations that print a key to use the new macros to print them in order to ensure a consistent style and avoid repetitive code. 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>
2025-11-24btrfs: add macros to facilitate printing of keysFilipe Manana
There's a lot of places where we need to print a key, and it's tiresome to type the format specifier, typically "(%llu %u %llu)", as well as passing 3 arguments to a prink family function (key->objectid, key->type, key->offset). So add a couple macros for this just like we have for csum values in btrfs_inode.h (CSUM_FMT and CSUM_FMT_VALUE). This also ensures that we consistently print a key in the same format, always as "(%llu %llu %llu)", which is the most common format we use, but we have a few variations such as "[%llu %llu %llu]" for no good reason. This patch introduces the macros while the next one makes use of it. This is to ease backports of future patches, since then we can backport this patch which is simple and short and then backport those future patches, as the next patch in the series that makes use of these new macros is quite large and may have some dependencies. 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>
2025-11-24btrfs: remove redundant refcount check in btrfs_put_transaction()Xuanqiang Luo
Eric Dumazet removed the redundant refcount check for sk_refcnt, I noticed a similar issue in btrfs_put_transaction(). refcount_dec_and_test() already checks for a zero refcount and complains, making the preceding WARN_ON redundant. This is a leftover from the atomic_t times. Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from btrfs_zoned_activate_one_bg()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. 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>
2025-11-24btrfs: remove fs_info argument from btrfs_sysfs_add_space_info_type()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. 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>
2025-11-24btrfs: more trivial BTRFS_PATH_AUTO_FREE conversionsSun YangKai
Convert more of the trivial pattern for the auto freeing of btrfs_path with goto -> return conversions where applicable. Signed-off-by: Sun YangKai <sunk67188@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from btrfs_reserve_metadata_bytes()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from __reserve_bytes()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: fix parameter documentation for btrfs_reserve_data_bytes()Filipe Manana
We don't have a fs_info argument anymore since commit 5d39fda880be ("btrfs: pass btrfs_space_info to btrfs_reserve_data_bytes()"), it was replaced by a space_info argument. So update the documentation. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from maybe_clamp_preempt()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from handle_reserve_ticket()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from steal_from_global_rsv()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from need_preemptive_reclaim()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from btrfs_calc_reclaim_metadata_size()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from shrink_delalloc() and flush_space()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from btrfs_dump_space_info()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from btrfs_can_overcommit()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from calc_available_free_space()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from maybe_fail_all_tickets()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from priority_reclaim_metadata_space()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from priority_reclaim_data_space()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove fs_info argument from btrfs_try_granting_tickets()Filipe Manana
We don't need it since we can grab fs_info from the given space_info. So remove the fs_info argument. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: avoid repeated computations in btrfs_mark_ordered_io_finished()Filipe Manana
We're computing a few values several times: 1) The current ordered extent's end offset inside the while loop, we have computed it and stored it in the 'entry_end' variable but then we compute it again later as the first argument to the min() macro; 2) The end file offset, open coded 3 times; 3) The current length (stored in variable 'len') computed 2 times, one inside an assertion and the other when assigning to the 'len' variable. So use existing variables and add new ones to prevent repeating these expressions and reduce the source code. We were also subtracting one from the result of min() macro call and then adding 1 back in the next line, making both operations pointless. So just remove the decrement and increment by 1. This also reduces very slightly the object code. Before: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 1916576 161679 15592 2093847 1ff317 fs/btrfs/btrfs.ko After: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 1916556 161679 15592 2093827 1ff303 fs/btrfs/btrfs.ko Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: avoid multiple i_size rounding in btrfs_truncate()Filipe Manana
We have the inode locked so no one can concurrently change its i_size and neither do we change it ourselves, so there's no point in keep rounding it in the while loop and setting it up in the control structure. That only causes confusion when reading the code. So move all the i_size setup and rounding out of the loop and assert the inode is locked. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: consistently round up or down i_size in btrfs_truncate()Filipe Manana
We're using different ways to round down the i_size by sector size, one with a bitwise and with a negated mask and another with ALIGN_DOWN(), and using ALIGN() to round up. Replace these uses with the round_down() and round_up() macros which have have names that make it clear the direction of the rounding (unlike the ALIGN() macro) and getting rid of the bitwise and, negated mask and local variable for the mask. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: add unlikely to unexpected error case in extent_writepages()Filipe Manana
We don't expect to hit errors and log the error message, so add the unlikely annotation to make it clear and to hint the compiler that it may reorganize code to be more efficient. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: split assertion into two in extent_writepage_io()Filipe Manana
If the assertion fails we don't get to know which of the two expressions failed and neither the values used in each expression. So split the assertion into two, each for a single expression, so that if any is triggered we see a line number reported in a stack trace that points to which expression failed. Also make the assertions use the verbose mode to print the values involved in the computations. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: use variable for end offset in extent_writepage_io()Filipe Manana
Instead of repeating the expression "start + len" multiple times, store it in a variable and use it where needed. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: truncate ordered extent when skipping writeback past i_sizeFilipe Manana
While running test case btrfs/192 from fstests with support for large folios (needs CONFIG_BTRFS_EXPERIMENTAL=y) I ended up getting very sporadic btrfs check failures reporting that csum items were missing. Looking into the issue it turned out that btrfs check searches for csum items of a file extent item with a range that spans beyond the i_size of a file and we don't have any, because the kernel's writeback code skips submitting bios for ranges beyond eof. It's not expected however to find a file extent item that crosses the rounded up (by the sector size) i_size value, but there is a short time window where we can end up with a transaction commit leaving this small inconsistency between the i_size and the last file extent item. Example btrfs check output when this happens: $ btrfs check /dev/sdc Opening filesystem to check... Checking filesystem on /dev/sdc UUID: 69642c61-5efb-4367-aa31-cdfd4067f713 [1/8] checking log skipped (none written) [2/8] checking root items [3/8] checking extents [4/8] checking free space tree [5/8] checking fs roots root 5 inode 332 errors 1000, some csum missing ERROR: errors found in fs roots (...) Looking at a tree dump of the fs tree (root 5) for inode 332 we have: $ btrfs inspect-internal dump-tree -t 5 /dev/sdc (...) item 28 key (332 INODE_ITEM 0) itemoff 2006 itemsize 160 generation 17 transid 19 size 610969 nbytes 86016 block group 0 mode 100666 links 1 uid 0 gid 0 rdev 0 sequence 11 flags 0x0(none) atime 1759851068.391327881 (2025-10-07 16:31:08) ctime 1759851068.410098267 (2025-10-07 16:31:08) mtime 1759851068.410098267 (2025-10-07 16:31:08) otime 1759851068.391327881 (2025-10-07 16:31:08) item 29 key (332 INODE_REF 340) itemoff 1993 itemsize 13 index 2 namelen 3 name: f1f item 30 key (332 EXTENT_DATA 589824) itemoff 1940 itemsize 53 generation 19 type 1 (regular) extent data disk byte 21745664 nr 65536 extent data offset 0 nr 65536 ram 65536 extent compression 0 (none) (...) We can see that the file extent item for file offset 589824 has a length of 64K and its number of bytes is 64K. Looking at the inode item we see that its i_size is 610969 bytes which falls within the range of that file extent item [589824, 655360[. Looking into the csum tree: $ btrfs inspect-internal dump-tree /dev/sdc (...) item 15 key (EXTENT_CSUM EXTENT_CSUM 21565440) itemoff 991 itemsize 200 range start 21565440 end 21770240 length 204800 item 16 key (EXTENT_CSUM EXTENT_CSUM 1104576512) itemoff 983 itemsize 8 range start 1104576512 end 1104584704 length 8192 (..) We see that the csum item number 15 covers the first 24K of the file extent item - it ends at offset 21770240 and the extent's disk_bytenr is 21745664, so we have: 21770240 - 21745664 = 24K We see that the next csum item (number 16) is completely outside the range, so the remaining 40K of the extent doesn't have csum items in the tree. If we round up the i_size to the sector size, we get: round_up(610969, 4096) = 614400 If we subtract from that the file offset for the extent item we get: 614400 - 589824 = 24K So the missing 40K corresponds to the end of the file extent item's range minus the rounded up i_size: 655360 - 614400 = 40K Normally we don't expect a file extent item to span over the rounded up i_size of an inode, since when truncating, doing hole punching and other operations that trim a file extent item, the number of bytes is adjusted. There is however a short time window where the kernel can end up, temporarily,persisting an inode with an i_size that falls in the middle of the last file extent item and the file extent item was not yet trimmed (its number of bytes reduced so that it doesn't cross i_size rounded up by the sector size). The steps (in the kernel) that lead to such scenario are the following: 1) We have inode I as an empty file, no allocated extents, i_size is 0; 2) A buffered write is done for file range [589824, 655360[ (length of 64K) and the i_size is updated to 655360. Note that we got a single large folio for the range (64K); 3) A truncate operation starts that reduces the inode's i_size down to 610969 bytes. The truncate sets the inode's new i_size at btrfs_setsize() by calling truncate_setsize() and before calling btrfs_truncate(); 4) At btrfs_truncate() we trigger writeback for the range starting at 610304 (which is the new i_size rounded down to the sector size) and ending at (u64)-1; 5) During the writeback, at extent_write_cache_pages(), we get from the call to filemap_get_folios_tag(), the 64K folio that starts at file offset 589824 since it contains the start offset of the writeback range (610304); 6) At writepage_delalloc() we find the whole range of the folio is dirty and therefore we run delalloc for that 64K range ([589824, 655360[), reserving a 64K extent, creating an ordered extent, etc; 7) At extent_writepage_io() we submit IO only for subrange [589824, 614400[ because the inode's i_size is 610969 bytes (rounded up by sector size is 614400). There, in the while loop we intentionally skip IO beyond i_size to avoid any unnecessay work and just call btrfs_mark_ordered_io_finished() for the range [614400, 655360[ (which has a 40K length); 8) Once the IO finishes we finish the ordered extent by ending up at btrfs_finish_one_ordered(), join transaction N, insert a file extent item in the inode's subvolume tree for file offset 589824 with a number of bytes of 64K, and update the inode's delayed inode item or directly the inode item with a call to btrfs_update_inode_fallback(), which results in storing the new i_size of 610969 bytes; 9) Transaction N is committed either by the transaction kthread or some other task committed it (in response to a sync or fsync for example). At this point we have inode I persisted with an i_size of 610969 bytes and file extent item that starts at file offset 589824 and has a number of bytes of 64K, ending at an offset of 655360 which is beyond the i_size rounded up to the sector size (614400). --> So after a crash or power failure here, the btrfs check program reports that error about missing checksum items for this inode, as it tries to lookup for checksums covering the whole range of the extent; 10) Only after transaction N is committed that at btrfs_truncate() the call to btrfs_start_transaction() starts a new transaction, N + 1, instead of joining transaction N. And it's with transaction N + 1 that it calls btrfs_truncate_inode_items() which updates the file extent item at file offset 589824 to reduce its number of bytes from 64K down to 24K, so that the file extent item's range ends at the i_size rounded up to the sector size (614400 bytes). Fix this by truncating the ordered extent at extent_writepage_io() when we skip writeback because the current offset in the folio is beyond i_size. This ensures we don't ever persist a file extent item with a number of bytes beyond the rounded up (by sector size) value of the i_size. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Anand Jain <asj@kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: implement remove_bdev and shutdown super operation callbacksQu Wenruo
For the ->remove_bdev() callback, btrfs will: - Mark the target device as missing - Go degraded if the fs can afford it - Return error other wise Thus falls back to the shutdown callback For the ->shutdown callback, btrfs will: - Set the SHUTDOWN flag Which will reject all new incoming operations, and make all writeback to fail. The behavior is the same as the NOLOGFLUSH behavior. To support the lookup from bdev to a btrfs_device, btrfs_dev_lookup_args is enhanced to have a new @devt member. If set, we should be able to use that @devt member to uniquely locating a btrfs device. I know the shutdown can be a little overkilled, if one has a RAID1 metadata and RAID0 data, in that case one can still read data with 50% chance to got some good data. But a filesystem returning -EIO for half of the time is not really considered usable. Further it can also be as bad as the only device went missing for a single device btrfs. So here we go safe other than sorry when handling missing device. And the remove_bdev callback will be hidden behind experimental features for now, the reasons are: - There are not enough btrfs specific bdev removal test cases The existing test cases are all removing the only device, thus only exercises the ->shutdown() behavior. - Not yet determined what's the expected behavior Although the current auto-degrade behavior is no worse than the old behavior, it may not always be what the end users want. Before there is a concrete interface, better hide the new feature from end users. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Tested-by: Anand Jain <asj@kernel.org> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: implement shutdown ioctlQu Wenruo
The shutdown ioctl should follow the XFS one, which use magic number 'X', and ioctl number 125, with a uint32 as flags. For now btrfs don't distinguish DEFAULT and LOGFLUSH flags (just like f2fs), both will freeze the fs first (implies committing the current transaction), setting the SHUTDOWN flag and finally thaw the fs. For NOLOGFLUSH flag, the freeze/thaw part is skipped thus the current transaction is aborted. The new shutdown ioctl is hidden behind experimental features for more testing. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Tested-by: Anand Jain <asj@kernel.org> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: introduce a new shutdown stateQu Wenruo
A new fs state EMERGENCY_SHUTDOWN is introduced, which is btrfs' equivalent of XFS_IOC_GOINGDOWN or EXT4_IOC_SHUTDOWN, after entering emergency shutdown state, all operations will return errors (-EIO), and can not be bring back to normal state until unmouont. The new state will reject the following file operations: - read_iter() - write_iter() - mmap() - open() - remap_file_range() - uring_cmd() - splice_read() This requires a small wrapper to do the extra shutdown check, then call the regular filemap_splice_read() function This should reject most of the file operations on a shutdown btrfs. And for the existing dirty folios, extra shutdown checks are introduced to the following functions: - run_delalloc_nocow() - run_delalloc_compressed() - cow_file_range() So that dirty ranges will still be properly cleaned without being submitted. Finally the shutdown state will also set the fs error, so that no new transaction will be committed, protecting the metadata from any possible further corruption. And when the fs entered shutdown mode for the first time, a critical level kernel message will show up to indicate the incident. That message will be important for end users as rejected delalloc ranges will output error messages, hopefully that shutdown message and the fact that all fs operations are returning error will prevent end users from getting too confused about the delalloc error messages. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <asj@kernel.org> Tested-by: Anand Jain <asj@kernel.org> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: use end_pos variable where needed in btrfs_dirty_folio()Filipe Manana
We have a couple places doing the computation "pos + write_bytes" when we already have it in the local variable "end_pos". Change then to use the variable instead and make source code smaller. Also make the variable const since it's not supposed to change. This also has a very slight reduction in the module size. Before: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 1915990 161647 15592 2093229 1ff0ad fs/btrfs/btrfs.ko After: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 1915974 161647 15592 2093213 1ff09d fs/btrfs/btrfs.ko 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>
2025-11-24btrfs: fix racy bitfield write in btrfs_clear_space_info_full()Boris Burkov
From the memory-barriers.txt document regarding memory barrier ordering guarantees: (*) These guarantees do not apply to bitfields, because compilers often generate code to modify these using non-atomic read-modify-write sequences. Do not attempt to use bitfields to synchronize parallel algorithms. (*) Even in cases where bitfields are protected by locks, all fields in a given bitfield must be protected by one lock. If two fields in a given bitfield are protected by different locks, the compiler's non-atomic read-modify-write sequences can cause an update to one field to corrupt the value of an adjacent field. btrfs_space_info has a bitfield sharing an underlying word consisting of the fields full, chunk_alloc, and flush: struct btrfs_space_info { struct btrfs_fs_info * fs_info; /* 0 8 */ struct btrfs_space_info * parent; /* 8 8 */ ... int clamp; /* 172 4 */ unsigned int full:1; /* 176: 0 4 */ unsigned int chunk_alloc:1; /* 176: 1 4 */ unsigned int flush:1; /* 176: 2 4 */ ... Therefore, to be safe from parallel read-modify-writes losing a write to one of the bitfield members protected by a lock, all writes to all the bitfields must use the lock. They almost universally do, except for btrfs_clear_space_info_full() which iterates over the space_infos and writes out found->full = 0 without a lock. Imagine that we have one thread completing a transaction in which we finished deleting a block_group and are thus calling btrfs_clear_space_info_full() while simultaneously the data reclaim ticket infrastructure is running do_async_reclaim_data_space(): T1 T2 btrfs_commit_transaction btrfs_clear_space_info_full data_sinfo->full = 0 READ: full:0, chunk_alloc:0, flush:1 do_async_reclaim_data_space(data_sinfo) spin_lock(&space_info->lock); if(list_empty(tickets)) space_info->flush = 0; READ: full: 0, chunk_alloc:0, flush:1 MOD/WRITE: full: 0, chunk_alloc:0, flush:0 spin_unlock(&space_info->lock); return; MOD/WRITE: full:0, chunk_alloc:0, flush:1 and now data_sinfo->flush is 1 but the reclaim worker has exited. This breaks the invariant that flush is 0 iff there is no work queued or running. Once this invariant is violated, future allocations that go into __reserve_bytes() will add tickets to space_info->tickets but will see space_info->flush is set to 1 and not queue the work. After this, they will block forever on the resulting ticket, as it is now impossible to kick the worker again. I also confirmed by looking at the assembly of the affected kernel that it is doing RMW operations. For example, to set the flush (3rd) bit to 0, the assembly is: andb $0xfb,0x60(%rbx) and similarly for setting the full (1st) bit to 0: andb $0xfe,-0x20(%rax) So I think this is really a bug on practical systems. I have observed a number of systems in this exact state, but am currently unable to reproduce it. Rather than leaving this footgun lying around for the future, take advantage of the fact that there is room in the struct anyway, and that it is already quite large and simply change the three bitfield members to bools. This avoids writes to space_info->full having any effect on writes to space_info->flush, regardless of locking. Fixes: 957780eb2788 ("Btrfs: introduce ticketed enospc infrastructure") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: fix comment in alloc_bitmap() and drop stale TODORajeev Tapadia
All callers of alloc_bitmap() hold a transaction handle, so GFP_NOFS is needed to avoid deadlocks on recursion. Update the comment and drop the stale TODO. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Rajeev Tapadia <rtapadia730@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: fix double free of qgroup record after failure to add delayed ref headMiquel Sabaté Solà
In the previous code it was possible to incur into a double kfree() scenario when calling add_delayed_ref_head(). This could happen if the record was reported to already exist in the btrfs_qgroup_trace_extent_nolock() call, but then there was an error later on add_delayed_ref_head(). In this case, since add_delayed_ref_head() returned an error, the caller went to free the record. Since add_delayed_ref_head() couldn't set this kfree'd pointer to NULL, then kfree() would have acted on a non-NULL 'record' object which was pointing to memory already freed by the callee. The problem comes from the fact that the responsibility to kfree the object is on both the caller and the callee at the same time. Hence, the fix for this is to shift the ownership of the 'qrecord' object out of the add_delayed_ref_head(). That is, we will never attempt to kfree() the given object inside of this function, and will expect the caller to act on the 'qrecord' object on its own. The only exception where the 'qrecord' object cannot be kfree'd is if it was inserted into the tracing logic, for which we already have the 'qrecord_inserted_ret' boolean to account for this. Hence, the caller has to kfree the object only if add_delayed_ref_head() reports not to have inserted it on the tracing logic. As a side-effect of the above, we must guarantee that 'qrecord_inserted_ret' is properly initialized at the start of the function, not at the end, and then set when an actual insert happens. This way we avoid 'qrecord_inserted_ret' having an invalid value on an early exit. The documentation from the add_delayed_ref_head() has also been updated to reflect on the exact ownership of the 'qrecord' object. Fixes: 6ef8fbce0104 ("btrfs: fix missing error handling when adding delayed ref with qgroups enabled") Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: subpage: rename macro variables to avoid shadowingDavid Sterba
When compiling with -Wshadow there are warnings in the subpage helper macros that are used in functions like btrfs_subpage_dump_bitmap() or btrfs_subpage_clear_and_test_dirty() that also use 'bfs' (for struct btrfs_folio_state) or blocks_per_folio. Add '__' to the macro variables and unify naming in all subpage macros. Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: refactor allocation size calculation in alloc_btrfs_io_context()Mehdi Ben Hadj Khelifa
Use struct_size() to replace the open-coded calculation, remove the comment as use of the helper is self explanatory. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: fix trivial -Wshadow warningsDavid Sterba
When compiling with -Wshadow (also in 'make W=2' build) there are several reports of shadowed variables that seem to be harmless: - btrfs_do_encoded_write() - we can reuse 'ordered', there's no previous value that would need to be preserved - scrub_write_endio() - we need a standalone 'i' for bio iteration - scrub_stripe() - duplicate ret2 for errors that must not overwrite 'ret' - btrfs_subpage_set_writeback() - 'flags' is used for another irqsave lock but is not overwritten when reused for xarray due to scoping, but for clarity let's rename it - process_dir_items_leaf() - duplicate 'ret', used only for immediate checks Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: print-tree: use string format for key namesDavid Sterba
There's a warning when -Wformat=2 is used: fs/btrfs/print-tree.c: In function ‘key_type_string’: fs/btrfs/print-tree.c:424:17: warning: format not a string literal and no format arguments [-Wformat-nonliteral] 424 | scnprintf(buf, buf_size, key_to_str[key->type]); We're printing fixed strings from a table so there's no problem but let's fix the warning so we could enable the warning in fs/btrfs/. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: remove unnecessary NULL fs_info check from find_lock_delalloc_range()Qu Wenruo
[STATIC CHECK REPORT] Smatch is reporting that find_lock_delalloc_range() used to do a null pointer check before accessing fs_info, but now we're accessing it for sectorsize unconditionally. [FALSE ALERT] This is a false alert, the existing null pointer check is introduced in commit f7b12a62f008 ("btrfs: replace BTRFS_MAX_EXTENT_SIZE with fs_info->max_extent_size"), but way before that, commit 7c0260ee098d ("btrfs: tests, require fs_info for root") is already forcing every btrfs_root to have a correct fs_info pointer. So there is no way that btrfs_root::fs_info is NULL. [FIX] Just remove the unnecessary NULL pointer checker. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Fixes: f7b12a62f008 ("btrfs: replace BTRFS_MAX_EXTENT_SIZE with fs_info->max_extent_size") Closes: https://lore.kernel.org/r/202509250925.4L4JQTtn-lkp@intel.com/ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24btrfs: use single return value variable in btrfs_relocate_block_group()Filipe Manana
We are using 'ret' and 'err' variables to track return values and errors, which is pattern that is error prone and we had quite some bugs due to this pattern in the past. Simplify this and use a single variable, named 'ret', to track errors and the return value. Also rename the variable 'rw' to 'bg_is_ro' which is more meaningful name, and change its type from int to bool. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.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>
2025-11-24xfs: move some code out of xfs_iget_recycleChristoph Hellwig
Having a function drop locks, reacquire them and release them again seems to confuse the clang lock analysis even more than it confuses humans. Keep the humans and machines sanity by moving a chunk of code into the caller to simplify the lock tracking. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-11-24btrfs: ignore ENOMEM from alloc_bitmap()Boris Burkov
btrfs_convert_free_space_to_bitmaps() and btrfs_convert_free_space_to_extents() both allocate a bitmap struct with: bitmap_size = free_space_bitmap_size(fs_info, block_group->length); bitmap = alloc_bitmap(bitmap_size); if (!bitmap) { ret = -ENOMEM; btrfs_abort_transaction(trans); return ret; } This conversion is done based on a heuristic and the check triggers each time we call update_free_space_extent_count() on a block group (each time we add/remove an extent or modify a bitmap). Furthermore, nothing relies on maintaining some invariant of bitmap density, it's just an optimization for space usage. Therefore, it is safe to simply ignore any memory allocation errors that occur, rather than aborting the transaction and leaving the fs read only. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24erofs: limit the level of fs stacking for file-backed mountsGao Xiang
Otherwise, it could cause potential kernel stack overflow (e.g., EROFS mounting itself). Reviewed-by: Sheng Yong <shengyong1@xiaomi.com> Fixes: fb176750266a ("erofs: add file-backed mount support") Reviewed-by: Chao Yu <chao@kernel.org> Reviewed-by: Hongbo Li <lihongbo22@huawei.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2025-11-24erofs: correct FSDAX detectionGao Xiang
The detection of the primary device is skipped incorrectly if the multiple or flattened feature is enabled. It also fixes the FSDAX misdetection for non-block extra blobs. Fixes: c6993c4cb918 ("erofs: Fallback to normal access if DAX is not supported on extra device") Reported-and-tested-by: syzbot+31b8fb02cb8a25bd5e78@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/691af9f6.a70a0220.3124cb.0097.GAE@google.com Cc: Yuezhang Mo <Yuezhang.Mo@sony.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2025-11-23NFS: Add a module option to disable directory delegationsAnna Schumaker
When this option is disabled then the client will not request directory delegations or check if we have one during the revalidation paths. Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2025-11-23NFS: Shortcut lookup revalidations if we have a directory delegationAnna Schumaker
Holding a directory delegation means we know that nobody else has modified the directory on the server, so we can take a few revalidation shortcuts. Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2025-11-23NFS: Request a directory delegation during RENAMEAnna Schumaker
If we notice that we're renaming a file within a directory then we take that as a sign that the user is working with the current directory and may want a delegation to avoid extra revalidations when possible. The nfs_request_directory_delegation() function exists within the NFS v4 module, so I add an extra flag to rename_setup() to indicate if a dentry is being renamed within the same parent directory. Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>