diff options
| author | Davide Libenzi <davidel@xmailserver.org> | 2007-10-16 23:30:19 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-17 08:43:00 -0700 |
| commit | 96fdc72ddfe8aa3eb1f51e78cc13babefbf26dda (patch) | |
| tree | 58038ee825096fec9f330fe187e615bb7c2e8422 /fs | |
| parent | 5e3c3ac9db432fbdd2da92ce0f12d7912706c689 (diff) | |
| download | linux-3.10-96fdc72ddfe8aa3eb1f51e78cc13babefbf26dda.tar.gz linux-3.10-96fdc72ddfe8aa3eb1f51e78cc13babefbf26dda.tar.bz2 linux-3.10-96fdc72ddfe8aa3eb1f51e78cc13babefbf26dda.zip | |
anon-inodes use open coded atomic_inc for the shared inode
Since we know the shared inode count is always >0, we can avoid igrab()
and use an open coded atomic_inc().
This also fixes a bug noticed by Yan Zheng <yanzheng@21cn.com>: were checking
for an IS_ERR() return from igrab(), but it actually returns NULL on error.
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Yan Zheng <yanzheng@21cn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/anon_inodes.c | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index b4a75880f6f..23321889d9b 100644 --- a/fs/anon_inodes.c +++ b/fs/anon_inodes.c @@ -76,7 +76,6 @@ int anon_inode_getfd(int *pfd, struct inode **pinode, struct file **pfile, { struct qstr this; struct dentry *dentry; - struct inode *inode; struct file *file; int error, fd; @@ -86,15 +85,9 @@ int anon_inode_getfd(int *pfd, struct inode **pinode, struct file **pfile, if (!file) return -ENFILE; - inode = igrab(anon_inode_inode); - if (IS_ERR(inode)) { - error = PTR_ERR(inode); - goto err_put_filp; - } - error = get_unused_fd(); if (error < 0) - goto err_iput; + goto err_put_filp; fd = error; /* @@ -108,14 +101,22 @@ int anon_inode_getfd(int *pfd, struct inode **pinode, struct file **pfile, dentry = d_alloc(anon_inode_mnt->mnt_sb->s_root, &this); if (!dentry) goto err_put_unused_fd; + + /* + * We know the anon_inode inode count is always greater than zero, + * so we can avoid doing an igrab() and we can use an open-coded + * atomic_inc(). + */ + atomic_inc(&anon_inode_inode->i_count); + dentry->d_op = &anon_inodefs_dentry_operations; /* Do not publish this dentry inside the global dentry hash table */ dentry->d_flags &= ~DCACHE_UNHASHED; - d_instantiate(dentry, inode); + d_instantiate(dentry, anon_inode_inode); file->f_path.mnt = mntget(anon_inode_mnt); file->f_path.dentry = dentry; - file->f_mapping = inode->i_mapping; + file->f_mapping = anon_inode_inode->i_mapping; file->f_pos = 0; file->f_flags = O_RDWR; @@ -127,14 +128,12 @@ int anon_inode_getfd(int *pfd, struct inode **pinode, struct file **pfile, fd_install(fd, file); *pfd = fd; - *pinode = inode; + *pinode = anon_inode_inode; *pfile = file; return 0; err_put_unused_fd: put_unused_fd(fd); -err_iput: - iput(inode); err_put_filp: put_filp(file); return error; |