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e8a7f49d9b
371 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Filipe Manana
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e8a7f49d9b |
btrfs: send: cache information about created directories
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> |
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Filipe Manana
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90b90d4ac0 |
btrfs: send: genericize the backref cache to allow it to be reused
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> |
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Filipe Manana
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d307d2f35c |
btrfs: send: initialize all the red black trees earlier
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>
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Filipe Manana
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8c139e1d78 |
btrfs: send: iterate waiting dir move rbtree only once when processing refs
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> |
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Filipe Manana
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474e4761f6 |
btrfs: send: reduce searches on parent root when checking if dir can be removed
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> |
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Filipe Manana
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78cf1a954d |
btrfs: send: avoid unnecessary orphan dir rbtree search at can_rmdir()
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> |
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Filipe Manana
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d921b9cf91 |
btrfs: send: avoid duplicated orphan dir allocation and initialization
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> |
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Filipe Manana
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24970ccb24 |
btrfs: send: remove send_progress argument from can_rmdir()
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> |
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Filipe Manana
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498581f33c |
btrfs: send: avoid extra b+tree searches when checking reference overrides
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> |
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Filipe Manana
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b3047a42f5 |
btrfs: send: directly return from will_overwrite_ref() and simplify it
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> |
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Filipe Manana
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cb68948194 |
btrfs: send: avoid unnecessary generation search at did_overwrite_ref()
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> |
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Filipe Manana
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e739ba307f |
btrfs: send: directly return from did_overwrite_ref() and simplify it
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> |
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Yushan Zhou
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ce394a7f39 |
btrfs: use PAGE_{ALIGN, ALIGNED, ALIGN_DOWN} macro
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> |
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Josef Bacik
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ab19901359 |
btrfs: fix uninitialized variable warning in get_inode_gen
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> |
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Linus Torvalds
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66fcf74e5c |
for-6.2-rc7-tag
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Merge tag 'for-6.2-rc7-tag' of 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
|
||
David Sterba
|
33e17b3f5a |
btrfs: send: limit number of clones and allocated memory size
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> |
||
|
Linus Torvalds
|
48ea09cdda |
hardening updates for v6.2-rc1
- 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.
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Merge tag 'hardening-v6.2-rc1' of 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
...
|
||
|
Filipe Manana
|
e2a0416577 |
btrfs: send: bump the extent reference count limit for backref walking
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> |
||
|
Filipe Manana
|
adf0241868 |
btrfs: send: skip resolution of our own backref when finding clone source
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>
|
||
|
Filipe Manana
|
f73853c716 |
btrfs: send: avoid double extent tree search when finding clone source
At find_extent_clone() we search twice for the extent item corresponding to the data extent that the current file extent items points to: 1) Once with a call to extent_from_logical(); 2) Once again during backref walking, through iterate_extent_inodes() which eventually leads to find_parent_nodes() where we will search again the extent tree for the same extent item. The extent tree can be huge, so doing this one extra search for every extent we want to send adds up and it's expensive. The first call is there since the send code was introduced and it accomplishes two things: 1) Check that the extent is flagged as a data extent in the extent tree. But it can not be anything else, otherwise we wouldn't have a file extent item in the send root pointing to it. This was probably added to catch bugs in the early days where send was yet too young and the interaction with everything else was far from perfect; 2) Check how many direct references there are on the extent, and if there's too many (more than SEND_MAX_EXTENT_REFS), avoid doing the backred walking as it may take too long and slowdown send. So improve on this by having a callback in the backref walking code that is called when it finds the extent item in the extent tree, and have those checks done in the callback. When the callback returns anything different from 0, it stops the backref walking code. This way we do a single search on the extent tree for the extent item of our data extent. Also, before this change we were only checking the number of references on the data extent against SEND_MAX_EXTENT_REFS, but after starting backref walking we will end up resolving backrefs for extent buffers in the path from a leaf having a file extent item pointing to our data extent, up to roots of trees from which the extent buffer is accessible from, due to shared subtrees resulting from snapshoting. We were therefore allowing for the possibility for send taking too long due to some node in the path from the leaf to a root node being shared too many times. After this change we check for reference counts being greater than SEND_MAX_EXTENT_REFS for both data extents and metadata extents. 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 Performance test results are in the changelog of patch 17/17. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Filipe Manana
|
88ffb665c8 |
btrfs: send: skip unnecessary backref iterations
When looking for a clone source for an extent, we are iterating over all the backreferences for an extent. This is often a waste of time, because once we find a good clone source we could stop immediately instead of continuing backref walking, which is expensive. Basically what happens currently is this: 1) Call iterate_extent_inodes() to iterate over all the backreferences; 2) It calls btrfs_find_all_leafs() which in turn calls the main function to walk over backrefs and collect them - find_parent_nodes(); 3) Then we collect all the references for our target data extent from the extent tree (and delayed refs if any), add them to the rb trees, resolve all the indirect backreferences and search for all the file extent items in fs trees, building a list of inodes for each one of them (struct extent_inode_elem); 4) Then back at iterate_extent_inodes() we find all the roots associated to each found leaf, and call the callback __iterate_backrefs defined at send.c for each inode in the inode list associated to each leaf. Some times one the first backreferences we find in a fs tree is optimal to satisfy the clone operation that send wants to perform, and in that case we could stop immediately and avoid resolving all the remaining indirect backreferences (search fs trees for the respective file extent items, etc). This possibly if when we find a fs tree leaf with a file extent item we are able to know what are all the roots that can lead to the leaf - this is now possible after the previous patch in the series that adds a cache that maps leaves to a list of roots. So we can now shortcircuit backref walking during send, by having the callback we pass to iterate_extent_inodes() to be called when we find a file extent item for an indirect backreference, and have it return a special value when it found a suitable backreference and it does not need to look for more backreferences. This change does that. 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 Performance test results are in the changelog of patch 17/17. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Filipe Manana
|
66d04209e5 |
btrfs: send: cache leaf to roots mapping during backref walking
During a send operation, when doing backref walking to determine which inodes/offsets/roots we can clone from, the most repetitive and expensive step is to map each leaf that has file extent items pointing to the target data extent to the IDs of the roots from which the leaves are accessible, which happens at iterate_extent_inodes(). That step requires finding every parent node of a leaf, then the parent of each parent, and so on until we reach a root node. So it's a naturally expensive operation, and repetitive because each leaf can have hundreds of file extent items (for a nodesize of 16K, that can be slightly over 200 file extent items). There's also temporal locality, as we process all file extent items from a leave before moving the next leaf. This change caches the mapping of leaves to root IDs, to avoid repeating those computations over and over again. The cache is limited to a maximum of 128 entries, with each entry being a struct with a size of 128 bytes, so the maximum cache size is 16K plus any nodes internally allocated by the maple tree that is used to index pointers to those structs. The cache is invalidated whenever we detect relocation happened since we started filling the cache, because if relocation happened then extent buffers for leaves and nodes of the trees used by a send operation may have been reallocated. This cache also allows for another important optimization that is introduced in the next patch in the series. 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 Performance test results are in the changelog of patch 17/17. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Filipe Manana
|
a2c8d27e5e |
btrfs: use a structure to pass arguments to backref walking functions
The public backref walking functions have quite a lot of arguments that are passed down the call stack to find_parent_nodes(), the core function of the backref walking code. The next patches in series will need to add even arguments to these functions that should be passed not only to find_parent_nodes(), but also to other functions used by the later (directly or even lower in the call stack). So create a structure to hold all these arguments and state used by the main backref walking function, find_parent_nodes(), and use it as the argument for the public backref walking functions iterate_extent_inodes(), btrfs_find_all_leafs() and btrfs_find_all_roots(). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Filipe Manana
|
6ce6ba5344 |
btrfs: use a single argument for extent offset in backref walking functions
The interface for find_parent_nodes() has two extent offset related
arguments:
1) One u64 pointer argument for the extent offset;
2) One boolean argument to tell if the extent offset should be ignored or
not.
These are confusing, becase the extent offset pointer can be NULL and in
some cases callers pass a NULL value as a way to tell the backref walking
code to ignore offsets in file extent items (and simply consider all file
extent items that point to the target data extent).
The boolean argument was added in commit
|
||
|
Filipe Manana
|
c7499a64dc |
btrfs: send: optimize clone detection to increase extent sharing
Currently send does not do the best decisions when it comes to decide
between multiple clone sources, which results in clone operations for
partial extent ranges, which has the following disadvantages:
1) We get less shared extents at the destination;
2) We have to read more data during the send operation and emit more
write commands.
Besides not being optimal behaviour, it also breaks user expectations and
is often reported by users, with a recent example in the Link tag at the
bottom of this change log.
Part of the reason for this non-optimal behaviour is that the backref
walking code does not provide information about the length of the file
extent items that were found for each backref, so send is blind about
which backref is the best to chose as a cloning source.
The other existing reasons are just silliness, namely always prefering
the inode with the lowest number when multiple are found for the same
root and when we can clone from multiple roots, always prefer the send
root over any of the other clone roots. This does not make any sense
since any inode or root is fine and as good as any other inode/root.
Fix this by making backref walking pass information about the number of
bytes referenced by each file extent item and then have send's backref
callback pick the inode with the highest number of bytes for each root.
Finally select the root from which we can clone more bytes from.
Example reproducer:
$ cat test.sh
#!/bin/bash
DEV=/dev/sdi
MNT=/mnt/sdi
mkfs.btrfs -f $DEV
mount $DEV $MNT
xfs_io -f -c "pwrite -S 0xab -b 2M 0 2M" $MNT/foo
cp --reflink=always $MNT/foo $MNT/bar
cp --reflink=always $MNT/foo $MNT/baz
sync
# Overwrite the second half of file foo.
xfs_io -c "pwrite -S 0xcd -b 1M 1M 1M" $MNT/foo
sync
echo
echo "*** fiemap in the original filesystem ***"
echo
xfs_io -c "fiemap -v" $MNT/foo
xfs_io -c "fiemap -v" $MNT/bar
xfs_io -c "fiemap -v" $MNT/baz
echo
btrfs filesystem du $MNT
btrfs subvolume snapshot -r $MNT $MNT/snap
btrfs send -f /tmp/send_stream $MNT/snap
umount $MNT
mkfs.btrfs -f $DEV &> /dev/null
mount $DEV $MNT
btrfs receive -f /tmp/send_stream $MNT
echo
echo "*** fiemap in the new filesystem ***"
echo
xfs_io -r -c "fiemap -v" $MNT/snap/foo
xfs_io -r -c "fiemap -v" $MNT/snap/bar
xfs_io -r -c "fiemap -v" $MNT/snap/baz
echo
btrfs filesystem du $MNT
rm -f /tmp/send_stream
rm -f /tmp/snap.fssum
umount $MNT
Before this change:
$ ./test.sh
(...)
*** fiemap in the original filesystem ***
/mnt/sdi/foo:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..2047]: 26624..28671 2048 0x2000
1: [2048..4095]: 30720..32767 2048 0x1
/mnt/sdi/bar:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..4095]: 26624..30719 4096 0x2001
/mnt/sdi/baz:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..4095]: 26624..30719 4096 0x2001
Total Exclusive Set shared Filename
2.00MiB 1.00MiB - /mnt/sdi/foo
2.00MiB 0.00B - /mnt/sdi/bar
2.00MiB 0.00B - /mnt/sdi/baz
6.00MiB 1.00MiB 2.00MiB /mnt/sdi
Create a readonly snapshot of '/mnt/sdi' in '/mnt/sdi/snap'
At subvol /mnt/sdi/snap
At subvol snap
*** fiemap in the new filesystem ***
/mnt/sdi/snap/foo:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..4095]: 26624..30719 4096 0x2001
/mnt/sdi/snap/bar:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..2047]: 26624..28671 2048 0x2000
1: [2048..4095]: 30720..32767 2048 0x1
/mnt/sdi/snap/baz:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..2047]: 26624..28671 2048 0x2000
1: [2048..4095]: 32768..34815 2048 0x1
Total Exclusive Set shared Filename
2.00MiB 0.00B - /mnt/sdi/snap/foo
2.00MiB 1.00MiB - /mnt/sdi/snap/bar
2.00MiB 1.00MiB - /mnt/sdi/snap/baz
6.00MiB 2.00MiB - /mnt/sdi/snap
6.00MiB 2.00MiB 2.00MiB /mnt/sdi
We end up with two 1M extents that are not shared for files bar and baz.
After this change:
$ ./test.sh
(...)
*** fiemap in the original filesystem ***
/mnt/sdi/foo:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..2047]: 26624..28671 2048 0x2000
1: [2048..4095]: 30720..32767 2048 0x1
/mnt/sdi/bar:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..4095]: 26624..30719 4096 0x2001
/mnt/sdi/baz:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..4095]: 26624..30719 4096 0x2001
Total Exclusive Set shared Filename
2.00MiB 1.00MiB - /mnt/sdi/foo
2.00MiB 0.00B - /mnt/sdi/bar
2.00MiB 0.00B - /mnt/sdi/baz
6.00MiB 1.00MiB 2.00MiB /mnt/sdi
Create a readonly snapshot of '/mnt/sdi' in '/mnt/sdi/snap'
At subvol /mnt/sdi/snap
At subvol snap
*** fiemap in the new filesystem ***
/mnt/sdi/snap/foo:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..4095]: 26624..30719 4096 0x2001
/mnt/sdi/snap/bar:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..2047]: 26624..28671 2048 0x2000
1: [2048..4095]: 30720..32767 2048 0x2001
/mnt/sdi/snap/baz:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..2047]: 26624..28671 2048 0x2000
1: [2048..4095]: 30720..32767 2048 0x2001
Total Exclusive Set shared Filename
2.00MiB 0.00B - /mnt/sdi/snap/foo
2.00MiB 0.00B - /mnt/sdi/snap/bar
2.00MiB 0.00B - /mnt/sdi/snap/baz
6.00MiB 0.00B - /mnt/sdi/snap
6.00MiB 0.00B 3.00MiB /mnt/sdi
Now there's a much better sharing, files bar and baz share 1M of the
extent of file foo and the second extent of files bar and baz is shared
between themselves.
This will later be turned into a test case for fstests.
Link: https://lore.kernel.org/linux-btrfs/20221008005704.795b44b0@crass-HP-ZBook-15-G2/
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
||
|
Filipe Manana
|
22a3c0ac8e |
btrfs: send: avoid unnecessary backref lookups when finding clone source
At find_extent_clone(), unless we are given an inline extent, a file
extent item that represents hole or an extent that starts beyond the
i_size, we always do backref walking to look for clone sources, unless
if we have more than SEND_MAX_EXTENT_REFS (64) known references on the
extent.
However if we know we only have one reference in the extent item and only
one clone source (the send root), then it's pointless to do the backref
walking to search for clone sources, as we can't clone from any other
root. So skip the backref walking in that case.
The following test was run on a non-debug kernel (Debian's default kernel
config):
$ cat test.sh
#!/bin/bash
DEV=/dev/sdi
MNT=/mnt/sdi
mkfs.btrfs -f $DEV
mount $DEV $MNT
# Create an extent tree that's not too small and none of the
# extents is shared.
for ((i = 1; i <= 50000; i++)); do
xfs_io -f -c "pwrite 0 4K" $MNT/file_$i > /dev/null
echo -ne "\r$i files created..."
done
echo
btrfs subvolume snapshot -r $MNT $MNT/snap
start=$(date +%s%N)
btrfs send $MNT/snap > /dev/null
end=$(date +%s%N)
dur=$(( (end - start) / 1000000 ))
echo -e "\nsend took $dur milliseconds"
umount $MNT
Before this change:
send took 5389 milliseconds
After this change:
send took 4519 milliseconds (-16.1%)
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
||
|
Filipe Manana
|
344174a1a6 |
btrfs: send: drop unnecessary backref context field initializations
At find_extent_clone() we are initializing to zero the 'found_itself' and
'found' fields of the backref context before we use it but we have already
initialized the structure to zeroes when we declared it on stack, so it's
pointless to initialize those fields and they are unnecessarily increasing
the object text size with two "mov" instructions (x86_64).
Similarly make the 'extent_len' initialization more clear by using an if-
-then-else instead of a double assignment to it in case the extent's end
crosses the i_size boundary.
Before this change:
$ size fs/btrfs/send.o
text data bss dec hex filename
68694 4252 16 72962 11d02 fs/btrfs/send.o
After this change:
$ size fs/btrfs/send.o
text data bss dec hex filename
68678 4252 16 72946 11cf2 fs/btrfs/send.o
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
||
|
Filipe Manana
|
d3f41317f0 |
btrfs: send: update comment at find_extent_clone()
We have this unclear comment at find_extent_clone() about extents starting at a file offset greater than or equals to the i_size of the inode. It's not really informative and it's misleading, since it mentions the author found such extents with snapshots and large files. Such extents are a result of fallocate with FALLOC_FL_KEEP_SIZE and there is no relation to snapshots or large files (all write paths update the i_size before inserting a new file extent item). So update the comment to be precise about it and why we don't bother looking for clone sources in that case. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Filipe Manana
|
61ce908a3c |
btrfs: send: avoid unnecessary path allocations when finding extent clone
When looking for an extent clone, at find_extent_clone(), we start by allocating a path and then check for cases where we can't have clones and exit immediately in those cases. It's a waste of time to allocate the path before those cases, so reorder the logic so that we check for those cases before allocating the path. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Josef Bacik
|
5c11adcc38 |
btrfs: move verity prototypes into verity.h
Move these out of ctree.h into verity.h to cut down on code in ctree.h. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Josef Bacik
|
7572dec8f5 |
btrfs: move ioctl prototypes into ioctl.h
Move these out of ctree.h into ioctl.h to cut down on code in ctree.h. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Josef Bacik
|
7c8ede1628 |
btrfs: move file-item prototypes into their own header
Move these prototypes out of ctree.h and into file-item.h. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Josef Bacik
|
f2b39277b8 |
btrfs: move dir-item prototypes into dir-item.h
Move these prototypes out of ctree.h and into their own header file. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
Omar Sandoval
|
94a48aef49 |
btrfs: extend btrfs_dir_item type to store encryption status
For directories with encrypted files/filenames, we need to store a flag indicating this fact. There's no room in other fields, so we'll need to borrow a bit from dir_type. Since it's now a combination of type and flags, we rename it to dir_flags to reflect its new usage. The new flag, FT_ENCRYPTED, indicates a directory containing encrypted data, which is orthogonal to file type; therefore, add the new flag, and make conversion from directory type to file type strip the flag. As the file types almost never change we can afford to use the bits. Actual usage will be guarded behind an incompat bit, this patch only adds the support for later use by fscrypt. Signed-off-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
Sweet Tea Dorminy
|
6db7531882 |
btrfs: use struct fscrypt_str instead of struct qstr
While struct qstr is more natural without fscrypt, since it's provided by dentries, struct fscrypt_str is provided by the fscrypt handlers processing dentries, and is thus more natural in the fscrypt world. Replace all of the struct qstr uses with struct fscrypt_str. Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Sweet Tea Dorminy
|
e43eec81c5 |
btrfs: use struct qstr instead of name and namelen pairs
Many functions throughout btrfs take name buffer and name length arguments. Most of these functions at the highest level are usually called with these arguments extracted from a supplied dentry's name. But the entire name can be passed instead, making each function a little more elegant. Each function whose arguments are currently the name and length extracted from a dentry is herein converted to instead take a pointer to the name in the dentry. The couple of calls to these calls without a struct dentry are converted to create an appropriate qstr to pass in. Additionally, every function which is only called with a name/len extracted directly from a qstr is also converted. This change has positive effect on stack consumption, frame of many functions is reduced but this will be used in the future for fscrypt related structures. Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Josef Bacik
|
07e81dc944 |
btrfs: move accessor helpers into accessors.h
This is a large patch, but because they're all macros it's impossible to split up. Simply copy all of the item accessors in ctree.h and paste them in accessors.h, and then update any files to include the header so everything compiles. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> [ reformat comments, style fixups ] Signed-off-by: David Sterba <dsterba@suse.com> |
||
Wang Yugui
|
875c627c5f |
btrfs: send add define for v2 buffer size
Add a define for the data buffer size (though the maximum size is not limited by it) BTRFS_SEND_BUF_SIZE_V2 so it's more visible. Signed-off-by: Wang Yugui <wangyugui@e16-tech.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Filipe Manana
|
a11452a370 |
btrfs: send: avoid unaligned encoded writes when attempting to clone range
When trying to see if we can clone a file range, there are cases where we
end up sending two write operations in case the inode from the source root
has an i_size that is not sector size aligned and the length from the
current offset to its i_size is less than the remaining length we are
trying to clone.
Issuing two write operations when we could instead issue a single write
operation is not incorrect. However it is not optimal, specially if the
extents are compressed and the flag BTRFS_SEND_FLAG_COMPRESSED was passed
to the send ioctl. In that case we can end up sending an encoded write
with an offset that is not sector size aligned, which makes the receiver
fallback to decompressing the data and writing it using regular buffered
IO (so re-compressing the data in case the fs is mounted with compression
enabled), because encoded writes fail with -EINVAL when an offset is not
sector size aligned.
The following example, which triggered a bug in the receiver code for the
fallback logic of decompressing + regular buffer IO and is fixed by the
patchset referred in a Link at the bottom of this changelog, is an example
where we have the non-optimal behaviour due to an unaligned encoded write:
$ cat test.sh
#!/bin/bash
DEV=/dev/sdj
MNT=/mnt/sdj
mkfs.btrfs -f $DEV > /dev/null
mount -o compress $DEV $MNT
# File foo has a size of 33K, not aligned to the sector size.
xfs_io -f -c "pwrite -S 0xab 0 33K" $MNT/foo
xfs_io -f -c "pwrite -S 0xcd 0 64K" $MNT/bar
# Now clone the first 32K of file bar into foo at offset 0.
xfs_io -c "reflink $MNT/bar 0 0 32K" $MNT/foo
# Snapshot the default subvolume and create a full send stream (v2).
btrfs subvolume snapshot -r $MNT $MNT/snap
btrfs send --compressed-data -f /tmp/test.send $MNT/snap
echo -e "\nFile bar in the original filesystem:"
od -A d -t x1 $MNT/snap/bar
umount $MNT
mkfs.btrfs -f $DEV > /dev/null
mount $DEV $MNT
echo -e "\nReceiving stream in a new filesystem..."
btrfs receive -f /tmp/test.send $MNT
echo -e "\nFile bar in the new filesystem:"
od -A d -t x1 $MNT/snap/bar
umount $MNT
Before this patch, the send stream included one regular write and one
encoded write for file 'bar', with the later being not sector size aligned
and causing the receiver to fallback to decompression + buffered writes.
The output of the btrfs receive command in verbose mode (-vvv):
(...)
mkfile o258-7-0
rename o258-7-0 -> bar
utimes
clone bar - source=foo source offset=0 offset=0 length=32768
write bar - offset=32768 length=1024
encoded_write bar - offset=33792, len=4096, unencoded_offset=33792, unencoded_file_len=31744, unencoded_len=65536, compression=1, encryption=0
encoded_write bar - falling back to decompress and write due to errno 22 ("Invalid argument")
(...)
This patch avoids the regular write followed by an unaligned encoded write
so that we end up sending a single encoded write that is aligned. So after
this patch the stream content is (output of btrfs receive -vvv):
(...)
mkfile o258-7-0
rename o258-7-0 -> bar
utimes
clone bar - source=foo source offset=0 offset=0 length=32768
encoded_write bar - offset=32768, len=4096, unencoded_offset=32768, unencoded_file_len=32768, unencoded_len=65536, compression=1, encryption=0
(...)
So we get more optimal behaviour and avoid the silent data loss bug in
versions of btrfs-progs affected by the bug referred by the Link tag
below (btrfs-progs v5.19, v5.19.1, v6.0 and v6.0.1).
Link: https://lore.kernel.org/linux-btrfs/cover.1668529099.git.fdmanana@suse.com/
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
||
Kees Cook
|
905889bc6c |
btrfs: send: Proactively round up to kmalloc bucket size
Instead of discovering the kmalloc bucket size _after_ allocation, round up proactively so the allocation is explicitly made for the full size, allowing the compiler to correctly reason about the resulting size of the buffer through the existing __alloc_size() hint. Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: linux-btrfs@vger.kernel.org Acked-by: David Sterba <dsterba@suse.com> Link: https://lore.kernel.org/lkml/20220922133014.GI32411@suse.cz Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220923202822.2667581-8-keescook@chromium.org |
||
BingJing Chang
|
9b8be45f1e |
btrfs: send: fix send failure of a subcase of orphan inodes
Commit |
||
|
David Sterba
|
c86eab81a2 |
btrfs: send: update command for protocol version check
For a protocol and command compatibility we have a helper that hasn't
been updated for v3 yet. We use it for verity so update where necessary.
Fixes:
|
||
Boris Burkov
|
9971a741c5 |
btrfs: send: allow protocol version 3 with CONFIG_BTRFS_DEBUG
We haven't finalized send stream v3 yet, so gate the send stream version behind CONFIG_BTRFS_DEBUG as we want some way to test it. The original verity send did not check the protocol version, so add that actual protection as well. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
BingJing Chang
|
9ed0a72e5b |
btrfs: send: fix failures when processing inodes with no links
There is a bug causing send failures when processing an orphan directory
with no links. In commit
|
||
|
BingJing Chang
|
7e93f6dc11 |
btrfs: send: refactor arguments of get_inode_info()
Refactor get_inode_info() to populate all wanted fields on an output structure. Besides, also introduce a helper function called get_inode_gen(), which is commonly used. Reviewed-by: Robbie Ko <robbieko@synology.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: BingJing Chang <bingjingc@synology.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Boris Burkov
|
38622010a6 |
btrfs: send: add support for fs-verity
Preserve the fs-verity status of a btrfs file across send/recv. There is no facility for installing the Merkle tree contents directly on the receiving filesystem, so we package up the parameters used to enable verity found in the verity descriptor. This gives the receive side enough information to properly enable verity again. Note that this means that receive will have to re-compute the whole Merkle tree, similar to how compression worked before encoded_write. Since the file becomes read-only after verity is enabled, it is important that verity is added to the send stream after any file writes. Therefore, when we process a verity item, merely note that it happened, then actually create the command in the send stream during 'finish_inode_if_needed'. This also creates V3 of the send stream format, without any format changes besides adding the new commands and attributes. Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Filipe Manana
|
0d8869fb6b |
btrfs: send: always use the rbtree based inode ref management infrastructure
After the patch "btrfs: send: fix sending link commands for existing file paths", we now have two infrastructures to detect and eliminate duplicated inode references (due to names that got removed and re-added between the send and parent snapshots): 1) One that works on a single inode ref/extref item; 2) A new one that works acrosss all ref/extref items for an inode, and it's also more efficient because even in the single ref/extref item case, it does not do a linear search for all the names encoded in the ref/extref item, it uses red black trees to speedup up the search. There's no good reason to keep both infrastructures, we can use the new one everywhere, and it's always more efficient. So remove the old infrastructure and change all sites that are using it to use the new one. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
BingJing Chang
|
3aa5bd367f |
btrfs: send: fix sending link commands for existing file paths
There is a bug sending link commands for existing file paths. When we're
processing an inode, we go over all references. All the new file paths are
added to the "new_refs" list. And all the deleted file paths are added to
the "deleted_refs" list. In the end, when we finish processing the inode,
we iterate over all the items in the "new_refs" list and send link commands
for those file paths. After that, we go over all the items in the
"deleted_refs" list and send unlink commands for them. If there are
duplicated file paths in both lists, we will try to create them before we
remove them. Then the receiver gets an -EEXIST error when trying the link
operations.
Example for having duplicated file paths in both list:
$ btrfs subvolume create vol
# create a file and 2000 hard links to the same inode
$ touch vol/foo
$ for i in {1..2000}; do link vol/foo vol/$i ; done
# take a snapshot for a parent snapshot
$ btrfs subvolume snapshot -r vol snap1
# remove 2000 hard links and re-create the last 1000 links
$ for i in {1..2000}; do rm vol/$i; done;
$ for i in {1001..2000}; do link vol/foo vol/$i; done
# take another one for a send snapshot
$ btrfs subvolume snapshot -r vol snap2
$ mkdir receive_dir
$ btrfs send snap2 -p snap1 | btrfs receive receive_dir/
At subvol snap2
link 1238 -> foo
ERROR: link 1238 -> foo failed: File exists
In this case, we will have the same file paths added to both lists. In the
parent snapshot, reference paths {1..1237} are stored in inode references,
but reference paths {1238..2000} are stored in inode extended references.
In the send snapshot, all reference paths {1001..2000} are stored in inode
references. During the incremental send, we process their inode references
first. In record_changed_ref(), we iterate all its inode references in the
send/parent snapshot. For every inode reference, we also use find_iref() to
check whether the same file path also appears in the parent/send snapshot
or not. Inode references {1238..2000} which appear in the send snapshot but
not in the parent snapshot are added to the "new_refs" list. On the other
hand, Inode references {1..1000} which appear in the parent snapshot but
not in the send snapshot are added to the "deleted_refs" list. Next, when
we process their inode extended references, reference paths {1238..2000}
are added to the "deleted_refs" list because all of them only appear in the
parent snapshot. Now two lists contain items as below:
"new_refs" list: {1238..2000}
"deleted_refs" list: {1..1000}, {1238..2000}
Reference paths {1238..2000} appear in both lists. And as the processing
order mentioned about before, the receiver gets an -EEXIST error when trying
the link operations.
To fix the bug, the idea is to process the "deleted_refs" list before
the "new_refs" list. However, it's not easy to reshuffle the processing
order. For one reason, if we do so, we may unlink all the existing paths
first, there's no valid path anymore for links. And it's inefficient
because we do a bunch of unlinks followed by links for the same paths.
Moreover, it makes less sense to have duplications in both lists. A
reference path cannot not only be regarded as new but also has been seen in
the past, or we won't call it a new path. However, it's also not a good
idea to make find_iref() check a reference against all inode references
and all inode extended references because it may result in large disk
reads.
So we introduce two rbtrees to make the references easier for lookups.
And we also introduce record_new_ref_if_needed() and
record_deleted_ref_if_needed() for changed_ref() to check and remove
duplicated references early.
Reviewed-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: BingJing Chang <bingjingc@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
||
|
BingJing Chang
|
71ecfc133b |
btrfs: send: introduce recorded_ref_alloc and recorded_ref_free
Introduce wrappers to allocate and free recorded_ref structures. Reviewed-by: Robbie Ko <robbieko@synology.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: BingJing Chang <bingjingc@synology.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
David Sterba
|
4824735918 |
btrfs: send: add new command FILEATTR for file attributes
There are file attributes inherited from previous ext2 SETFLAGS/GETFLAGS and later from XFLAGS interfaces, now commonly found under the 'fileattr' API. This corresponds to the individual inode bits and that's part of the on-disk format, so this is suitable for the protocol. The other interfaces contain a lot of cruft or bits that btrfs does not support yet. Currently the value is u64 and matches btrfs_inode_item. Not all the bits can be set by ioctls (like NODATASUM or READONLY), but we can send them over the protocol and leave it up to the receiving side what and how to apply. As some of the flags, eg. IMMUTABLE, can prevent any further changes, the receiving side needs to understand that and apply the changes in the right order, or possibly with some intermediate steps. This should be easier, future proof and simpler on the protocol layer than implementing in kernel. Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> |