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| author | Miklos Szeredi <mszeredi@suse.cz> | 2012-05-21 17:30:09 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-06-01 12:11:58 -0400 |
| commit | d45ea86792db9679ed010b2c3df3db32b2ce5bde (patch) | |
| tree | 573f99f16911ce9e14087a5559a11e876d676859 /fs/namei.c | |
| parent | decf3400879d02d0eafedea52c7f208587be062a (diff) | |
| download | lwn-d45ea86792db9679ed010b2c3df3db32b2ce5bde.tar.gz lwn-d45ea86792db9679ed010b2c3df3db32b2ce5bde.zip | |
vfs: make follow_link check RCU safe
This will allow this code to be used in RCU mode.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/fs/namei.c b/fs/namei.c index 41445e7fd339..c6b996817bb3 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2201,6 +2201,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path, int acc_mode = op->acc_mode; struct file *filp; struct inode *inode; + int symlink_ok = 0; int error; nd->flags &= ~LOOKUP_PARENT; @@ -2232,7 +2233,6 @@ static struct file *do_last(struct nameidata *nd, struct path *path, } if (!(open_flag & O_CREAT)) { - int symlink_ok = 0; if (nd->last.name[nd->last.len]) nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY; if (open_flag & O_PATH && !(nd->flags & LOOKUP_FOLLOW)) @@ -2364,8 +2364,16 @@ static struct file *do_last(struct nameidata *nd, struct path *path, if (!inode) goto exit_dput; - if (inode->i_op->follow_link) + if (should_follow_link(inode, !symlink_ok)) { + if (nd->flags & LOOKUP_RCU) { + if (unlikely(unlazy_walk(nd, path->dentry))) { + error = -ECHILD; + goto exit; + } + } + BUG_ON(inode != path->dentry->d_inode); return NULL; + } path_to_nameidata(path, nd); nd->inode = inode; |