mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-24 01:30:55 +07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: vfs: fix race in rcu lookup of pruned dentry Fix cifs_get_root() [ Edited the last commit to get rid of a 'unused variable "seq"' warning due to Al editing the patch. - Linus ]
This commit is contained in:
commit
e501f29c72
@ -35,6 +35,7 @@
|
||||
#include <linux/delay.h>
|
||||
#include <linux/kthread.h>
|
||||
#include <linux/freezer.h>
|
||||
#include <linux/namei.h>
|
||||
#include <net/ipv6.h>
|
||||
#include "cifsfs.h"
|
||||
#include "cifspdu.h"
|
||||
@ -542,14 +543,12 @@ static const struct super_operations cifs_super_ops = {
|
||||
static struct dentry *
|
||||
cifs_get_root(struct smb_vol *vol, struct super_block *sb)
|
||||
{
|
||||
int xid, rc;
|
||||
struct inode *inode;
|
||||
struct qstr name;
|
||||
struct dentry *dparent = NULL, *dchild = NULL, *alias;
|
||||
struct dentry *dentry;
|
||||
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
|
||||
unsigned int i, full_len, len;
|
||||
char *full_path = NULL, *pstart;
|
||||
char *full_path = NULL;
|
||||
char *s, *p;
|
||||
char sep;
|
||||
int xid;
|
||||
|
||||
full_path = cifs_build_path_to_root(vol, cifs_sb,
|
||||
cifs_sb_master_tcon(cifs_sb));
|
||||
@ -560,73 +559,32 @@ cifs_get_root(struct smb_vol *vol, struct super_block *sb)
|
||||
|
||||
xid = GetXid();
|
||||
sep = CIFS_DIR_SEP(cifs_sb);
|
||||
dparent = dget(sb->s_root);
|
||||
full_len = strlen(full_path);
|
||||
full_path[full_len] = sep;
|
||||
pstart = full_path + 1;
|
||||
dentry = dget(sb->s_root);
|
||||
p = s = full_path;
|
||||
|
||||
for (i = 1, len = 0; i <= full_len; i++) {
|
||||
if (full_path[i] != sep || !len) {
|
||||
len++;
|
||||
continue;
|
||||
}
|
||||
do {
|
||||
struct inode *dir = dentry->d_inode;
|
||||
struct dentry *child;
|
||||
|
||||
full_path[i] = 0;
|
||||
cFYI(1, "get dentry for %s", pstart);
|
||||
/* skip separators */
|
||||
while (*s == sep)
|
||||
s++;
|
||||
if (!*s)
|
||||
break;
|
||||
p = s++;
|
||||
/* next separator */
|
||||
while (*s && *s != sep)
|
||||
s++;
|
||||
|
||||
name.name = pstart;
|
||||
name.len = len;
|
||||
name.hash = full_name_hash(pstart, len);
|
||||
dchild = d_lookup(dparent, &name);
|
||||
if (dchild == NULL) {
|
||||
cFYI(1, "not exists");
|
||||
dchild = d_alloc(dparent, &name);
|
||||
if (dchild == NULL) {
|
||||
dput(dparent);
|
||||
dparent = ERR_PTR(-ENOMEM);
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
|
||||
cFYI(1, "get inode");
|
||||
if (dchild->d_inode == NULL) {
|
||||
cFYI(1, "not exists");
|
||||
inode = NULL;
|
||||
if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext)
|
||||
rc = cifs_get_inode_info_unix(&inode, full_path,
|
||||
sb, xid);
|
||||
else
|
||||
rc = cifs_get_inode_info(&inode, full_path,
|
||||
NULL, sb, xid, NULL);
|
||||
if (rc) {
|
||||
dput(dchild);
|
||||
dput(dparent);
|
||||
dparent = ERR_PTR(rc);
|
||||
goto out;
|
||||
}
|
||||
alias = d_materialise_unique(dchild, inode);
|
||||
if (alias != NULL) {
|
||||
dput(dchild);
|
||||
if (IS_ERR(alias)) {
|
||||
dput(dparent);
|
||||
dparent = ERR_PTR(-EINVAL); /* XXX */
|
||||
goto out;
|
||||
}
|
||||
dchild = alias;
|
||||
}
|
||||
}
|
||||
cFYI(1, "parent %p, child %p", dparent, dchild);
|
||||
|
||||
dput(dparent);
|
||||
dparent = dchild;
|
||||
len = 0;
|
||||
pstart = full_path + i + 1;
|
||||
full_path[i] = sep;
|
||||
}
|
||||
out:
|
||||
mutex_lock(&dir->i_mutex);
|
||||
child = lookup_one_len(p, dentry, s - p);
|
||||
mutex_unlock(&dir->i_mutex);
|
||||
dput(dentry);
|
||||
dentry = child;
|
||||
} while (!IS_ERR(dentry));
|
||||
_FreeXid(xid);
|
||||
kfree(full_path);
|
||||
return dparent;
|
||||
return dentry;
|
||||
}
|
||||
|
||||
static int cifs_set_super(struct super_block *sb, void *data)
|
||||
|
@ -942,7 +942,6 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
|
||||
* Don't forget we might have a non-mountpoint managed dentry
|
||||
* that wants to block transit.
|
||||
*/
|
||||
*inode = path->dentry->d_inode;
|
||||
if (unlikely(managed_dentry_might_block(path->dentry)))
|
||||
return false;
|
||||
|
||||
@ -955,6 +954,12 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
|
||||
path->mnt = mounted;
|
||||
path->dentry = mounted->mnt_root;
|
||||
nd->seq = read_seqcount_begin(&path->dentry->d_seq);
|
||||
/*
|
||||
* Update the inode too. We don't need to re-check the
|
||||
* dentry sequence number here after this d_inode read,
|
||||
* because a mount-point is always pinned.
|
||||
*/
|
||||
*inode = path->dentry->d_inode;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
|
Loading…
Reference in New Issue
Block a user