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| author | Al Viro <viro@zeniv.linux.org.uk> | 2024-04-18 06:21:25 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2024-05-02 23:39:44 +0200 |
| commit | b85c42981ac4abeeb15d16437c40f52a8a64787d (patch) | |
| tree | da3a99d999fedb54b571e9b7c96c2c6d1f714eb5 /fs/btrfs | |
| parent | swsusp: don't bother with setting block size (diff) | |
| download | linux-b85c42981ac4abeeb15d16437c40f52a8a64787d.tar.xz linux-b85c42981ac4abeeb15d16437c40f52a8a64787d.zip | |
btrfs_get_bdev_and_sb(): call set_blocksize() only for exclusive opens
btrfs_get_bdev_and_sb() has two callers - btrfs_open_one_device(),
which asks for open to be exclusive and btrfs_get_dev_args_from_path(),
which doesn't. Currently it does set_blocksize() in all cases.
I'm rather dubious about the need to do set_blocksize() anywhere in btrfs,
to be honest - there's some access to page cache of underlying block
devices in there, but it's nowhere near the hot paths, AFAICT.
In any case, btrfs_get_dev_args_from_path() only needs to read
the on-disk superblock and copy several fields out of it; all
callers are only interested in devices that are already opened
and brought into per-filesystem set, so setting the block size
is redundant for those and actively harmful if we are given
a pathname of unrelated device.
So we only need btrfs_get_bdev_and_sb() to call set_blocksize()
when it's asked to open exclusive.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/volumes.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index f15591f3e54f..43af5a9fb547 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -482,10 +482,12 @@ btrfs_get_bdev_and_sb(const char *device_path, blk_mode_t flags, void *holder, if (flush) sync_blockdev(bdev); - ret = set_blocksize(bdev, BTRFS_BDEV_BLOCKSIZE); - if (ret) { - fput(*bdev_file); - goto error; + if (holder) { + ret = set_blocksize(bdev, BTRFS_BDEV_BLOCKSIZE); + if (ret) { + fput(*bdev_file); + goto error; + } } invalidate_bdev(bdev); *disk_super = btrfs_read_dev_super(bdev); @@ -498,6 +500,7 @@ btrfs_get_bdev_and_sb(const char *device_path, blk_mode_t flags, void *holder, return 0; error: + *disk_super = NULL; *bdev_file = NULL; return ret; } |