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| author | Ming Lei <ming.lei@redhat.com> | 2022-01-26 11:58:30 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-02-11 15:10:49 -0700 |
| commit | 06582bc86d7f48d35cd044098ca1e246e8c7c52e (patch) | |
| tree | d6038c855d863a83b254063fd3f6bea8887a1bad /drivers/block/loop.c | |
| parent | a12821d5e012a42673f6fe521971f193441d8aa4 (diff) | |
| download | linux-06582bc86d7f48d35cd044098ca1e246e8c7c52e.tar.gz | |
block: loop:use kstatfs.f_bsize of backing file to set discard granularity
If backing file's filesystem has implemented ->fallocate(), we think the
loop device can support discard, then pass sb->s_blocksize as
discard_granularity. However, some underlying FS, such as overlayfs,
doesn't set sb->s_blocksize, and causes discard_granularity to be set as
zero, then the warning in __blkdev_issue_discard() is triggered.
Christoph suggested to pass kstatfs.f_bsize as discard granularity, and
this way is fine because kstatfs.f_bsize means 'Optimal transfer block
size', which still matches with definition of discard granularity.
So fix the issue by setting discard_granularity as kstatfs.f_bsize if it
is available, otherwise claims discard isn't supported.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Reported-by: Pei Zhang <pezhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220126035830.296465-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/loop.c')
| -rw-r--r-- | drivers/block/loop.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 150012ffb387f5..19fe19eaa50e93 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -79,6 +79,7 @@ #include <linux/ioprio.h> #include <linux/blk-cgroup.h> #include <linux/sched/mm.h> +#include <linux/statfs.h> #include "loop.h" @@ -774,8 +775,13 @@ static void loop_config_discard(struct loop_device *lo) granularity = 0; } else { + struct kstatfs sbuf; + max_discard_sectors = UINT_MAX >> 9; - granularity = inode->i_sb->s_blocksize; + if (!vfs_statfs(&file->f_path, &sbuf)) + granularity = sbuf.f_bsize; + else + max_discard_sectors = 0; } if (max_discard_sectors) { |