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2023-02-15btrfs: remove struct btrfs_bio::device fieldChristoph Hellwig2-7/+5
The device field is only used by the simple end I/O handler, and for that it can simply be stored in the bi_private field of the bio, which is currently used for the fs_info that can be retrieved through bbio->inode as well. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: remove now unused checksumming helpersChristoph Hellwig2-113/+16
Remove the unused btrfs_verify_data_csum helper, and fold btrfs_check_data_csum into its only caller. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: remove btrfs_bio_for_each_sectorChristoph Hellwig1-16/+0
btrfs_bio_for_each_sector is unused now, so remove it. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: open code btrfs_bio_free_csumChristoph Hellwig2-11/+2
btrfs_bio_free_csum has only one caller left, and that caller is always for an data inode and doesn't need zeroing of the csum pointer as that pointer will never be touched again. Just open code the conditional kfree there. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: handle checksum validation and repair at the storage layerChristoph Hellwig4-234/+202
Currently btrfs handles checksum validation and repair in the end I/O handler for the btrfs_bio. This leads to a lot of duplicate code plus issues with varying semantics or bugs, e.g. - the until recently broken repair for compressed extents - the fact that encoded reads validate the checksums but do not kick of read repair - the inconsistent checking of the BTRFS_FS_STATE_NO_CSUMS flag This commit revamps the checksum validation and repair code to instead work below the btrfs_submit_bio interfaces. In case of a checksum failure (or a plain old I/O error), the repair is now kicked off before the upper level ->end_io handler is invoked. Progress of an in-progress repair is tracked by a small structure that is allocated using a mempool for each original bio with failed sectors, which holds a reference to the original bio. This new structure is allocated using a mempool to guarantee forward progress even under memory pressure. The mempool will be replenished when the repair completes, just as the mempools backing the bios. There is one significant behavior change here: If repair fails or is impossible to start with, the whole bio will be failed to the upper layer. This is the behavior that all I/O submitters except for buffered I/O already emulated in their end_io handler. For buffered I/O this now means that a large readahead request can fail due to a single bad sector, but as readahead errors are ignored the following readpage if the sector is actually accessed will still be able to read. This also matches the I/O failure handling in other file systems. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: add a btrfs_data_csum_ok helperChristoph Hellwig2-0/+40
Add a new checksumming helper that wraps btrfs_check_data_csum and does all the checks to if we're dealing with some form of nodatacsum I/O. This helper will be used by the new storage layer checksum validation and repair code. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: pre-load data checksum for reads in btrfs_submit_bioChristoph Hellwig3-32/+10
Instead of calling btrfs_lookup_bio_sums in every caller of btrfs_submit_bio that reads data, do the call once in btrfs_submit_bio. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: save the bio iter for checksum validation in common codeChristoph Hellwig4-13/+4
All callers of btrfs_submit_bio that want to validate checksums currently have to store a copy of the iter in the btrfs_bio. Move the assignment into common code. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: refactor error handling in btrfs_submit_bioChristoph Hellwig1-9/+15
Add a bbio local variable and to prepare for calling functions that return a blk_status_t, rename the existing int used for error handling so that ret can be reused for the blk_status_t, and a label that can be reused for failing the passed in bio. Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: simplify parameters of btrfs_lookup_bio_sumsChristoph Hellwig4-37/+25
The csums argument is always NULL now, so remove it and always allocate the csums array in the btrfs_bio. Also pass the btrfs_bio instead of inode + bio to document that this function requires a btrfs_bio and not just any bio. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: remove the direct I/O read checksum lookup optimizationChristoph Hellwig1-27/+5
To prepare for pending changes drop the optimization to only look up csums once per bio that is submitted from the iomap layer. In the short run this does cause additional lookups for fragmented direct reads, but later in the series, the bio based lookup will be used on the entire bio submitted from iomap, restoring the old behavior in common code. Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: add a btrfs_inode pointer to struct btrfs_bioChristoph Hellwig5-9/+19
All btrfs_bio I/Os are associated with an inode. Add a pointer to that inode, which will allow to simplify a lot of calling conventions, and which will be needed in the I/O completion path in the future. This grow the btrfs_bio structure by a pointer, but that grows will be offset by the removal of the device pointer soon. Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: better document struct btrfs_bioChristoph Hellwig1-5/+4
Update the comments on btrfs_bio to better describe the structure. Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: raid56: reduce overhead to calculate the bio lengthQu Wenruo1-2/+1
In rbio_update_error_bitmap(), we need to calculate the length of the rbio. As since it's called in the endio function, we can not directly grab the length from bi_iter. Currently we call bio_for_each_segment_all(), which will always return a range inside a page. But that's not necessary as we don't really care about anything inside the page. So use bio_for_each_bvec_all(), which can return a bvec across multiple continuous pages thus reduce the loops. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: fix spelling mistakes found using codespellColin Ian King9-16/+16
There quite a few spelling mistakes as found using codespell. Fix them. Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: skip backref walking during fiemap if we know the leaf is sharedFilipe Manana1-1/+20
During fiemap, when checking if a data extent is shared we are doing the backref walking even if we already know the leaf is shared, which is a waste of time since if the leaf shared then the data extent is also shared. So skip the backref walking when we know we are in a shared leaf. The following test was measures the gains for a case where all leaves are shared due to a snapshot: $ cat test.sh #!/bin/bash DEV=/dev/sdj MNT=/mnt/sdj umount $DEV &> /dev/null mkfs.btrfs -f $DEV # Use compression to quickly create files with a lot of extents # (each with a size of 128K). mount -o compress=lzo $DEV $MNT # 40G gives 327680 extents, each with a size of 128K. xfs_io -f -c "pwrite -S 0xab -b 1M 0 40G" $MNT/foobar # Add some more files to increase the size of the fs and extent # trees (in the real world there's a lot of files and extents # from other files). xfs_io -f -c "pwrite -S 0xcd -b 1M 0 20G" $MNT/file1 xfs_io -f -c "pwrite -S 0xef -b 1M 0 20G" $MNT/file2 xfs_io -f -c "pwrite -S 0x73 -b 1M 0 20G" $MNT/file3 # Create a snapshot so all the extents become indirectly shared # through subtrees, with a generation less than or equals to the # generation used to create the snapshot. btrfs subvolume snapshot -r $MNT $MNT/snap1 # Unmount and mount again to clear cached metadata. umount $MNT mount -o compress=lzo $DEV $MNT start=$(date +%s%N) # The filefrag tool uses the fiemap ioctl. filefrag $MNT/foobar end=$(date +%s%N) dur=$(( (end - start) / 1000000 )) echo "fiemap took $dur milliseconds (metadata not cached)" echo start=$(date +%s%N) filefrag $MNT/foobar end=$(date +%s%N) dur=$(( (end - start) / 1000000 )) echo "fiemap took $dur milliseconds (metadata cached)" umount $MNT The results were the following on a non-debug kernel (Debian's default kernel config). Before this patch: (...) /mnt/sdi/foobar: 327680 extents found fiemap took 1821 milliseconds (metadata not cached) /mnt/sdi/foobar: 327680 extents found fiemap took 399 milliseconds (metadata cached) After this patch: (...) /mnt/sdi/foobar: 327680 extents found fiemap took 591 milliseconds (metadata not cached) /mnt/sdi/foobar: 327680 extents found fiemap took 123 milliseconds (metadata cached) That's a speedup of 3.1x and 3.2x. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: assert commit root semaphore is held when accessing backref cacheFilipe Manana1-2/+10
During fiemap, when accessing the cache that stores the sharedness of an extent, we need to either be holding a transaction handle or the commit root semaphore. I left comments about this in the comment that precedes store_backref_shared_cache() and lookup_backref_shared_cache(), but have actually not enforced it through assertions. So assert that the commit root semaphore is held if we are not holding a transaction handle. 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>
2023-02-15btrfs: hold block group refcount during async discardBoris Burkov1-3/+38
Async discard does not acquire the block group reference count while it holds a reference on the discard list. This is generally OK, as the paths which destroy block groups tend to try to synchronize on cancelling async discard work. However, relying on cancelling work requires careful analysis to be sure it is safe from races with unpinning scheduling more work. While I am unable to find a race with unpinning in the current code for either the unused bgs or relocation paths, I believe we have one in an older version of auto relocation in a Meta internal build. This suggests that this is in fact an error prone model, and could be fragile to future changes to these bg deletion paths. To make this ownership more clear, add a refcount for async discard. If work is queued for a block group, its refcount should be incremented, and when work is completed or canceled, it should be decremented. CC: stable@vger.kernel.org # 5.15+ Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: send: cache utimes operations for directories if possibleFilipe Manana3-6/+117
Whenever we add or remove an entry to a directory, we issue an utimes command for the directory. If we add 1000 entries to a directory (create 1000 files under it or move 1000 files to it), then we issue the same utimes command 1000 times, which increases the send stream size, results in more pipe IO, one search in the send b+tree, allocating one path for the search, etc, as well as making the receiver do a system call for each duplicated utimes command. We also issue an utimes command when we create a new directory, but later we might add entries to it corresponding to inodes with an higher inode number, so it's pointless to issue the utimes command before we create the last inode under the directory. So use a lru cache to track directories for which we must send a utimes command. When we need to remove an entry from the cache, we issue the utimes command for the respective directory. When finishing the send operation, we go over each cache element and issue the respective utimes command. Finally the caching is entirely optional, just a performance optimization, meaning that if we fail to cache (due to memory allocation failure), we issue the utimes command right away, that is, we fallback to the previous, unoptimized, behaviour. This patch belongs to a patchset comprised of the following patches: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible The following test was run before and after applying the whole patchset, and on a non-debug kernel (Debian's default kernel config): #!/bin/bash MNT=/mnt/sdi DEV=/dev/sdi mkfs.btrfs -f $DEV > /dev/null mount $DEV $MNT mkdir $MNT/A for ((i = 1; i <= 20000; i++)); do echo -n > $MNT/A/file_$i done btrfs subvolume snapshot -r $MNT $MNT/snap1 mkdir $MNT/B for ((i = 20000; i <= 40000; i++)); do echo -n > $MNT/B/file_$i done mv $MNT/A/file_* $MNT/B/ btrfs subvolume snapshot -r $MNT $MNT/snap2 start=$(date +%s%N) btrfs send -p $MNT/snap1 $MNT/snap2 > /dev/null end=$(date +%s%N) dur=$(( (end - start) / 1000000 )) echo "Incremental send took $dur milliseconds" umount $MNT Before the whole patchset: 18408 milliseconds After the whole patchset: 1942 milliseconds (9.5x speedup) Using 60000 files instead of 40000: Before the whole patchset: 39764 milliseconds After the whole patchset: 3076 milliseconds (12.9x speedup) Using 20000 files instead of 40000: Before the whole patchset: 5072 milliseconds After the whole patchset: 916 milliseconds (5.5x speedup) Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: send: update size of roots array for backref cache entriesFilipe Manana1-7/+8
Currently we limit the size of the roots array, for backref cache entries, to 12 elements. This is because that number is enough for most cases and to make the backref cache entry size to be exactly 128 bytes, so that memory is allocated from the kmalloc-128 slab and no space is wasted. However recent changes in the series refactored the backref cache to be more generic and allow it to be reused for other purposes, which resulted in increasing the size of the embedded structure btrfs_lru_cache_entry in order to allow for supporting inode numbers as keys on 32 bits system and allow multiple generations per key. This resulted in increasing the size of struct backref_cache_entry from 128 bytes to 152 bytes. Since the cache entries are allocated with kmalloc(), it means we end up using the slab kmalloc-192, so we end up wasting 40 bytes of memory. So bump the size of the roots array from 12 elements to 17 elements, so we end up using 192 bytes for each backref cache entry. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: send: use the lru cache to implement the name cacheFilipe Manana1-141/+27
The name cache in send is basically a lru cache implemented with a radix tree and linked lists, very similar to the lru cache module which is used for the send backref cache and the cache of previously created directories during a send operation. So remove all the custom caching code for the name cache and make it use the lru cache instead. One particular detail to note is that the current cache behaves a bit differently when it comes to eviction of entries. Namely when after inserting a new name in the cache, if the cache now has 256 entries, we evict the last 128 LRU entries. The lru_cache.{c,h} module behaves a bit differently in that once we reach the cache limit, we evict a single LRU entry. In practice this doesn't make much difference, but it's actually better to evict just one entry instead of half of the entries, as there's always a chance we will need a name stored in one of that last 128 removed entries. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: add an api to delete a specific entry from the lru cacheFilipe Manana2-4/+14
In order to replace the open coded name cache in send with the lru cache, we need an API for the lru cache to delete a specific entry for which we did a previous lookup. This adds the API for it, and a next patch in the series will use it. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: allow a generation number to be associated with lru cache entriesFilipe Manana3-9/+20
This allows an optional generation number to be associated to each entry of the lru cache. Entries with the same key but different generations, are stored in the linked list to which the maple tree points to. This is meant to be used when there's a small number of different generations, so the impact of searching a linked list is negligible. The goal is to get rid of the open coded name cache in the send code (which uses a radix tree and a similar linked list of values/entries) and use instead the lru cache module. For that particular use case we have at most 2 generations that are associated to each key (inode number): one generation for the send root and another generation for the parent root. The actual migration of the send name cache is done in the next patch in the series. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: send: cache information about created directoriesFilipe Manana1-1/+40
During an incremental send, when processing the reference for an inode we need to check if the directory where the new reference is located was already created before creating the new reference. This check, which is done by the helper did_create_dir(), can be expensive if the directory has many entries, since it consists in searching the send root's b+tree and visiting every single dir index key until we either find one which points to an inode with a number smaller than the current inode's number or until we visited all index keys. So it doesn't scale well for very large directories. So improve on this by caching created directories using a lru cache, and limiting its size to 64 entries, which results in using at most 4096 bytes of memory. The caching is optional, if we fail to allocate memory, we just proceed as before and use the existing slower path. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systemsFilipe Manana2-15/+84
The lru cache is backed by a maple tree, which uses the unsigned long type for keys, and that type has a width of 32 bits on 32 bits systems and a width of 64 bits on 64 bits systems. Currently there is only one user of the lru cache, the send backref cache, which uses a sector number as a key, a logical address right shifted by fs_info->sectorsize_bits, so a 32 bits width is not yet a problem (the same happens with the radix tree we use to track extent buffers, fs_info->buffer_radix). However the next patches in the series will start using the lru cache for cases where inode numbers are the keys, and the inode numbers are always 64 bits, even if we are running on a 32 bits system. So adapt the lru cache to allow multiple values under the same key, by having the maple tree store a head entry that points to a list of entries instead of pointing to a single entry. This is a similar approach to what we currently do for the name cache in send (which uses a radix tree that has indexes with an unsigned long type as well), and will allow later to use the lru cache for the send name cache as well. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: send: genericize the backref cache to allow it to be reusedFilipe Manana4-57/+167
The backref cache is a cache backed by a maple tree and a linked list to keep track of temporal access to cached entries (the LRU entry always at the head of the list). This type of caching method is going to be useful in other scenarios, so make the cache implementation more generic and move it into its own header and source files. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: send: initialize all the red black trees earlierFilipe Manana1-6/+6
After we allocate the send context object and before we initialize all the red black trees, we can jump to the 'out' label if some errors happen, and then under the 'out' label we use RB_EMPTY_ROOT() against some of the those trees, which we have not yet initialized. This happens to work out ok because the send context object was initialized to zeroes with kzalloc and the RB_ROOT initializer just happens to have the following definition: #define RB_ROOT (struct rb_root) { NULL, } But it's really neither clean nor a good practice as RB_ROOT is supposed to be opaque and in case it changes or we change those red black trees to some other data structure, it leaves us in a precarious situation. So initialize all the red black trees immediately after allocating the send context and before any jump into the 'out' label. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: send: iterate waiting dir move rbtree only once when processing refsFilipe Manana1-5/+2
When processing the new references for an inode, we unnecessarily iterate twice the waiting dir moves rbtree, once with is_waiting_for_move() and if we found an entry in the rbtree, we iterate it again with a call to get_waiting_dir_move(). This is pointless, we can make this simpler and more efficient by calling only get_waiting_dir_move(), so just do that. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: send: reduce searches on parent root when checking if dir can be removedFilipe Manana1-6/+59
During an incremental send, every time we remove a reference (dentry) for an inode and the parent directory does not exists anymore in the send root, we go check if we can remove the directory by making a call to can_rmdir(). This helper can only return true (value 1) if all dentries were already removed, and for that it always does a search on the parent root for dir index keys - if it finds any dentry referring to an inode with a number higher then the inode currently being processed, then the directory can not be removed and it must return false (value 0). However that means if a directory that was deleted had 1000 dentries, and each one pointed to an inode with a number higher then the number of the directory's inode, we end up doing 1000 searches on the parent root. Typically files are created in a directory after the directory was created and therefore they get an higher inode number than the directory. It's also common to have the each dentry pointing to an inode with a higher number then the inodes the previous dentries point to, for example when creating a series of files inside a directory, a very common pattern. So improve on that by having the first call to can_rmdir() for a directory to check the number of the inode that the last dentry points to and cache that inode number in the orphan dir structure. Then every subsequent call to can_rmdir() can avoid doing a search on the parent root if the number of the inode currently being processed is smaller than cached inode number at the directory's orphan dir structure. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()Filipe Manana1-4/+7
At can_rmdir() we start by searching the orphan dirs rbtree for an orphan dir object for the target directory. Later when iterating over the dir index keys, if we find that any dir entry points to inode for which there is a pending dir move or the inode was not yet processed, we exit because we can't remove the directory yet. However we end up always calling add_orphan_dir_info(), which will iterate again the rbtree and if there is already an orphan dir object (created by the first call to can_rmdir()), it returns the existing object. This is unnecessary work because in case there is already an existing orphan dir object, we got a reference to it at the start of can_rmdir(). So skip the call to add_orphan_dir_info() if we already have a reference for an orphan dir object. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: send: avoid duplicated orphan dir allocation and initializationFilipe Manana1-15/+12
At can_rmdir() we are allocating and initializing an orphan dir object twice. This can be deduplicated outside of the loop that iterates over the dir index keys. So deduplicate that code, even because other patch in the series will need to add more initialization code and another one will add one more condition. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: send: remove send_progress argument from can_rmdir()Filipe Manana1-8/+5
All callers of can_rmdir() pass sctx->cur_ino as the value for the send_progress argument, so remove the argument and directly use sctx->cur_ino. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: send: avoid extra b+tree searches when checking reference overridesFilipe Manana1-32/+29
During an incremental send, when processing the new references of an inode (either it's a new inode or an existing one renamed/moved), he will search the b+tree of the send or parent roots in order to find out the inode item of the parent directory and extract its generation. However we are doing that search twice, once with is_inode_existent() -> get_cur_inode_state() and then again at did_overwrite_ref() or will_overwrite_ref(). So avoid that and get the generation at get_cur_inode_state() and then propagate it up to did_overwrite_ref() and will_overwrite_ref(). This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: send: directly return from will_overwrite_ref() and simplify itFilipe Manana1-22/+16
There are no resources to release before will_overwrite_ref() returns, so we don't really need the 'out' label and jumping to it when conditions are met - we can directly return and get rid of the label and jumps. Also we can deal with -ENOENT and other errors in a single if-else logic, as it's more straightforward. This helps the next patch in the series to be more simple as well. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: send: avoid unnecessary generation search at did_overwrite_ref()Filipe Manana1-9/+22
At did_overwrite_ref() we always call get_inode_gen() to find out the generation of the inode 'ow_inode'. However we don't always need to use that generation, and in fact it's very common to not use it, so we end up doing a b+tree search on the send root, allocating a path, etc, for nothing. So improve on this by getting the generation only if we need to use it. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: send: directly return from did_overwrite_ref() and simplify itFilipe Manana1-25/+18
There are no resources to release before did_overwrite_ref() returns, so we don't really need the 'out' label and jumping to it when conditions are met - we can directly return and get rid of the label and jumps. Also we can deal with -ENOENT and other errors in a single if-else logic, as it's more straightforward. This helps the next patch in the series to be more simple as well. This patch is part of a larger patchset and the changelog of the last patch in the series contains a sample performance test and results. The patches that comprise the patchset are the following: btrfs: send: directly return from did_overwrite_ref() and simplify it btrfs: send: avoid unnecessary generation search at did_overwrite_ref() btrfs: send: directly return from will_overwrite_ref() and simplify it btrfs: send: avoid extra b+tree searches when checking reference overrides btrfs: send: remove send_progress argument from can_rmdir() btrfs: send: avoid duplicated orphan dir allocation and initialization btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir() btrfs: send: reduce searches on parent root when checking if dir can be removed btrfs: send: iterate waiting dir move rbtree only once when processing refs btrfs: send: initialize all the red black trees earlier btrfs: send: genericize the backref cache to allow it to be reused btrfs: adapt lru cache to allow for 64 bits keys on 32 bits systems btrfs: send: cache information about created directories btrfs: allow a generation number to be associated with lru cache entries btrfs: add an api to delete a specific entry from the lru cache btrfs: send: use the lru cache to implement the name cache btrfs: send: update size of roots array for backref cache entries btrfs: send: cache utimes operations for directories if possible Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: sysfs: update fs features directory asynchronouslyQu Wenruo6-23/+27
[BUG] Since the introduction of per-fs feature sysfs interface (/sys/fs/btrfs/<UUID>/features/), the content of that directory is never updated. Thus for the following case, that directory will not show the new features like RAID56: # mkfs.btrfs -f $dev1 $dev2 $dev3 # mount $dev1 $mnt # btrfs balance start -f -mconvert=raid5 $mnt # ls /sys/fs/btrfs/$uuid/features/ extended_iref free_space_tree no_holes skinny_metadata While after unmount and mount, we got the correct features: # umount $mnt # mount $dev1 $mnt # ls /sys/fs/btrfs/$uuid/features/ extended_iref free_space_tree no_holes raid56 skinny_metadata [CAUSE] Because we never really try to update the content of per-fs features/ directory. We had an attempt to update the features directory dynamically in commit 14e46e04958d ("btrfs: synchronize incompat feature bits with sysfs files"), but unfortunately it get reverted in commit e410e34fad91 ("Revert "btrfs: synchronize incompat feature bits with sysfs files""). The problem in the original patch is, in the context of btrfs_create_chunk(), we can not afford to update the sysfs group. The exported but never utilized function, btrfs_sysfs_feature_update() is the leftover of such attempt. As even if we go sysfs_update_group(), new files will need extra memory allocation, and we have no way to specify the sysfs update to go GFP_NOFS. [FIX] This patch will address the old problem by doing asynchronous sysfs update in the cleaner thread. This involves the following changes: - Make __btrfs_(set|clear)_fs_(incompat|compat_ro) helpers to set BTRFS_FS_FEATURE_CHANGED flag when needed - Update btrfs_sysfs_feature_update() to use sysfs_update_group() And drop unnecessary arguments. - Call btrfs_sysfs_feature_update() in cleaner_kthread If we have the BTRFS_FS_FEATURE_CHANGED flag set. - Wake up cleaner_kthread in btrfs_commit_transaction if we have BTRFS_FS_FEATURE_CHANGED flag By this, all the previously dangerous call sites like btrfs_create_chunk() need no new changes, as above helpers would have already set the BTRFS_FS_FEATURE_CHANGED flag. The real work happens at cleaner_kthread, thus we pay the cost of delaying the update to sysfs directory, but the delayed time should be small enough that end user can not distinguish though it might get delayed if the cleaner thread is busy with removing subvolumes or defrag. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: remove duplicate include header in extent-tree.cye xingchen1-1/+0
extent-tree.h is included more than once, added in a0231804affe ("btrfs: move extent-tree helpers into their own header file"). Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: scrub: improve tree block error reportingQu Wenruo1-9/+40
[BUG] When debugging a scrub related metadata error, it turns out that our metadata error reporting is not ideal. The only 3 error messages are: - BTRFS error (device dm-2): bdev /dev/mapper/test-scratch1 errs: wr 0, rd 0, flush 0, corrupt 0, gen 1 Showing we have metadata generation mismatch errors. - BTRFS error (device dm-2): unable to fixup (regular) error at logical 7110656 on dev /dev/mapper/test-scratch1 Showing which tree blocks are corrupted. - BTRFS warning (device dm-2): checksum/header error at logical 24772608 on dev /dev/mapper/test-scratch2, physical 3801088: metadata node (level 1) in tree 5 Showing which physical range the corrupted metadata is at. We have to combine the above 3 to know we have a corrupted metadata with generation mismatch. And this is already the better case, if we have other problems, like fsid mismatch, we can not even know the cause. [CAUSE] The problem is caused by the fact that, scrub_checksum_tree_block() never outputs any error message. It just return two bits for scrub: sblock->header_error, and sblock->generation_error. And later we report error in scrub_print_warning(), but unfortunately we only have two bits, there is not really much thing we can done to print any detailed errors. [FIX] This patch will do the following to enhance the error reporting of metadata scrub: - Add extra warning (ratelimited) for every error we hit This can help us to distinguish the different types of errors. Some errors can help us to know what's going wrong immediately, like bytenr mismatch. - Re-order the checks Currently we check bytenr first, then immediately generation. This can lead to false generation mismatch reports, while the fsid mismatches. Here is the new output for the bug I'm debugging (we forgot to writeback tree blocks for commit roots): BTRFS warning (device dm-2): tree block 24117248 mirror 1 has bad fsid, has b77cd862-f150-4c71-90ec-7baf0544d83f want 17df6abf-23cd-445f-b350-5b3e40bfd2fc BTRFS warning (device dm-2): tree block 24117248 mirror 0 has bad fsid, has b77cd862-f150-4c71-90ec-7baf0544d83f want 17df6abf-23cd-445f-b350-5b3e40bfd2fc Now we can immediately know it's some tree blocks didn't even get written back, other than the original confusing generation mismatch. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: don't use size classes for zoned file systemsBoris Burkov3-3/+13
When a file system has ZNS devices which are constrained by a maximum number of active block groups, then not being able to use all the block groups for every allocation is not ideal, and could cause us to loop a ton with mixed size allocations. In general, since zoned doesn't write into gaps behind where block groups are writing, it is not susceptible to the same sort of fragmentation that size classes are designed to solve, so we can skip size classes for zoned file systems in general, even though there would probably be no harm for SMR devices. Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: load block group size class when cachingBoris Burkov1-0/+148
Since the size class is an artifact of an arbitrary anti fragmentation strategy, it doesn't really make sense to persist it. Furthermore, most of the size class logic assumes fresh block groups. That is of course not a reasonable assumption -- we will be upgrading kernels with existing filesystems whose block groups are not classified. To work around those issues, implement logic to compute the size class of the block groups as we cache them in. To perfectly assess the state of a block group, we would have to read the entire extent tree (since the free space cache mashes together contiguous extent items) which would be prohibitively expensive for larger file systems with more extents. We can do it relatively cheaply by implementing a simple heuristic of sampling a handful of extents and picking the smallest one we see. In the happy case where the block group was classified, we will only see extents of the correct size. In the unhappy case, we will hopefully find one of the smaller extents, but there is no perfect answer anyway. Autorelocation will eventually churn up the block group if there is significant freeing anyway. There was no regression in mount performance at end state of the fsperf test suite, and the delay until the block group is marked cached is minimized by the constant number of extent samples. Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: introduce size class to block group allocatorBoris Burkov4-51/+148
The aim of this patch is to reduce the fragmentation of block groups under certain unhappy workloads. It is particularly effective when the size of extents correlates with their lifetime, which is something we have observed causing fragmentation in the fleet at Meta. This patch categorizes extents into size classes: - x < 128KiB: "small" - 128KiB < x < 8MiB: "medium" - x > 8MiB: "large" and as much as possible reduces allocations of extents into block groups that don't match the size class. This takes advantage of any (possible) correlation between size and lifetime and also leaves behind predictable re-usable gaps when extents are freed; small writes don't gum up bigger holes. Size classes are implemented in the following way: - Mark each new block group with a size class of the first allocation that goes into it. - Add two new passes to ffe: "unset size class" and "wrong size class". First, try only matching block groups, then try unset ones, then allow allocation of new ones, and finally allow mismatched block groups. - Filtering is done just by skipping inappropriate ones, there is no special size class indexing. Other solutions I considered were: - A best fit allocator with an rb-tree. This worked well, as small writes didn't leak big holes from large freed extents, but led to regressions in ffe and write performance due to lock contention on the rb-tree with every allocation possibly updating it in parallel. Perhaps something clever could be done to do the updates in the background while being "right enough". - A fixed size "working set". This prevents freeing an extent drastically changing where writes currently land, and seems like a good option too. Doesn't take advantage of size in any way. - The same size class idea, but implemented with xarray marks. This turned out to be slower than looping the linked list and skipping wrong block groups, and is also less flexible since we must have only 3 size classes (max #marks). With the current approach we can have as many as we like. Performance testing was done via: https://github.com/josefbacik/fsperf Of particular relevance are the new fragmentation specific tests. A brief summary of the testing results: - Neutral results on existing tests. There are some minor regressions and improvements here and there, but nothing that truly stands out as notable. - Improvement on new tests where size class and extent lifetime are correlated. Fragmentation in these cases is completely eliminated and write performance is generally a little better. There is also significant improvement where extent sizes are just a bit larger than the size class boundaries. - Regression on one new tests: where the allocations are sized intentionally a hair under the borders of the size classes. Results are neutral on the test that intentionally attacks this new scheme by mixing extent size and lifetime. The full dump of the performance results can be found here: https://bur.io/fsperf/size-class-2022-11-15.txt (there are ANSI escape codes, so best to curl and view in terminal) Here is a snippet from the full results for a new test which mixes buffered writes appending to a long lived set of files and large short lived fallocates: bufferedappendvsfallocate results metric baseline current stdev diff ====================================================================================== avg_commit_ms 31.13 29.20 2.67 -6.22% bg_count 14 15.60 0 11.43% commits 11.10 12.20 0.32 9.91% elapsed 27.30 26.40 2.98 -3.30% end_state_mount_ns 11122551.90 10635118.90 851143.04 -4.38% end_state_umount_ns 1.36e+09 1.35e+09 12248056.65 -1.07% find_free_extent_calls 116244.30 114354.30 964.56 -1.63% find_free_extent_ns_max 599507.20 1047168.20 103337.08 74.67% find_free_extent_ns_mean 3607.19 3672.11 101.20 1.80% find_free_extent_ns_min 500 512 6.67 2.40% find_free_extent_ns_p50 2848 2876 37.65 0.98% find_free_extent_ns_p95 4916 5000 75.45 1.71% find_free_extent_ns_p99 20734.49 20920.48 1670.93 0.90% frag_pct_max 61.67 0 8.05 -100.00% frag_pct_mean 43.59 0 6.10 -100.00% frag_pct_min 25.91 0 16.60 -100.00% frag_pct_p50 42.53 0 7.25 -100.00% frag_pct_p95 61.67 0 8.05 -100.00% frag_pct_p99 61.67 0 8.05 -100.00% fragmented_bg_count 6.10 0 1.45 -100.00% max_commit_ms 49.80 46 5.37 -7.63% sys_cpu 2.59 2.62 0.29 1.39% write_bw_bytes 1.62e+08 1.68e+08 17975843.50 3.23% write_clat_ns_mean 57426.39 54475.95 2292.72 -5.14% write_clat_ns_p50 46950.40 42905.60 2101.35 -8.62% write_clat_ns_p99 148070.40 143769.60 2115.17 -2.90% write_io_kbytes 4194304 4194304 0 0.00% write_iops 2476.15 2556.10 274.29 3.23% write_lat_ns_max 2101667.60 2251129.50 370556.59 7.11% write_lat_ns_mean 59374.91 55682.00 2523.09 -6.22% write_lat_ns_min 17353.10 16250 1646.08 -6.36% There are some mixed improvements/regressions in most metrics along with an elimination of fragmentation in this workload. On the balance, the drastic 1->0 improvement in the happy cases seems worth the mix of regressions and improvements we do observe. Some considerations for future work: - Experimenting with more size classes - More hinting/search ordering work to approximate a best-fit allocator Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: add more find_free_extent tracepointsBoris Burkov2-0/+7
find_free_extent is a complicated function. It consists (at least) of: - a hint that jumps into the middle of a for loop macro - a middle loop trying every raid level - an outer loop ascending through ffe loop levels - complicated logic for skipping some of those ffe loop levels - multiple underlying in-bg allocators (zoned, cluster, no cluster) Which is all to say that more tracing is helpful for debugging its behavior. Add two new tracepoints: at the entrance to the block_groups loop (hit for every raid level and every ffe_ctl loop) and at the point we seriously consider a block_group for allocation. This way we can see the whole path through the algorithm, including hints, multiple loops, etc. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Boris Burkov <boris@bur.io> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: pass find_free_extent_ctl to allocator tracepointsBoris Burkov3-86/+82
The allocator tracepoints currently have a pile of values from ffe_ctl. In modifying the allocator and adding more tracepoints, I found myself adding to the already long argument list of the tracepoints. It makes it a lot simpler to just send in the ffe_ctl itself. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Boris Burkov <boris@bur.io> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: remove the wait argument to btrfs_start_ordered_extentChristoph Hellwig5-21/+18
Given that wait is always set to 1, so remove the argument. Last use of wait with 0 was in 0c304304feab ("Btrfs: remove csum_bytes_left"). Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: use a single variable to track return value for log_dir_items()Filipe Manana1-19/+18
We currently use 'ret' and 'err' to track the return value for log_dir_items(), which is confusing and likely the cause for previous bugs where log_dir_items() did not return an error when it should, fixed in previous patches. So change this and use only a single variable, 'ret', to track the return value. This is simpler and makes it similar to most of the existing code. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: use a negative value for BTRFS_LOG_FORCE_COMMITFilipe Manana2-9/+10
Currently we use the value 1 for BTRFS_LOG_FORCE_COMMIT, but that value has a few inconveniences: 1) If it's ever used by btrfs_log_inode(), or any function down the call chain, we have to remember to btrfs_set_log_full_commit(), which is repetitive and has a chance to be forgotten in future use cases. btrfs_log_inode_parent() only calls btrfs_set_log_full_commit() when it gets a negative value from btrfs_log_inode(); 2) Down the call chain of btrfs_log_inode(), we may have functions that need to force a log commit, but can return either an error (negative value), false (0) or true (1). So they are forced to return some random negative to force a log commit - using BTRFS_LOG_FORCE_COMMIT would make the intention more clear. Currently the only example is flush_dir_items_batch(). So turn BTRFS_LOG_FORCE_COMMIT into a negative value. The chosen value is -(MAX_ERRNO + 1), so that it does not overlap any errno value and makes it easier to debug. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: use PAGE_{ALIGN, ALIGNED, ALIGN_DOWN} macroYushan Zhou6-9/+8
The header file linux/mm.h provides PAGE_ALIGN, PAGE_ALIGNED, PAGE_ALIGN_DOWN macros. Use these macros to make code more concise. Signed-off-by: Yushan Zhou <katrinzhou@tencent.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: go to matching label when cleaning em in btrfs_submit_directPeng Hao1-1/+1
When btrfs_get_chunk_map fails to allocate a new em the cleanup does not need to be done so the goto target is out_err, which is consistent with current coding style. Signed-off-by: Peng Hao <flyingpeng@tencent.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-13btrfs: turn on -Wmaybe-uninitializedJosef Bacik1-1/+2
We had a recent bug that would have been caught by a newer compiler with -Wmaybe-uninitialized and would have saved us a month of failing tests that I didn't have time to investigate. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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