From: Jan Kara <jack@xxxxxxx>
fsnotify_unmount_inodes() played complex tricks to pin next inode in the
sb->s_inodes list when iterating over all inodes. If we switch to
keeping current inode pinned somewhat longer, we can make the code much
simpler and standard.
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Waiman Long <Waiman.Long@xxxxxxx>
---
fs/notify/inode_mark.c | 45 +++++++++------------------------------------
1 files changed, 9 insertions(+), 36 deletions(-)
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 741077d..a364524 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -150,12 +150,10 @@ int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
*/
void fsnotify_unmount_inodes(struct super_block *sb)
{
- struct inode *inode, *next_i, *need_iput = NULL;
+ struct inode *inode, *iput_inode = NULL;
spin_lock(&sb->s_inode_list_lock);
- list_for_each_entry_safe(inode, next_i, &sb->s_inodes, i_sb_list) {
- struct inode *need_iput_tmp;
-
+ list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
/*
* We cannot __iget() an inode in state I_FREEING,
* I_WILL_FREE, or I_NEW which is fine because by that point
@@ -178,49 +176,24 @@ void fsnotify_unmount_inodes(struct super_block *sb)
continue;
}
- need_iput_tmp = need_iput;
- need_iput = NULL;
-
- /* In case fsnotify_inode_delete() drops a reference. */
- if (inode != need_iput_tmp)
- __iget(inode);
- else
- need_iput_tmp = NULL;
+ __iget(inode);
spin_unlock(&inode->i_lock);
-
- /* In case the dropping of a reference would nuke next_i. */
- while (&next_i->i_sb_list != &sb->s_inodes) {
- spin_lock(&next_i->i_lock);
- if (!(next_i->i_state & (I_FREEING | I_WILL_FREE)) &&
- atomic_read(&next_i->i_count)) {
- __iget(next_i);
- need_iput = next_i;
- spin_unlock(&next_i->i_lock);
- break;
- }
- spin_unlock(&next_i->i_lock);
- next_i = list_next_entry(next_i, i_sb_list);
- }
-
- /*
- * We can safely drop s_inode_list_lock here because either
- * we actually hold references on both inode and next_i or
- * end of list. Also no new inodes will be added since the
- * umount has begun.
- */
spin_unlock(&sb->s_inode_list_lock);
- if (need_iput_tmp)
- iput(need_iput_tmp);
+ if (iput_inode)
+ iput(iput_inode);
/* for each watch, send FS_UNMOUNT and then remove it */
fsnotify(inode, FS_UNMOUNT, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
fsnotify_inode_delete(inode);
- iput(inode);
+ iput_inode = inode;
spin_lock(&sb->s_inode_list_lock);
}
spin_unlock(&sb->s_inode_list_lock);
+
+ if (iput_inode)
+ iput(iput_inode);
}
--
1.7.1
--
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