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| author | shunki-fujita <shunki-fujita@cybozu.co.jp> | 2018-04-05 16:20:07 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-05 21:36:23 -0700 |
| commit | 849cf55963dfd877ad92996195e0fe7218eaf0e9 (patch) | |
| tree | 3c1dab29c873beb615163ff832024b3c9e09752e /fs/block_dev.c | |
| parent | 9421c3e64137ec69e5cf4ed024dc777a09b7779f (diff) | |
| download | linux-849cf55963dfd877ad92996195e0fe7218eaf0e9.tar.gz linux-849cf55963dfd877ad92996195e0fe7218eaf0e9.tar.bz2 linux-849cf55963dfd877ad92996195e0fe7218eaf0e9.zip | |
fs: don't flush pagecache when expanding block device
When changing the size of a block device, its all caches are freed.
It's necessary on shrinking to prevent spurious I/Os to the disappeared
region. However, on expanding, such kind of I/Os doesn't happen.
Similar things can be considered for btrfs filesystem resize and
resize2fs, but they are designed not to drop caches when expanding.
Therefore this patch removes unnecessary cache drop.
Link: http://lkml.kernel.org/r/1521457240-153390-1-git-send-email-shunki-fujita@cybozu.co.jp
Signed-off-by: Shunki Fujita <shunki-fujita@cybozu.co.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/block_dev.c')
| -rw-r--r-- | fs/block_dev.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index fe09ef9c21f3..7a506c55a993 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1324,7 +1324,8 @@ static void flush_disk(struct block_device *bdev, bool kill_dirty) * @bdev: struct bdev to adjust. * * This routine checks to see if the bdev size does not match the disk size - * and adjusts it if it differs. + * and adjusts it if it differs. When shrinking the bdev size, its all caches + * are freed. */ void check_disk_size_change(struct gendisk *disk, struct block_device *bdev) { @@ -1337,7 +1338,8 @@ void check_disk_size_change(struct gendisk *disk, struct block_device *bdev) "%s: detected capacity change from %lld to %lld\n", disk->disk_name, bdev_size, disk_size); i_size_write(bdev->bd_inode, disk_size); - flush_disk(bdev, false); + if (bdev_size > disk_size) + flush_disk(bdev, false); } } EXPORT_SYMBOL(check_disk_size_change); |