- 16 May, 2022 40 commits
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Qu Wenruo authored
[BUG] Test case generic/475 have a very high chance (almost 100%) to hit a fs hang, where a data page will never be unlocked and hang all later operations. [CAUSE] In btrfs_do_readpage(), if we hit an error from submit_extent_page() we will try to do the cleanup for our current io range, and exit. This works fine for PAGE_SIZE == sectorsize cases, but not for subpage. For subpage btrfs_do_readpage() will lock the full page first, which can contain several different sectors and extents: btrfs_do_readpage() |- begin_page_read() | |- btrfs_subpage_start_reader(); | Now the page will have PAGE_SIZE / sectorsize reader pending, | and the page is locked. | |- end_page_read() for different branches | This function will reduce subpage readers, and when readers | reach 0, it will unlock the page. But when submit_extent_page() failed, we only cleanup the current io range, while the remaining io range will never be cleaned up, and the page remains locked forever. [FIX] Update the error handling of submit_extent_page() to cleanup all the remaining subpage range before exiting the loop. Please note that, now submit_extent_page() can only fail due to sanity check in alloc_new_bio(). Thus regular IO errors are impossible to trigger the error path. CC: stable@vger.kernel.org # 5.15+ Signed-off-by:
Qu Wenruo <wqu@suse.com> Signed-off-by:
David Sterba <dsterba@suse.com>
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Qu Wenruo authored
[BUG] When running generic/475 with 64K page size and 4K sector size, it has a very high chance (almost 100%) to hang, with mostly data page locked but no one is going to unlock it. [CAUSE] With commit 1784b7d5 ("btrfs: handle csum lookup errors properly on reads"), if we failed to lookup checksum due to metadata IO error, we will return error for btrfs_submit_data_bio(). This will cause the page to be unlocked twice in btrfs_do_readpage(): btrfs_do_readpage() |- submit_extent_page() | |- submit_one_bio() | |- btrfs_submit_data_bio() | |- if (ret) { | |- bio->bi_status = ret; | |- bio_endio(bio); } | In the endio function, we will call end_page_read() | and unlock_extent() to cleanup the subpage range. | |- if (ret) { |- unlock_extent(); end_page_read() } Here we unlock the extent and cleanup the subpage range again. For unlock_extent(), it's mostly double unlock safe. But for end_page_read(), it's not, especially for subpage case, as for subpage case we will call btrfs_subpage_end_reader() to reduce the reader number, and use that to number to determine if we need to unlock the full page. If double accounted, it can underflow the number and leave the page locked without anyone to unlock it. [FIX] The commit 1784b7d5 ("btrfs: handle csum lookup errors properly on reads") itself is completely fine, it's our existing code not properly handling the error from bio submission hook properly. This patch will make submit_one_bio() to return void so that the callers will never be able to do cleanup when bio submission hook fails. Signed-off-by:
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Schspa Shi authored
This is an optimization for fix fee13fe9 ("btrfs: correct zstd workspace manager lock to use spin_lock_bh()") The critical region for wsm.lock is only accessed by the process context and the softirq context. Because in the soft interrupt, the critical section will not be preempted by the soft interrupt again, there is no need to call spin_lock_bh(&wsm.lock) to turn off the soft interrupt, spin_lock(&wsm.lock) is enough for this situation. Signed-off-by:
Schspa Shi <schspa@gmail.com> [ minor comment update ] Signed-off-by:
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Filipe Manana authored
We are still using the magic value of 2 at btrfs_create_new_inode(), but there's now a constant for that, named BTRFS_DIR_START_INDEX, which was introduced in commit 528ee697 ("btrfs: put initial index value of a directory in a constant"). So change that to use the constant. Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Signed-off-by:
Filipe Manana <fdmanana@suse.com> Reviewed-by:
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Qu Wenruo authored
Cleanup the function submit_read_repair() by: - Remove the fixed argument submit_bio_hook() The function is only called on buffered data read path, so the @submit_bio_hook argument is always btrfs_submit_data_bio(). Since it's fixed, then there is no need to pass that argument at all. - Rename the function to submit_data_read_repair() Just to be more explicit on all the 3 things, data, read and repair. Reviewed-by:
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Christoph Hellwig authored
Reading a value from a different member of a union is not just a great way to obfuscate code, but also creates an aliasing violation. Switch btrfs_is_zoned to look at ->zone_size and remove the union. Note: union was to simplify the detection of zoned filesystem but now this is wrapped behind btrfs_is_zoned so we can drop the union. Reviewed-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by:
Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
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Lv Ruyi authored
iput() already handles NULL and non-NULL parameter, so it is not needed to check that. This unifies all iput calls. Reported-by:
Zeal Robot <zealci@zte.com.cn> Signed-off-by:
Lv Ruyi <lv.ruyi@zte.com.cn> Reviewed-by:
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Christoph Hellwig authored
The bios added to ->bio_list are the original bios fed into btrfs_map_bio, which are never advanced. Just use the iter in the bio itself. Reviewed-by:
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Christoph Hellwig authored
All the scrub bios go straight to the block device or the raid56 code, none of which looks at the btrfs_bio. Reviewed-by:
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Christoph Hellwig authored
Except for the spurious initialization of ->device just after allocation nothing uses the btrfs_bio, so just allocate a normal bio without extra data. Reviewed-by:
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Christoph Hellwig authored
Prepare for further refactoring by moving this initialization to a single place instead of setting it in the callers. Signed-off-by:
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Christoph Hellwig authored
Pass the block_device to bio_alloc_clone instead of setting it later. Signed-off-by:
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Christoph Hellwig authored
Prepare for additional refactoring, btrfs_map_bio is direct caller of submit_stripe_bio. Signed-off-by:
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Christoph Hellwig authored
The I/O in repair_io_failue is synchronous and doesn't need a btrfs_bio, so just use an on-stack bio. Reviewed-by:
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Christoph Hellwig authored
The I/O in repair_io_failue is synchronous and doesn't need a btrfs_bio, so just use an on-stack bio. Reviewed-by:
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Christoph Hellwig authored
The I/O in repair_io_failue is synchronous and doesn't need a btrfs_bio, so just use an on-stack bio. Also cleanup the error handling to use goto labels and not discard the actual return values. Reviewed-by:
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Christoph Hellwig authored
btrfsic_read_block does not need the btrfs_bio structure, so switch to plain bio_alloc (that also does not fail as it's backed by a bioset). Reviewed-by:
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Christoph Hellwig authored
Require a separate call to the integrity checking helpers from the actual bio submission. Reviewed-by:
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Christoph Hellwig authored
Split out two helpers to make __btrfsic_submit_bio more readable. Reviewed-by:
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Johannes Thumshirn authored
The current auto-reclaim algorithm starts reclaiming all block groups with a zone_unusable value above a configured threshold. This is causing a lot of reclaim IO even if there would be enough free zones on the device. Instead of only accounting a block groups zone_unusable value, also take the ratio of free and not usable (written as well as zone_unusable) bytes a device has into account. Tested-by:
Pankaj Raghav <p.raghav@samsung.com> Signed-off-by:
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Josef Bacik authored
For the non-zoned case we may want to set the threshold for reclaim to something below 50%. Change the acceptable threshold from 50-100 to 0-100. Tested-by:
Josef Bacik <josef@toxicpanda.com> Signed-off-by:
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Josef Bacik authored
This will allow us to set a threshold for block groups to be automatically relocated even if we don't have zoned devices. We have found this feature invaluable at Facebook due to how our workload interacts with the allocator. We have been using this in production for months with only a single problem that has already been fixed. Tested-by:
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Josef Bacik authored
For non-zoned file systems it's useful to have the auto reclaim feature, however there are different use cases for non-zoned, for example we may not want to reclaim metadata chunks ever, only data chunks. Move this sysfs flag to per-space_info. This won't affect current users because this tunable only ever did anything for zoned, and that is currently hidden behind BTRFS_CONFIG_DEBUG. Tested-by:
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Filipe Manana authored
When checking if we can do a NOCOW write against a range covered by a file extent item, we do a quick a check to determine if the inode's root was snapshotted in a generation older than the generation of the file extent item or not. This is to quickly determine if the extent is likely shared and avoid the expensive check for cross references (this was added in commit 78d4295b ("btrfs: lift some btrfs_cross_ref_exist checks in nocow path"). We restrict that check to the case where the inode is not a free space inode (since commit 27a7ff55 ("btrfs: skip file_extent generation check for free_space_inode in run_delalloc_nocow")). That is because when we had the inode cache feature, inode caches were backed by a free space inode that belonged to the inode's root. However we don't have support for the inode cache feature since kernel 5.11, so we don't need this check anymore since free space inodes are now always related to free space caches, which are always associated to the root tree (which can't be snapshotted, and its last_snapshot field is always 0). So remove that condition. Signed-off-by:
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Filipe Manana authored
Verifying if we can do a NOCOW write against a range fully or partially covered by a file extent item requires verifying several constraints, and these are currently duplicated at two different places: can_nocow_extent() and run_delalloc_nocow(). This change moves those checks into a common helper function to avoid duplication. It adds some comments and also preserves all existing behaviour like for example can_nocow_extent() treating errors from the calls to btrfs_cross_ref_exist() and csum_exist_in_range() as meaning we can not NOCOW, instead of propagating the error back to the caller. That specific behaviour is questionable but also reasonable to some degree. Signed-off-by:
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Sweet Tea Dorminy authored
When allocating memory in a loop, each iteration should call memalloc_retry_wait() in order to prevent starving memory-freeing processes (and to mark where allocation loops are). Other filesystems do that as well. The bulk page allocation is the only place in btrfs with an allocation retry loop, so add an appropriate call to it. Signed-off-by:
Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Reviewed-by:
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Sweet Tea Dorminy authored
While calling alloc_page() in a loop is an effective way to populate an array of pages, the MM subsystem provides a method to allocate pages in bulk. alloc_pages_bulk_array() populates the NULL slots in a page array, trying to grab more than one page at a time. Unfortunately, it doesn't guarantee allocating all slots in the array, but it's easy to call it in a loop and return an error if no progress occurs. Reviewed-by:
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Sweet Tea Dorminy authored
Several functions currently populate an array of page pointers one allocated page at a time. Factor out the common code so as to allow improvements to all of the sites at once. Reviewed-by:
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Yu Zhe authored
Explicit type casts are not necessary when it's void* to another pointer type. Signed-off-by:
Yu Zhe <yuzhe@nfschina.com> Reviewed-by:
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Qu Wenruo authored
With the recent change in metadata handling, we can handle metadata in the following cases: - nodesize < PAGE_SIZE and sectorsize < PAGE_SIZE Go subpage routine for both metadata and data. - nodesize < PAGE_SIZE and sectorsize >= PAGE_SIZE Invalid case for now. As we require nodesize >= sectorsize. - nodesize >= PAGE_SIZE and sectorsize < PAGE_SIZE Go subpage routine for data, but regular page routine for metadata. - nodesize >= PAGE_SIZE and sectorsize >= PAGE_SIZE Go regular page routine for both metadata and data. Now we can handle any sectorsize < PAGE_SIZE, plus the existing sectorsize == PAGE_SIZE support. But here we introduce an artificial limit, any PAGE_SIZE > 4K case, we will only support 4K and PAGE_SIZE as sector size. The idea here is to reduce the test combinations, and push 4K as the default standard in the future. Signed-off-by:
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Qu Wenruo authored
The reason why we only support 64K page size for subpage is, for 64K page size we can ensure no matter what the nodesize is, we can fit it into one page. When other page size come, especially like 16K, the limitation is a bit limiting. To remove such limitation, we allow nodesize >= PAGE_SIZE case to go the non-subpage routine. By this, we can allow 4K sectorsize on 16K page size. Although this introduces another smaller limitation, the metadata can not cross page boundary, which is already met by most recent mkfs. Another small improvement is, we can avoid the overhead for metadata if nodesize >= PAGE_SIZE. For 4K sector size and 64K page size/node size, or 4K sector size and 16K page size/node size, we don't need to allocate extra memory for the metadata pages. Please note that, this patch will not yet enable other page size support yet. Signed-off-by:
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Qu Wenruo authored
In function btrfs_read_sys_array(), we allocate a real extent buffer using btrfs_find_create_tree_block(). Such extent buffer will be even cached into buffer_radix tree, and using btree inode address space. However we only use such extent buffer to enable the accessors, thus we don't even need to bother using real extent buffer, a dummy one is what we really need. And for dummy extent buffer, we no longer need to do any special handling for the first page, as subpage helper is already doing it properly. Signed-off-by:
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Naohiro Aota authored
Relocation of a data block group creates ordered extents. They can cause a hang when a process is trying to thaw the filesystem. We should have called sb_start_write(), so the filesystem is not being frozen. Add an ASSERT to check it is protected. Reviewed-by:
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Naohiro Aota authored
Add a function sb_write_started() to allow callers to verify if sb_start_write() is properly called. It will be used for assertion in btrfs. Reviewed-by:
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Nikolay Borisov authored
Move code in btrfs_ioctl_balance to simplify its flow. This is possible thanks to the removal of balance v1 ioctl and ensuring 'arg' argument is always present. First move the code duplicating the userspace arg to the kernel 'barg'. This makes the out_unlock label redundant. Secondly, check the validity of bargs::flags before copying to the dynamically allocated 'bctl'. This removes the need for the out_bctl label. Reviewed-by:
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Nikolay Borisov authored
With the removal of balance v1 ioctl the 'arg' argument is guaranteed to be present so simply remove all conditional code which checks for its presence. Reviewed-by:
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Qu Wenruo authored
The original code resets the page to 0x1 for not apparent reason, it's been like that since the initial 2007 code added in commit 07157aac ("Btrfs: Add file data csums back in via hooks in the extent map code"). It could mean that a failed buffer can be detected from the data but that's just a guess and any value is good. Reviewed-by:
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Filipe Manana authored
When doing a NOWAIT direct IO write, if we can NOCOW then it means we can proceed with the non-blocking, NOWAIT path. However reserving the metadata space and qgroup meta space can often result in blocking - flushing delalloc, wait for ordered extents to complete, trigger transaction commits, etc, going against the semantics of a NOWAIT write. So make the NOWAIT write path to try to reserve all the metadata it needs without resulting in a blocking behaviour - if we get -ENOSPC or -EDQUOT then return -EAGAIN to make the caller fallback to a blocking direct IO write. This is part of a patchset comprised of the following patches: btrfs: avoid blocking on page locks with nowait dio on compressed range btrfs: avoid blocking nowait dio when locking file range btrfs: avoid double nocow check when doing nowait dio writes btrfs: stop allocating a path when checking if cross reference exists btrfs: free path at can_nocow_extent() before checking for checksum items btrfs: release path earlier at can_nocow_extent() btrfs: avoid blocking when allocating context for nowait dio read/write btrfs: avoid blocking on space revervation when doing nowait dio writes The following test was run before and after applying this patchset: $ cat io-uring-nodatacow-test.sh #!/bin/bash DEV=/dev/sdc MNT=/mnt/sdc MOUNT_OPTIONS="-o ssd -o nodatacow" MKFS_OPTIONS="-R free-space-tree -O no-holes" NUM_JOBS=4 FILE_SIZE=8G RUN_TIME=300 cat <<EOF > /tmp/fio-job.ini [io_uring_rw] rw=randrw fsync=0 fallocate=posix group_reporting=1 direct=1 ioengine=io_uring iodepth=64 bssplit=4k/20:8k/20:16k/20:32k/10:64k/10:128k/5:256k/5:512k/5:1m/5 filesize=$FILE_SIZE runtime=$RUN_TIME time_based filename=foobar directory=$MNT numjobs=$NUM_JOBS thread EOF echo performance | \ tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor umount $MNT &> /dev/null mkfs.btrfs -f $MKFS_OPTIONS $DEV &> /dev/null mount $MOUNT_OPTIONS $DEV $MNT fio /tmp/fio-job.ini umount $MNT The test was run a 12 cores box with 64G of ram, using a non-debug kernel config (Debian's default config) and a spinning disk. Result before the patchset: READ: bw=407MiB/s (427MB/s), 407MiB/s-407MiB/s (427MB/s-427MB/s), io=119GiB (128GB), run=300175-300175msec WRITE: bw=407MiB/s (427MB/s), 407MiB/s-407MiB/s (427MB/s-427MB/s), io=119GiB (128GB), run=300175-300175msec Result after the patchset: READ: bw=436MiB/s (457MB/s), 436MiB/s-436MiB/s (457MB/s-457MB/s), io=128GiB (137GB), run=300044-300044msec WRITE: bw=435MiB/s (456MB/s), 435MiB/s-435MiB/s (456MB/s-456MB/s), io=128GiB (137GB), run=300044-300044msec That's about +7.2% throughput for reads and +6.9% for writes. Signed-off-by: -
Filipe Manana authored
When doing a NOWAIT direct IO read/write, we allocate a context object (struct btrfs_dio_data) with GFP_NOFS, which can result in blocking waiting for memory allocation (GFP_NOFS is __GFP_RECLAIM | __GFP_IO). This is undesirable for the NOWAIT semantics, so do the allocation with GFP_NOWAIT if we are serving a NOWAIT request and if the allocation fails return -EAGAIN, so that the caller can fallback to a blocking context and retry with a non-blocking write. Signed-off-by:
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Filipe Manana authored
At can_nocow_extent(), we are releasing the path only after checking if the block group that has the target extent is read only, and after checking if there's delalloc in the range in case our extent is a preallocated extent. The read only extent check can be expensive if we have a very large filesystem with many block groups, as well as the check for delalloc in the inode's io_tree in case the io_tree is big due to IO on other file ranges. Our path is holding a read lock on a leaf and there's no need to keep the lock while doing those two checks, so release the path before doing them, immediately after the last use of the leaf. Signed-off-by:
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