5.10-stable review patch. If anyone has any objections, please let me know.
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From: Amir Goldstein amir73il@gmail.com
[ Upstream commit ec44610fe2b86daef70f3f53f47d2a2542d7094f ]
Rename s_fsnotify_inode_refs to s_fsnotify_connectors and count all objects with attached connectors, not only inodes with attached connectors.
This will be used to optimize fsnotify() calls on sb without any type of marks.
Link: https://lore.kernel.org/r/20210810151220.285179-4-amir73il@gmail.com Signed-off-by: Amir Goldstein amir73il@gmail.com Reviewed-by: Matthew Bobrowski repnop@google.com Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/notify/fsnotify.c | 6 +++--- fs/notify/fsnotify.h | 15 +++++++++++++++ fs/notify/mark.c | 24 +++++++++++++++++++++--- include/linux/fs.h | 7 +++++-- 4 files changed, 44 insertions(+), 8 deletions(-)
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 30d422b8c0fc7..963e6ce75b961 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -87,15 +87,15 @@ static void fsnotify_unmount_inodes(struct super_block *sb)
if (iput_inode) iput(iput_inode); - /* Wait for outstanding inode references from connectors */ - wait_var_event(&sb->s_fsnotify_inode_refs, - !atomic_long_read(&sb->s_fsnotify_inode_refs)); }
void fsnotify_sb_delete(struct super_block *sb) { fsnotify_unmount_inodes(sb); fsnotify_clear_marks_by_sb(sb); + /* Wait for outstanding object references from connectors */ + wait_var_event(&sb->s_fsnotify_connectors, + !atomic_long_read(&sb->s_fsnotify_connectors)); }
/* diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h index ff2063ec6b0f3..87d8a50ee8038 100644 --- a/fs/notify/fsnotify.h +++ b/fs/notify/fsnotify.h @@ -27,6 +27,21 @@ static inline struct super_block *fsnotify_conn_sb( return container_of(conn->obj, struct super_block, s_fsnotify_marks); }
+static inline struct super_block *fsnotify_connector_sb( + struct fsnotify_mark_connector *conn) +{ + switch (conn->type) { + case FSNOTIFY_OBJ_TYPE_INODE: + return fsnotify_conn_inode(conn)->i_sb; + case FSNOTIFY_OBJ_TYPE_VFSMOUNT: + return fsnotify_conn_mount(conn)->mnt.mnt_sb; + case FSNOTIFY_OBJ_TYPE_SB: + return fsnotify_conn_sb(conn); + default: + return NULL; + } +} + /* destroy all events sitting in this groups notification queue */ extern void fsnotify_flush_notify(struct fsnotify_group *group);
diff --git a/fs/notify/mark.c b/fs/notify/mark.c index f6d1ad3ecca2a..796946eb0c2e2 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -172,7 +172,7 @@ static void fsnotify_connector_destroy_workfn(struct work_struct *work) static void fsnotify_get_inode_ref(struct inode *inode) { ihold(inode); - atomic_long_inc(&inode->i_sb->s_fsnotify_inode_refs); + atomic_long_inc(&inode->i_sb->s_fsnotify_connectors); }
static void fsnotify_put_inode_ref(struct inode *inode) @@ -180,8 +180,24 @@ static void fsnotify_put_inode_ref(struct inode *inode) struct super_block *sb = inode->i_sb;
iput(inode); - if (atomic_long_dec_and_test(&sb->s_fsnotify_inode_refs)) - wake_up_var(&sb->s_fsnotify_inode_refs); + if (atomic_long_dec_and_test(&sb->s_fsnotify_connectors)) + wake_up_var(&sb->s_fsnotify_connectors); +} + +static void fsnotify_get_sb_connectors(struct fsnotify_mark_connector *conn) +{ + struct super_block *sb = fsnotify_connector_sb(conn); + + if (sb) + atomic_long_inc(&sb->s_fsnotify_connectors); +} + +static void fsnotify_put_sb_connectors(struct fsnotify_mark_connector *conn) +{ + struct super_block *sb = fsnotify_connector_sb(conn); + + if (sb && atomic_long_dec_and_test(&sb->s_fsnotify_connectors)) + wake_up_var(&sb->s_fsnotify_connectors); }
static void *fsnotify_detach_connector_from_object( @@ -203,6 +219,7 @@ static void *fsnotify_detach_connector_from_object( fsnotify_conn_sb(conn)->s_fsnotify_mask = 0; }
+ fsnotify_put_sb_connectors(conn); rcu_assign_pointer(*(conn->obj), NULL); conn->obj = NULL; conn->type = FSNOTIFY_OBJ_TYPE_DETACHED; @@ -504,6 +521,7 @@ static int fsnotify_attach_connector_to_object(fsnotify_connp_t *connp, inode = fsnotify_conn_inode(conn); fsnotify_get_inode_ref(inode); } + fsnotify_get_sb_connectors(conn);
/* * cmpxchg() provides the barrier so that readers of *connp can see diff --git a/include/linux/fs.h b/include/linux/fs.h index cc3b6ddf58223..a9ac60d3be1d6 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1512,8 +1512,11 @@ struct super_block { /* Number of inodes with nlink == 0 but still referenced */ atomic_long_t s_remove_count;
- /* Pending fsnotify inode refs */ - atomic_long_t s_fsnotify_inode_refs; + /* + * Number of inode/mount/sb objects that are being watched, note that + * inodes objects are currently double-accounted. + */ + atomic_long_t s_fsnotify_connectors;
/* Being remounted read-only */ int s_readonly_remount;