[PATCH 02/11] fs: provide unlocked helper thaw_super()
From: "Luis R. Rodriguez" <mcgrof@kernel.org>
Date: 2017-11-29 23:24:03
Also in:
linux-block, linux-fsdevel, linux-xfs, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
thaw_super() hold a write lock, however we wish to also enable callers which already hold the write lock. To do this provide a helper and make thaw_super() use it. This way, all that thaw_super() does now is lock handling and active count management. This change has no functional changes. Suggested-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> --- fs/super.c | 39 ++++++++++++++++++++++++++------------- 1 file changed, 26 insertions(+), 13 deletions(-)
diff --git a/fs/super.c b/fs/super.c
index a7650ff22f0e..cecc279beecd 100644
--- a/fs/super.c
+++ b/fs/super.c@@ -1493,21 +1493,13 @@ int freeze_super(struct super_block *sb) } EXPORT_SYMBOL(freeze_super); -/** - * thaw_super -- unlock filesystem - * @sb: the super to thaw - * - * Unlocks the filesystem and marks it writeable again after freeze_super(). - */ -int thaw_super(struct super_block *sb) +/* Caller takes lock and handles active count */ +static int thaw_locked_super(struct super_block *sb) { int error; - down_write(&sb->s_umount); - if (sb->s_writers.frozen != SB_FREEZE_COMPLETE) { - up_write(&sb->s_umount); + if (sb->s_writers.frozen != SB_FREEZE_COMPLETE) return -EINVAL; - } if (sb_rdonly(sb)) { sb->s_writers.frozen = SB_UNFROZEN;
@@ -1522,7 +1514,6 @@ int thaw_super(struct super_block *sb) printk(KERN_ERR "VFS:Filesystem thaw failed\n"); lockdep_sb_freeze_release(sb); - up_write(&sb->s_umount); return error; } }
@@ -1531,7 +1522,29 @@ int thaw_super(struct super_block *sb) sb_freeze_unlock(sb); out: wake_up(&sb->s_writers.wait_unfrozen); - deactivate_locked_super(sb); return 0; } + +/** + * thaw_super -- unlock filesystem + * @sb: the super to thaw + * + * Unlocks the filesystem and marks it writeable again after freeze_super(). + */ +int thaw_super(struct super_block *sb) +{ + int error; + + down_write(&sb->s_umount); + error = thaw_locked_super(sb); + if (error) { + up_write(&sb->s_umount); + goto out; + } + + deactivate_locked_super(sb); + +out: + return error; +} EXPORT_SYMBOL(thaw_super);
--
2.15.0