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reiserfs: Expand i_mutex to enclose lookup_one_len

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2.6.30-rc3 introduced some sanity checks in the VFS code to avoid NFS
 bugs by ensuring that lookup_one_len is always called under i_mutex.

 This patch expands the i_mutex locking to enclose lookup_one_len. This was
 always required, but not not enforced in the reiserfs code since it
 does locking around the xattr interactions with the xattr_sem.

 This is obvious enough, and it survived an overnight 50 thread ACL test.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Jeff Mahoney 2009-05-01 12:11:12 -04:00 committed by Al Viro
parent 67e55205ec
commit 5a6059c358
1 changed files with 14 additions and 18 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

32
fs/reiserfs/xattr.c
View file

@ -120,25 +120,20 @@ static struct dentry *lookup_or_create_dir(struct dentry *parent,
struct dentry *dentry;
BUG_ON(!parent);
mutex_lock_nested(&parent->d_inode->i_mutex, I_MUTEX_XATTR);
dentry = lookup_one_len(name, parent, strlen(name));
if (IS_ERR(dentry))
return dentry;
else if (!dentry->d_inode) {
if (!IS_ERR(dentry) && !dentry->d_inode) {
int err = -ENODATA;
if (xattr_may_create(flags)) {
mutex_lock_nested(&parent->d_inode->i_mutex,
I_MUTEX_XATTR);
if (xattr_may_create(flags))
err = xattr_mkdir(parent->d_inode, dentry, 0700);
mutex_unlock(&parent->d_inode->i_mutex);
}
if (err) {
dput(dentry);
dentry = ERR_PTR(err);
}
}
mutex_unlock(&parent->d_inode->i_mutex);
return dentry;
}
@ -184,6 +179,7 @@ fill_with_dentries(void *buf, const char *name, int namelen, loff_t offset,
{
struct reiserfs_dentry_buf *dbuf = buf;
struct dentry *dentry;
WARN_ON_ONCE(!mutex_is_locked(&dbuf->xadir->d_inode->i_mutex));
if (dbuf->count == ARRAY_SIZE(dbuf->dentries))
return -ENOSPC;
@ -349,6 +345,7 @@ static struct dentry *xattr_lookup(struct inode *inode, const char *name,
if (IS_ERR(xadir))
return ERR_CAST(xadir);
mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
xafile = lookup_one_len(name, xadir, strlen(name));
if (IS_ERR(xafile)) {
err = PTR_ERR(xafile);
@ -360,18 +357,15 @@ static struct dentry *xattr_lookup(struct inode *inode, const char *name,
if (!xafile->d_inode) {
err = -ENODATA;
if (xattr_may_create(flags)) {
mutex_lock_nested(&xadir->d_inode->i_mutex,
I_MUTEX_XATTR);
if (xattr_may_create(flags))
err = xattr_create(xadir->d_inode, xafile,
0700|S_IFREG);
mutex_unlock(&xadir->d_inode->i_mutex);
}
}
if (err)
dput(xafile);
out:
mutex_unlock(&xadir->d_inode->i_mutex);
dput(xadir);
if (err)
return ERR_PTR(err);
@ -435,6 +429,7 @@ static int lookup_and_delete_xattr(struct inode *inode, const char *name)
if (IS_ERR(xadir))
return PTR_ERR(xadir);
mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
dentry = lookup_one_len(name, xadir, strlen(name));
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
@ -442,14 +437,13 @@ static int lookup_and_delete_xattr(struct inode *inode, const char *name)
}
if (dentry->d_inode) {
mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
err = xattr_unlink(xadir->d_inode, dentry);
mutex_unlock(&xadir->d_inode->i_mutex);
update_ctime(inode);
}
dput(dentry);
out_dput:
mutex_unlock(&xadir->d_inode->i_mutex);
dput(xadir);
return err;
}
@ -906,9 +900,9 @@ static int create_privroot(struct dentry *dentry)
{
int err;
struct inode *inode = dentry->d_parent->d_inode;
mutex_lock_nested(&inode->i_mutex, I_MUTEX_XATTR);
WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex));
err = xattr_mkdir(inode, dentry, 0700);
mutex_unlock(&inode->i_mutex);
if (err) {
dput(dentry);
dentry = NULL;
@ -980,6 +974,7 @@ int reiserfs_xattr_init(struct super_block *s, int mount_flags)
/* If we don't have the privroot located yet - go find it */
if (!REISERFS_SB(s)->priv_root) {
struct dentry *dentry;
mutex_lock_nested(&s->s_root->d_inode->i_mutex, I_MUTEX_CHILD);
dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
strlen(PRIVROOT_NAME));
if (!IS_ERR(dentry)) {
@ -993,6 +988,7 @@ int reiserfs_xattr_init(struct super_block *s, int mount_flags)
}
} else
err = PTR_ERR(dentry);
mutex_unlock(&s->s_root->d_inode->i_mutex);
if (!err && dentry) {
s->s_root->d_op = &xattr_lookup_poison_ops;