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Always lookup priv_root on reiserfs mount and keep it 

... even if it's a negative dentry.  That way we can set ->d_op on
root before anyone could race with us.  Simplify d_compare(), while
we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2009-05-03 06:00:05 -04:00
parent 5a6059c358
commit edcc37a047
3 changed files with 41 additions and 52 deletions
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6
fs/reiserfs/super.c
View File

@ -1842,7 +1842,8 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent)
goto error;
}
if ((errval = reiserfs_xattr_init(s, s->s_flags))) {
if ((errval = reiserfs_lookup_privroot(s)) ||
(errval = reiserfs_xattr_init(s, s->s_flags))) {
dput(s->s_root);
s->s_root = NULL;
goto error;
@ -1855,7 +1856,8 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent)
reiserfs_info(s, "using 3.5.x disk format\n");
}
if ((errval = reiserfs_xattr_init(s, s->s_flags))) {
if ((errval = reiserfs_lookup_privroot(s)) ||
(errval = reiserfs_xattr_init(s, s->s_flags))) {
dput(s->s_root);
s->s_root = NULL;
goto error;

86
fs/reiserfs/xattr.c
View File

@ -903,16 +903,19 @@ static int create_privroot(struct dentry *dentry)
WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex));
err = xattr_mkdir(inode, dentry, 0700);
if (err) {
dput(dentry);
dentry = NULL;
if (err || !dentry->d_inode) {
reiserfs_warning(dentry->d_sb, "jdm-20006",
"xattrs/ACLs enabled and couldn't "
"find/create .reiserfs_priv. "
"Failing mount.");
return -EOPNOTSUPP;
}
if (dentry && dentry->d_inode)
reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
"storage.\n", PRIVROOT_NAME);
dentry->d_inode->i_flags |= S_PRIVATE;
reiserfs_info(dentry->d_sb, "Created %s - reserved for xattr "
"storage.\n", PRIVROOT_NAME);
return err;
return 0;
}
static int xattr_mount_check(struct super_block *s)
@ -944,11 +947,9 @@ static int
xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
{
struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
if (name->len == priv_root->d_name.len &&
name->hash == priv_root->d_name.hash &&
!memcmp(name->name, priv_root->d_name.name, name->len)) {
if (container_of(q1, struct dentry, d_name) == priv_root)
return -ENOENT;
} else if (q1->len == name->len &&
if (q1->len == name->len &&
!memcmp(q1->name, name->name, name->len))
return 0;
return 1;
@ -958,6 +959,27 @@ static const struct dentry_operations xattr_lookup_poison_ops = {
.d_compare = xattr_lookup_poison,
};
int reiserfs_lookup_privroot(struct super_block *s)
{
struct dentry *dentry;
int err = 0;
/* If we don't have the privroot located yet - go find it */
mutex_lock(&s->s_root->d_inode->i_mutex);
dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
strlen(PRIVROOT_NAME));
if (!IS_ERR(dentry)) {
REISERFS_SB(s)->priv_root = dentry;
s->s_root->d_op = &xattr_lookup_poison_ops;
if (dentry->d_inode)
dentry->d_inode->i_flags |= S_PRIVATE;
} else
err = PTR_ERR(dentry);
mutex_unlock(&s->s_root->d_inode->i_mutex);
return err;
}
/* We need to take a copy of the mount flags since things like
* MS_RDONLY don't get set until *after* we're called.
* mount_flags != mount_options */
@ -969,48 +991,12 @@ int reiserfs_xattr_init(struct super_block *s, int mount_flags)
err = xattr_mount_check(s);
if (err)
goto error;
#endif
/* 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)) {
#ifdef CONFIG_REISERFS_FS_XATTR
if (!(mount_flags & MS_RDONLY) && !dentry->d_inode)
err = create_privroot(dentry);
#endif
if (!dentry->d_inode) {
dput(dentry);
dentry = NULL;
}
} else
err = PTR_ERR(dentry);
if (!REISERFS_SB(s)->priv_root->d_inode && !(mount_flags & MS_RDONLY)) {
mutex_lock(&s->s_root->d_inode->i_mutex);
err = create_privroot(REISERFS_SB(s)->priv_root);
mutex_unlock(&s->s_root->d_inode->i_mutex);
if (!err && dentry) {
s->s_root->d_op = &xattr_lookup_poison_ops;
dentry->d_inode->i_flags |= S_PRIVATE;
REISERFS_SB(s)->priv_root = dentry;
#ifdef CONFIG_REISERFS_FS_XATTR
/* xattrs are unavailable */
} else if (!(mount_flags & MS_RDONLY)) {
/* If we're read-only it just means that the dir
* hasn't been created. Not an error -- just no
* xattrs on the fs. We'll check again if we
* go read-write */
reiserfs_warning(s, "jdm-20006",
"xattrs/ACLs enabled and couldn't "
"find/create .reiserfs_priv. "
"Failing mount.");
err = -EOPNOTSUPP;
#endif
}
}
#ifdef CONFIG_REISERFS_FS_XATTR
if (!err)
s->s_xattr = reiserfs_xattr_handlers;

1
include/linux/reiserfs_xattr.h
View File

@ -38,6 +38,7 @@ struct nameidata;
int reiserfs_xattr_register_handlers(void) __init;
void reiserfs_xattr_unregister_handlers(void);
int reiserfs_xattr_init(struct super_block *sb, int mount_flags);
int reiserfs_lookup_privroot(struct super_block *sb);
int reiserfs_delete_xattrs(struct inode *inode);
int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs);