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2018-01-30Merge tag 'for-4.16-tag' of ↵Linus Torvalds1-27/+17
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs updates from David Sterba: "Features or user visible changes: - fallocate: implement zero range mode - avoid losing data raid profile when deleting a device - tree item checker: more checks for directory items and xattrs Notable fixes: - raid56 recovery: don't use cached stripes, that could be potentially changed and a later RMW or recovery would lead to corruptions or failures - let raid56 try harder to rebuild damaged data, reading from all stripes if necessary - fix scrub to repair raid56 in a similar way as in the case above Other: - cleanups: device freeing, removed some call indirections, redundant bio_put/_get, unused parameters, refactorings and renames - RCU list traversal fixups - simplify mount callchain, remove recursing back when mounting a subvolume - plug for fsync, may improve bio merging on multiple devices - compression heurisic: replace heap sort with radix sort, gains some performance - add extent map selftests, buffered write vs dio" * tag 'for-4.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (155 commits) btrfs: drop devid as device_list_add() arg btrfs: get device pointer from device_list_add() btrfs: set the total_devices in device_list_add() btrfs: move pr_info into device_list_add btrfs: make btrfs_free_stale_devices() to match the path btrfs: rename btrfs_free_stale_devices() arg to skip_dev btrfs: make btrfs_free_stale_devices() argument optional btrfs: make btrfs_free_stale_device() to iterate all stales btrfs: no need to check for btrfs_fs_devices::seeding btrfs: Use IS_ALIGNED in btrfs_truncate_block instead of opencoding it Btrfs: noinline merge_extent_mapping Btrfs: add WARN_ONCE to detect unexpected error from merge_extent_mapping Btrfs: extent map selftest: dio write vs dio read Btrfs: extent map selftest: buffered write vs dio read Btrfs: add extent map selftests Btrfs: move extent map specific code to extent_map.c Btrfs: add helper for em merge logic Btrfs: fix unexpected EEXIST from btrfs_get_extent Btrfs: fix incorrect block_len in merge_extent_mapping btrfs: Remove unused readahead spinlock ...
2018-01-29fs: new API for handling inode->i_versionJeff Layton1-0/+1
Add a documentation blob that explains what the i_version field is, how it is expected to work, and how it is currently implemented by various filesystems. We already have inode_inc_iversion. Add several other functions for manipulating and accessing the i_version counter. For now, the implementation is trivial and basically works the way that all of the open-coded i_version accesses work today. Future patches will convert existing users of i_version to use the new API, and then convert the backend implementation to do things more efficiently. Signed-off-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz>
2018-01-22btrfs: use correct string length in DEV_INFO ioctlXiongfeng Wang1-1/+1
gcc-8 reports: fs/btrfs/ioctl.c: In function 'btrfs_ioctl': ./include/linux/string.h:245:9: warning: '__builtin_strncpy' specified bound 1024 equals destination size [-Wstringop-truncation] We need one less byte or call strlcpy() to make it a nul-terminated string. This is done on the next line anyway, but we want to avoid the warning. Signed-off-by: Xiongfeng Wang <xiongfeng.wang@linaro.org> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: sink unlock_extent parameter gfp_flagsDavid Sterba1-4/+3
All callers pass either GFP_NOFS or GFP_KERNEL now, so we can sink the parameter to the function, though we lose some of the slightly better semantics of GFP_KERNEL in some places, it's worth cleaning up the callchains. Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: SETFLAGS ioctl: use helper for compression type conversionDavid Sterba1-6/+4
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: cleanup device states define BTRFS_DEV_STATE_REPLACE_TGTAnand Jain1-1/+1
Currently device state is being managed by each individual int variable such as struct btrfs_device::is_tgtdev_for_dev_replace. Instead of that declare btrfs_device::dev_state BTRFS_DEV_STATE_MISSING and use the bit operations. Signed-off-by: Anand Jain <anand.jain@oracle.com> [ whitespace adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: cleanup device states define BTRFS_DEV_STATE_WRITEABLEAnand Jain1-1/+1
Currently device state is being managed by each individual int variable such as struct btrfs_device::writeable. Instead of that declare device state BTRFS_DEV_STATE_WRITEABLE and use the bit operations. Signed-off-by: Anand Jain <anand.jain@oracle.com> [ whitespace adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: sink gfp parameter to clear_extent_bitDavid Sterba1-1/+1
All callers use GFP_NOFS, we don't have to pass it as an argument. The built-in tests pass GFP_KERNEL, but they run only at module load time and NOFS works there as well. Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: switch to RCU for device traversal in btrfs_ioctl_fs_infoDavid Sterba1-4/+4
We don't need to use the mutex as we do not modify the devices nor the list itself and just read information about device counts. Move copying fsid out of the protected section, not applicable to RCU same as the rest of the retrieved information. Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: switch to RCU for device traversal in btrfs_ioctl_dev_infoDavid Sterba1-5/+2
We don't need to use the mutex as we do not modify the devices nor the list itself and just read some information: does not change during device lifetime: - devid - uuid - name (ie. the path) may change in parallel to the ioctl call, but can lead only to reporting inacurracy: - bytes_used - total_bytes Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: move volume_mutex into the btrfs_rm_device()Anand Jain1-4/+0
A cleanup patch no functional change, we hold volume_mutex before calling btrfs_rm_device, so move it into the function itself. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-12-10Merge tag 'for-4.15-rc3-tag' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "This contains a few fixes (error handling, quota leak, FUA vs nobarrier mount option). There's one one worth mentioning separately - an off-by-one fix that leads to overwriting first byte of an adjacent page with 0, out of bounds of the memory allocated by an ioctl. This is under a privileged part of the ioctl, can be triggerd in some subvolume layouts" * tag 'for-4.15-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: Fix possible off-by-one in btrfs_search_path_in_tree Btrfs: disable FUA if mounted with nobarrier btrfs: fix missing error return in btrfs_drop_snapshot btrfs: handle errors while updating refcounts in update_ref_for_cow btrfs: Fix quota reservation leak on preallocated files
2017-12-07btrfs: Fix possible off-by-one in btrfs_search_path_in_treeNikolay Borisov1-1/+1
The name char array passed to btrfs_search_path_in_tree is of size BTRFS_INO_LOOKUP_PATH_MAX (4080). So the actual accessible char indexes are in the range of [0, 4079]. Currently the code uses the define but this represents an off-by-one. Implications: Size of btrfs_ioctl_ino_lookup_args is 4096, so the new byte will be written to extra space, not some padding that could be provided by the allocator. btrfs-progs store the arguments on stack, but kernel does own copy of the ioctl buffer and the off-by-one overwrite does not affect userspace, but the ending 0 might be lost. Kernel ioctl buffer is allocated dynamically so we're overwriting somebody else's memory, and the ioctl is privileged if args.objectid is not 256. Which is in most cases, but resolving a subvolume stored in another directory will trigger that path. Before this patch the buffer was one byte larger, but then the -1 was not added. Fixes: ac8e9819d71f907 ("Btrfs: add search and inode lookup ioctls") Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ added implications ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-28Rename superblock flags (MS_xyz -> SB_xyz)Linus Torvalds1-2/+2
This is a pure automated search-and-replace of the internal kernel superblock flags. The s_flags are now called SB_*, with the names and the values for the moment mirroring the MS_* flags that they're equivalent to. Note how the MS_xyz flags are the ones passed to the mount system call, while the SB_xyz flags are what we then use in sb->s_flags. The script to do this was: # places to look in; re security/*: it generally should *not* be # touched (that stuff parses mount(2) arguments directly), but # there are two places where we really deal with superblock flags. FILES="drivers/mtd drivers/staging/lustre fs ipc mm \ include/linux/fs.h include/uapi/linux/bfs_fs.h \ security/apparmor/apparmorfs.c security/apparmor/include/lib.h" # the list of MS_... constants SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \ DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \ POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \ I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \ ACTIVE NOUSER" SED_PROG= for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done # we want files that contain at least one of MS_..., # with fs/namespace.c and fs/pnode.c excluded. L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c') for f in $L; do sed -i $f $SED_PROG; done Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-01Btrfs: rework outstanding_extentsJosef Bacik1-0/+2
Right now we do a lot of weird hoops around outstanding_extents in order to keep the extent count consistent. This is because we logically transfer the outstanding_extent count from the initial reservation through the set_delalloc_bits. This makes it pretty difficult to get a handle on how and when we need to mess with outstanding_extents. Fix this by revamping the rules of how we deal with outstanding_extents. Now instead everybody that is holding on to a delalloc extent is required to increase the outstanding extents count for itself. This means we'll have something like this btrfs_delalloc_reserve_metadata - outstanding_extents = 1 btrfs_set_extent_delalloc - outstanding_extents = 2 btrfs_release_delalloc_extents - outstanding_extents = 1 for an initial file write. Now take the append write where we extend an existing delalloc range but still under the maximum extent size btrfs_delalloc_reserve_metadata - outstanding_extents = 2 btrfs_set_extent_delalloc btrfs_set_bit_hook - outstanding_extents = 3 btrfs_merge_extent_hook - outstanding_extents = 2 btrfs_delalloc_release_extents - outstanding_extnets = 1 In order to make the ordered extent transition we of course must now make ordered extents carry their own outstanding_extent reservation, so for cow_file_range we end up with btrfs_add_ordered_extent - outstanding_extents = 2 clear_extent_bit - outstanding_extents = 1 btrfs_remove_ordered_extent - outstanding_extents = 0 This makes all manipulations of outstanding_extents much more explicit. Every successful call to btrfs_delalloc_reserve_metadata _must_ now be combined with btrfs_release_delalloc_extents, even in the error case, as that is the only function that actually modifies the outstanding_extents counter. The drawback to this is now we are much more likely to have transient cases where outstanding_extents is much larger than it actually should be. This could happen before as we manipulated the delalloc bits, but now it happens basically at every write. This may put more pressure on the ENOSPC flushing code, but I think making this code simpler is worth the cost. I have another change coming to mitigate this side-effect somewhat. I also added trace points for the counter manipulation. These were used by a bpf script I wrote to help track down leak issues. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01btrfs: increase output size for LOGICAL_INO_V2 ioctlZygo Blaxell1-1/+2
Build-server workloads have hundreds of references per file after dedup. Multiply by a few snapshots and we quickly exhaust the limit of 2730 references per extent that can fit into a 64K buffer. Raise the limit to 16M to be consistent with other btrfs ioctls (e.g. TREE_SEARCH_V2, FILE_EXTENT_SAME). To minimize surprising userspace behavior, apply this change only to the LOGICAL_INO_V2 ioctl. Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> Tested-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01btrfs: add a flags argument to LOGICAL_INO and call it LOGICAL_INO_V2Zygo Blaxell1-3/+23
Now that check_extent_in_eb()'s extent offset filter can be turned off, we need a way to do it from userspace. Add a 'flags' field to the btrfs_logical_ino_args structure to disable extent offset filtering, taking the place of one of the existing reserved[] fields. Previous versions of LOGICAL_INO neglected to check whether any of the reserved fields have non-zero values. Assigning meaning to those fields now may change the behavior of existing programs that left these fields uninitialized. The lack of a zero check also means that new programs have no way to know whether the kernel is honoring the flags field. To avoid these problems, define a new ioctl LOGICAL_INO_V2. We can use the same argument layout as LOGICAL_INO, but shorten the reserved[] array by one element and turn it into the 'flags' field. The V2 ioctl explicitly checks that reserved fields and unsupported flag bits are zero so that userspace can negotiate future feature bits as they are defined. Since the memory layouts of the two ioctls' arguments are compatible, there is no need for a separate function for logical_to_ino_v2 (contrast with tree_search_v2 vs tree_search where the layout and code are quite different). A version parameter and an 'if' statement will suffice. Now that we have a flags field in logical_ino_args, add a flag BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET to get the behavior we want, and pass it down the stack to iterate_inodes_from_logical. Motivation and background, copied from the patchset cover letter: Suppose we have a file with one extent: root@tester:~# zcat /usr/share/doc/cpio/changelog.gz > /test/a root@tester:~# sync Split the extent by overwriting it in the middle: root@tester:~# cat /dev/urandom | dd bs=4k seek=2 skip=2 count=1 conv=notrunc of=/test/a We should now have 3 extent refs to 2 extents, with one block unreachable. The extent tree looks like: root@tester:~# btrfs-debug-tree /dev/vdc -t 2 [...] item 9 key (1103101952 EXTENT_ITEM 73728) itemoff 15942 itemsize 53 extent refs 2 gen 29 flags DATA extent data backref root 5 objectid 261 offset 0 count 2 [...] item 11 key (1103175680 EXTENT_ITEM 4096) itemoff 15865 itemsize 53 extent refs 1 gen 30 flags DATA extent data backref root 5 objectid 261 offset 8192 count 1 [...] and the ref tree looks like: root@tester:~# btrfs-debug-tree /dev/vdc -t 5 [...] item 6 key (261 EXTENT_DATA 0) itemoff 15825 itemsize 53 extent data disk byte 1103101952 nr 73728 extent data offset 0 nr 8192 ram 73728 extent compression(none) item 7 key (261 EXTENT_DATA 8192) itemoff 15772 itemsize 53 extent data disk byte 1103175680 nr 4096 extent data offset 0 nr 4096 ram 4096 extent compression(none) item 8 key (261 EXTENT_DATA 12288) itemoff 15719 itemsize 53 extent data disk byte 1103101952 nr 73728 extent data offset 12288 nr 61440 ram 73728 extent compression(none) [...] There are two references to the same extent with different, non-overlapping byte offsets: [------------------72K extent at 1103101952----------------------] [--8K----------------|--4K unreachable----|--60K-----------------] ^ ^ | | [--8K ref offset 0--][--4K ref offset 0--][--60K ref offset 12K--] | v [-----4K extent-----] at 1103175680 We want to find all of the references to extent bytenr 1103101952. Without the patch (and without running btrfs-debug-tree), we have to do it with 18 LOGICAL_INO calls: root@tester:~# btrfs ins log 1103101952 -P /test/ Using LOGICAL_INO inode 261 offset 0 root 5 root@tester:~# for x in $(seq 0 17); do btrfs ins log $((1103101952 + x * 4096)) -P /test/; done 2>&1 | grep inode inode 261 offset 0 root 5 inode 261 offset 4096 root 5 <- same extent ref as offset 0 (offset 8192 returns empty set, not reachable) inode 261 offset 12288 root 5 inode 261 offset 16384 root 5 \ inode 261 offset 20480 root 5 | inode 261 offset 24576 root 5 | inode 261 offset 28672 root 5 | inode 261 offset 32768 root 5 | inode 261 offset 36864 root 5 \ inode 261 offset 40960 root 5 > all the same extent ref as offset 12288. inode 261 offset 45056 root 5 / More processing required in userspace inode 261 offset 49152 root 5 | to figure out these are all duplicates. inode 261 offset 53248 root 5 | inode 261 offset 57344 root 5 | inode 261 offset 61440 root 5 | inode 261 offset 65536 root 5 | inode 261 offset 69632 root 5 / In the worst case the extents are 128MB long, and we have to do 32768 iterations of the loop to find one 4K extent ref. With the patch, we just use one call to map all refs to the extent at once: root@tester:~# btrfs ins log 1103101952 -P /test/ Using LOGICAL_INO_V2 inode 261 offset 0 root 5 inode 261 offset 12288 root 5 The TREE_SEARCH ioctl allows userspace to retrieve the offset and extent bytenr fields easily once the root, inode and offset are known. This is sufficient information to build a complete map of the extent and all of its references. Userspace can use this information to make better choices to dedup or defrag. Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> Tested-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> [ copy background and motivation from cover letter ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01btrfs: add a flag to iterate_inodes_from_logical to find all extent refs for ↵Zygo Blaxell1-1/+1
uncompressed extents The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and offset (encoded as a single logical address) to a list of extent refs. LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping (extent ref -> extent bytenr and offset, or logical address). These are useful capabilities for programs that manipulate extents and extent references from userspace (e.g. dedup and defrag utilities). When the extents are uncompressed (and not encrypted and not other), check_extent_in_eb performs filtering of the extent refs to remove any extent refs which do not contain the same extent offset as the 'logical' parameter's extent offset. This prevents LOGICAL_INO from returning references to more than a single block. To find the set of extent references to an uncompressed extent from [a, b), userspace has to run a loop like this pseudocode: for (i = a; i < b; ++i) extent_ref_set += LOGICAL_INO(i); At each iteration of the loop (up to 32768 iterations for a 128M extent), data we are interested in is collected in the kernel, then deleted by the filter in check_extent_in_eb. When the extents are compressed (or encrypted or other), the 'logical' parameter must be an extent bytenr (the 'a' parameter in the loop). No filtering by extent offset is done (or possible?) so the result is the complete set of extent refs for the entire extent. This removes the need for the loop, since we get all the extent refs in one call. Add an 'ignore_offset' argument to iterate_inodes_from_logical, [...several levels of function call graph...], and check_extent_in_eb, so that we can disable the extent offset filtering for uncompressed extents. This flag can be set by an improved version of the LOGICAL_INO ioctl to get either behavior as desired. There is no functional change in this patch. The new flag is always false. Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: David Sterba <dsterba@suse.com> [ minor coding style fixes ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30btrfs: pass root to various extent ref mod functionsJosef Bacik1-1/+1
We need the actual root for the ref verifier tool to work, so change these functions to pass the root around instead. This will be used in a subsequent patch. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30btrfs: fix send ioctl on 32bit with 64bit kernelJosef Bacik1-1/+53
We pass in a pointer in our send arg struct, this means the struct size doesn't match with 32bit user space and 64bit kernel space. Fix this by adding a compat mode and doing the appropriate conversion. Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> [ move structure to the beginning, next to receive 32bit compat ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30Btrfs: do not make defrag wait on async_delalloc_pagesLiu Bo1-15/+0
By setting compression for a defrag task, the task will start IO at the end of defrag. After the combo of filemap_flush(), we've already made sure that dirty pages have made progress via async compress thread because the second filemap_flush() will wait for page lock, which won't be unlocked until those pages have been marked as writeback and ordered extents have been queued. And this is for per-inode defrag, it's not helpful to wait on a global %async_delalloc_pages and %nr_async_submits from fs_info. Although waiting on %nr_async_submits means that all bios are submitted down to per-device schedule IO lists, it doesn't wait for their completions, thus users still need to do fsync/sync to make sure the data is on disk. While with this change, it makes sure that pages are marked with writeback bits and will be submitted asynchronously shortly, therefore, the behavior of defrag option '-c' remains unchanged. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30btrfs: Refactor transaction handling in received subvolume ioctlNikolay Borisov1-5/+1
If btrfs_transaction_commit fails it will proceed to call cleanup_transaction, which in turn already does btrfs_abort_transaction. So let's remove the unnecessary code duplication. Also let's be explicit about handling failure of btrfs_uuid_tree_add by calling btrfs_end_transaction. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30btrfs: Explicitly handle btrfs_update_root failureNikolay Borisov1-1/+6
btrfs_udpate_root can fail and it aborts the transaction, the correct way to handle an aborted transaction is to explicitly end with btrfs_end_transaction. Even now the code is correct since btrfs_commit_transaction would handle an aborted transaction but this is more of an implementation detail. So let's be explicit in handling failure in btrfs_update_root. Furthermore btrfs_commit_transaction can also fail and by ignoring it's return value we could have left the in-memory copy of the root item in an inconsistent state. So capture the error value which allows us to correctly revert the RO/RW flags in case of commit failure. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30btrfs: make array types static const, reduces object code sizeColin Ian King1-4/+6
Don't populate the read-only array types on the stack, instead make it static const. Makes the object code smaller by nearly 60 bytes: Before: text data bss dec hex filename 90536 6552 64 97152 17b80 fs/btrfs/ioctl.o After: text data bss dec hex filename 90414 6616 64 97094 17b46 fs/btrfs/ioctl.o Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30Btrfs: fix __user casting in ioctl.cOmar Sandoval1-5/+5
Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30Btrfs: use wait_event instead of a single functionLiu Bo1-18/+3
Since TASK_UNINTERRUPTIBLE has been used here, wait_event() can do the same job. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30Btrfs: move finish_wait out of the loopLiu Bo1-1/+1
If we're still going to wait after schedule(), we don't have to do finish_wait() to remove our %wait_queue_entry since prepare_to_wait() won't add the same %wait_queue_entry twice. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-09-29Merge branch 'for-4.14-rc3' of ↵Linus Torvalds1-4/+8
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "We've collected a bunch of isolated fixes, for crashes, user-visible behaviour or missing bits from other subsystem cleanups from the past. The overall number is not small but I was not able to make it significantly smaller. Most of the patches are supposed to go to stable" * 'for-4.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: log csums for all modified extents Btrfs: fix unexpected result when dio reading corrupted blocks btrfs: Report error on removing qgroup if del_qgroup_item fails Btrfs: skip checksum when reading compressed data if some IO have failed Btrfs: fix kernel oops while reading compressed data Btrfs: use btrfs_op instead of bio_op in __btrfs_map_block Btrfs: do not backup tree roots when fsync btrfs: remove BTRFS_FS_QUOTA_DISABLING flag btrfs: propagate error to btrfs_cmp_data_prepare caller btrfs: prevent to set invalid default subvolid Btrfs: send: fix error number for unknown inode types btrfs: fix NULL pointer dereference from free_reloc_roots() btrfs: finish ordered extent cleaning if no progress is found btrfs: clear ordered flag on cleaning up ordered extents Btrfs: fix incorrect {node,sector}size endianness from BTRFS_IOC_FS_INFO Btrfs: do not reset bio->bi_ops while writing bio Btrfs: use the new helper wbc_to_write_flags
2017-09-26btrfs: propagate error to btrfs_cmp_data_prepare callerNaohiro Aota1-1/+1
btrfs_cmp_data_prepare() (almost) always returns 0 i.e. ignoring errors from gather_extent_pages(). While the pages are freed by btrfs_cmp_data_free(), cmp->num_pages still has > 0. Then, btrfs_extent_same() try to access the already freed pages causing faults (or violates PageLocked assertion). This patch just return the error as is so that the caller stop the process. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Fixes: f441460202cb ("btrfs: fix deadlock with extent-same and readpage") Cc: <stable@vger.kernel.org> # 4.2 Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-09-26btrfs: prevent to set invalid default subvolidsatoru takeuchi1-0/+4
`btrfs sub set-default` succeeds to set an ID which isn't corresponding to any fs/file tree. If such the bad ID is set to a filesystem, we can't mount this filesystem without specifying `subvol` or `subvolid` mount options. Fixes: 6ef5ed0d386b ("Btrfs: add ioctl and incompat flag to set the default mount subvol") Cc: <stable@vger.kernel.org> Signed-off-by: Satoru Takeuchi <satoru.takeuchi@gmail.com> Reviewed-by: Qu Wenruo <quwenruo.btrfs@gmx.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-09-26Btrfs: fix incorrect {node,sector}size endianness from BTRFS_IOC_FS_INFOOmar Sandoval1-3/+3
fs_info->super_copy->{node,sector}size are little-endian, but the ioctl should return the values in native endianness. Use the cached values in btrfs_fs_info instead. Found with sparse. Fixes: 80a773fbfc2d ("btrfs: retrieve more info from FS_INFO ioctl") Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-09-15Merge branch 'work.mount' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull mount flag updates from Al Viro: "Another chunk of fmount preparations from dhowells; only trivial conflicts for that part. It separates MS_... bits (very grotty mount(2) ABI) from the struct super_block ->s_flags (kernel-internal, only a small subset of MS_... stuff). This does *not* convert the filesystems to new constants; only the infrastructure is done here. The next step in that series is where the conflicts would be; that's the conversion of filesystems. It's purely mechanical and it's better done after the merge, so if you could run something like list=$(for i in MS_RDONLY MS_NOSUID MS_NODEV MS_NOEXEC MS_SYNCHRONOUS MS_MANDLOCK MS_DIRSYNC MS_NOATIME MS_NODIRATIME MS_SILENT MS_POSIXACL MS_KERNMOUNT MS_I_VERSION MS_LAZYTIME; do git grep -l $i fs drivers/staging/lustre drivers/mtd ipc mm include/linux; done|sort|uniq|grep -v '^fs/namespace.c$') sed -i -e 's/\<MS_RDONLY\>/SB_RDONLY/g' \ -e 's/\<MS_NOSUID\>/SB_NOSUID/g' \ -e 's/\<MS_NODEV\>/SB_NODEV/g' \ -e 's/\<MS_NOEXEC\>/SB_NOEXEC/g' \ -e 's/\<MS_SYNCHRONOUS\>/SB_SYNCHRONOUS/g' \ -e 's/\<MS_MANDLOCK\>/SB_MANDLOCK/g' \ -e 's/\<MS_DIRSYNC\>/SB_DIRSYNC/g' \ -e 's/\<MS_NOATIME\>/SB_NOATIME/g' \ -e 's/\<MS_NODIRATIME\>/SB_NODIRATIME/g' \ -e 's/\<MS_SILENT\>/SB_SILENT/g' \ -e 's/\<MS_POSIXACL\>/SB_POSIXACL/g' \ -e 's/\<MS_KERNMOUNT\>/SB_KERNMOUNT/g' \ -e 's/\<MS_I_VERSION\>/SB_I_VERSION/g' \ -e 's/\<MS_LAZYTIME\>/SB_LAZYTIME/g' \ $list and commit it with something along the lines of 'convert filesystems away from use of MS_... constants' as commit message, it would save a quite a bit of headache next cycle" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: VFS: Differentiate mount flags (MS_*) from internal superblock flags VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb) vfs: Add sb_rdonly(sb) to query the MS_RDONLY flag on s_flags
2017-09-15Merge branch 'zstd-minimal' of ↵Linus Torvalds1-1/+5
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull zstd support from Chris Mason: "Nick Terrell's patch series to add zstd support to the kernel has been floating around for a while. After talking with Dave Sterba, Herbert and Phillip, we decided to send the whole thing in as one pull request. zstd is a big win in speed over zlib and in compression ratio over lzo, and the compression team here at FB has gotten great results using it in production. Nick will continue to update the kernel side with new improvements from the open source zstd userland code. Nick has a number of benchmarks for the main zstd code in his lib/zstd commit: I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM. The VM is running on a MacBook Pro with a 3.1 GHz Intel Core i7 processor, 16 GB of RAM, and a SSD. I benchmarked using `silesia.tar` [3], which is 211,988,480 B large. Run the following commands for the benchmark: sudo modprobe zstd_compress_test sudo mknod zstd_compress_test c 245 0 sudo cp silesia.tar zstd_compress_test The time is reported by the time of the userland `cp`. The MB/s is computed with 1,536,217,008 B / time(buffer size, hash) which includes the time to copy from userland. The Adjusted MB/s is computed with 1,536,217,088 B / (time(buffer size, hash) - time(buffer size, none)). The memory reported is the amount of memory the compressor requests. | Method | Size (B) | Time (s) | Ratio | MB/s | Adj MB/s | Mem (MB) | |----------|----------|----------|-------|---------|----------|----------| | none | 11988480 | 0.100 | 1 | 2119.88 | - | - | | zstd -1 | 73645762 | 1.044 | 2.878 | 203.05 | 224.56 | 1.23 | | zstd -3 | 66988878 | 1.761 | 3.165 | 120.38 | 127.63 | 2.47 | | zstd -5 | 65001259 | 2.563 | 3.261 | 82.71 | 86.07 | 2.86 | | zstd -10 | 60165346 | 13.242 | 3.523 | 16.01 | 16.13 | 13.22 | | zstd -15 | 58009756 | 47.601 | 3.654 | 4.45 | 4.46 | 21.61 | | zstd -19 | 54014593 | 102.835 | 3.925 | 2.06 | 2.06 | 60.15 | | zlib -1 | 77260026 | 2.895 | 2.744 | 73.23 | 75.85 | 0.27 | | zlib -3 | 72972206 | 4.116 | 2.905 | 51.50 | 52.79 | 0.27 | | zlib -6 | 68190360 | 9.633 | 3.109 | 22.01 | 22.24 | 0.27 | | zlib -9 | 67613382 | 22.554 | 3.135 | 9.40 | 9.44 | 0.27 | I benchmarked zstd decompression using the same method on the same machine. The benchmark file is located in the upstream zstd repo under `contrib/linux-kernel/zstd_decompress_test.c` [4]. The memory reported is the amount of memory required to decompress data compressed with the given compression level. If you know the maximum size of your input, you can reduce the memory usage of decompression irrespective of the compression level. | Method | Time (s) | MB/s | Adjusted MB/s | Memory (MB) | |----------|----------|---------|---------------|-------------| | none | 0.025 | 8479.54 | - | - | | zstd -1 | 0.358 | 592.15 | 636.60 | 0.84 | | zstd -3 | 0.396 | 535.32 | 571.40 | 1.46 | | zstd -5 | 0.396 | 535.32 | 571.40 | 1.46 | | zstd -10 | 0.374 | 566.81 | 607.42 | 2.51 | | zstd -15 | 0.379 | 559.34 | 598.84 | 4.61 | | zstd -19 | 0.412 | 514.54 | 547.77 | 8.80 | | zlib -1 | 0.940 | 225.52 | 231.68 | 0.04 | | zlib -3 | 0.883 | 240.08 | 247.07 | 0.04 | | zlib -6 | 0.844 | 251.17 | 258.84 | 0.04 | | zlib -9 | 0.837 | 253.27 | 287.64 | 0.04 | I ran a long series of tests and benchmarks on the btrfs side and the gains are very similar to the core benchmarks Nick ran" * 'zstd-minimal' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: squashfs: Add zstd support btrfs: Add zstd support lib: Add zstd modules lib: Add xxhash module
2017-08-18btrfs: Fix -EOVERFLOW handling in btrfs_ioctl_tree_search_v2Nikolay Borisov1-3/+0
The buffer passed to btrfs_ioctl_tree_search* functions have to be at least sizeof(struct btrfs_ioctl_search_header). If this is not the case then the ioctl should return -EOVERFLOW and set the uarg->buf_size to the minimum required size. Currently btrfs_ioctl_tree_search_v2 would return an -EOVERFLOW error with ->buf_size being set to the value passed by user space. Fix this by removing the size check and relying on search_ioctl, which already includes it and correctly sets buf_size. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Chris Mason <clm@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: fix readdir deadlock with pagefaultJosef Bacik1-7/+15
Readdir does dir_emit while under the btree lock. dir_emit can trigger the page fault which means we can deadlock. Fix this by allocating a buffer on opening a directory and copying the readdir into this buffer and doing dir_emit from outside of the tree lock. Thread A readdir <holding tree lock> dir_emit <page fault> down_read(mmap_sem) Thread B mmap write down_write(mmap_sem) page_mkwrite wait_ordered_extents Process C finish_ordered_extent insert_reserved_file_extent try to lock leaf <hang> Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> [ copy the deadlock scenario to changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: defrag: cleanup checking for compression statusDavid Sterba1-6/+6
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: separate defrag and property compressionDavid Sterba1-2/+2
Add new value for compression to distinguish between defrag and property. Previously, a single variable was used and this caused clashes when the per-file 'compression' was set and a defrag -c was called. The property-compression is loaded when the file is open, defrag will overwrite the same variable and reset to 0 (ie. NONE) at when the file defragmentaion is finished. That's considered a usability bug. Now we won't touch the property value, use the defrag-compression. The precedence of defrag is higher than for property (and whole-filesystem). Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: rename variable holding per-inode compression typeDavid Sterba1-2/+2
This is preparatory for separating inode compression requested by defrag and set via properties. This will fix a usability bug when defrag will reset compression type to NONE. If the file has compression set via property, it will not apply anymore (until next mount or reset through command line). We're going to fix that by adding another variable just for the defrag call and won't touch the property. The defrag will have higher priority when deciding whether to compress the data. Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: remove trivial wrapper btrfs_force_raDavid Sterba1-2/+2
It's a simple call page_cache_sync_readahead, same arguments in the same order. Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: fix spelling of snapshottingDavid Sterba1-5/+5
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: Deprecate userspace transaction ioctlsNikolay Borisov1-0/+11
Userspace transactions were introduced in commit 6bf13c0cc833 ("Btrfs: transaction ioctls") to provide semantics that Ceph's object store required. However, things have changed significantly since then, to the point where btrfs is no longer suitable as a backend for ceph and in fact it's actively advised against such usages. Considering this, there doesn't seem to be a widespread, legit use case of userspace transaction. They also clutter the file->private pointer. So to end the agony let's nuke the userspace transaction ioctls. As a first step let's give time for people to voice their objection by just WARN()ining when the userspace transaction is used. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ move the warning past perm checks, keep the has-been-printed state; we're ok with just one warning over all filesystems ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: defrag: make readahead state allocation failure non-fatalDavid Sterba1-7/+8
All sorts of readahead errors are not considered fatal. We can continue defragmentation without it, with some potential slow down, which will last only for the current inode. Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: use GFP_KERNEL in btrfs_defrag_fileDavid Sterba1-3/+2
We can safely use GFP_KERNEL, the function is called from two contexts: - ioctl handler, called directly, no locks taken - cleaner thread, running all queued defrag work, outside of any locks Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: Use explicit round_down macro in btrfs resize ioctl handlerNikolay Borisov1-2/+1
No functional changes, just make the code more self-explanatory. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: btrfs_inherit_iflags() can be staticAnand Jain1-31/+0
btrfs_new_inode() is the only consumer move it to inode.c, from ioctl.c. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-15btrfs: Add zstd supportNick Terrell1-1/+5
Add zstd compression and decompression support to BtrFS. zstd at its fastest level compresses almost as well as zlib, while offering much faster compression and decompression, approaching lzo speeds. I benchmarked btrfs with zstd compression against no compression, lzo compression, and zlib compression. I benchmarked two scenarios. Copying a set of files to btrfs, and then reading the files. Copying a tarball to btrfs, extracting it to btrfs, and then reading the extracted files. After every operation, I call `sync` and include the sync time. Between every pair of operations I unmount and remount the filesystem to avoid caching. The benchmark files can be found in the upstream zstd source repository under `contrib/linux-kernel/{btrfs-benchmark.sh,btrfs-extract-benchmark.sh}` [1] [2]. I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM. The VM is running on a MacBook Pro with a 3.1 GHz Intel Core i7 processor, 16 GB of RAM, and a SSD. The first compression benchmark is copying 10 copies of the unzipped Silesia corpus [3] into a BtrFS filesystem mounted with `-o compress-force=Method`. The decompression benchmark times how long it takes to `tar` all 10 copies into `/dev/null`. The compression ratio is measured by comparing the output of `df` and `du`. See the benchmark file [1] for details. I benchmarked multiple zstd compression levels, although the patch uses zstd level 1. | Method | Ratio | Compression MB/s | Decompression speed | |---------|-------|------------------|---------------------| | None | 0.99 | 504 | 686 | | lzo | 1.66 | 398 | 442 | | zlib | 2.58 | 65 | 241 | | zstd 1 | 2.57 | 260 | 383 | | zstd 3 | 2.71 | 174 | 408 | | zstd 6 | 2.87 | 70 | 398 | | zstd 9 | 2.92 | 43 | 406 | | zstd 12 | 2.93 | 21 | 408 | | zstd 15 | 3.01 | 11 | 354 | The next benchmark first copies `linux-4.11.6.tar` [4] to btrfs. Then it measures the compression ratio, extracts the tar, and deletes the tar. Then it measures the compression ratio again, and `tar`s the extracted files into `/dev/null`. See the benchmark file [2] for details. | Method | Tar Ratio | Extract Ratio | Copy (s) | Extract (s)| Read (s) | |--------|-----------|---------------|----------|------------|----------| | None | 0.97 | 0.78 | 0.981 | 5.501 | 8.807 | | lzo | 2.06 | 1.38 | 1.631 | 8.458 | 8.585 | | zlib | 3.40 | 1.86 | 7.750 | 21.544 | 11.744 | | zstd 1 | 3.57 | 1.85 | 2.579 | 11.479 | 9.389 | [1] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/btrfs-benchmark.sh [2] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/btrfs-extract-benchmark.sh [3] http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia [4] https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.11.6.tar.xz zstd source repository: https://github.com/facebook/zstd Signed-off-by: Nick Terrell <terrelln@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2017-07-17VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)David Howells1-1/+1
Firstly by applying the following with coccinelle's spatch: @@ expression SB; @@ -SB->s_flags & MS_RDONLY +sb_rdonly(SB) to effect the conversion to sb_rdonly(sb), then by applying: @@ expression A, SB; @@ ( -(!sb_rdonly(SB)) && A +!sb_rdonly(SB) && A | -A != (sb_rdonly(SB)) +A != sb_rdonly(SB) | -A == (sb_rdonly(SB)) +A == sb_rdonly(SB) | -!(sb_rdonly(SB)) +!sb_rdonly(SB) | -A && (sb_rdonly(SB)) +A && sb_rdonly(SB) | -A || (sb_rdonly(SB)) +A || sb_rdonly(SB) | -(sb_rdonly(SB)) != A +sb_rdonly(SB) != A | -(sb_rdonly(SB)) == A +sb_rdonly(SB) == A | -(sb_rdonly(SB)) && A +sb_rdonly(SB) && A | -(sb_rdonly(SB)) || A +sb_rdonly(SB) || A ) @@ expression A, B, SB; @@ ( -(sb_rdonly(SB)) ? 1 : 0 +sb_rdonly(SB) | -(sb_rdonly(SB)) ? A : B +sb_rdonly(SB) ? A : B ) to remove left over excess bracketage and finally by applying: @@ expression A, SB; @@ ( -(A & MS_RDONLY) != sb_rdonly(SB) +(bool)(A & MS_RDONLY) != sb_rdonly(SB) | -(A & MS_RDONLY) == sb_rdonly(SB) +(bool)(A & MS_RDONLY) == sb_rdonly(SB) ) to make comparisons against the result of sb_rdonly() (which is a bool) work correctly. Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-29btrfs: fix integer overflow in calc_reclaim_items_nrChris Mason1-1/+1
Dave Jones hit a WARN_ON(nr < 0) in btrfs_wait_ordered_roots() with v4.12-rc6. This was because commit 70e7af244 made it possible for calc_reclaim_items_nr() to return a negative number. It's not really a bug in that commit, it just didn't go far enough down the stack to find all the possible 64->32 bit overflows. This switches calc_reclaim_items_nr() to return a u64 and changes everyone that uses the results of that math to u64 as well. Reported-by: Dave Jones <davej@codemonkey.org.uk> Fixes: 70e7af2 ("Btrfs: fix delalloc accounting leak caused by u32 overflow") Signed-off-by: Chris Mason <clm@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ↵Qu Wenruo1-2/+2
ranges [BUG] For the following case, btrfs can underflow qgroup reserved space at an error path: (Page size 4K, function name without "btrfs_" prefix) Task A | Task B ---------------------------------------------------------------------- Buffered_write [0, 2K) | |- check_data_free_space() | | |- qgroup_reserve_data() | | Range aligned to page | | range [0, 4K) <<< | | 4K bytes reserved <<< | |- copy pages to page cache | | Buffered_write [2K, 4K) | |- check_data_free_space() | | |- qgroup_reserved_data() | | Range alinged to page | | range [0, 4K) | | Already reserved by A <<< | | 0 bytes reserved <<< | |- delalloc_reserve_metadata() | | And it *FAILED* (Maybe EQUOTA) | |- free_reserved_data_space() |- qgroup_free_data() Range aligned to page range [0, 4K) Freeing 4K (Special thanks to Chandan for the detailed report and analyse) [CAUSE] Above Task B is freeing reserved data range [0, 4K) which is actually reserved by Task A. And at writeback time, page dirty by Task A will go through writeback routine, which will free 4K reserved data space at file extent insert time, causing the qgroup underflow. [FIX] For btrfs_qgroup_free_data(), add @reserved parameter to only free data ranges reserved by previous btrfs_qgroup_reserve_data(). So in above case, Task B will try to free 0 byte, so no underflow. Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29btrfs: qgroup: Introduce extent changeset for qgroup reserve functionsQu Wenruo1-1/+4
Introduce a new parameter, struct extent_changeset for btrfs_qgroup_reserved_data() and its callers. Such extent_changeset was used in btrfs_qgroup_reserve_data() to record which range it reserved in current reserve, so it can free it in error paths. The reason we need to export it to callers is, at buffered write error path, without knowing what exactly which range we reserved in current allocation, we can free space which is not reserved by us. This will lead to qgroup reserved space underflow. Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
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