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2018-03-26btrfs: manage thread_pool mount option as %uAnand Jain
The mount option thread_pool is always unsigned. Manage it that way all around. 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>
2018-03-01btrfs: use kvzalloc to allocate btrfs_fs_infoJeff Mahoney
The srcu_struct in btrfs_fs_info scales in size with NR_CPUS. On kernels built with NR_CPUS=8192, this can result in kmalloc failures that prevent mounting. There is work in progress to try to resolve this for every user of srcu_struct but using kvzalloc will work around the failures until that is complete. As an example with NR_CPUS=512 on x86_64: the overall size of subvol_srcu is 3460 bytes, fs_info is 6496. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfS: collapse btrfs_handle_error() into __btrfs_handle_fs_error()Anand Jain
There is no other consumer for btrfs_handle_error() other than __btrfs_handle_fs_error(), further this function quite small. Merge it into its parent. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> [ reformat comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: remove check for BTRFS_FS_STATE_ERROR which we just setAnand Jain
__btrfs_handle_fs_error() sets BTRFS_FS_STATE_ERROR, and calls btrfs_handle_error() so no need to check if the BTRFS_FS_STATE_ERROR is set in btrfs_handle_error(). And there is no other user of btrfs_handle_error() as well. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: factor btrfs_check_rw_degradable() to check given deviceAnand Jain
Update btrfs_check_rw_degradable() to check against the given device if its lost. We can use this function to know if the volume is going to be in degraded mode OR failed state, when the given device fails. Which is needed when we are handling the device failed state. A preparatory patch does not affect the flow as such. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Qu Wenruo <wqu@suse.com> [ enhance comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: drop unused parameters from mount_subvolDavid Sterba
Recent patches reworking the mount path left some unused parameters. We pass a vfsmount to mount_subvol, the flags and data (ie. mount options) have been already applied and we will not need them. Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: cleanup unnecessary string dup in btrfs_parse_options()Misono, Tomohiro
Long ago, commit edf24abe51493 ("btrfs: sanity mount option parsing and early mount code") split the btrfs_parse_options() into two parts (btrfs_parse_early_options() and btrfs_parse_options()). As a result, btrfs_parse_optins no longer gets called twice and is the last one to parse mount option string. Therefore there is no need to dup it. Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: remove unused arg from parse_subvol_options()Misono, Tomohiro
Remove unused arg 'holder' from parse_subvol_options(), which has been forgotten to be cleaned in the commit b99beb110e2d ("btrfs: split parse_early_options() in two"). Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: remove unused setup_root_args()Misono, Tomohiro
Since setup_root_args() is not used anymore, just remove it. Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: split parse_early_options() in twoMisono, Tomohiro
Now parse_early_options() is used by both btrfs_mount() and btrfs_mount_root(). However, the former only needs subvol related part and the latter needs the others. Therefore extract the subvol related parts from parse_early_options() and move it to new parse function (parse_subvol_options()). Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: cleanup btrfs_mount() using btrfs_mount_root()Misono, Tomohiro
Cleanup btrfs_mount() by using btrfs_mount_root(). This avoids getting btrfs_mount() called twice in mount path. Old btrfs_mount() will do: 0. VFS layer calls vfs_kern_mount() with registered file_system_type (for btrfs, btrfs_fs_type). btrfs_mount() is called on the way. 1. btrfs_parse_early_options() parses "subvolid=" mount option and set the value to subvol_objectid. Otherwise, subvol_objectid has the initial value of 0 2. check subvol_objectid is 5 or not. Assume this time id is not 5, then btrfs_mount() returns by calling mount_subvol() 3. In mount_subvol(), original mount options are modified to contain "subvolid=0" in setup_root_args(). Then, vfs_kern_mount() is called with btrfs_fs_type and new options 4. btrfs_mount() is called again 5. btrfs_parse_early_options() parses "subvolid=0" and set 5 (instead of 0) to subvol_objectid 6. check subvol_objectid is 5 or not. This time id is 5 and mount_subvol() is not called. btrfs_mount() finishes mounting a root 7. (in mount_subvol()) with using a return vale of vfs_kern_mount(), it calls mount_subtree() 8. return subvolume's dentry Reusing the same file_system_type (and btrfs_mount()) for vfs_kern_mount() is the cause of complication. Instead, new btrfs_mount() will do: 1. parse subvol id related options for later use in mount_subvol() 2. mount device's root by calling vfs_kern_mount() with btrfs_root_fs_type, which is not registered to VFS by register_filesystem(). As a result, btrfs_mount_root() is called 3. return by calling mount_subvol() The code of 2. is moved from the first part of mount_subvol(). The semantics of device holder changes from btrfs_fs_type to btrfs_root_fs_type and has to be used in all contexts. Otherwise we'd get wrong results when mount and dev scan would not check the same thing. (this has been found indendently and the fix is folded into this patch) Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> [ fold the btrfs_control_ioctl fixup, extend the comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: add btrfs_mount_root() and new file_system_typeMisono, Tomohiro
Add btrfs_mount_root() and new file_system_type for preparation of cleanup of btrfs_mount(). Code path is not changed yet. btrfs_mount_root() is almost the same as current btrfs_mount(), but doesn't have subvolume related part. Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: remove duplicate includesPravin Shedge
These duplicate includes have been found with scripts/checkincludes.pl but they have been removed manually to avoid removing false positives. Signed-off-by: Pravin Shedge <pravin.shedge4linux@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: show options: use helper to convert compression type stringDavid Sterba
Use the helper, if the COMPRESS option is set, the result is always defined and not empty. Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: cleanup device states define BTRFS_DEV_STATE_REPLACE_TGTAnand Jain
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_MISSINGAnand Jain
Currently device state is being managed by each individual int variable such as struct btrfs_device::missing. 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> Reviewed-by : Nikolay Borisov <nborisov@suse.com> [ whitespace adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22btrfs: cleanup device states define BTRFS_DEV_STATE_IN_FS_METADATAAnand Jain
Currently device state is being managed by each individual int variable such as struct btrfs_device::in_fs_metadata. Instead of that declare device state BTRFS_DEV_STATE_IN_FS_METADATA and use the bit operations. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> [ whitespace adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22Btrfs: add __init macro to btrfs init functionsLiu Bo
Adding __init macro gives kernel a hint that this function is only used during the initialization phase and its memory resources can be freed up after. 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>
2017-11-29Merge tag 'for-4.15-rc2-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "We've collected some fixes in since the pre-merge window freeze. There's technically only one regression fix for 4.15, but the rest seems important and candidates for stable. - fix missing flush bio puts in error cases (is serious, but rarely happens) - fix reporting stat::st_blocks for buffered append writes - fix space cache invalidation - fix out of bound memory access when setting zlib level - fix potential memory corruption when fsync fails in the middle - fix crash in integrity checker - incremetnal send fix, path mixup for certain unlink/rename combination - pass flags to writeback so compressed writes can be throttled properly - error handling fixes" * tag 'for-4.15-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: incremental send, fix wrong unlink path after renaming file btrfs: tree-checker: Fix false panic for sanity test Btrfs: fix list_add corruption and soft lockups in fsync btrfs: Fix wild memory access in compression level parser btrfs: fix deadlock when writing out space cache btrfs: clear space cache inode generation always Btrfs: fix reported number of inode blocks after buffered append writes Btrfs: move definition of the function btrfs_find_new_delalloc_bytes Btrfs: bail out gracefully rather than BUG_ON btrfs: dev_alloc_list is not protected by RCU, use normal list_del btrfs: add missing device::flush_bio puts btrfs: Fix transaction abort during failure in btrfs_rm_dev_item Btrfs: add write_flags for compression bio
2017-11-27Rename superblock flags (MS_xyz -> SB_xyz)Linus Torvalds
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>
2017-11-27btrfs: Fix wild memory access in compression level parserQu Wenruo
[BUG] Kernel panic when mounting with "-o compress" mount option. KASAN will report like: ------ ================================================================== BUG: KASAN: wild-memory-access in strncmp+0x31/0xc0 Read of size 1 at addr d86735fce994f800 by task mount/662 ... Call Trace: dump_stack+0xe3/0x175 kasan_report+0x163/0x370 __asan_load1+0x47/0x50 strncmp+0x31/0xc0 btrfs_compress_str2level+0x20/0x70 [btrfs] btrfs_parse_options+0xff4/0x1870 [btrfs] open_ctree+0x2679/0x49f0 [btrfs] btrfs_mount+0x1b7f/0x1d30 [btrfs] mount_fs+0x49/0x190 vfs_kern_mount.part.29+0xba/0x280 vfs_kern_mount+0x13/0x20 btrfs_mount+0x31e/0x1d30 [btrfs] mount_fs+0x49/0x190 vfs_kern_mount.part.29+0xba/0x280 do_mount+0xaad/0x1a00 SyS_mount+0x98/0xe0 entry_SYSCALL_64_fastpath+0x1f/0xbe ------ [Cause] For 'compress' and 'compress_force' options, its token doesn't expect any parameter so its args[0] contains uninitialized data. Accessing args[0] will cause above wild memory access. [Fix] For Opt_compress and Opt_compress_force, set compression level to the default. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ set the default in advance ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01btrfs: allow setting zlib compression level via :9Adam Borowski
This is bikeshedding, but it seems people are drastically more likely to understand "zlib:9" as compression level rather than an algorithm version compared to "zlib9". Based on feedback on the mailinglist, the ":9" will be the only accepted syntax. The level must be a single digit. Unrecognized format will result to the default, for forward compatibility in a similar way the compression algorithm specifier was relaxed in commit a7164fa4e055daf6368c ("btrfs: prepare for extensions in compression options"). Signed-off-by: Adam Borowski <kilobyte@angband.pl> Reviewed-by: David Sterba <dsterba@suse.com> [ tighten the accepted format ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01btrfs: allow to set compression level for zlibDavid Sterba
Preliminary support for setting compression level for zlib, the following works: $ mount -o compess=zlib # default $ mount -o compess=zlib0 # same $ mount -o compess=zlib9 # level 9, slower sync, less data $ mount -o compess=zlib1 # level 1, faster sync, more data $ mount -o remount,compress=zlib3 # level set by remount The compress-force works the same as compress'. The level is visible in the same format in /proc/mounts. Level set via file property does not work yet. Required patch: "btrfs: prepare for extensions in compression options" Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30btrfs: Replace opencoded sizes with their symbolic constantsNikolay Borisov
Currently btrfs' code uses a mix of opencoded sizes and defines from sizes.h. Let's unifiy the code base to always use the symbolic constants. No functional changes Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30btrfs: add ref-verify mount optionJosef Bacik
This adds the infrastructure for turning ref verify on and off for a mount, to be used by a later patch. Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> [ enhnance btrfs_print_mod_info to print if ref-verify is compiled in ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30btrfs: use appropriate replacements for __sb_{start,end}_write callsRakesh Pandit
Commit a53f4f8e9c8eb ("btrfs: Don't call btrfs_start_transaction() on frozen fs to avoid deadlock.") started using internal calls and we replace them with more suitable ones. Signed-off-by: Rakesh Pandit <rakesh@tuxera.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30btrfs: convert all mount option checking code to use btrfs_test_optSatoru Takeuchi
Signed-off-by: Satoru Takeuchi <satoru.takeuchi@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30btrfs: avoid null pointer dereference on fs_info when calling btrfs_critColin Ian King
There are checks on fs_info in __btrfs_panic to avoid dereferencing a null fs_info, however, there is a call to btrfs_crit that may also dereference a null fs_info. Fix this by adding a check to see if fs_info is null and only print the s_id if fs_info is non-null. Detected by CoverityScan CID#401973 ("Dereference after null check") Fixes: efe120a067c8 ("Btrfs: convert printk to btrfs_ and fix BTRFS prefix") 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>
2017-10-18Convert fs/*/* to SB_I_VERSIONMatthew Garrett
[AV: in addition to the fix in previous commit] Signed-off-by: Matthew Garrett <mjg59@google.com> Cc: David Howells <dhowells@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-09-14Merge branch 'work.mount' of ↵Linus Torvalds
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
2017-09-14Merge branch 'zstd-minimal' of ↵Linus Torvalds
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
2017-08-21btrfs: Do not use data_alloc_cluster in ssd modeHans van Kranenburg
This patch provides a band aid to improve the 'out of the box' behaviour of btrfs for disks that are detected as being an ssd. In a general purpose mixed workload scenario, the current ssd mode causes overallocation of available raw disk space for data, while leaving behind increasing amounts of unused fragmented free space. This situation leads to early ENOSPC problems which are harming user experience and adoption of btrfs as a general purpose filesystem. This patch modifies the data extent allocation behaviour of the ssd mode to make it behave identical to nossd mode. The metadata behaviour and additional ssd_spread option stay untouched so far. Recommendations for future development are to reconsider the current oversimplified nossd / ssd distinction and the broken detection mechanism based on the rotational attribute in sysfs and provide experienced users with a more flexible way to choose allocator behaviour for data and metadata, optimized for certain use cases, while keeping sane 'out of the box' default settings. The internals of the current btrfs code have more potential than what currently gets exposed to the user to choose from. The SSD story... In the first year of btrfs development, around early 2008, btrfs gained a mount option which enables specific functionality for filesystems on solid state devices. The first occurance of this functionality is in commit e18e4809, labeled "Add mount -o ssd, which includes optimizations for seek free storage". The effect on allocating free space for doing (data) writes is to 'cluster' writes together, writing them out in contiguous space, as opposed to a 'tetris' way of putting all separate writes into any free space fragment that fits (which is what the -o nossd behaviour does). A somewhat simplified explanation of what happens is that, when for example, the 'cluster' size is set to 2MiB, when we do some writes, the data allocator will search for a free space block that is 2MiB big, and put the writes in there. The ssd mode itself might allow a 2MiB cluster to be composed of multiple free space extents with some existing data in between, while the additional ssd_spread mount option kills off this option and requires fully free space. The idea behind this is (commit 536ac8ae): "The [...] clusters make it more likely a given IO will completely overwrite the ssd block, so it doesn't have to do an internal rwm cycle."; ssd block meaning nand erase block. So, effectively this means applying a "locality based algorithm" and trying to outsmart the actual ssd. Since then, various changes have been made to the involved code, but the basic idea is still present, and gets activated whenever the ssd mount option is active. This also happens by default, when the rotational flag as seen at /sys/block/<device>/queue/rotational is set to 0. However, there's a number of problems with this approach. First, what the optimization is trying to do is outsmart the ssd by assuming there is a relation between the physical address space of the block device as seen by btrfs and the actual physical storage of the ssd, and then adjusting data placement. However, since the introduction of the Flash Translation Layer (FTL) which is a part of the internal controller of an ssd, these attempts are futile. The use of good quality FTL in consumer ssd products might have been limited in 2008, but this situation has changed drastically soon after that time. Today, even the flash memory in your automatic cat feeding machine or your grandma's wheelchair has a full featured one. Second, the behaviour as described above results in the filesystem being filled up with badly fragmented free space extents because of relatively small pieces of space that are freed up by deletes, but not selected again as part of a 'cluster'. Since the algorithm prefers allocating a new chunk over going back to tetris mode, the end result is a filesystem in which all raw space is allocated, but which is composed of underutilized chunks with a 'shotgun blast' pattern of fragmented free space. Usually, the next problematic thing that happens is the filesystem wanting to allocate new space for metadata, which causes the filesystem to fail in spectacular ways. Third, the default mount options you get for an ssd ('ssd' mode enabled, 'discard' not enabled), in combination with spreading out writes over the full address space and ignoring freed up space leads to worst case behaviour in providing information to the ssd itself, since it will never learn that all the free space left behind is actually free. There are two ways to let an ssd know previously written data does not have to be preserved, which are sending explicit signals using discard or fstrim, or by simply overwriting the space with new data. The worst case behaviour is the btrfs ssd_spread mount option in combination with not having discard enabled. It has a side effect of minimizing the reuse of free space previously written in. Fourth, the rotational flag in /sys/ does not reliably indicate if the device is a locally attached ssd. For example, iSCSI or NBD displays as non-rotational, while a loop device on an ssd shows up as rotational. The combination of the second and third problem effectively means that despite all the good intentions, the btrfs ssd mode reliably causes the ssd hardware and the filesystem structures and performance to be choked to death. The clickbait version of the title of this story would have been "Btrfs ssd optimizations considered harmful for ssds". The current nossd 'tetris' mode (even still without discard) allows a pattern of overwriting much more previously used space, causing many more implicit discards to happen because of the overwrite information the ssd gets. The actual location in the physical address space, as seen from the point of view of btrfs is irrelevant, because the actual writes to the low level flash are reordered anyway thanks to the FTL. Changes made in the code 1. Make ssd mode data allocation identical to tetris mode, like nossd. 2. Adjust and clean up filesystem mount messages so that we can easily identify if a kernel has this patch applied or not, when providing support to end users. Also, make better use of the *_and_info helpers to only trigger messages on actual state changes. Backporting notes Notes for whoever wants to backport this patch to their 4.9 LTS kernel: * First apply commit 951e7966 "btrfs: drop the nossd flag when remounting with -o ssd", or fixup the differences manually. * The rest of the conflicts are because of the fs_info refactoring. So, for example, instead of using fs_info, it's root->fs_info in extent-tree.c Signed-off-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: prepare for extensions in compression optionsDavid Sterba
This is a minimal patch intended to be backported to older kernels. We're going to extend the string specifying the compression method and this would fail on kernels before that change (the string is compared exactly). Relax the string matching only to the prefix, ie. ignoring anything that goes after "zlib" or "lzo", regardless of th format extension we decide to use. This applies to the mount options and properties. That way, patched old kernels could be booted on systems already utilizing the new compression spec. Applicable since commit 63541927c8d11, v3.14. Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: use GFP_KERNEL in mount and remountDavid Sterba
We don't need to restrict the allocation flags in btrfs_mount or _remount. No big filesystem locks are held (possibly s_umount but that does no count here). Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: Do chunk level check for degraded remountQu Wenruo
Just the same for mount time check, use btrfs_check_rw_degradable() to check if we are OK to be remounted rw. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: resume qgroup rescan on rw remountAleksa Sarai
Several distributions mount the "proper root" as ro during initrd and then remount it as rw before pivot_root(2). Thus, if a rescan had been aborted by a previous shutdown, the rescan would never be resumed. This issue would manifest itself as several btrfs ioctl(2)s causing the entire machine to hang when btrfs_qgroup_wait_for_completion was hit (due to the fs_info->qgroup_rescan_running flag being set but the rescan itself not being resumed). Notably, Docker's btrfs storage driver makes regular use of BTRFS_QUOTA_CTL_DISABLE and BTRFS_IOC_QUOTA_RESCAN_WAIT (causing this problem to be manifested on boot for some machines). Cc: <stable@vger.kernel.org> # v3.11+ Cc: Jeff Mahoney <jeffm@suse.com> Fixes: b382a324b60f ("Btrfs: fix qgroup rescan resume on mount") Signed-off-by: Aleksa Sarai <asarai@suse.de> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16btrfs: backref, add tracepoints for prelim_ref insertion and mergingJeff Mahoney
This patch adds a tracepoint event for prelim_ref insertion and merging. For each, the ref being inserted or merged and the count of tree nodes is issued. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-15btrfs: Add zstd supportNick Terrell
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 Howells
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>
2017-07-15Merge branch 'work.mount' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull ->s_options removal from Al Viro: "Preparations for fsmount/fsopen stuff (coming next cycle). Everything gets moved to explicit ->show_options(), killing ->s_options off + some cosmetic bits around fs/namespace.c and friends. Basically, the stuff needed to work with fsmount series with minimum of conflicts with other work. It's not strictly required for this merge window, but it would reduce the PITA during the coming cycle, so it would be nice to have those bits and pieces out of the way" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: isofs: Fix isofs_show_options() VFS: Kill off s_options and helpers orangefs: Implement show_options 9p: Implement show_options isofs: Implement show_options afs: Implement show_options affs: Implement show_options befs: Implement show_options spufs: Implement show_options bpf: Implement show_options ramfs: Implement show_options pstore: Implement show_options omfs: Implement show_options hugetlbfs: Implement show_options VFS: Don't use save/replace_mount_options if not using generic_show_options VFS: Provide empty name qstr VFS: Make get_filesystem() return the affected filesystem VFS: Clean up whitespace in fs/namespace.c and fs/super.c Provide a function to create a NUL-terminated string from unterminated data
2017-07-06VFS: Don't use save/replace_mount_options if not using generic_show_optionsDavid Howells
btrfs, debugfs, reiserfs and tracefs call save_mount_options() and reiserfs calls replace_mount_options(), but they then implement their own ->show_options() methods and don't touch s_options, rendering the saved options unnecessary. I'm trying to eliminate s_options to make it easier to implement a context-based mount where the mount options can be passed individually over a file descriptor. Remove the calls to save/replace_mount_options() call in these cases. Signed-off-by: David Howells <dhowells@redhat.com> cc: Chris Mason <clm@fb.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Steven Rostedt <rostedt@goodmis.org> cc: linux-btrfs@vger.kernel.org cc: reiserfs-devel@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-29btrfs: fix integer overflow in calc_reclaim_items_nrChris Mason
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>
2017-06-20btrfs: obsolete and remove mount option alloc_startDavid Sterba
The mount option alloc_start was used in the past for debugging and stressing the chunk allocator. Not meant to be used by users, so we're not breaking anybody's setup. There was some added complexity handling changes of the value and when it was not same as default. Such code has likely been untested and I think it's better to remove it. This patch kills all use of alloc_start, and by doing that also fixes a bug when alloc_size is set, potentially called from statfs: in btrfs_calc_avail_data_space, traversing the list in RCU, the RCU protection is temporarily dropped so btrfs_account_dev_extents_size can be called and then RCU is locked again! Doing that inside list_for_each_entry_rcu is just asking for trouble, but unlikely to be observed in practice. Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-20btrfs: move fs_info::fs_frozen to the flagsDavid Sterba
We can keep the state among the other fs_info flags, there's no reason why fs_frozen would need to be separate. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19btrfs: use GFP_KERNEL in btrfs_calc_avail_data_spaceDavid Sterba
We don't hold any locks here. Inidirectly called from statfs. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19btrfs: cleanup root usage by btrfs_get_alloc_profileJeff Mahoney
There are two places where we don't already know what kind of alloc profile we need before calling btrfs_get_alloc_profile, but we need access to a root everywhere we call it. This patch adds helpers for btrfs_{data,metadata,system}_alloc_profile() and relegates btrfs_system_alloc_profile to a static for use in those two cases. The next patch will eliminate one of those. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-05-10Merge branch 'for-linus-4.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "This has fixes and cleanups Dave Sterba collected for the merge window. The biggest functional fixes are between btrfs raid5/6 and scrub, and raid5/6 and device replacement. Some of our pending qgroup fixes are included as well while I bash on the rest in testing. We also have the usual set of cleanups, including one that makes __btrfs_map_block() much more maintainable, and conversions from atomic_t to refcount_t" * 'for-linus-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (71 commits) btrfs: fix the gfp_mask for the reada_zones radix tree Btrfs: fix reported number of inode blocks Btrfs: send, fix file hole not being preserved due to inline extent Btrfs: fix extent map leak during fallocate error path Btrfs: fix incorrect space accounting after failure to insert inline extent Btrfs: fix invalid attempt to free reserved space on failure to cow range btrfs: Handle delalloc error correctly to avoid ordered extent hang btrfs: Fix metadata underflow caused by btrfs_reloc_clone_csum error btrfs: check if the device is flush capable btrfs: delete unused member nobarriers btrfs: scrub: Fix RAID56 recovery race condition btrfs: scrub: Introduce full stripe lock for RAID56 btrfs: Use ktime_get_real_ts for root ctime Btrfs: handle only applicable errors returned by btrfs_get_extent btrfs: qgroup: Fix qgroup corruption caused by inode_cache mount option btrfs: use q which is already obtained from bdev_get_queue Btrfs: switch to div64_u64 if with a u64 divisor Btrfs: update scrub_parity to use u64 stripe_len Btrfs: enable repair during read for raid56 profile btrfs: use clear_page where appropriate ...
2017-05-01Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block layer updates from Jens Axboe: - Add BFQ IO scheduler under the new blk-mq scheduling framework. BFQ was initially a fork of CFQ, but subsequently changed to implement fairness based on B-WF2Q+, a modified variant of WF2Q. BFQ is meant to be used on desktop type single drives, providing good fairness. From Paolo. - Add Kyber IO scheduler. This is a full multiqueue aware scheduler, using a scalable token based algorithm that throttles IO based on live completion IO stats, similary to blk-wbt. From Omar. - A series from Jan, moving users to separately allocated backing devices. This continues the work of separating backing device life times, solving various problems with hot removal. - A series of updates for lightnvm, mostly from Javier. Includes a 'pblk' target that exposes an open channel SSD as a physical block device. - A series of fixes and improvements for nbd from Josef. - A series from Omar, removing queue sharing between devices on mostly legacy drivers. This helps us clean up other bits, if we know that a queue only has a single device backing. This has been overdue for more than a decade. - Fixes for the blk-stats, and improvements to unify the stats and user windows. This both improves blk-wbt, and enables other users to register a need to receive IO stats for a device. From Omar. - blk-throttle improvements from Shaohua. This provides a scalable framework for implementing scalable priotization - particularly for blk-mq, but applicable to any type of block device. The interface is marked experimental for now. - Bucketized IO stats for IO polling from Stephen Bates. This improves efficiency of polled workloads in the presence of mixed block size IO. - A few fixes for opal, from Scott. - A few pulls for NVMe, including a lot of fixes for NVMe-over-fabrics. From a variety of folks, mostly Sagi and James Smart. - A series from Bart, improving our exposed info and capabilities from the blk-mq debugfs support. - A series from Christoph, cleaning up how handle WRITE_ZEROES. - A series from Christoph, cleaning up the block layer handling of how we track errors in a request. On top of being a nice cleanup, it also shrinks the size of struct request a bit. - Removal of mg_disk and hd (sorry Linus) by Christoph. The former was never used by platforms, and the latter has outlived it's usefulness. - Various little bug fixes and cleanups from a wide variety of folks. * 'for-4.12/block' of git://git.kernel.dk/linux-block: (329 commits) block: hide badblocks attribute by default blk-mq: unify hctx delay_work and run_work block: add kblock_mod_delayed_work_on() blk-mq: unify hctx delayed_run_work and run_work nbd: fix use after free on module unload MAINTAINERS: bfq: Add Paolo as maintainer for the BFQ I/O scheduler blk-mq-sched: alloate reserved tags out of normal pool mtip32xx: use runtime tag to initialize command header scsi: Implement blk_mq_ops.show_rq() blk-mq: Add blk_mq_ops.show_rq() blk-mq: Show operation, cmd_flags and rq_flags names blk-mq: Make blk_flags_show() callers append a newline character blk-mq: Move the "state" debugfs attribute one level down blk-mq: Unregister debugfs attributes earlier blk-mq: Only unregister hctxs for which registration succeeded blk-mq-debugfs: Rename functions for registering and unregistering the mq directory blk-mq: Let blk_mq_debugfs_register() look up the queue name blk-mq: Register <dev>/queue/mq after having registered <dev>/queue ide-pm: always pass 0 error to ide_complete_rq in ide_do_devset ide-pm: always pass 0 error to __blk_end_request_all ..
2017-04-20btrfs: Convert to separately allocated bdiJan Kara
Allocate struct backing_dev_info separately instead of embedding it inside superblock. This unifies handling of bdi among users. CC: Chris Mason <clm@fb.com> CC: Josef Bacik <jbacik@fb.com> CC: David Sterba <dsterba@suse.com> CC: linux-btrfs@vger.kernel.org Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-18btrfs: No need to check !(flags & MS_RDONLY) twiceGoldwyn Rodrigues
Code cleanup. The code block is for !(*flags & MS_RDONLY). We don't need to check it again. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-06-11 17:12:18 +0000