Commit 384d87ef2c95 ("block: Do not discard buffers under a mounted filesystem") made paths issuing discard or zeroout requests to the underlying device try to grab block device in exclusive mode. If that failed we returned EBUSY to userspace. This however caused unexpected fallout in userspace where e.g. FUSE filesystems issue discard requests from userspace daemons although the device is open exclusively by the kernel. Also shrinking of logical volume by LVM issues discard requests to a device which may be claimed exclusively because there's another LV on the same PV. So to avoid these userspace regressions, fall back to invalidate_inode_pages2_range() instead of returning EBUSY to userspace and return EBUSY only of that call fails as well (meaning that there's indeed someone using the particular device range we are trying to discard).
Link: https://bugzilla.kernel.org/show_bug.cgi?id=211167 Fixes: 384d87ef2c95 ("block: Do not discard buffers under a mounted filesystem") CC: stable@vger.kernel.org Signed-off-by: Jan Kara jack@suse.cz --- fs/block_dev.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c index 235b5042672e..c33151020bcd 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -118,13 +118,22 @@ int truncate_bdev_range(struct block_device *bdev, fmode_t mode, if (!(mode & FMODE_EXCL)) { int err = bd_prepare_to_claim(bdev, truncate_bdev_range); if (err) - return err; + goto invalidate; }
truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend); if (!(mode & FMODE_EXCL)) bd_abort_claiming(bdev, truncate_bdev_range); return 0; + +invalidate: + /* + * Someone else has handle exclusively open. Try invalidating instead. + * The 'end' argument is inclusive so the rounding is safe. + */ + return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping, + lstart >> PAGE_SHIFT, + lend >> PAGE_SHIFT); } EXPORT_SYMBOL(truncate_bdev_range);
On Mon 22-02-21 10:48:09, Jan Kara wrote:
Commit 384d87ef2c95 ("block: Do not discard buffers under a mounted filesystem") made paths issuing discard or zeroout requests to the underlying device try to grab block device in exclusive mode. If that failed we returned EBUSY to userspace. This however caused unexpected fallout in userspace where e.g. FUSE filesystems issue discard requests from userspace daemons although the device is open exclusively by the kernel. Also shrinking of logical volume by LVM issues discard requests to a device which may be claimed exclusively because there's another LV on the same PV. So to avoid these userspace regressions, fall back to invalidate_inode_pages2_range() instead of returning EBUSY to userspace and return EBUSY only of that call fails as well (meaning that there's indeed someone using the particular device range we are trying to discard).
Link: https://bugzilla.kernel.org/show_bug.cgi?id=211167 Fixes: 384d87ef2c95 ("block: Do not discard buffers under a mounted filesystem") CC: stable@vger.kernel.org Signed-off-by: Jan Kara jack@suse.cz
Before I forget: I'd like to add two tested by tags to give credit to people who helped with testing.
Tested-by: Richard W.M. Jones rjones@redhat.com Tested-by: Andreas Klauer Andreas.Klauer@metamorpher.de
Honza
fs/block_dev.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c index 235b5042672e..c33151020bcd 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -118,13 +118,22 @@ int truncate_bdev_range(struct block_device *bdev, fmode_t mode, if (!(mode & FMODE_EXCL)) { int err = bd_prepare_to_claim(bdev, truncate_bdev_range); if (err)
return err;
goto invalidate;truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend); if (!(mode & FMODE_EXCL)) bd_abort_claiming(bdev, truncate_bdev_range); return 0;
+invalidate:
- /*
* Someone else has handle exclusively open. Try invalidating instead.* The 'end' argument is inclusive so the rounding is safe.*/- return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping,
lstart >> PAGE_SHIFT,lend >> PAGE_SHIFT);} EXPORT_SYMBOL(truncate_bdev_range); -- 2.26.2
On Mon 22-02-21 10:48:09, Jan Kara wrote:
Commit 384d87ef2c95 ("block: Do not discard buffers under a mounted filesystem") made paths issuing discard or zeroout requests to the underlying device try to grab block device in exclusive mode. If that failed we returned EBUSY to userspace. This however caused unexpected fallout in userspace where e.g. FUSE filesystems issue discard requests from userspace daemons although the device is open exclusively by the kernel. Also shrinking of logical volume by LVM issues discard requests to a device which may be claimed exclusively because there's another LV on the same PV. So to avoid these userspace regressions, fall back to invalidate_inode_pages2_range() instead of returning EBUSY to userspace and return EBUSY only of that call fails as well (meaning that there's indeed someone using the particular device range we are trying to discard).
Link: https://bugzilla.kernel.org/show_bug.cgi?id=211167 Fixes: 384d87ef2c95 ("block: Do not discard buffers under a mounted filesystem") CC: stable@vger.kernel.org Signed-off-by: Jan Kara jack@suse.cz
Ping guys? Can we get this reviewed and merged? Thanks!
Honza
fs/block_dev.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c index 235b5042672e..c33151020bcd 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -118,13 +118,22 @@ int truncate_bdev_range(struct block_device *bdev, fmode_t mode, if (!(mode & FMODE_EXCL)) { int err = bd_prepare_to_claim(bdev, truncate_bdev_range); if (err)
return err;
goto invalidate;truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend); if (!(mode & FMODE_EXCL)) bd_abort_claiming(bdev, truncate_bdev_range); return 0;
+invalidate:
- /*
* Someone else has handle exclusively open. Try invalidating instead.* The 'end' argument is inclusive so the rounding is safe.*/- return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping,
lstart >> PAGE_SHIFT,lend >> PAGE_SHIFT);} EXPORT_SYMBOL(truncate_bdev_range); -- 2.26.2
On 2/22/21 2:48 AM, Jan Kara wrote:
Commit 384d87ef2c95 ("block: Do not discard buffers under a mounted filesystem") made paths issuing discard or zeroout requests to the underlying device try to grab block device in exclusive mode. If that failed we returned EBUSY to userspace. This however caused unexpected fallout in userspace where e.g. FUSE filesystems issue discard requests from userspace daemons although the device is open exclusively by the kernel. Also shrinking of logical volume by LVM issues discard requests to a device which may be claimed exclusively because there's another LV on the same PV. So to avoid these userspace regressions, fall back to invalidate_inode_pages2_range() instead of returning EBUSY to userspace and return EBUSY only of that call fails as well (meaning that there's indeed someone using the particular device range we are trying to discard).
This missed -rc2, but I'll queue it up for -rc3.
linux-stable-mirror@lists.linaro.org
-
Christoph Hellwig -
Jan Kara -
Jens Axboe