| Message ID | 20180420235904.27496-4-mcgrof@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri 20-04-18 16:59:04, Luis R. Rodriguez wrote: > freeze_bdev() will bail but leave the bd_fsfreeze_count incremented > if the get_active_super() does not find the superblock on our > super_blocks list to match. > > This issue has been present since v2.6.29 during the introduction of the > ioctl_fsfreeze() and ioctl_fsthaw() via commit fcccf502540e3 ("filesystem > freeze: implement generic freeze feature"). > > I am not aware of any existing races which have triggered this > situation, however, if it does trigger it could mean leaving a > superblock with bd_fsfreeze_count always positive. > > Fixes: fcccf502540e3 ("filesystem freeze: implement generic freeze feature") > Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Looks good to me. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/block_dev.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/block_dev.c b/fs/block_dev.c > index b54966679833..7a532aa58c07 100644 > --- a/fs/block_dev.c > +++ b/fs/block_dev.c > @@ -507,8 +507,10 @@ struct super_block *freeze_bdev(struct block_device *bdev) > } > > sb = get_active_super(bdev); > - if (!sb) > + if (!sb) { > + bdev->bd_fsfreeze_count--; > goto out; > + } > if (sb->s_op->freeze_super) > error = sb->s_op->freeze_super(sb); > else > -- > 2.16.3 >
diff --git a/fs/block_dev.c b/fs/block_dev.c index b54966679833..7a532aa58c07 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -507,8 +507,10 @@ struct super_block *freeze_bdev(struct block_device *bdev) } sb = get_active_super(bdev); - if (!sb) + if (!sb) { + bdev->bd_fsfreeze_count--; goto out; + } if (sb->s_op->freeze_super) error = sb->s_op->freeze_super(sb); else
freeze_bdev() will bail but leave the bd_fsfreeze_count incremented if the get_active_super() does not find the superblock on our super_blocks list to match. This issue has been present since v2.6.29 during the introduction of the ioctl_fsfreeze() and ioctl_fsthaw() via commit fcccf502540e3 ("filesystem freeze: implement generic freeze feature"). I am not aware of any existing races which have triggered this situation, however, if it does trigger it could mean leaving a superblock with bd_fsfreeze_count always positive. Fixes: fcccf502540e3 ("filesystem freeze: implement generic freeze feature") Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> --- fs/block_dev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)