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path: root/fs/btrfs/send.c (follow)
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2025-03-18btrfs: make btrfs_iget() return a btrfs inode insteadFilipe Manana1-13/+12
It's an internal function and most of the time the callers are doing a lot of BTRFS_I() calls on the returned VFS inode to get the btrfs inode, so change the return type to struct btrfs_inode instead. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from send_encoded_extent()Filipe Manana1-8/+5
The 'out' label is pointless as we don't have anything to cleanup anymore (we used to have an inode to iput), so remove it and make error paths directly return an error. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: remove unnecessary inode lookup at send_encoded_inline_extent()Filipe Manana1-8/+1
We are doing a lookup of the inode but we don't use it at all. So just remove this pointless lookup. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: pass btrfs_root pointers to send ioctl parametersDavid Sterba1-2/+1
The ioctl switch btrfs_ioctl() provides several parameter types for convenience so we don't have to do the conversion in the callbacks. Pass root pointers to the send related functions. Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from send_set_xattr()Filipe Manana1-2/+1
There's no longer any need for the 'out' label as there are no resources to cleanup anymore in case of an error and we can directly return if begin_cmd() fails. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: avoid path allocation for the current inode when issuing commandsFilipe Manana1-118/+97
Whenever we issue a command we allocate a path and then compute it. For the current inode this is not necessary since we have one preallocated and computed in the send context structure, so we can use it instead and avoid allocating and freeing a path. For example if we have 100 extents to send (100 write commands) for a file, we are allocating and freeing paths 100 times. So improve on this by avoiding path allocation and freeing whenever a command is for the current inode by using the current inode's path stored in the send context structure. A test was run before applying this patch and the previous one in the series: "btrfs: send: keep the current inode's path cached" The test script is the following: $ cat test.sh #!/bin/bash DEV=/dev/nullb0 MNT=/mnt/nullb0 mkfs.btrfs -f $DEV > /dev/null mount $DEV $MNT DIR="$MNT/one/two/three/four" FILE="$DIR/foobar" mkdir -p $DIR # Create some empty files to get a deeper btree and therefore make # path computations slower. for ((i = 1; i <= 30000; i++)); do echo -n > "$DIR/filler_$i" done for ((i = 0; i < 10000; i += 2)); do offset=$(( i * 4096 )) xfs_io -f -c "pwrite -S 0xab $offset 4K" $FILE > /dev/null done btrfs subvolume snapshot -r $MNT $MNT/snap start=$(date +%s%N) btrfs send -f /dev/null $MNT/snap end=$(date +%s%N) echo -e "\nsend took $(( (end - start) / 1000000 )) milliseconds" umount $MNT Result before applying the 2 patches: 1121 milliseconds Result after applying the 2 patches: 815 milliseconds (-31.6%) Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: keep the current inode's path cachedFilipe Manana1-5/+48
Whenever we need to send a command for the current inode, like sending writes, xattr updates, truncates, utimes, etc, we compute the inode's path each time, which implies doing some memory allocations and traversing the inode hierarchy to extract the name of the inode and each ancestor directory, and that implies doing lookups in the subvolume tree amongst other operations. Most of the time, by far, the current inode's path doesn't change while we are processing it (like if we need to issue 100 write commands, the path remains the same and it's pointless to compute it 100 times). To avoid this keep the current inode's path cached in the send context and invalidate it or update it whenever it's needed (after unlinks or renames). A performance test, and its results, is mentioned in the next patch in the series (subject: "btrfs: send: avoid path allocation for the current inode when issuing commands"). Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from send_rmdir()Filipe Manana1-2/+1
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from send_unlink()Filipe Manana1-2/+1
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from send_link()Filipe Manana1-2/+1
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from send_rename()Filipe Manana1-2/+1
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from send_verity()Filipe Manana1-2/+1
There's no need for the 'out' label as there are no resources to cleanup in case of an error and we can directly return if begin_cmd() fails. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from process_changed_xattr()Filipe Manana1-6/+4
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: remove unnecessary return variable from process_new_xattr()Filipe Manana1-6/+2
There's no need for the 'ret' variable, we can just return directly the result of the call to iterate_dir_item(). Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from record_changed_ref()Filipe Manana1-6/+4
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from record_deleted_ref()Filipe Manana1-4/+2
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from record_new_ref()Filipe Manana1-4/+2
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from record_deleted_ref_if_needed()Filipe Manana1-3/+3
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from record_new_ref_if_needed()Filipe Manana1-3/+3
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from send_remove_xattr()Filipe Manana1-3/+2
There's no need for the 'out' label as there are no resources to cleanup in case of an error and we can directly return if begin_cmd() fails. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: add and use helper to rename current inode when processing refsFilipe Manana1-8/+15
Extract the logic to rename the current inode at process_recorded_refs() into a helper function and use it, therefore removing duplicated logic and making it easier for an upcoming patch by avoiding yet more duplicated logic. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: only use boolean variables at process_recorded_refs()Filipe Manana1-6/+6
We have several local variables at process_recorded_refs() that are used as booleans, with some of them having a 'bool' type while two of them having an 'int' type. Change this to make them all use the 'bool' type which is more clear and to make everything more consistent. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: factor out common logic when sending xattrsFilipe Manana1-26/+15
We always send xattrs for the current inode only and both callers of send_set_xattr() pass a path for the current inode. So move the path allocation and computation to send_set_xattr(), reducing duplicated code. This also facilitates an upcoming patch. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from get_cur_inode_state()Filipe Manana1-3/+2
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from is_inode_existent()Filipe Manana1-6/+3
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from __get_cur_name_and_parent()Filipe Manana1-14/+10
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: return -ENAMETOOLONG when attempting a path that is too longFilipe Manana1-4/+2
When attempting to build a too long path we are currently returning -ENOMEM, which is very odd and misleading. So update fs_path_ensure_buf() to return -ENAMETOOLONG instead. Also, while at it, move the WARN_ON() into the if statement's expression, as it makes it clear what is being tested and also has the effect of adding 'unlikely' to the statement, which allows the compiler to generate better code as this condition is never expected to happen. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from fs_path_add_from_extent_buffer()Filipe Manana1-3/+2
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: implement fs_path_add_path() using fs_path_add()Filipe Manana1-12/+2
The helper fs_path_add_path() is basically a copy of fs_path_add() and it can be made a wrapper around fs_path_add(). So do that and also make it inline and constify its second argument. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from fs_path_add()Filipe Manana1-3/+2
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: simplify return logic from fs_path_prepare_for_add()Filipe Manana1-3/+2
There is no need to have an 'out' label and jump into it since there are no resource cleanups to perform (release locks, free memory, etc), so make this simpler by removing the label and goto and instead return directly. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: always use fs_path_len() to determine a path's lengthFilipe Manana1-7/+8
Several places are hardcoding the path length calculation instead of using the helper fs_path_len() for that. Update all those places to instead use fs_path_len(). Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: make fs_path_len() inline and constify its argumentFilipe Manana1-1/+1
The helper function fs_path_len() is trivial and doesn't need to change its path argument, so make it inline and constify the argument. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: send: remove duplicated logic from fs_path_reset()Filipe Manana1-7/+5
There's duplicated logic in both branches of the if statement, so move it outside the branches. This also reduces the object code size. Before this change: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 1746279 163600 16920 1926799 1d668f fs/btrfs/btrfs.ko After this change: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 1746047 163592 16920 1926559 1d659f fs/btrfs/btrfs.ko Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18btrfs: update include and forward declarations in headersDavid Sterba1-1/+0
Pass over all header files and add missing forward declarations, includes or fix include types. Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13btrfs: send: remove redundant assignments to variable retColin Ian King1-2/+1
The variable ret is being initialized to zero and also later re-assigned to zero. In both cases the assignment is redundant since the value is never read after the assignment and hence they can be removed. Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-23btrfs: check folio mapping after unlock in put_file_data()Boris Burkov1-0/+6
When we call btrfs_read_folio() we get an unlocked folio, so it is possible for a different thread to concurrently modify folio->mapping. We must check that this hasn't happened once we do have the lock. CC: stable@vger.kernel.org # 6.12+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: send: check for read-only send root under critical sectionFilipe Manana1-10/+6
We're checking if the send root is read-only without being under the protection of the root's root_item_lock spinlock, which is what protects the root's flags when clearing the read-only flag, done at btrfs_ioctl_subvol_setflags(). Furthermore, it should be done in the same critical section that increments the root's send_in_progress counter, as btrfs_ioctl_subvol_setflags() clears the read-only flag in the same critical section that checks the counter's value. So fix this by moving the read-only check under the critical section delimited by the root's root_item_lock which also increments the root's send_in_progress counter. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: send: check for dead send root under critical sectionFilipe Manana1-9/+8
We're checking if the send root is dead without the protection of the root's root_item_lock spinlock, which is what protects the root's flags. The inverse, setting the dead flag on a root, is done under the protection of that lock, at btrfs_delete_subvolume(). Also checking and updating the root's send_in_progress counter is supposed to be done in the same critical section as checking for or setting the root dead flag, so that these operations are done atomically as a single step (which is correctly done by btrfs_delete_subvolume()). So fix this by checking if the send root is dead in the same critical section that updates the send_in_progress counter, which is protected by the root's root_item_lock spinlock. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)Mark Harmstone1-1/+2
Add an io_uring command for encoded reads, using the same interface as the existing BTRFS_IOC_ENCODED_READ ioctl. btrfs_uring_encoded_read() is an io_uring version of btrfs_ioctl_encoded_read(), which validates the user input and calls btrfs_encoded_read() to read the appropriate metadata. If we determine that we need to read an extent from disk, we call btrfs_encoded_read_regular_fill_pages() through btrfs_uring_read_extent() to prepare the bio. The existing btrfs_encoded_read_regular_fill_pages() is changed so that if it is passed a valid uring_ctx, rather than waking up any waiting threads it calls btrfs_uring_read_extent_endio(). This in turn copies the read data back to userspace, and calls io_uring_cmd_done() to complete the io_uring command. Because we're potentially doing a non-blocking read, btrfs_uring_read_extent() doesn't clean up after itself if it returns -EIOCBQUEUED. Instead, it allocates a priv struct, populates the fields there that we will need to unlock the inode and free our allocations, and defers this to the btrfs_uring_read_finished() that gets called when the bio completes. Signed-off-by: Mark Harmstone <maharmstone@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: drop unused parameter fs_info from btrfs_match_dir_item_name()David Sterba1-2/+1
Cascaded removal of fs_info that is not needed in several functions. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: drop unused parameter file_offset from btrfs_encoded_read_regular_fill_pages()David Sterba1-1/+1
The file_offset parameter used to be passed to encoded read struct but was removed in commit b665affe93d8 ("btrfs: remove unused members from struct btrfs_encoded_read_private"). Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: send: drop unused parameter index from iterate_inode_ref_t callbacksDavid Sterba1-13/+5
None of the ref iteration callbacks needs the index parameter (this is for the directory item iteration), so we can drop it. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11btrfs: send: drop unused parameter num from iterate_inode_ref_t callbacksDavid Sterba1-7/+5
None of the ref iteration callbacks needs the num parameter (this is for the directory item iteration), so we can drop it. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-11btrfs: send: cleanup unneeded return variable in changed_verity()Christian Heusel1-3/+1
As all changed_* functions need to return something, just return 0 directly here, as the verity status is passed via the context. Reported by LKP: fs/btrfs/send.c:6877:5-8: Unneeded variable: "ret". Return "0" on line 6883 Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202410092305.WbyqspH8-lkp@intel.com/ Signed-off-by: Christian Heusel <christian@heusel.eu> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-01btrfs: send: fix invalid clone operation for file that got its size decreasedFilipe Manana1-1/+22
During an incremental send we may end up sending an invalid clone operation, for the last extent of a file which ends at an unaligned offset that matches the final i_size of the file in the send snapshot, in case the file had its initial size (the size in the parent snapshot) decreased in the send snapshot. In this case the destination will fail to apply the clone operation because its end offset is not sector size aligned and it ends before the current size of the file. Sending the truncate operation always happens when we finish processing an inode, after we process all its extents (and xattrs, names, etc). So fix this by ensuring the file has a valid size before we send a clone operation for an unaligned extent that ends at the final i_size of the file. The size we truncate to matches the start offset of the clone range but it could be any value between that start offset and the final size of the file since the clone operation will expand the i_size if the current size is smaller than the end offset. The start offset of the range was chosen because it's always sector size aligned and avoids a truncation into the middle of a page, which results in dirtying the page due to filling part of it with zeroes and then making the clone operation at the receiver trigger IO. The following test reproduces the issue: $ cat test.sh #!/bin/bash DEV=/dev/sdi MNT=/mnt/sdi mkfs.btrfs -f $DEV mount $DEV $MNT # Create a file with a size of 256K + 5 bytes, having two extents, one # with a size of 128K and another one with a size of 128K + 5 bytes. last_ext_size=$((128 * 1024 + 5)) xfs_io -f -d -c "pwrite -S 0xab -b 128K 0 128K" \ -c "pwrite -S 0xcd -b $last_ext_size 128K $last_ext_size" \ $MNT/foo # Another file which we will later clone foo into, but initially with # a larger size than foo. xfs_io -f -c "pwrite -S 0xef 0 1M" $MNT/bar btrfs subvolume snapshot -r $MNT/ $MNT/snap1 # Now resize bar and clone foo into it. xfs_io -c "truncate 0" \ -c "reflink $MNT/foo" $MNT/bar btrfs subvolume snapshot -r $MNT/ $MNT/snap2 rm -f /tmp/send-full /tmp/send-inc btrfs send -f /tmp/send-full $MNT/snap1 btrfs send -p $MNT/snap1 -f /tmp/send-inc $MNT/snap2 umount $MNT mkfs.btrfs -f $DEV mount $DEV $MNT btrfs receive -f /tmp/send-full $MNT btrfs receive -f /tmp/send-inc $MNT umount $MNT Running it before this patch: $ ./test.sh (...) At subvol snap1 At snapshot snap2 ERROR: failed to clone extents to bar: Invalid argument A test case for fstests will be sent soon. Reported-by: Ben Millwood <thebenmachine@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CAJhrHS2z+WViO2h=ojYvBPDLsATwLbg+7JaNCyYomv0fUxEpQQ@mail.gmail.com/ Fixes: 46a6e10a1ab1 ("btrfs: send: allow cloning non-aligned extent if it ends at i_size") CC: stable@vger.kernel.org # 6.11 Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-01btrfs: send: fix buffer overflow detection when copying path to cache entryFilipe Manana1-3/+5
Starting with commit c0247d289e73 ("btrfs: send: annotate struct name_cache_entry with __counted_by()") we annotated the variable length array "name" from the name_cache_entry structure with __counted_by() to improve overflow detection. However that alone was not correct, because the length of that array does not match the "name_len" field - it matches that plus 1 to include the NUL string terminator, so that makes a fortified kernel think there's an overflow and report a splat like this: strcpy: detected buffer overflow: 20 byte write of buffer size 19 WARNING: CPU: 3 PID: 3310 at __fortify_report+0x45/0x50 CPU: 3 UID: 0 PID: 3310 Comm: btrfs Not tainted 6.11.0-prnet #1 Hardware name: CompuLab Ltd. sbc-ihsw/Intense-PC2 (IPC2), BIOS IPC2_3.330.7 X64 03/15/2018 RIP: 0010:__fortify_report+0x45/0x50 Code: 48 8b 34 (...) RSP: 0018:ffff97ebc0d6f650 EFLAGS: 00010246 RAX: 7749924ef60fa600 RBX: ffff8bf5446a521a RCX: 0000000000000027 RDX: 00000000ffffdfff RSI: ffff97ebc0d6f548 RDI: ffff8bf84e7a1cc8 RBP: ffff8bf548574080 R08: ffffffffa8c40e10 R09: 0000000000005ffd R10: 0000000000000004 R11: ffffffffa8c70e10 R12: ffff8bf551eef400 R13: 0000000000000000 R14: 0000000000000013 R15: 00000000000003a8 FS: 00007fae144de8c0(0000) GS:ffff8bf84e780000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fae14691690 CR3: 00000001027a2003 CR4: 00000000001706f0 Call Trace: <TASK> ? __warn+0x12a/0x1d0 ? __fortify_report+0x45/0x50 ? report_bug+0x154/0x1c0 ? handle_bug+0x42/0x70 ? exc_invalid_op+0x1a/0x50 ? asm_exc_invalid_op+0x1a/0x20 ? __fortify_report+0x45/0x50 __fortify_panic+0x9/0x10 __get_cur_name_and_parent+0x3bc/0x3c0 get_cur_path+0x207/0x3b0 send_extent_data+0x709/0x10d0 ? find_parent_nodes+0x22df/0x25d0 ? mas_nomem+0x13/0x90 ? mtree_insert_range+0xa5/0x110 ? btrfs_lru_cache_store+0x5f/0x1e0 ? iterate_extent_inodes+0x52d/0x5a0 process_extent+0xa96/0x11a0 ? __pfx_lookup_backref_cache+0x10/0x10 ? __pfx_store_backref_cache+0x10/0x10 ? __pfx_iterate_backrefs+0x10/0x10 ? __pfx_check_extent_item+0x10/0x10 changed_cb+0x6fa/0x930 ? tree_advance+0x362/0x390 ? memcmp_extent_buffer+0xd7/0x160 send_subvol+0xf0a/0x1520 btrfs_ioctl_send+0x106b/0x11d0 ? __pfx___clone_root_cmp_sort+0x10/0x10 _btrfs_ioctl_send+0x1ac/0x240 btrfs_ioctl+0x75b/0x850 __se_sys_ioctl+0xca/0x150 do_syscall_64+0x85/0x160 ? __count_memcg_events+0x69/0x100 ? handle_mm_fault+0x1327/0x15c0 ? __se_sys_rt_sigprocmask+0xf1/0x180 ? syscall_exit_to_user_mode+0x75/0xa0 ? do_syscall_64+0x91/0x160 ? do_user_addr_fault+0x21d/0x630 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fae145eeb4f Code: 00 48 89 (...) RSP: 002b:00007ffdf1cb09b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fae145eeb4f RDX: 00007ffdf1cb0ad0 RSI: 0000000040489426 RDI: 0000000000000004 RBP: 00000000000078fe R08: 00007fae144006c0 R09: 00007ffdf1cb0927 R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffdf1cb1ce8 R13: 0000000000000003 R14: 000055c499fab2e0 R15: 0000000000000004 </TASK> Fix this by not storing the NUL string terminator since we don't actually need it for name cache entries, this way "name_len" corresponds to the actual size of the "name" array. This requires marking the "name" array field with __nonstring and using memcpy() instead of strcpy() as recommended by the guidelines at: https://github.com/KSPP/linux/issues/90 Reported-by: David Arendt <admin@prnet.org> Link: https://lore.kernel.org/linux-btrfs/cee4591a-3088-49ba-99b8-d86b4242b8bd@prnet.org/ Fixes: c0247d289e73 ("btrfs: send: annotate struct name_cache_entry with __counted_by()") CC: stable@vger.kernel.org # 6.11 Tested-by: David Arendt <admin@prnet.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-09-10btrfs: send: fix grammar in commentsThorsten Blum1-2/+2
Fix a few obvious grammar mistakes: a -> an, then -> than. Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-15btrfs: send: annotate struct name_cache_entry with __counted_by()Thorsten Blum1-1/+1
Add the __counted_by compiler attribute to the flexible array member name to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE. Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-08-13btrfs: send: allow cloning non-aligned extent if it ends at i_sizeFilipe Manana1-13/+39
If we a find that an extent is shared but its end offset is not sector size aligned, then we don't clone it and issue write operations instead. This is because the reflink (remap_file_range) operation does not allow to clone unaligned ranges, except if the end offset of the range matches the i_size of the source and destination files (and the start offset is sector size aligned). While this is not incorrect because send can only guarantee that a file has the same data in the source and destination snapshots, it's not optimal and generates confusion and surprising behaviour for users. For example, running this test: $ cat test.sh #!/bin/bash DEV=/dev/sdi MNT=/mnt/sdi mkfs.btrfs -f $DEV mount $DEV $MNT # Use a file size not aligned to any possible sector size. file_size=$((1 * 1024 * 1024 + 5)) # 1MB + 5 bytes dd if=/dev/random of=$MNT/foo bs=$file_size count=1 cp --reflink=always $MNT/foo $MNT/bar btrfs subvolume snapshot -r $MNT/ $MNT/snap rm -f /tmp/send-test btrfs send -f /tmp/send-test $MNT/snap umount $MNT mkfs.btrfs -f $DEV mount $DEV $MNT btrfs receive -vv -f /tmp/send-test $MNT xfs_io -r -c "fiemap -v" $MNT/snap/bar umount $MNT Gives the following result: (...) mkfile o258-7-0 rename o258-7-0 -> bar write bar - offset=0 length=49152 write bar - offset=49152 length=49152 write bar - offset=98304 length=49152 write bar - offset=147456 length=49152 write bar - offset=196608 length=49152 write bar - offset=245760 length=49152 write bar - offset=294912 length=49152 write bar - offset=344064 length=49152 write bar - offset=393216 length=49152 write bar - offset=442368 length=49152 write bar - offset=491520 length=49152 write bar - offset=540672 length=49152 write bar - offset=589824 length=49152 write bar - offset=638976 length=49152 write bar - offset=688128 length=49152 write bar - offset=737280 length=49152 write bar - offset=786432 length=49152 write bar - offset=835584 length=49152 write bar - offset=884736 length=49152 write bar - offset=933888 length=49152 write bar - offset=983040 length=49152 write bar - offset=1032192 length=16389 chown bar - uid=0, gid=0 chmod bar - mode=0644 utimes bar utimes BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=06d640da-9ca1-604c-b87c-3375175a8eb3, stransid=7 /mnt/sdi/snap/bar: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..2055]: 26624..28679 2056 0x1 There's no clone operation to clone extents from the file foo into file bar and fiemap confirms there's no shared flag (0x2000). So update send_write_or_clone() so that it proceeds with cloning if the source and destination ranges end at the i_size of the respective files. After this changes the result of the test is: (...) mkfile o258-7-0 rename o258-7-0 -> bar clone bar - source=foo source offset=0 offset=0 length=1048581 chown bar - uid=0, gid=0 chmod bar - mode=0644 utimes bar utimes BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=582420f3-ea7d-564e-bbe5-ce440d622190, stransid=7 /mnt/sdi/snap/bar: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..2055]: 26624..28679 2056 0x2001 A test case for fstests will also follow up soon. Link: https://github.com/kdave/btrfs-progs/issues/572#issuecomment-2282841416 CC: stable@vger.kernel.org # 5.10+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>