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2023-04-17btrfs: fix uninitialized variable warningsGenjian Zhang1-1/+1
There are some warnings on older compilers (gcc 10, 7) or non-x86_64 architectures (aarch64). As btrfs wants to enable -Wmaybe-uninitialized by default, fix the warnings even though it's not necessary on recent compilers (gcc 12+). ../fs/btrfs/volumes.c: In function ‘btrfs_init_new_device’: ../fs/btrfs/volumes.c:2703:3: error: ‘seed_devices’ may be used uninitialized in this function [-Werror=maybe-uninitialized] 2703 | btrfs_setup_sprout(fs_info, seed_devices); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../fs/btrfs/send.c: In function ‘get_cur_inode_state’: ../include/linux/compiler.h:70:32: error: ‘right_gen’ may be used uninitialized in this function [-Werror=maybe-uninitialized] 70 | (__if_trace.miss_hit[1]++,1) : \ | ^ ../fs/btrfs/send.c:1878:6: note: ‘right_gen’ was declared here 1878 | u64 right_gen; | ^~~~~~~~~ Reported-by: k2ci <kernel-bot@kylinos.cn> Signed-off-by: Genjian Zhang <zhanggenjian@kylinos.cn> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2023-02-15btrfs: send: cache utimes operations for directories if possibleFilipe Manana1-5/+99
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: allow a generation number to be associated with lru cache entriesFilipe Manana1-3/+5
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: send: genericize the backref cache to allow it to be reusedFilipe Manana1-56/+24
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: use PAGE_{ALIGN, ALIGNED, ALIGN_DOWN} macroYushan Zhou1-2/+2
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: fix uninitialized variable warning in get_inode_genJosef Bacik1-5/+3
Anybody that calls get_inode_gen() can have an uninitialized gen if there's an error. This isn't a big deal because all the users just exit if they get an error, however it makes -Wmaybe-uninitialized complain, so fix this up to always initialize the passed in gen, this quiets all of the uninitialized warnings in send.c. Reviewed-by: Qu Wenruo <wqu@suse.com> 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>
2023-02-06Merge tag 'for-6.2-rc7-tag' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - explicitly initialize zlib work memory to fix a KCSAN warning - limit number of send clones by maximum memory allocated - limit device size extent in case it device shrink races with chunk allocation - raid56 fixes: - fix copy&paste error in RAID6 stripe recovery - make error bitmap update atomic * tag 'for-6.2-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: raid56: make error_bitmap update atomic btrfs: send: limit number of clones and allocated memory size btrfs: zlib: zero-initialize zlib workspace btrfs: limit device extents to the device size btrfs: raid56: fix stripes if vertical errors are found
2023-01-27btrfs: send: limit number of clones and allocated memory sizeDavid Sterba1-3/+3
The arg->clone_sources_count is u64 and can trigger a warning when a huge value is passed from user space and a huge array is allocated. Limit the allocated memory to 8MiB (can be increased if needed), which in turn limits the number of clone sources to 8M / sizeof(struct clone_root) = 8M / 40 = 209715. Real world number of clones is from tens to hundreds, so this is future proof. Reported-by: syzbot+4376a9a073770c173269@syzkaller.appspotmail.com Signed-off-by: David Sterba <dsterba@suse.com>
2022-12-14Merge tag 'hardening-v6.2-rc1' of ↵Linus Torvalds1-5/+6
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull kernel hardening updates from Kees Cook: - Convert flexible array members, fix -Wstringop-overflow warnings, and fix KCFI function type mismatches that went ignored by maintainers (Gustavo A. R. Silva, Nathan Chancellor, Kees Cook) - Remove the remaining side-effect users of ksize() by converting dma-buf, btrfs, and coredump to using kmalloc_size_roundup(), add more __alloc_size attributes, and introduce full testing of all allocator functions. Finally remove the ksize() side-effect so that each allocation-aware checker can finally behave without exceptions - Introduce oops_limit (default 10,000) and warn_limit (default off) to provide greater granularity of control for panic_on_oops and panic_on_warn (Jann Horn, Kees Cook) - Introduce overflows_type() and castable_to_type() helpers for cleaner overflow checking - Improve code generation for strscpy() and update str*() kern-doc - Convert strscpy and sigphash tests to KUnit, and expand memcpy tests - Always use a non-NULL argument for prepare_kernel_cred() - Disable structleak plugin in FORTIFY KUnit test (Anders Roxell) - Adjust orphan linker section checking to respect CONFIG_WERROR (Xin Li) - Make sure siginfo is cleared for forced SIGKILL (haifeng.xu) - Fix um vs FORTIFY warnings for always-NULL arguments * tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (31 commits) ksmbd: replace one-element arrays with flexible-array members hpet: Replace one-element array with flexible-array member um: virt-pci: Avoid GCC non-NULL warning signal: Initialize the info in ksignal lib: fortify_kunit: build without structleak plugin panic: Expose "warn_count" to sysfs panic: Introduce warn_limit panic: Consolidate open-coded panic_on_warn checks exit: Allow oops_limit to be disabled exit: Expose "oops_count" to sysfs exit: Put an upper limit on how often we can oops panic: Separate sysctl logic from CONFIG_SMP mm/pgtable: Fix multiple -Wstringop-overflow warnings mm: Make ksize() a reporting-only function kunit/fortify: Validate __alloc_size attribute results drm/sti: Fix return type of sti_{dvo,hda,hdmi}_connector_mode_valid() drm/fsl-dcu: Fix return type of fsl_dcu_drm_connector_mode_valid() driver core: Add __alloc_size hint to devm allocators overflow: Introduce overflows_type() and castable_to_type() coredump: Proactively round up to kmalloc bucket size ...
2022-12-05btrfs: send: bump the extent reference count limit for backref walkingFilipe Manana1-1/+1
After the previous patchset which is comprised of the following patches: 01/17 btrfs: fix inode list leak during backref walking at resolve_indirect_refs() 02/17 btrfs: fix inode list leak during backref walking at find_parent_nodes() 03/17 btrfs: fix ulist leaks in error paths of qgroup self tests 04/17 btrfs: remove pointless and double ulist frees in error paths of qgroup tests 05/17 btrfs: send: avoid unnecessary path allocations when finding extent clone 06/17 btrfs: send: update comment at find_extent_clone() 07/17 btrfs: send: drop unnecessary backref context field initializations 08/17 btrfs: send: avoid unnecessary backref lookups when finding clone source 09/17 btrfs: send: optimize clone detection to increase extent sharing 10/17 btrfs: use a single argument for extent offset in backref walking functions 11/17 btrfs: use a structure to pass arguments to backref walking functions 12/17 btrfs: reuse roots ulist on each leaf iteration for iterate_extent_inodes() 13/17 btrfs: constify ulist parameter of ulist_next() 14/17 btrfs: send: cache leaf to roots mapping during backref walking 15/17 btrfs: send: skip unnecessary backref iterations 16/17 btrfs: send: avoid double extent tree search when finding clone source 17/17 btrfs: send: skip resolution of our own backref when finding clone source we have now much better performance when doing backref walking in the send code, so we can increase the current limit from 64 to 1024 references. This limit is still a bit conservative because there are still edge cases where backref walking will be too slow and spend a lot of cpu time, some IO reading b+tree nodes/leaves and memory. The goal is to eventually get rid of any limit, but for now bump it as it benefits users with extents shared more than 64 times and up to 1024 times, allowing for more deduplication at the destination without having to run a dedupe tool after a receive. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-12-05btrfs: send: skip resolution of our own backref when finding clone sourceFilipe Manana1-0/+33
When doing backref walking to determine a source range to clone from, it is worthless to collect and resolve our own data backref, as we can't obviously use it as a clone source and it represents the range we want to clone into. Collecting the backref implies doing the extra work to resolve it, doing the search for a file extent item in a subvolume tree, etc. Skipping the data backref is valid as long as we only have the send root as the single clone root, otherwise the leaf with the file extent item may be accessible from another clone root due to shared subtrees created by snapshots, and therefore we have to collect the backref and resolve it. So add a callback to the backref walking code to guide it to skip data backrefs. This change is part of a patchset comprised of the following patches: 01/17 btrfs: fix inode list leak during backref walking at resolve_indirect_refs() 02/17 btrfs: fix inode list leak during backref walking at find_parent_nodes() 03/17 btrfs: fix ulist leaks in error paths of qgroup self tests 04/17 btrfs: remove pointless and double ulist frees in error paths of qgroup tests 05/17 btrfs: send: avoid unnecessary path allocations when finding extent clone 06/17 btrfs: send: update comment at find_extent_clone() 07/17 btrfs: send: drop unnecessary backref context field initializations 08/17 btrfs: send: avoid unnecessary backref lookups when finding clone source 09/17 btrfs: send: optimize clone detection to increase extent sharing 10/17 btrfs: use a single argument for extent offset in backref walking functions 11/17 btrfs: use a structure to pass arguments to backref walking functions 12/17 btrfs: reuse roots ulist on each leaf iteration for iterate_extent_inodes() 13/17 btrfs: constify ulist parameter of ulist_next() 14/17 btrfs: send: cache leaf to roots mapping during backref walking 15/17 btrfs: send: skip unnecessary backref iterations 16/17 btrfs: send: avoid double extent tree search when finding clone source 17/17 btrfs: send: skip resolution of our own backref when finding clone source The following test was run on non-debug kernel (Debian's default kernel config) before and after applying the patchset: $ cat test-send-many-shared-extents.sh #!/bin/bash DEV=/dev/sdh MNT=/mnt/sdh umount $DEV &> /dev/null mkfs.btrfs -f $DEV mount $DEV $MNT num_files=50000 num_clones_per_file=50 for ((i = 1; i <= $num_files; i++)); do xfs_io -f -c "pwrite 0 64K" $MNT/file_$i > /dev/null echo -ne "\r$i files created..." done echo btrfs subvolume snapshot -r $MNT $MNT/snap1 cloned=0 for ((i = 1; i <= $num_clones_per_file; i++)); do for ((j = 1; j <= $num_files; j++)); do cp --reflink=always $MNT/file_$j $MNT/file_${j}_clone_${i} cloned=$((cloned + 1)) echo -ne "\r$cloned / $((num_files * num_clones_per_file)) clone operations" done done echo btrfs subvolume snapshot -r $MNT $MNT/snap2 # Unmount and mount again to clear all cached metadata (and data). umount $DEV mount $DEV $MNT start=$(date +%s%N) btrfs send $MNT/snap2 > /dev/null end=$(date +%s%N) dur=$(( (end - start) / 1000000000 )) echo -e "\nFull send took $dur seconds" # Unmount and mount again to clear all cached metadata (and data). umount $DEV mount $DEV $MNT start=$(date +%s%N) btrfs send -p $MNT/snap1 $MNT/snap2 > /dev/null end=$(date +%s%N) dur=$(( (end - start) / 1000000000 )) echo -e "\nIncremental send took $dur seconds" umount $MNT Before applying the patchset: (...) Full send took 1108 seconds (...) Incremental send took 1135 seconds After applying the whole patchset: (...) Full send took 268 seconds (-75.8%) (...) Incremental send took 316 seconds (-72.2%) Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2022-12-05