| Message ID | 20230927-vfs-super-freeze-v1-6-ecc36d9ab4d9@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Implement freeze and thaw as holder operations | expand |
On Wed, Sep 27, 2023 at 03:21:19PM +0200, Christian Brauner wrote: > The grab_super() helper is now only used by grab_super_dead(). Merge the > two helpers into one. > > Signed-off-by: Christian Brauner <brauner@kernel.org> Yup, nice cleanup... Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > --- > fs/super.c | 44 +++++++------------------------------------- > 1 file changed, 7 insertions(+), 37 deletions(-) > > diff --git a/fs/super.c b/fs/super.c > index 181ac8501301..6cdce2b31622 100644 > --- a/fs/super.c > +++ b/fs/super.c > @@ -517,35 +517,6 @@ void deactivate_super(struct super_block *s) > > EXPORT_SYMBOL(deactivate_super); > > -/** > - * grab_super - acquire an active reference > - * @s: reference we are trying to make active > - * > - * Tries to acquire an active reference. grab_super() is used when we > - * had just found a superblock in super_blocks or fs_type->fs_supers > - * and want to turn it into a full-blown active reference. grab_super() > - * is called with sb_lock held and drops it. Returns 1 in case of > - * success, 0 if we had failed (superblock contents was already dead or > - * dying when grab_super() had been called). Note that this is only > - * called for superblocks not in rundown mode (== ones still on ->fs_supers > - * of their type), so increment of ->s_count is OK here. > - */ > -static int grab_super(struct super_block *s) __releases(sb_lock) > -{ > - bool born; > - > - s->s_count++; > - spin_unlock(&sb_lock); > - born = super_lock_excl(s); > - if (born && atomic_inc_not_zero(&s->s_active)) { > - put_super(s); > - return 1; > - } > - super_unlock_excl(s); > - put_super(s); > - return 0; > -} > - > static inline bool wait_dead(struct super_block *sb) > { > unsigned int flags; > @@ -559,7 +530,7 @@ static inline bool wait_dead(struct super_block *sb) > } > > /** > - * grab_super_dead - acquire an active reference to a superblock > + * grab_super - acquire an active reference to a superblock > * @sb: superblock to acquire > * > * Acquire a temporary reference on a superblock and try to trade it for > @@ -570,17 +541,16 @@ static inline bool wait_dead(struct super_block *sb) > * Return: This returns true if an active reference could be acquired, > * false if not. > */ > -static bool grab_super_dead(struct super_block *sb) > +static bool grab_super(struct super_block *sb) > { > - > sb->s_count++; > - if (grab_super(sb)) { > + spin_unlock(&sb_lock); > + if (super_lock_excl(sb) && atomic_inc_not_zero(&sb->s_active)) { > put_super(sb); > - lockdep_assert_held(&sb->s_umount); > return true; > } > + super_unlock_excl(sb); > wait_var_event(&sb->s_flags, wait_dead(sb)); > - lockdep_assert_not_held(&sb->s_umount); > put_super(sb); > return false; > } > @@ -831,7 +801,7 @@ struct super_block *sget_fc(struct fs_context *fc, > warnfc(fc, "reusing existing filesystem in another namespace not allowed"); > return ERR_PTR(-EBUSY); > } > - if (!grab_super_dead(old)) > + if (!grab_super(old)) > goto retry; > destroy_unused_super(s); > return old; > @@ -875,7 +845,7 @@ struct super_block *sget(struct file_system_type *type, > destroy_unused_super(s); > return ERR_PTR(-EBUSY); > } > - if (!grab_super_dead(old)) > + if (!grab_super(old)) > goto retry; > destroy_unused_super(s); > return old; > > -- > 2.34.1 >
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
On Wed 27-09-23 15:21:19, Christian Brauner wrote: > The grab_super() helper is now only used by grab_super_dead(). Merge the > two helpers into one. > > Signed-off-by: Christian Brauner <brauner@kernel.org> Yeah, nice! Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/super.c | 44 +++++++------------------------------------- > 1 file changed, 7 insertions(+), 37 deletions(-) > > diff --git a/fs/super.c b/fs/super.c > index 181ac8501301..6cdce2b31622 100644 > --- a/fs/super.c > +++ b/fs/super.c > @@ -517,35 +517,6 @@ void deactivate_super(struct super_block *s) > > EXPORT_SYMBOL(deactivate_super); > > -/** > - * grab_super - acquire an active reference > - * @s: reference we are trying to make active > - * > - * Tries to acquire an active reference. grab_super() is used when we > - * had just found a superblock in super_blocks or fs_type->fs_supers > - * and want to turn it into a full-blown active reference. grab_super() > - * is called with sb_lock held and drops it. Returns 1 in case of > - * success, 0 if we had failed (superblock contents was already dead or > - * dying when grab_super() had been called). Note that this is only > - * called for superblocks not in rundown mode (== ones still on ->fs_supers > - * of their type), so increment of ->s_count is OK here. > - */ > -static int grab_super(struct super_block *s) __releases(sb_lock) > -{ > - bool born; > - > - s->s_count++; > - spin_unlock(&sb_lock); > - born = super_lock_excl(s); > - if (born && atomic_inc_not_zero(&s->s_active)) { > - put_super(s); > - return 1; > - } > - super_unlock_excl(s); > - put_super(s); > - return 0; > -} > - > static inline bool wait_dead(struct super_block *sb) > { > unsigned int flags; > @@ -559,7 +530,7 @@ static inline bool wait_dead(struct super_block *sb) > } > > /** > - * grab_super_dead - acquire an active reference to a superblock > + * grab_super - acquire an active reference to a superblock > * @sb: superblock to acquire > * > * Acquire a temporary reference on a superblock and try to trade it for > @@ -570,17 +541,16 @@ static inline bool wait_dead(struct super_block *sb) > * Return: This returns true if an active reference could be acquired, > * false if not. > */ > -static bool grab_super_dead(struct super_block *sb) > +static bool grab_super(struct super_block *sb) > { > - > sb->s_count++; > - if (grab_super(sb)) { > + spin_unlock(&sb_lock); > + if (super_lock_excl(sb) && atomic_inc_not_zero(&sb->s_active)) { > put_super(sb); > - lockdep_assert_held(&sb->s_umount); > return true; > } > + super_unlock_excl(sb); > wait_var_event(&sb->s_flags, wait_dead(sb)); > - lockdep_assert_not_held(&sb->s_umount); > put_super(sb); > return false; > } > @@ -831,7 +801,7 @@ struct super_block *sget_fc(struct fs_context *fc, > warnfc(fc, "reusing existing filesystem in another namespace not allowed"); > return ERR_PTR(-EBUSY); > } > - if (!grab_super_dead(old)) > + if (!grab_super(old)) > goto retry; > destroy_unused_super(s); > return old; > @@ -875,7 +845,7 @@ struct super_block *sget(struct file_system_type *type, > destroy_unused_super(s); > return ERR_PTR(-EBUSY); > } > - if (!grab_super_dead(old)) > + if (!grab_super(old)) > goto retry; > destroy_unused_super(s); > return old; > > -- > 2.34.1 >
diff --git a/fs/super.c b/fs/super.c index 181ac8501301..6cdce2b31622 100644 --- a/fs/super.c +++ b/fs/super.c @@ -517,35 +517,6 @@ void deactivate_super(struct super_block *s) EXPORT_SYMBOL(deactivate_super); -/** - * grab_super - acquire an active reference - * @s: reference we are trying to make active - * - * Tries to acquire an active reference. grab_super() is used when we - * had just found a superblock in super_blocks or fs_type->fs_supers - * and want to turn it into a full-blown active reference. grab_super() - * is called with sb_lock held and drops it. Returns 1 in case of - * success, 0 if we had failed (superblock contents was already dead or - * dying when grab_super() had been called). Note that this is only - * called for superblocks not in rundown mode (== ones still on ->fs_supers - * of their type), so increment of ->s_count is OK here. - */ -static int grab_super(struct super_block *s) __releases(sb_lock) -{ - bool born; - - s->s_count++; - spin_unlock(&sb_lock); - born = super_lock_excl(s); - if (born && atomic_inc_not_zero(&s->s_active)) { - put_super(s); - return 1; - } - super_unlock_excl(s); - put_super(s); - return 0; -} - static inline bool wait_dead(struct super_block *sb) { unsigned int flags; @@ -559,7 +530,7 @@ static inline bool wait_dead(struct super_block *sb) } /** - * grab_super_dead - acquire an active reference to a superblock + * grab_super - acquire an active reference to a superblock * @sb: superblock to acquire * * Acquire a temporary reference on a superblock and try to trade it for @@ -570,17 +541,16 @@ static inline bool wait_dead(struct super_block *sb) * Return: This returns true if an active reference could be acquired, * false if not. */ -static bool grab_super_dead(struct super_block *sb) +static bool grab_super(struct super_block *sb) { - sb->s_count++; - if (grab_super(sb)) { + spin_unlock(&sb_lock); + if (super_lock_excl(sb) && atomic_inc_not_zero(&sb->s_active)) { put_super(sb); - lockdep_assert_held(&sb->s_umount); return true; } + super_unlock_excl(sb); wait_var_event(&sb->s_flags, wait_dead(sb)); - lockdep_assert_not_held(&sb->s_umount); put_super(sb); return false; } @@ -831,7 +801,7 @@ struct super_block *sget_fc(struct fs_context *fc, warnfc(fc, "reusing existing filesystem in another namespace not allowed"); return ERR_PTR(-EBUSY); } - if (!grab_super_dead(old)) + if (!grab_super(old)) goto retry; destroy_unused_super(s); return old; @@ -875,7 +845,7 @@ struct super_block *sget(struct file_system_type *type, destroy_unused_super(s); return ERR_PTR(-EBUSY); } - if (!grab_super_dead(old)) + if (!grab_super(old)) goto retry; destroy_unused_super(s); return old;
The grab_super() helper is now only used by grab_super_dead(). Merge the two helpers into one. Signed-off-by: Christian Brauner <brauner@kernel.org> --- fs/super.c | 44 +++++++------------------------------------- 1 file changed, 7 insertions(+), 37 deletions(-)