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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-07-26 11:36:34 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2011-07-26 12:57:09 -0400 |
| commit | a209dfc7b0d94bd6fa94553c097836a2e6d0f0ba (patch) | |
| tree | 7dacc92b08264c675a0dfcbae83982b7d3ad5135 /fs | |
| parent | 5b9f4567726513a359e70f85029482c7c3714dbd (diff) | |
| download | op-kernel-dev-a209dfc7b0d94bd6fa94553c097836a2e6d0f0ba.zip op-kernel-dev-a209dfc7b0d94bd6fa94553c097836a2e6d0f0ba.tar.gz | |
vfs: dont chain pipe/anon/socket on superblock s_inodes list
Workloads using pipes and sockets hit inode_sb_list_lock contention.
superblock s_inodes list is needed for quota, dirty, pagecache and
fsnotify management. pipe/anon/socket fs are clearly not candidates for
these.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/anon_inodes.c | 2 | ||||
| -rw-r--r-- | fs/inode.c | 39 | ||||
| -rw-r--r-- | fs/pipe.c | 2 |
3 files changed, 32 insertions, 11 deletions
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index 4d433d3..f11e43e 100644 --- a/fs/anon_inodes.c +++ b/fs/anon_inodes.c @@ -187,7 +187,7 @@ EXPORT_SYMBOL_GPL(anon_inode_getfd); */ static struct inode *anon_inode_mkinode(void) { - struct inode *inode = new_inode(anon_inode_mnt->mnt_sb); + struct inode *inode = new_inode_pseudo(anon_inode_mnt->mnt_sb); if (!inode) return ERR_PTR(-ENOMEM); @@ -362,9 +362,11 @@ EXPORT_SYMBOL_GPL(inode_sb_list_add); static inline void inode_sb_list_del(struct inode *inode) { - spin_lock(&inode_sb_list_lock); - list_del_init(&inode->i_sb_list); - spin_unlock(&inode_sb_list_lock); + if (!list_empty(&inode->i_sb_list)) { + spin_lock(&inode_sb_list_lock); + list_del_init(&inode->i_sb_list); + spin_unlock(&inode_sb_list_lock); + } } static unsigned long hash(struct super_block *sb, unsigned long hashval) @@ -797,6 +799,29 @@ unsigned int get_next_ino(void) EXPORT_SYMBOL(get_next_ino); /** + * new_inode_pseudo - obtain an inode + * @sb: superblock + * + * Allocates a new inode for given superblock. + * Inode wont be chained in superblock s_inodes list + * This means : + * - fs can't be unmount + * - quotas, fsnotify, writeback can't work + */ +struct inode *new_inode_pseudo(struct super_block *sb) +{ + struct inode *inode = alloc_inode(sb); + + if (inode) { + spin_lock(&inode->i_lock); + inode->i_state = 0; + spin_unlock(&inode->i_lock); + INIT_LIST_HEAD(&inode->i_sb_list); + } + return inode; +} + +/** * new_inode - obtain an inode * @sb: superblock * @@ -814,13 +839,9 @@ struct inode *new_inode(struct super_block *sb) spin_lock_prefetch(&inode_sb_list_lock); - inode = alloc_inode(sb); - if (inode) { - spin_lock(&inode->i_lock); - inode->i_state = 0; - spin_unlock(&inode->i_lock); + inode = new_inode_pseudo(sb); + if (inode) inode_sb_list_add(inode); - } return inode; } EXPORT_SYMBOL(new_inode); @@ -948,7 +948,7 @@ static const struct dentry_operations pipefs_dentry_operations = { static struct inode * get_pipe_inode(void) { - struct inode *inode = new_inode(pipe_mnt->mnt_sb); + struct inode *inode = new_inode_pseudo(pipe_mnt->mnt_sb); struct pipe_inode_info *pipe; if (!inode) |
