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2024-11-11btrfs: drop unused parameter path from btrfs_tree_mod_log_rewind()David Sterba
The path parameter was used for our own locking, that got converted to rwsem eventually. Last usage in ac5887c8e013d6 ("btrfs: locking: remove all the blocking helpers"). Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: zstd: assert the timer pointer in callbackDavid Sterba
Make sure we got the right timer struct for the zstd workspace reclaim work. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove btrfs_set_range_writeback()Qu Wenruo
The function btrfs_set_range_writeback() was originally a callback for metadata and data, to mark a range with writeback flag. Then it was converted into a common function call for both metadata and data. From the very beginning, the function had been only called on a full page, later converted to handle range inside a page. But it never needed to handle multiple pages, and since commit 8189197425e7 ("btrfs: refactor __extent_writepage_io() to do sector-by-sector submission") the function was only called on a sector-by-sector basis. This makes the function unnecessary, and can be converted to a simple btrfs_folio_set_writeback() call instead. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: qgroup: run delayed iputs after ordered extent completionFilipe Manana
When trying to flush qgroups in order to release space we run delayed iputs in order to release space from recently deleted files (their link counted reached zero), and then we start delalloc and wait for any existing ordered extents to complete. However there's a time window here where we end up not doing the final iput on a deleted file which could release necessary space: 1) An unlink operation starts; 2) During the unlink, or right before it completes, delalloc is flushed and an ordered extent is created; 3) When the ordered extent is created, the inode's ref count is incremented (with igrab() at alloc_ordered_extent()); 4) When the unlink finishes it doesn't drop the last reference on the inode and so it doesn't trigger inode eviction to delete all of the inode's items in its root and drop all references on its data extents; 5) Another task enters try_flush_qgroup() to try to release space, it runs all delayed iputs, but there's no delayed iput yet for that deleted file because the ordered extent hasn't completed yet; 6) Then at try_flush_qgroup() we wait for the ordered extent to complete and that results in adding a delayed iput at btrfs_put_ordered_extent() when called from btrfs_finish_one_ordered(); 7) Adding the delayed iput results in waking the cleaner kthread if it's not running already. However it may take some time for it to be scheduled, or it may be running but busy running auto defrag, dropping deleted snapshots or doing other work, so by the time we return from try_flush_qgroup() the space for deleted file isn't released. Improve on this by running delayed iputs only after flushing delalloc and waiting for ordered extent completion. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: scrub: skip initial RST lookup errorsJohannes Thumshirn
Performing the initial extent sector read on a RAID stripe-tree backed filesystem with pre-allocated extents will cause the RAID stripe-tree lookup code to return ENODATA, as pre-allocated extents do not have any on-disk bytes and thus no RAID stripe-tree entries. But the current scrub read code marks these extents as errors, because the lookup fails. If btrfs_map_block() returns -ENODATA, it means that the call to btrfs_get_raid_extent_offset() returned -ENODATA, because there is no entry for the corresponding range in the RAID stripe-tree. But as this range is in the extent tree it means we've hit a pre-allocated extent. In this case, don't mark the sector in the stripe's error bitmaps as faulty and carry on to the next. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: return ENODATA in case RST lookup failsJohannes Thumshirn
In case a lookup in the RAID stripe-tree fails, return ENODATA instead of ENOENT to better distinguish stripe-tree lookups from other code paths where we return ENOENT. Suggested-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: handle empty list of NOCOW ordered extents with checksum listJohannes Thumshirn
Currently we BUG_ON() in btrfs_finish_one_ordered() if we are finishing an ordered extent that is flagged as NOCOW, but it's checksum list is not empty. This is clearly a logic error which we can recover from by aborting the transaction. For developer builds which enable CONFIG_BTRFS_ASSERT, also ASSERT() that the list is empty. Suggested-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: simplify the page uptodate preparation for prepare_pages()Qu Wenruo
Currently inside prepare_pages(), we handle the leading and tailing page differently, and skip the middle pages (if any). This is to avoid reading pages which are fully covered by the dirty range. Refactor the code by moving all checks (alignment check, range check, force read check) into prepare_uptodate_page(). So that prepare_pages() only needs to iterate all the pages unconditionally. And since we're here, also update prepare_uptodate_page() to use folio API other than the old page API. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove the dirty_page local variableQu Wenruo
Inside btrfs_buffered_write(), we have a local variable @dirty_pages, recording the number of pages we dirtied in the current iteration. However we do not really need that variable, since it can be calculated from @pos and @copied. In fact there is already a problem inside the short copy path, where we use @dirty_pages to calculate the range we need to release. But that usage assumes sectorsize == PAGE_SIZE, which is no longer true. Instead of keeping @dirty_pages and cause incorrect usage, just calculate the number of dirtied pages inside btrfs_dirty_pages(). Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove unused btrfs_try_tree_write_lock()Dr. David Alan Gilbert
btrfs_try_tree_write_lock() has been unused since commit 50b21d7a066f ("btrfs: submit a writeback bio per extent_buffer"). Remove it as we don't need it anymore. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove unused btrfs_is_parity_mirror()Dr. David Alan Gilbert
btrfs_is_parity_mirror() has been unused since commit 4886ff7b50f6 ("btrfs: introduce a new helper to submit write bio for repair"). Remove it as the code was refactored and we don't need the helper anymore. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove unused btrfs_free_squota_rsv()Dr. David Alan Gilbert
btrfs_free_squota_rsv() was added in commit e85a0adacf17 ("btrfs: ensure releasing squota reserve on head refs") but has remained unused since then. Remove it as we don't seem to need it and was probably a leftover. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: tests: add selftests for raid-stripe-treeJohannes Thumshirn
Add first stash of very basic self tests for the RAID stripe-tree. More test cases will follow exercising the tree. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: correct typos in multiple comments across various filesShen Lichuan
Fix some confusing spelling errors that were currently identified, the details are as follows: block-group.c: 2800: uncompressible ==> incompressible extent-tree.c: 3131: EXTEMT ==> EXTENT extent_io.c: 3124: utlizing ==> utilizing extent_map.c: 1323: ealier ==> earlier extent_map.c: 1325: possiblity ==> possibility fiemap.c: 189: emmitted ==> emitted fiemap.c: 197: emmitted ==> emitted fiemap.c: 203: emmitted ==> emitted transaction.h: 36: trasaction ==> transaction volumes.c: 5312: filesysmte ==> filesystem zoned.c: 1977: trasnsaction ==> transaction Signed-off-by: Shen Lichuan <shenlichuan@vivo.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove unused page_to_inode and page_to_fs_info macrosYouling Tang
This macro is no longer used after the "btrfs: Cleaned up folio->page conversion" series patch [1] was applied, so remove it. [1]: https://patchwork.kernel.org/project/linux-btrfs/cover/20240828182908.3735344-1-lizetao1@huawei.com/ Reviewed-by: Neal Gompa <neal@gompa.dev> Signed-off-by: Youling Tang <tangyouling@kylinos.cn> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove redundant stop_loop variable in scrub_stripe()Riyan Dhiman
The variable stop_loop was originally introduced in commit 625f1c8dc66d7 ("Btrfs: improve the loop of scrub_stripe"). It was initialized to 0 in commit 3b080b2564287 ("Btrfs: scrub raid56 stripes in the right way"). However, in a later commit 18d30ab961497 ("btrfs: scrub: use scrub_simple_mirror() to handle RAID56 data stripe scrub"), the code that modified stop_loop was removed, making the variable redundant. Currently, stop_loop is only initialized with 0 and is never used or modified within the scrub_stripe() function. As a result, this patch removes the stop_loop variable to clean up the code and eliminate unnecessary redundancy. This change has no impact on functionality, as stop_loop was never utilized in any meaningful way in the final version of the code. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Riyan Dhiman <riyandhiman14@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: remove pointless initialization at btrfs_qgroup_trace_extent()Filipe Manana
The qgroup record was allocated with kzalloc(), so it's pointless to set its old_roots member to NULL. Remove the assignment. 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>
2024-11-11btrfs: always use delayed_refs local variable at btrfs_qgroup_trace_extent()Filipe Manana
Instead of dereferencing the delayed refs from the transaction multiple times, store it early in the local variable and then always use the variable. 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>
2024-11-11btrfs: remove unnecessary delayed refs locking at btrfs_qgroup_trace_extent()Filipe Manana
There's no need to hold the delayed refs spinlock when calling btrfs_qgroup_trace_extent_nolock() from btrfs_qgroup_trace_extent(), since it doesn't change anything in delayed refs and it only changes the xarray used to track qgroup extent records, which is protected by the xarray's lock. Holding the lock is only adding unnecessary lock contention with other tasks that actually need to take the lock to add/remove/change delayed references. So remove the locking. 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>
2024-11-11btrfs: store fs_info in a local variable at btrfs_qgroup_trace_extent_post()Filipe Manana
Instead of extracting fs_info from the transaction multiples times, store it in a local variable and use it. 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>
2024-11-11btrfs: qgroups: remove bytenr field from struct btrfs_qgroup_extent_recordFilipe Manana
Now that we track qgroup extent records in a xarray we don't need to have a "bytenr" field in struct btrfs_qgroup_extent_record, since we can get it from the index of the record in the xarray. So remove the field and grab the bytenr from either the index key or any other place where it's available (delayed refs). This reduces the size of struct btrfs_qgroup_extent_record from 40 bytes down to 32 bytes, meaning that we now can store 128 instances of this structure instead of 102 per 4K page. 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>
2024-11-11btrfs: remove code duplication in ordered extent finishingJohannes Thumshirn
Remove the duplicated transaction joining, block reserve setting and raid extent inserting in btrfs_finish_ordered_extent(). While at it, also abort the transaction in case inserting a RAID stripe-tree entry fails. Suggested-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: canonicalize the device path before adding itQu Wenruo
[PROBLEM] Currently btrfs accepts any file path for its device, resulting some weird situation: # ./mount_by_fd /dev/test/scratch1 /mnt/btrfs/ The program has the following source code: #include <fcntl.h> #include <stdio.h> #include <sys/mount.h> int main(int argc, char *argv[]) { int fd = open(argv[1], O_RDWR); char path[256]; snprintf(path, sizeof(path), "/proc/self/fd/%d", fd); return mount(path, argv[2], "btrfs", 0, NULL); } Then we can have the following weird device path: BTRFS: device fsid 2378be81-fe12-46d2-a9e8-68cf08dd98d5 devid 1 transid 7 /proc/self/fd/3 (253:2) scanned by mount_by_fd (18440) Normally it's not a big deal, and later udev can trigger a device path rename. But if udev didn't trigger, the device path "/proc/self/fd/3" will show up in mtab. [CAUSE] For filename "/proc/self/fd/3", it means the opened file descriptor 3. In above case, it's exactly the device we want to open, aka points to "/dev/test/scratch1" which is another symlink pointing to "/dev/dm-2". Inside kernel we solve the mount source using LOOKUP_FOLLOW, which follows the symbolic link and grab the proper block device. But inside btrfs we also save the filename into btrfs_device::name, and utilize that member to report our mount source, which leads to the above situation. [FIX] Instead of unconditionally trust the path, check if the original file (not following the symbolic link) is inside "/dev/", if not, then manually lookup the path to its final destination, and use that as our device path. This allows us to still use symbolic links, like "/dev/mapper/test-scratch" from LVM2, which is required for fstests runs with LVM2 setup. And for really weird names, like the above case, we solve it to "/dev/dm-2" instead. Reviewed-by: Filipe Manana <fdmanana@suse.com> Link: https://bugzilla.suse.com/show_bug.cgi?id=1230641 Reported-by: Fabian Vogt <fvogt@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: avoid unnecessary device path update for the same deviceQu Wenruo
[PROBLEM] It is very common for udev to trigger device scan, and every time a mounted btrfs device got re-scan from different soft links, we will get some of unnecessary device path updates, this is especially common for LVM based storage: # lvs scratch1 test -wi-ao---- 10.00g scratch2 test -wi-a----- 10.00g scratch3 test -wi-a----- 10.00g scratch4 test -wi-a----- 10.00g scratch5 test -wi-a----- 10.00g test test -wi-a----- 10.00g # mkfs.btrfs -f /dev/test/scratch1 # mount /dev/test/scratch1 /mnt/btrfs # dmesg -c [ 205.705234] BTRFS: device fsid 7be2602f-9e35-4ecf-a6ff-9e91d2c182c9 devid 1 transid 6 /dev/mapper/test-scratch1 (253:4) scanned by mount (1154) [ 205.710864] BTRFS info (device dm-4): first mount of filesystem 7be2602f-9e35-4ecf-a6ff-9e91d2c182c9 [ 205.711923] BTRFS info (device dm-4): using crc32c (crc32c-intel) checksum algorithm [ 205.713856] BTRFS info (device dm-4): using free-space-tree [ 205.722324] BTRFS info (device dm-4): checking UUID tree So far so good, but even if we just touched any soft link of "dm-4", we will get quite some unnecessary device path updates. # touch /dev/mapper/test-scratch1 # dmesg -c [ 469.295796] BTRFS info: devid 1 device path /dev/mapper/test-scratch1 changed to /dev/dm-4 scanned by (udev-worker) (1221) [ 469.300494] BTRFS info: devid 1 device path /dev/dm-4 changed to /dev/mapper/test-scratch1 scanned by (udev-worker) (1221) Such device path rename is unnecessary and can lead to random path change due to the udev race. [CAUSE] Inside device_list_add(), we are using a very primitive way checking if the device has changed, strcmp(). Which can never handle links well, no matter if it's hard or soft links. So every different link of the same device will be treated as a different device, causing the unnecessary device path update. [FIX] Introduce a helper, is_same_device(), and use path_equal() to properly detect the same block device. So that the different soft links won't trigger the rename race. Reviewed-by: Filipe Manana <fdmanana@suse.com> Link: https://bugzilla.suse.com/show_bug.cgi?id=1230641 Reported-by: Fabian Vogt <fvogt@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: allow compression even if the range is not page alignedQu Wenruo
Previously for btrfs with sector size smaller than page size (subpage), we only allow compression if the range is fully page aligned. This is to work around the asynchronous submission of compressed range, which delayed the page unlock and writeback into a workqueue, furthermore asynchronous submission can lock multiple sector range across page boundary. Such asynchronous submission makes it very hard to co-operate with other regular writes. With the recent changes to the subpage folio unlock path, now asynchronous submission of compressed pages can co-operate with regular submission, so enable sector perfect compression if it's an experimental build. The ETA for moving this feature out of experimental is 6.15, and I hope all remaining corner cases can be exposed before that. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: mark all dirty sectors as locked inside writepage_delalloc()Qu Wenruo
Currently we only mark sectors as locked if there is a *NEW* delalloc range for it. But NEW delalloc range is not the same as dirty sectors we want to submit, e.g: 0 32K 64K 96K 128K | |////////||///////| |////| 120K For above 64K page size case, writepage_delalloc() for page 0 will find and lock the delalloc range [32K, 96K), which is beyond the page boundary. Then when writepage_delalloc() is called for the page 64K, since [64K, 96K) is already locked, only [120K, 128K) will be locked. This means, although range [64K, 96K) is dirty and will be submitted later by extent_writepage_io(), it will not be marked as locked. This is fine for now, as we call btrfs_folio_end_writer_lock_bitmap() to free every non-compressed sector, and compression is only allowed for full page range. But this is not safe for future sector perfect compression support, as this can lead to double folio unlock: Thread A | Thread B ---------------------------------------+-------------------------------- | submit_one_async_extent() | |- extent_clear_unlock_delalloc() extent_writepage() | |- btrfs_folio_end_writer_lock() |- btrfs_folio_end_writer_lock_bitmap()| |- btrfs_subpage_end_and_test_writer() | | | |- atomic_sub_and_test() | | | /* Now the atomic value is 0 */ |- if (atomic_read() == 0) | | |- folio_unlock() | |- folio_unlock() The root cause is the above range [64K, 96K) is dirtied and should also be locked but it isn't. So to make everything more consistent and prepare for the incoming sector perfect compression, mark all dirty sectors as locked. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: move the delalloc range bitmap search into extent_io.cQu Wenruo
Currently for subpage (sector size < page size) cases, we reuse subpage locked bitmap to find out all delalloc ranges we have locked, and run all those found ranges. However such reuse is not perfect, e.g.: 0 32K 64K 96K 128K | |////////||///////| |////| 120K For above range, writepage_delalloc() for page 0 will handle the range [32K, 96k), note delalloc range can be beyond the page boundary. But writepage_delalloc() for page 64K will only handle range [120K, 128K), as the previous run on page 0 has already handled range [64K, 96K). Meanwhile for the writeback we should expect range [64K, 96K) to also be locked, this leads to the mismatch from locked bitmap and delalloc range. This is not causing problems yet, but it's still an inconsistent behavior. So instead of relying on the subpage locked bitmap, move the delalloc range search using local @delalloc_bitmap, so that we can remove the existing btrfs_folio_find_writer_locked(). Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: do not assume the full page range is not dirty in extent_writepage_io()Qu Wenruo
The function extent_writepage_io() will submit the dirty sectors inside the page for the write. But recently to co-operate with the incoming subpage compression enhancement, a new bitmap is introduced to btrfs_bio_ctrl::submit_bitmap, to only avoid a subset of the dirty range. This is because we can have the following cases with 64K page size: 0 16K 32K 48K 64K | |/////////| |/| 52K For range [16K, 32K), we queue the dirty range for compression, which is ran in a delayed workqueue. Then for range [48K, 52K), we go through the regular submission path. In that case, our btrfs_bio_ctrl::submit_bitmap will exclude the range [16K, 32K). The dirty flags for the range [16K, 32K) is only cleared when the compression is done, by the extent_clear_unlock_delalloc() call inside submit_one_async_extent(). This patch fix the false alert by removing the btrfs_folio_assert_not_dirty() check, since it's no longer correct for subpage compression cases. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: make extent_range_clear_dirty_for_io() to handle sector size < page ↵Qu Wenruo
size cases For btrfs with sector size < page size (e.g. 4K sector size, 64K page size), and enable the sector perfect compression support, then the following dirty range can lead to problems: 0 32K 64K 96K 128K | |///////||//////| |/| 124K In above case, if we start writeback for that inode, the last dirty range [124K, 128K) will not be submitted and cause reserved space leakage: - Start writeback for page 0 We find the range [32K, 96K) is suitable for compression, and queue it into a workqueue to do the delayed compression and submission. - Compression happens for range [32K, 96K) Function extent_range_clear_dirty_for_io() is called, however it is only doing full page handling, not considering any the extra bitmaps for subpage cases. That function will clear page dirty for both page 0 and page 64K. - Writeback for the inode is done Because page 64K has its dirty flag cleared, it will not be considered as a writeback target. This means the range [124K, 128K) will not be submitted, and reserved space for it will be leaked. Fix this problem by using the subpage helper to clear the dirty flag. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: wait for writeback if sector size is smaller than page sizeQu Wenruo
[PROBLEM] If sector perfect compression is enabled for sector size < page size case, the following case can lead dirty ranges not being written back: 0 32K 64K 96K 128K | |///////||//////| |/| 124K In above example, the page size is 64K, and we need to write back above two pages. - Submit for page 0 (main thread) We found delalloc range [32K, 96K), which can be compressed. So we queue an async range for [32K, 96K). This means, the page unlock/clearing dirty/setting writeback will all happen in a workqueue context. - The compression is done, and compressed range is submitted (workqueue) Since the compression is done in asynchronously, the compression can be done before the main thread to submit for page 64K. Now the whole range [32K, 96K), involving two pages, will be marked writeback. - Submit for page 64K (main thread) extent_write_cache_pages() got its wbc->sync_mode is WB_SYNC_NONE, so it skips the writeback wait. And unlock the page and exit. This means the dirty range [124K, 128K) will never be submitted, until next writeback happens for page 64K. This will never happen for previous kernels because: - For sector size == page size case Since one page is one sector, if a page is marked writeback it will not have dirty flags. So this corner case will never hit. - For sector size < page size case We never do subpage compression, a range can only be submitted for compression if the range is fully page aligned. This change makes the subpage behavior mostly the same as non-subpage cases. [ENHANCEMENT] Instead of relying WB_SYNC_NONE check only, if it's a subpage case, then always wait for writeback flags. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: compression: add an ASSERT() to ensure the read-in length is saneQu Wenruo
There are already two bugs (one in zlib, one in zstd) that involved compression path is not handling sector size < page size cases well. So it makes more sense to make sure that btrfs_compress_folios() returns Since we already have two bugs (one in zlib, one in zstd) in the compression path resulting the @total_in be to larger than the to-be-compressed range length, there is enough reason to add an ASSERT() to make sure the total read-in length doesn't exceed the input length. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: zstd: make the compression path to handle sector size < page sizeQu Wenruo
Inside zstd_compress_folios(), after exhausted one input page, we need to switch to the next page as input. However when counting the total input bytes (@tot_in), we always increase it by PAGE_SIZE. For the following case, it can cause incorrect value: 0 32K 64K 96K | |///////////||///////////| After compressing range [32K, 64K), we switch to the next page, and increasing @tot_in by 64K, while we only read 32K. This will cause the @total_in to return a value larger than the input length. Fix it by only increase @tot_in by the input size. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: zlib: make the compression path to handle sector size < page sizeQu Wenruo
Inside zlib_compress_folios(), each time we switch the input page cache, the @start is increased by PAGE_SIZE. But for the incoming compression support for sector size < page size (previously we support compression only when the range is fully page aligned), this is not going to handle the following case: 0 32K 64K 96K | |///////////||///////////| @start has the initial value 32K, indicating the start filepos of the to-be-compressed range. And when grabbing the first page as input, we always call "start += PAGE_SIZE;". But since @start is starting at 32K, it will be increased by 64K, resulting it to be 96K for the next range, causing incorrect input range and corruption for the future subpage compression. Fix it by only increase @start by the input size. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: split out CONFIG_BTRFS_EXPERIMENTAL from CONFIG_BTRFS_DEBUGQu Wenruo
Currently CONFIG_BTRFS_EXPERIMENTAL is not only for the extra debugging output, but also for experimental features. This is not ideal to distinguish planned but not yet stable features from those purely designed for debugging. This patch splits the following features into CONFIG_BTRFS_EXPERIMENTAL: - Extent map shrinker This seems to be the first one to exit experimental. - Extent tree v2 This seems to be the last one to graduate from experimental. - Raid stripe tree - Csum offload mode - Send protocol v3 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>
2024-11-11btrfs: make assert_rbio() to only check CONFIG_BTRFS_ASSERTQu Wenruo
According to the description, CONFIG_BTRFS_DEBUG is only for extra debug info, meanwhile sanity checks should be managed by CONFIG_BTRFS_ASSERT. There is no need to check both to enable assert_rbio(). Just remove the check for CONFIG_BTRFS_DEBUG. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: don't take dev_replace rwsem on task already holding itJohannes Thumshirn
Running fstests btrfs/011 with MKFS_OPTIONS="-O rst" to force the usage of the RAID stripe-tree, we get the following splat from lockdep: BTRFS info (device sdd): dev_replace from /dev/sdd (devid 1) to /dev/sdb started ============================================ WARNING: possible recursive locking detected 6.11.0-rc3-btrfs-for-next #599 Not tainted -------------------------------------------- btrfs/2326 is trying to acquire lock: ffff88810f215c98 (&fs_info->dev_replace.rwsem){++++}-{3:3}, at: btrfs_map_block+0x39f/0x2250 but task is already holding lock: ffff88810f215c98 (&fs_info->dev_replace.rwsem){++++}-{3:3}, at: btrfs_map_block+0x39f/0x2250 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&fs_info->dev_replace.rwsem); lock(&fs_info->dev_replace.rwsem); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by btrfs/2326: #0: ffff88810f215c98 (&fs_info->dev_replace.rwsem){++++}-{3:3}, at: btrfs_map_block+0x39f/0x2250 stack backtrace: CPU: 1 UID: 0 PID: 2326 Comm: btrfs Not tainted 6.11.0-rc3-btrfs-for-next #599 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl+0x5b/0x80 __lock_acquire+0x2798/0x69d0 ? __pfx___lock_acquire+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 lock_acquire+0x19d/0x4a0 ? btrfs_map_block+0x39f/0x2250 ? __pfx_lock_acquire+0x10/0x10 ? find_held_lock+0x2d/0x110 ? lock_is_held_type+0x8f/0x100 down_read+0x8e/0x440 ? btrfs_map_block+0x39f/0x2250 ? __pfx_down_read+0x10/0x10 ? do_raw_read_unlock+0x44/0x70 ? _raw_read_unlock+0x23/0x40 btrfs_map_block+0x39f/0x2250 ? btrfs_dev_replace_by_ioctl+0xd69/0x1d00 ? btrfs_bio_counter_inc_blocked+0xd9/0x2e0 ? __kasan_slab_alloc+0x6e/0x70 ? __pfx_btrfs_map_block+0x10/0x10 ? __pfx_btrfs_bio_counter_inc_blocked+0x10/0x10 ? kmem_cache_alloc_noprof+0x1f2/0x300 ? mempool_alloc_noprof+0xed/0x2b0 btrfs_submit_chunk+0x28d/0x17e0 ? __pfx_btrfs_submit_chunk+0x10/0x10 ? bvec_alloc+0xd7/0x1b0 ? bio_add_folio+0x171/0x270 ? __pfx_bio_add_folio+0x10/0x10 ? __kasan_check_read+0x20/0x20 btrfs_submit_bio+0x37/0x80 read_extent_buffer_pages+0x3df/0x6c0 btrfs_read_extent_buffer+0x13e/0x5f0 read_tree_block+0x81/0xe0 read_block_for_search+0x4bd/0x7a0 ? __pfx_read_block_for_search+0x10/0x10 btrfs_search_slot+0x78d/0x2720 ? __pfx_btrfs_search_slot+0x10/0x10 ? lock_is_held_type+0x8f/0x100 ? kasan_save_track+0x14/0x30 ? __kasan_slab_alloc+0x6e/0x70 ? kmem_cache_alloc_noprof+0x1f2/0x300 btrfs_get_raid_extent_offset+0x181/0x820 ? __pfx_lock_acquire+0x10/0x10 ? __pfx_btrfs_get_raid_extent_offset+0x10/0x10 ? down_read+0x194/0x440 ? __pfx_down_read+0x10/0x10 ? do_raw_read_unlock+0x44/0x70 ? _raw_read_unlock+0x23/0x40 btrfs_map_block+0x5b5/0x2250 ? __pfx_btrfs_map_block+0x10/0x10 scrub_submit_initial_read+0x8fe/0x11b0 ? __pfx_scrub_submit_initial_read+0x10/0x10 submit_initial_group_read+0x161/0x3a0 ? lock_release+0x20e/0x710 ? __pfx_submit_initial_group_read+0x10/0x10 ? __pfx_lock_release+0x10/0x10 scrub_simple_mirror.isra.0+0x3eb/0x580 scrub_stripe+0xe4d/0x1440 ? lock_release+0x20e/0x710 ? __pfx_scrub_stripe+0x10/0x10 ? __pfx_lock_release+0x10/0x10 ? do_raw_read_unlock+0x44/0x70 ? _raw_read_unlock+0x23/0x40 scrub_chunk+0x257/0x4a0 scrub_enumerate_chunks+0x64c/0xf70 ? __mutex_unlock_slowpath+0x147/0x5f0 ? __pfx_scrub_enumerate_chunks+0x10/0x10 ? bit_wait_timeout+0xb0/0x170 ? __up_read+0x189/0x700 ? scrub_workers_get+0x231/0x300 ? up_write+0x490/0x4f0 btrfs_scrub_dev+0x52e/0xcd0 ? create_pending_snapshots+0x230/0x250 ? __pfx_btrfs_scrub_dev+0x10/0x10 btrfs_dev_replace_by_ioctl+0xd69/0x1d00 ? lock_acquire+0x19d/0x4a0 ? __pfx_btrfs_dev_replace_by_ioctl+0x10/0x10 ? lock_release+0x20e/0x710 ? btrfs_ioctl+0xa09/0x74f0 ? __pfx_lock_release+0x10/0x10 ? do_raw_spin_lock+0x11e/0x240 ? __pfx_do_raw_spin_lock+0x10/0x10 btrfs_ioctl+0xa14/0x74f0 ? lock_acquire+0x19d/0x4a0 ? find_held_lock+0x2d/0x110 ? __pfx_btrfs_ioctl+0x10/0x10 ? lock_release+0x20e/0x710 ? do_sigaction+0x3f0/0x860 ? __pfx_do_vfs_ioctl+0x10/0x10 ? do_raw_spin_lock+0x11e/0x240 ? lockdep_hardirqs_on_prepare+0x270/0x3e0 ? _raw_spin_unlock_irq+0x28/0x50 ? do_sigaction+0x3f0/0x860 ? __pfx_do_sigaction+0x10/0x10 ? __x64_sys_rt_sigaction+0x18e/0x1e0 ? __pfx___x64_sys_rt_sigaction+0x10/0x10 ? __x64_sys_close+0x7c/0xd0 __x64_sys_ioctl+0x137/0x190 do_syscall_64+0x71/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f0bd1114f9b Code: Unable to access opcode bytes at 0x7f0bd1114f71. RSP: 002b:00007ffc8a8c3130 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f0bd1114f9b RDX: 00007ffc8a8c35e0 RSI: 00000000ca289435 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000007 R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffc8a8c6c85 R13: 00000000398e72a0 R14: 0000000000004361 R15: 0000000000000004 </TASK> This happens because on RAID stripe-tree filesystems we recurse back into btrfs_map_block() on scrub to perform the logical to device physical mapping. But as the device replace task is already holding the dev_replace::rwsem we deadlock. So don't take the dev_replace::rwsem in case our task is the task performing the device replace. Suggested-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-08Merge tag 'for-6.12-rc6-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "A few more one-liners that fix some user visible problems: - use correct range when clearing qgroup reservations after COW - properly reset freed delayed ref list head - fix ro/rw subvolume mounts to be backward compatible with old and new mount API" * tag 'for-6.12-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix the length of reserved qgroup to free btrfs: reinitialize delayed ref list after deleting it from the list btrfs: fix per-subvolume RO/RW flags with new mount API
2024-11-08range: Add range_overlaps()Ira Weiny
Code to support CXL Dynamic Capacity devices will have extent ranges which need to be compared for intersection not a subset as is being checked in range_contains(). range_overlaps() is defined in btrfs with a different meaning from what is required in the standard range code. Dan Williams pointed this out in [1]. Adjust the btrfs call according to his suggestion there. Then add a generic range_overlaps(). Cc: Dan Williams <dan.j.williams@intel.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: David Sterba <dsterba@suse.com> Cc: linux-btrfs@vger.kernel.org Link: https://lore.kernel.org/all/65949f79ef908_8dc68294f2@dwillia2-xfh.jf.intel.com.notmuch/ [1] Acked-by: David Sterba <dsterba@suse.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Fan Ni <fan.ni@samsung.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://patch.msgid.link/20241107-dcd-type2-upstream-v7-1-56a84e66bc36@intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-11-07btrfs: fix the length of reserved qgroup to freeHaisu Wang
The dealloc flag may be cleared and the extent won't reach the disk in cow_file_range when errors path. The reserved qgroup space is freed in commit 30479f31d44d ("btrfs: fix qgroup reserve leaks in cow_file_range"). However, the length of untouched region to free needs to be adjusted with the correct remaining region size. Fixes: 30479f31d44d ("btrfs: fix qgroup reserve leaks in cow_file_range") CC: stable@vger.kernel.org # 6.11+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Haisu Wang <haisuwang@tencent.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-07btrfs: reinitialize delayed ref list after deleting it from the listFilipe Manana
At insert_delayed_ref() if we need to update the action of an existing ref to BTRFS_DROP_DELAYED_REF, we delete the ref from its ref head's ref_add_list using list_del(), which leaves the ref's add_list member not reinitialized, as list_del() sets the next and prev members of the list to LIST_POISON1 and LIST_POISON2, respectively. If later we end up calling drop_delayed_ref() against the ref, which can happen during merging or when destroying delayed refs due to a transaction abort, we can trigger a crash since at drop_delayed_ref() we call list_empty() against the ref's add_list, which returns false since the list was not reinitialized after the list_del() and as a consequence we call list_del() again at drop_delayed_ref(). This results in an invalid list access since the next and prev members are set to poison pointers, resulting in a splat if CONFIG_LIST_HARDENED and CONFIG_DEBUG_LIST are set or invalid poison pointer dereferences otherwise. So fix this by deleting from the list with list_del_init() instead. Fixes: 1d57ee941692 ("btrfs: improve delayed refs iterations") CC: stable@vger.kernel.org # 4.19+ 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>
2024-11-07btrfs: fix per-subvolume RO/RW flags with new mount APIQu Wenruo
[BUG] With util-linux 2.40.2, the 'mount' utility is already utilizing the new mount API. e.g: # strace mount -o subvol=subv1,ro /dev/test/scratch1 /mnt/test/ ... fsconfig(3, FSCONFIG_SET_STRING, "source", "/dev/mapper/test-scratch1", 0) = 0 fsconfig(3, FSCONFIG_SET_STRING, "subvol", "subv1", 0) = 0 fsconfig(3, FSCONFIG_SET_FLAG, "ro", NULL, 0) = 0 fsconfig(3, FSCONFIG_CMD_CREATE, NULL, NULL, 0) = 0 fsmount(3, FSMOUNT_CLOEXEC, 0) = 4 mount_setattr(4, "", AT_EMPTY_PATH, {attr_set=MOUNT_ATTR_RDONLY, attr_clr=0, propagation=0 /* MS_??? */, userns_fd=0}, 32) = 0 move_mount(4, "", AT_FDCWD, "/mnt/test", MOVE_MOUNT_F_EMPTY_PATH) = 0 But this leads to a new problem, that per-subvolume RO/RW mount no longer works, if the initial mount is RO: # mount -o subvol=subv1,ro /dev/test/scratch1 /mnt/test # mount -o rw,subvol=subv2 /dev/test/scratch1 /mnt/scratch # mount | grep mnt /dev/mapper/test-scratch1 on /mnt/test type btrfs (ro,relatime,discard=async,space_cache=v2,subvolid=256,subvol=/subv1) /dev/mapper/test-scratch1 on /mnt/scratch type btrfs (ro,relatime,discard=async,space_cache=v2,subvolid=257,subvol=/subv2) # touch /mnt/scratch/foobar touch: cannot touch '/mnt/scratch/foobar': Read-only file system This is a common use cases on distros. [CAUSE] We have a workaround for remount to handle the RO->RW change, but if the mount is using the new mount API, we do not do that, and rely on the mount tool NOT to set the ro flag. But that's not how the mount tool is doing for the new API: fsconfig(3, FSCONFIG_SET_STRING, "source", "/dev/mapper/test-scratch1", 0) = 0 fsconfig(3, FSCONFIG_SET_STRING, "subvol", "subv1", 0) = 0 fsconfig(3, FSCONFIG_SET_FLAG, "ro", NULL, 0) = 0 <<<< Setting RO flag for super block fsconfig(3, FSCONFIG_CMD_CREATE, NULL, NULL, 0) = 0 fsmount(3, FSMOUNT_CLOEXEC, 0) = 4 mount_setattr(4, "", AT_EMPTY_PATH, {attr_set=MOUNT_ATTR_RDONLY, attr_clr=0, propagation=0 /* MS_??? */, userns_fd=0}, 32) = 0 move_mount(4, "", AT_FDCWD, "/mnt/test", MOVE_MOUNT_F_EMPTY_PATH) = 0 This means we will set the super block RO at the first mount. Later RW mount will not try to reconfigure the fs to RW because the mount tool is already using the new API. This totally breaks the per-subvolume RO/RW mount behavior. [FIX] Do not skip the reconfiguration even if using the new API. The old comments are just expecting any mount tool to properly skip the RO flag set even if we specify "ro", which is not the reality. Update the comments regarding the backward compatibility on the kernel level so it works with old and new mount utilities. CC: stable@vger.kernel.org # 6.8+ Fixes: f044b318675f ("btrfs: handle the ro->rw transition for mounting different subvolumes") Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-03fdget(), trivial conversionsAl Viro
fdget() is the first thing done in scope, all matching fdput() are immediately followed by leaving the scope. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-11-01Merge tag 'for-6.12-rc5-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "A few more stability fixes. There's one patch adding export of MIPS cmpxchg helper, used in the error propagation fix. - fix error propagation from split bios to the original btrfs bio - fix merging of adjacent extents (normal operation, defragmentation) - fix potential use after free after freeing btrfs device structures" * tag 'for-6.12-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix defrag not merging contiguous extents due to merged extent maps btrfs: fix extent map merging not happening for adjacent extents btrfs: fix use-after-free of block device file in __btrfs_free_extra_devids() btrfs: fix error propagation of split bios MIPS: export __cmpxchg_small()
2024-10-31btrfs: fix defrag not merging contiguous extents due to merged extent mapsFilipe Manana
When running defrag (manual defrag) against a file that has extents that are contiguous and we already have the respective extent maps loaded and merged, we end up not defragging the range covered by those contiguous extents. This happens when we have an extent map that was the result of merging multiple extent maps for contiguous extents and the length of the merged extent map is greater than or equals to the defrag threshold length. The script below reproduces this scenario: $ cat test.sh #!/bin/bash DEV=/dev/sdi MNT=/mnt/sdi mkfs.btrfs -f $DEV mount $DEV $MNT # Create a 256K file with 4 extents of 64K each. xfs_io -f -c "falloc 0 64K" \ -c "pwrite 0 64K" \ -c "falloc 64K 64K" \ -c "pwrite 64K 64K" \ -c "falloc 128K 64K" \ -c "pwrite 128K 64K" \ -c "falloc 192K 64K" \ -c "pwrite 192K 64K" \ $MNT/foo umount $MNT echo -n "Initial number of file extent items: " btrfs inspect-internal dump-tree -t 5 $DEV | grep EXTENT_DATA | wc -l mount $DEV $MNT # Read the whole file in order to load and merge extent maps. cat $MNT/foo > /dev/null btrfs filesystem defragment -t 128K $MNT/foo umount $MNT echo -n "Number of file extent items after defrag with 128K threshold: " btrfs inspect-internal dump-tree -t 5 $DEV | grep EXTENT_DATA | wc -l mount $DEV $MNT # Read the whole file in order to load and merge extent maps. cat $MNT/foo > /dev/null btrfs filesystem defragment -t 256K $MNT/foo umount $MNT echo -n "Number of file extent items after defrag with 256K threshold: " btrfs inspect-internal dump-tree -t 5 $DEV | grep EXTENT_DATA | wc -l Running it: $ ./test.sh Initial number of file extent items: 4 Number of file extent items after defrag with 128K threshold: 4 Number of file extent items after defrag with 256K threshold: 4 The 4 extents don't get merged because we have an extent map with a size of 256K that is the result of merging the individual extent maps for each of the four 64K extents and at defrag_lookup_extent() we have a value of zero for the generation threshold ('newer_than' argument) since this is a manual defrag. As a consequence we don't call defrag_get_extent() to get an extent map representing a single file extent item in the inode's subvolume tree, so we end up using the merged extent map at defrag_collect_targets() and decide not to defrag. Fix this by updating defrag_lookup_extent() to always discard extent maps that were merged and call defrag_get_extent() regardless of the minimum generation threshold ('newer_than' argument). A test case for fstests will be sent along soon. CC: stable@vger.kernel.org # 6.1+ Fixes: 199257a78bb0 ("btrfs: defrag: don't use merged extent map for their generation check") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-31btrfs: fix extent map merging not happening for adjacent extentsFilipe Manana
If we have 3 or more adjacent extents in a file, that is, consecutive file extent items pointing to adjacent extents, within a contiguous file range and compatible flags, we end up not merging all the extents into a single extent map. For example: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt/sdc $ xfs_io -f -d -c "pwrite -b 64K 0 64K" \ -c "pwrite -b 64K 64K 64K" \ -c "pwrite -b 64K 128K 64K" \ -c "pwrite -b 64K 192K 64K" \ /mnt/sdc/foo After all the ordered extents complete we unpin the extent maps and try to merge them, but instead of getting a single extent map we get two because: 1) When the first ordered extent completes (file range [0, 64K)) we unpin its extent map and attempt to merge it with the extent map for the range [64K, 128K), but we can't because that extent map is still pinned; 2) When the second ordered extent completes (file range [64K, 128K)), we unpin its extent map and merge it with the previous extent map, for file range [0, 64K), but we can't merge with the next extent map, for the file range [128K, 192K), because this one is still pinned. The merged extent map for the file range [0, 128K) gets the flag EXTENT_MAP_MERGED set; 3) When the third ordered extent completes (file range [128K, 192K)), we unpin its extent map and attempt to merge it with the previous extent map, for file range [0, 128K), but we can't because that extent map has the flag EXTENT_MAP_MERGED set (mergeable_maps() returns false due to different flags) while the extent map for the range [128K, 192K) doesn't have that flag set. We also can't merge it with the next extent map, for file range [192K, 256K), because that one is still pinned. At this moment we have 3 extent maps: One for file range [0, 128K), with the flag EXTENT_MAP_MERGED set. One for file range [128K, 192K). One for file range [192K, 256K) which is still pinned; 4) When the fourth and final extent completes (file range [192K, 256K)), we unpin its extent map and attempt to merge it with the previous extent map, for file range [128K, 192K), which succeeds since none of these extent maps have the EXTENT_MAP_MERGED flag set. So we end up with 2 extent maps: One for file range [0, 128K), with the flag EXTENT_MAP_MERGED set. One for file range [128K, 256K), with the flag EXTENT_MAP_MERGED set. Since after merging extent maps we don't attempt to merge again, that is, merge the resulting extent map with the one that is now preceding it (and the one following it), we end up with those two extent maps, when we could have had a single extent map to represent the whole file. Fix this by making mergeable_maps() ignore the EXTENT_MAP_MERGED flag. While this doesn't present any functional issue, it prevents the merging of extent maps which allows to save memory, and can make defrag not merging extents too (that will be addressed in the next patch). Fixes: 199257a78bb0 ("btrfs: defrag: don't use merged extent map for their generation check") CC: stable@vger.kernel.org # 6.1+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-29btrfs: fix use-after-free of block device file in __btrfs_free_extra_devids()Zhihao Cheng
Mounting btrfs from two images (which have the same one fsid and two different dev_uuids) in certain executing order may trigger an UAF for variable 'device->bdev_file' in __btrfs_free_extra_devids(). And following are the details: 1. Attach image_1 to loop0, attach image_2 to loop1, and scan btrfs devices by ioctl(BTRFS_IOC_SCAN_DEV): / btrfs_device_1 → loop0 fs_device \ btrfs_device_2 → loop1 2. mount /dev/loop0 /mnt btrfs_open_devices btrfs_device_1->bdev_file = btrfs_get_bdev_and_sb(loop0) btrfs_device_2->bdev_file = btrfs_get_bdev_and_sb(loop1) btrfs_fill_super open_ctree fail: btrfs_close_devices // -ENOMEM btrfs_close_bdev(btrfs_device_1) fput(btrfs_device_1->bdev_file) // btrfs_device_1->bdev_file is freed btrfs_close_bdev(btrfs_device_2) fput(btrfs_device_2->bdev_file) 3. mount /dev/loop1 /mnt btrfs_open_devices btrfs_get_bdev_and_sb(&bdev_file) // EIO, btrfs_device_1->bdev_file is not assigned, // which points to a freed memory area btrfs_device_2->bdev_file = btrfs_get_bdev_and_sb(loop1) btrfs_fill_super open_ctree btrfs_free_extra_devids if (btrfs_device_1->bdev_file) fput(btrfs_device_1->bdev_file) // UAF ! Fix it by setting 'device->bdev_file' as 'NULL' after closing the btrfs_device in btrfs_close_one_device(). Fixes: 142388194191 ("btrfs: do not background blkdev_put()") CC: stable@vger.kernel.org # 4.19+ Link: https://bugzilla.kernel.org/show_bug.cgi?id=219408 Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-29block: add a bdev_limits helperChristoph Hellwig
Add a helper to get the queue_limits from the bdev without having to poke into the request_queue. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20241029141937.249920-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-28fs/writeback: convert wbc_account_cgroup_owner to take a folioPankaj Raghav
Most of the callers of wbc_account_cgroup_owner() are converting a folio to page before calling the function. wbc_account_cgroup_owner() is converting the page back to a folio to call mem_cgroup_css_from_folio(). Convert wbc_account_cgroup_owner() to take a folio instead of a page, and convert all callers to pass a folio directly except f2fs. Convert the page to folio for all the callers from f2fs as they were the only callers calling wbc_account_cgroup_owner() with a page. As f2fs is already in the process of converting to folios, these call sites might also soon be calling wbc_account_cgroup_owner() with a folio directly in the future. No functional changes. Only compile tested. Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Link: https://lore.kernel.org/r/20240926140121.203821-1-kernel@pankajraghav.com Acked-by: David Sterba <dsterba@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-24Merge tag 'for-6.12-rc4-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - mount option fixes: - fix handling of compression mount options on remount - reject rw remount in case there are options that don't work in read-write mode (like rescue options) - fix zone accounting of unusable space - fix in-memory corruption when merging extent maps - fix delalloc range locking for sector < page - use more convenient default value of drop subtree threshold, clean more subvolumes without the fallback to marking quotas inconsistent - fix smatch warning about incorrect value passed to ERR_PTR * tag 'for-6.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix passing 0 to ERR_PTR in btrfs_search_dir_index_item() btrfs: reject ro->rw reconfiguration if there are hard ro requirements btrfs: fix read corruption due to race with extent map merging btrfs: fix the delalloc range locking if sector size < page size btrfs: qgroup: set a more sane default value for subtree drop threshold btrfs: clear force-compress on remount when compress mount option is given btrfs: zoned: fix zone unusable accounting for freed reserved extent
2024-10-23btrfs: fix error propagation of split biosNaohiro Aota
The purpose of btrfs_bbio_propagate_error() shall be propagating an error of split bio to its original btrfs_bio, and tell the error to the upper layer. However, it's not working well on some cases. * Case 1. Immediate (or quick) end_bio with an error When btrfs sends btrfs_bio to mirrored devices, btrfs calls btrfs_bio_end_io() when all the mirroring bios are completed. If that btrfs_bio was split, it is from btrfs_clone_bioset and its end_io function is btrfs_orig_write_end_io. For this case, btrfs_bbio_propagate_error() accesses the orig_bbio's bio context to increase the error count. That works well in most cases. However, if the end_io is called enough fast, orig_bbio's (remaining part after split) bio context may not be properly set at that time. Since the bio context is set when the orig_bbio (the last btrfs_bio) is sent to devices, that might be too late for earlier split btrfs_bio's completion. That will result in NULL pointer dereference. That bug is easily reproducible by running btrfs/146 on zoned devices [1] and it shows the following trace. [1] You need raid-stripe-tree feature as it create "-d raid0 -m raid1" FS. BUG: kernel NULL pointer dereference, address: 0000000000000020 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 UID: 0 PID: 13 Comm: kworker/u32:1 Not tainted 6.11.0-rc7-BTRFS-ZNS+ #474 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Workqueue: writeback wb_workfn (flush-btrfs-5) RIP: 0010:btrfs_bio_end_io+0xae/0xc0 [btrfs] BTRFS error (device dm-0): bdev /dev/mapper/error-test errs: wr 2, rd 0, flush 0, corrupt 0, gen 0 RSP: 0018:ffffc9000006f248 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888005a7f080 RCX: ffffc9000006f1dc RDX: 0000000000000000 RSI: 000000000000000a RDI: ffff888005a7f080 RBP: ffff888011dfc540 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff82e508e0 R11: 0000000000000005 R12: ffff88800ddfbe58 R13: ffff888005a7f080 R14: ffff888005a7f158 R15: ffff888005a7f158 FS: 0000000000000000(0000) GS:ffff88803ea80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000020 CR3: 0000000002e22006 CR4: 0000000000370ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? __die_body.cold+0x19/0x26 ? page_fault_oops+0x13e/0x2b0 ? _printk+0x58/0x73 ? do_user_addr_fault+0x5f/0x750 ? exc_page_fault+0x76/0x240 ? asm_exc_page_fault+0x22/0x30 ? btrfs_bio_end_io+0xae/0xc0 [btrfs] ? btrfs_log_dev_io_error+0x7f/0x90 [btrfs] btrfs_orig_write_end_io+0x51/0x90 [btrfs] dm_submit_bio+0x5c2/0xa50 [dm_mod] ? find_held_lock+0x2b/0x80 ? blk_try_enter_queue+0x90/0x1e0 __submit_bio+0xe0/0x130 ? ktime_get+0x10a/0x160 ? lockdep_hardirqs_on+0x74/0x100 submit_bio_noacct_nocheck+0x199/0x410 btrfs_submit_bio+0x7d/0x150 [btrfs] btrfs_submit_chunk+0x1a1/0x6d0 [btrfs] ? lockdep_hardirqs_on+0x74/0x100 ? __folio_start_writeback+0x10/0x2c0 btrfs_submit_bbio+0x1c/0x40 [btrfs] submit_one_bio+0x44/0x60 [btrfs] submit_extent_folio+0x13f/0x330 [btrfs] ? btrfs_set_range_writeback+0xa3/0xd0 [btrfs] extent_writepage_io+0x18b/0x360 [btrfs] extent_write_locked_range+0x17c/0x340 [btrfs] ? __pfx_end_bbio_data_write+0x10/0x10 [btrfs] run_delalloc_cow+0x71/0xd0 [btrfs] btrfs_run_delalloc_range+0x176/0x500 [btrfs] ? find_lock_delalloc_range+0x119/0x260 [btrfs] writepage_delalloc+0x2ab/0x480 [btrfs] extent_write_cache_pages+0x236/0x7d0 [btrfs] btrfs_writepages+0x72/0x130 [btrfs] do_writepages+0xd4/0x240 ? find_held_lock+0x2b/0x80 ? wbc_attach_and_unlock_inode+0x12c/0x290 ? wbc_attach_and_unlock_inode+0x12c/0x290 __writeback_single_inode+0x5c/0x4c0 ? do_raw_spin_unlock+0x49/0xb0 writeback_sb_inodes+0x22c/0x560 __writeback_inodes_wb+0x4c/0xe0 wb_writeback+0x1d6/0x3f0 wb_workfn+0x334/0x520 process_one_work+0x1ee/0x570 ? lock_is_held_type+0xc6/0x130 worker_thread+0x1d1/0x3b0 ? __pfx_worker_thread+0x10/0x10 kthread+0xee/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x30/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Modules linked in: dm_mod btrfs blake2b_generic xor raid6_pq rapl CR2: 0000000000000020 * Case 2. Earlier completion of orig_bbio for mirrored btrfs_bios btrfs_bbio_propagate_error() assumes the end_io function for orig_bbio is called last among split bios. In that case, btrfs_orig_write_end_io() sets the bio->bi_status to BLK_STS_IOERR by seeing the bioc->error [2]. Otherwise, the increased orig_bio's bioc->error is not checked by anyone and return BLK_STS_OK to the upper layer. [2] Actually, this is not true. Because we only increases orig_bioc->errors by max_errors, the condition "atomic_read(&bioc->error) > bioc->max_errors" is still not met if only one split btrfs_bio fails. * Case 3. Later completion of orig_bbio for un-mirrored btrfs_bios In contrast to the above case, btrfs_bbio_propagate_error() is not working well if un-mirrored orig_bbio is completed last. It sets orig_bbio->bio.bi_status to the btrfs_bio's error. But, that is easily over-written by orig_bbio's completion status. If the status is BLK_STS_OK, the upper layer would not know the failure. * Solution Considering the above cases, we can only save the error status in the orig_bbio (remaining part after split) itself as it is always available. Also, the saved error status should be propagated when all the split btrfs_bios are finished (i.e, bbio->pending_ios == 0). This commit introduces "status" to btrfs_bbio and saves the first error of split bios to original btrfs_bio's "status" variable. When all the split bios are finished, the saved status is loaded into original btrfs_bio's status. With this commit, btrfs/146 on zoned devices does not hit the NULL pointer dereference anymore. Fixes: 852eee62d31a ("btrfs: allow btrfs_submit_bio to split bios") CC: stable@vger.kernel.org # 6.6+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>