#include <linux/device_cgroup.h>
#include <linux/fs_struct.h>
#include <linux/posix_acl.h>
+#include <linux/hash.h>
#include <asm/uaccess.h>
#include "internal.h"
static __always_inline void set_root(struct nameidata *nd)
{
- if (!nd->root.mnt)
- get_fs_root(current->fs, &nd->root);
+ get_fs_root(current->fs, &nd->root);
}
static int link_path_walk(const char *, struct nameidata *);
-static __always_inline void set_root_rcu(struct nameidata *nd)
+static __always_inline unsigned set_root_rcu(struct nameidata *nd)
{
- if (!nd->root.mnt) {
- struct fs_struct *fs = current->fs;
- unsigned seq;
+ struct fs_struct *fs = current->fs;
+ unsigned seq, res;
- do {
- seq = read_seqcount_begin(&fs->seq);
- nd->root = fs->root;
- nd->seq = __read_seqcount_begin(&nd->root.dentry->d_seq);
- } while (read_seqcount_retry(&fs->seq, seq));
- }
+ do {
+ seq = read_seqcount_begin(&fs->seq);
+ nd->root = fs->root;
+ res = __read_seqcount_begin(&nd->root.dentry->d_seq);
+ } while (read_seqcount_retry(&fs->seq, seq));
+ return res;
}
static void path_put_conditional(struct path *path, struct nameidata *nd)
return PTR_ERR(s);
}
if (*s == '/') {
- set_root(nd);
+ if (!nd->root.mnt)
+ set_root(nd);
path_put(&nd->path);
nd->path = nd->root;
path_get(&nd->root);
}
EXPORT_SYMBOL(follow_down_one);
-static inline bool managed_dentry_might_block(struct dentry *dentry)
+static inline int managed_dentry_rcu(struct dentry *dentry)
{
- return (dentry->d_flags & DCACHE_MANAGE_TRANSIT &&
- dentry->d_op->d_manage(dentry, true) < 0);
+ return (dentry->d_flags & DCACHE_MANAGE_TRANSIT) ?
+ dentry->d_op->d_manage(dentry, true) : 0;
}
/*
* Don't forget we might have a non-mountpoint managed dentry
* that wants to block transit.
*/
- if (unlikely(managed_dentry_might_block(path->dentry)))
+ switch (managed_dentry_rcu(path->dentry)) {
+ case -ECHILD:
+ default:
return false;
+ case -EISDIR:
+ return true;
+ case 0:
+ break;
+ }
if (!d_mountpoint(path->dentry))
- return true;
+ return !(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT);
mounted = __lookup_mnt(path->mnt, path->dentry);
if (!mounted)
*/
*inode = path->dentry->d_inode;
}
- return read_seqretry(&mount_lock, nd->m_seq);
+ return !read_seqretry(&mount_lock, nd->m_seq) &&
+ !(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT);
}
static int follow_dotdot_rcu(struct nameidata *nd)
{
- set_root_rcu(nd);
+ struct inode *inode = nd->inode;
+ if (!nd->root.mnt)
+ set_root_rcu(nd);
while (1) {
if (nd->path.dentry == nd->root.dentry &&
struct dentry *parent = old->d_parent;
unsigned seq;
+ inode = parent->d_inode;
seq = read_seqcount_begin(&parent->d_seq);
if (read_seqcount_retry(&old->d_seq, nd->seq))
goto failed;
}
if (!follow_up_rcu(&nd->path))
break;
+ inode = nd->path.dentry->d_inode;
nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
}
while (d_mountpoint(nd->path.dentry)) {
break;
nd->path.mnt = &mounted->mnt;
nd->path.dentry = mounted->mnt.mnt_root;
+ inode = nd->path.dentry->d_inode;
nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
- if (!read_seqretry(&mount_lock, nd->m_seq))
+ if (read_seqretry(&mount_lock, nd->m_seq))
goto failed;
}
- nd->inode = nd->path.dentry->d_inode;
+ nd->inode = inode;
return 0;
failed:
static void follow_dotdot(struct nameidata *nd)
{
- set_root(nd);
+ if (!nd->root.mnt)
+ set_root(nd);
while(1) {
struct dentry *old = nd->path.dentry;
}
path->mnt = mnt;
path->dentry = dentry;
- if (unlikely(!__follow_mount_rcu(nd, path, inode)))
- goto unlazy;
- if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT))
- goto unlazy;
- return 0;
+ if (likely(__follow_mount_rcu(nd, path, inode)))
+ return 0;
unlazy:
if (unlazy_walk(nd, dentry))
return -ECHILD;
static inline unsigned int fold_hash(unsigned long hash)
{
- hash += hash >> (8*sizeof(int));
- return hash;
+ return hash_64(hash, 32);
}
#else /* 32-bit case */
/*
* Calculate the length and hash of the path component, and
- * return the length of the component;
+ * return the "hash_len" as the result.
*/
-static inline unsigned long hash_name(const char *name, unsigned int *hashp)
+static inline u64 hash_name(const char *name)
{
unsigned long a, b, adata, bdata, mask, hash, len;
const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
mask = create_zero_mask(adata | bdata);
hash += a & zero_bytemask(mask);
- *hashp = fold_hash(hash);
-
- return len + find_zero(mask);
+ len += find_zero(mask);
+ return hashlen_create(fold_hash(hash), len);
}
#else
* We know there's a real path component here of at least
* one character.
*/
-static inline unsigned long hash_name(const char *name, unsigned int *hashp)
+static inline u64 hash_name(const char *name)
{
unsigned long hash = init_name_hash();
unsigned long len = 0, c;
hash = partial_name_hash(c, hash);
c = (unsigned char)name[len];
} while (c && c != '/');
- *hashp = end_name_hash(hash);
- return len;
+ return hashlen_create(end_name_hash(hash), len);
}
#endif
/* At this point we know we have a real path component. */
for(;;) {
- struct qstr this;
- long len;
+ u64 hash_len;
int type;
err = may_lookup(nd);
if (err)
break;
- len = hash_name(name, &this.hash);
- this.name = name;
- this.len = len;
+ hash_len = hash_name(name);
type = LAST_NORM;
- if (name[0] == '.') switch (len) {
+ if (name[0] == '.') switch (hashlen_len(hash_len)) {
case 2:
if (name[1] == '.') {
type = LAST_DOTDOT;
struct dentry *parent = nd->path.dentry;
nd->flags &= ~LOOKUP_JUMPED;
if (unlikely(parent->d_flags & DCACHE_OP_HASH)) {
+ struct qstr this = { { .hash_len = hash_len }, .name = name };
err = parent->d_op->d_hash(parent, &this);
if (err < 0)
break;
+ hash_len = this.hash_len;
+ name = this.name;
}
}
- nd->last = this;
+ nd->last.hash_len = hash_len;
+ nd->last.name = name;
nd->last_type = type;
- if (!name[len])
+ name += hashlen_len(hash_len);
+ if (!*name)
return 0;
/*
* If it wasn't NUL, we know it was '/'. Skip that
* slash, and continue until no more slashes.
*/
do {
- len++;
- } while (unlikely(name[len] == '/'));
- if (!name[len])
+ name++;
+ } while (unlikely(*name == '/'));
+ if (!*name)
return 0;
- name += len;
-
err = walk_component(nd, &next, LOOKUP_FOLLOW);
if (err < 0)
return err;
if (*name=='/') {
if (flags & LOOKUP_RCU) {
rcu_read_lock();
- set_root_rcu(nd);
+ nd->seq = set_root_rcu(nd);
} else {
set_root(nd);
path_get(&nd->root);
}
nd->inode = nd->path.dentry->d_inode;
- return 0;
+ if (!(flags & LOOKUP_RCU))
+ return 0;
+ if (likely(!read_seqcount_retry(&nd->path.dentry->d_seq, nd->seq)))
+ return 0;
+ if (!(nd->flags & LOOKUP_ROOT))
+ nd->root.mnt = NULL;
+ rcu_read_unlock();
+ return -ECHILD;
}
static inline int lookup_last(struct nameidata *nd, struct path *path)
* The worst of all namespace operations - renaming directory. "Perverted"
* doesn't even start to describe it. Somebody in UCB had a heck of a trip...
* Problems:
- * a) we can get into loop creation. Check is done in is_subdir().
+ * a) we can get into loop creation.
* b) race potential - two innocent renames can create a loop together.
* That's where 4.4 screws up. Current fix: serialization on
* sb->s_vfs_rename_mutex. We might be more accurate, but that's another
if (error)
return error;
- if (!old_dir->i_op->rename)
+ if (!old_dir->i_op->rename && !old_dir->i_op->rename2)
return -EPERM;
if (flags && !old_dir->i_op->rename2)
if (error)
goto out;
}
- if (!flags) {
+ if (!old_dir->i_op->rename2) {
error = old_dir->i_op->rename(old_dir, old_dentry,
new_dir, new_dentry);
} else {
+ WARN_ON(old_dir->i_op->rename != NULL);
error = old_dir->i_op->rename2(old_dir, old_dentry,
new_dir, new_dentry, flags);
}
projects / firefly-linux-kernel-4.4.55.git / blobdiff