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: Switch !O_CREAT case to use of do_last() Get rid of symlink body copying Finish pulling of -ESTALE handling to upper level in do_filp_open() Turn do_link spaghetty into a normal loop Unify exits in O_CREAT handling Kill is_link argument of do_last() Pull handling of LAST_BIND into do_last(), clean up ok: part in do_filp_open() Leave mangled flag only for setting nd.intent.open.flag Get rid of passing mangled flag to do_last() Don't pass mangled open_flag to finish_open() pull more into do_last() bail out with ELOOP earlier in do_link loop pull the common predecessors into do_last() postpone __putname() until after do_last() unroll do_last: loop in do_filp_open() Shift releasing nd->root from do_last() to its caller gut do_filp_open() a bit more (do_last separation) beginning to untangle do_filp_open()
This commit is contained in:
Linus Torvalds
commit
35c2e967d0
545
fs/namei.c
545
fs/namei.c
|
|
@ -498,8 +498,6 @@ static int link_path_walk(const char *, struct nameidata *);
|
|||
|
||||
static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *link)
|
||||
{
|
||||
int res = 0;
|
||||
char *name;
|
||||
if (IS_ERR(link))
|
||||
goto fail;
|
||||
|
||||
|
|
@ -510,22 +508,7 @@ static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *l
|
|||
path_get(&nd->root);
|
||||
}
|
||||
|
||||
res = link_path_walk(link, nd);
|
||||
if (nd->depth || res || nd->last_type!=LAST_NORM)
|
||||
return res;
|
||||
/*
|
||||
* If it is an iterative symlinks resolution in open_namei() we
|
||||
* have to copy the last component. And all that crap because of
|
||||
* bloody create() on broken symlinks. Furrfu...
|
||||
*/
|
||||
name = __getname();
|
||||
if (unlikely(!name)) {
|
||||
path_put(&nd->path);
|
||||
return -ENOMEM;
|
||||
}
|
||||
strcpy(name, nd->last.name);
|
||||
nd->last.name = name;
|
||||
return 0;
|
||||
return link_path_walk(link, nd);
|
||||
fail:
|
||||
path_put(&nd->path);
|
||||
return PTR_ERR(link);
|
||||
|
|
@ -547,10 +530,10 @@ static inline void path_to_nameidata(struct path *path, struct nameidata *nd)
|
|||
nd->path.dentry = path->dentry;
|
||||
}
|
||||
|
||||
static __always_inline int __do_follow_link(struct path *path, struct nameidata *nd)
|
||||
static __always_inline int
|
||||
__do_follow_link(struct path *path, struct nameidata *nd, void **p)
|
||||
{
|
||||
int error;
|
||||
void *cookie;
|
||||
struct dentry *dentry = path->dentry;
|
||||
|
||||
touch_atime(path->mnt, dentry);
|
||||
|
|
@ -562,9 +545,9 @@ static __always_inline int __do_follow_link(struct path *path, struct nameidata
|
|||
}
|
||||
mntget(path->mnt);
|
||||
nd->last_type = LAST_BIND;
|
||||
cookie = dentry->d_inode->i_op->follow_link(dentry, nd);
|
||||
error = PTR_ERR(cookie);
|
||||
if (!IS_ERR(cookie)) {
|
||||
*p = dentry->d_inode->i_op->follow_link(dentry, nd);
|
||||
error = PTR_ERR(*p);
|
||||
if (!IS_ERR(*p)) {
|
||||
char *s = nd_get_link(nd);
|
||||
error = 0;
|
||||
if (s)
|
||||
|
|
@ -574,8 +557,6 @@ static __always_inline int __do_follow_link(struct path *path, struct nameidata
|
|||
if (error)
|
||||
path_put(&nd->path);
|
||||
}
|
||||
if (dentry->d_inode->i_op->put_link)
|
||||
dentry->d_inode->i_op->put_link(dentry, nd, cookie);
|
||||
}
|
||||
return error;
|
||||
}
|
||||
|
|
@ -589,6 +570,7 @@ static __always_inline int __do_follow_link(struct path *path, struct nameidata
|
|||
*/
|
||||
static inline int do_follow_link(struct path *path, struct nameidata *nd)
|
||||
{
|
||||
void *cookie;
|
||||
int err = -ELOOP;
|
||||
if (current->link_count >= MAX_NESTED_LINKS)
|
||||
goto loop;
|
||||
|
|
@ -602,7 +584,9 @@ static inline int do_follow_link(struct path *path, struct nameidata *nd)
|
|||
current->link_count++;
|
||||
current->total_link_count++;
|
||||
nd->depth++;
|
||||
err = __do_follow_link(path, nd);
|
||||
err = __do_follow_link(path, nd, &cookie);
|
||||
if (!IS_ERR(cookie) && path->dentry->d_inode->i_op->put_link)
|
||||
path->dentry->d_inode->i_op->put_link(path->dentry, nd, cookie);
|
||||
path_put(path);
|
||||
current->link_count--;
|
||||
nd->depth--;
|
||||
|
|
@ -1375,22 +1359,6 @@ static inline int may_create(struct inode *dir, struct dentry *child)
|
|||
return inode_permission(dir, MAY_WRITE | MAY_EXEC);
|
||||
}
|
||||
|
||||
/*
|
||||
* O_DIRECTORY translates into forcing a directory lookup.
|
||||
*/
|
||||
static inline int lookup_flags(unsigned int f)
|
||||
{
|
||||
unsigned long retval = LOOKUP_FOLLOW;
|
||||
|
||||
if (f & O_NOFOLLOW)
|
||||
retval &= ~LOOKUP_FOLLOW;
|
||||
|
||||
if (f & O_DIRECTORY)
|
||||
retval |= LOOKUP_DIRECTORY;
|
||||
|
||||
return retval;
|
||||
}
|
||||
|
||||
/*
|
||||
* p1 and p2 should be directories on the same fs.
|
||||
*/
|
||||
|
|
@ -1590,129 +1558,135 @@ static int open_will_truncate(int flag, struct inode *inode)
|
|||
return (flag & O_TRUNC);
|
||||
}
|
||||
|
||||
/*
|
||||
* Note that the low bits of the passed in "open_flag"
|
||||
* are not the same as in the local variable "flag". See
|
||||
* open_to_namei_flags() for more details.
|
||||
*/
|
||||
struct file *do_filp_open(int dfd, const char *pathname,
|
||||
int open_flag, int mode, int acc_mode)
|
||||
static struct file *finish_open(struct nameidata *nd,
|
||||
int open_flag, int acc_mode)
|
||||
{
|
||||
struct file *filp;
|
||||
struct nameidata nd;
|
||||
int error;
|
||||
struct path path;
|
||||
struct dentry *dir;
|
||||
int count = 0;
|
||||
int will_truncate;
|
||||
int flag = open_to_namei_flags(open_flag);
|
||||
int force_reval = 0;
|
||||
int error;
|
||||
|
||||
/*
|
||||
* O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only
|
||||
* check for O_DSYNC if the need any syncing at all we enforce it's
|
||||
* always set instead of having to deal with possibly weird behaviour
|
||||
* for malicious applications setting only __O_SYNC.
|
||||
*/
|
||||
if (open_flag & __O_SYNC)
|
||||
open_flag |= O_DSYNC;
|
||||
|
||||
if (!acc_mode)
|
||||
acc_mode = MAY_OPEN | ACC_MODE(open_flag);
|
||||
|
||||
/* O_TRUNC implies we need access checks for write permissions */
|
||||
if (flag & O_TRUNC)
|
||||
acc_mode |= MAY_WRITE;
|
||||
|
||||
/* Allow the LSM permission hook to distinguish append
|
||||
access from general write access. */
|
||||
if (flag & O_APPEND)
|
||||
acc_mode |= MAY_APPEND;
|
||||
|
||||
/*
|
||||
* The simplest case - just a plain lookup.
|
||||
*/
|
||||
if (!(flag & O_CREAT)) {
|
||||
filp = get_empty_filp();
|
||||
|
||||
if (filp == NULL)
|
||||
return ERR_PTR(-ENFILE);
|
||||
nd.intent.open.file = filp;
|
||||
filp->f_flags = open_flag;
|
||||
nd.intent.open.flags = flag;
|
||||
nd.intent.open.create_mode = 0;
|
||||
error = do_path_lookup(dfd, pathname,
|
||||
lookup_flags(flag)|LOOKUP_OPEN, &nd);
|
||||
if (IS_ERR(nd.intent.open.file)) {
|
||||
if (error == 0) {
|
||||
error = PTR_ERR(nd.intent.open.file);
|
||||
path_put(&nd.path);
|
||||
}
|
||||
} else if (error)
|
||||
release_open_intent(&nd);
|
||||
will_truncate = open_will_truncate(open_flag, nd->path.dentry->d_inode);
|
||||
if (will_truncate) {
|
||||
error = mnt_want_write(nd->path.mnt);
|
||||
if (error)
|
||||
return ERR_PTR(error);
|
||||
goto exit;
|
||||
}
|
||||
error = may_open(&nd->path, acc_mode, open_flag);
|
||||
if (error) {
|
||||
if (will_truncate)
|
||||
mnt_drop_write(nd->path.mnt);
|
||||
goto exit;
|
||||
}
|
||||
filp = nameidata_to_filp(nd);
|
||||
if (!IS_ERR(filp)) {
|
||||
error = ima_file_check(filp, acc_mode);
|
||||
if (error) {
|
||||
fput(filp);
|
||||
filp = ERR_PTR(error);
|
||||
}
|
||||
}
|
||||
if (!IS_ERR(filp)) {
|
||||
if (acc_mode & MAY_WRITE)
|
||||
vfs_dq_init(nd->path.dentry->d_inode);
|
||||
|
||||
if (will_truncate) {
|
||||
error = handle_truncate(&nd->path);
|
||||
if (error) {
|
||||
fput(filp);
|
||||
filp = ERR_PTR(error);
|
||||
}
|
||||
}
|
||||
}
|
||||
/*
|
||||
* It is now safe to drop the mnt write
|
||||
* because the filp has had a write taken
|
||||
* on its behalf.
|
||||
*/
|
||||
if (will_truncate)
|
||||
mnt_drop_write(nd->path.mnt);
|
||||
return filp;
|
||||
|
||||
exit:
|
||||
if (!IS_ERR(nd->intent.open.file))
|
||||
release_open_intent(nd);
|
||||
path_put(&nd->path);
|
||||
return ERR_PTR(error);
|
||||
}
|
||||
|
||||
static struct file *do_last(struct nameidata *nd, struct path *path,
|
||||
int open_flag, int acc_mode,
|
||||
int mode, const char *pathname,
|
||||
int *want_dir)
|
||||
{
|
||||
struct dentry *dir = nd->path.dentry;
|
||||
struct file *filp;
|
||||
int error = -EISDIR;
|
||||
|
||||
switch (nd->last_type) {
|
||||
case LAST_DOTDOT:
|
||||
follow_dotdot(nd);
|
||||
dir = nd->path.dentry;
|
||||
if (nd->path.mnt->mnt_sb->s_type->fs_flags & FS_REVAL_DOT) {
|
||||
if (!dir->d_op->d_revalidate(dir, nd)) {
|
||||
error = -ESTALE;
|
||||
goto exit;
|
||||
}
|
||||
}
|
||||
/* fallthrough */
|
||||
case LAST_DOT:
|
||||
case LAST_ROOT:
|
||||
if (open_flag & O_CREAT)
|
||||
goto exit;
|
||||
/* fallthrough */
|
||||
case LAST_BIND:
|
||||
audit_inode(pathname, dir);
|
||||
goto ok;
|
||||
}
|
||||
|
||||
/*
|
||||
* Create - we need to know the parent.
|
||||
*/
|
||||
reval:
|
||||
error = path_init(dfd, pathname, LOOKUP_PARENT, &nd);
|
||||
if (error)
|
||||
return ERR_PTR(error);
|
||||
if (force_reval)
|
||||
nd.flags |= LOOKUP_REVAL;
|
||||
error = path_walk(pathname, &nd);
|
||||
if (error) {
|
||||
if (nd.root.mnt)
|
||||
path_put(&nd.root);
|
||||
return ERR_PTR(error);
|
||||
/* trailing slashes? */
|
||||
if (nd->last.name[nd->last.len]) {
|
||||
if (open_flag & O_CREAT)
|
||||
goto exit;
|
||||
*want_dir = 1;
|
||||
}
|
||||
if (unlikely(!audit_dummy_context()))
|
||||
audit_inode(pathname, nd.path.dentry);
|
||||
|
||||
/*
|
||||
* We have the parent and last component. First of all, check
|
||||
* that we are not asked to creat(2) an obvious directory - that
|
||||
* will not do.
|
||||
*/
|
||||
error = -EISDIR;
|
||||
if (nd.last_type != LAST_NORM || nd.last.name[nd.last.len])
|
||||
goto exit_parent;
|
||||
/* just plain open? */
|
||||
if (!(open_flag & O_CREAT)) {
|
||||
error = do_lookup(nd, &nd->last, path);
|
||||
if (error)
|
||||
goto exit;
|
||||
error = -ENOENT;
|
||||
if (!path->dentry->d_inode)
|
||||
goto exit_dput;
|
||||
if (path->dentry->d_inode->i_op->follow_link)
|
||||
return NULL;
|
||||
error = -ENOTDIR;
|
||||
if (*want_dir & !path->dentry->d_inode->i_op->lookup)
|
||||
goto exit_dput;
|
||||
path_to_nameidata(path, nd);
|
||||
audit_inode(pathname, nd->path.dentry);
|
||||
goto ok;
|
||||
}
|
||||
|
||||
error = -ENFILE;
|
||||
filp = get_empty_filp();
|
||||
if (filp == NULL)
|
||||
goto exit_parent;
|
||||
nd.intent.open.file = filp;
|
||||
filp->f_flags = open_flag;
|
||||
nd.intent.open.flags = flag;
|
||||
nd.intent.open.create_mode = mode;
|
||||
dir = nd.path.dentry;
|
||||
nd.flags &= ~LOOKUP_PARENT;
|
||||
nd.flags |= LOOKUP_CREATE | LOOKUP_OPEN;
|
||||
if (flag & O_EXCL)
|
||||
nd.flags |= LOOKUP_EXCL;
|
||||
/* OK, it's O_CREAT */
|
||||
mutex_lock(&dir->d_inode->i_mutex);
|
||||
path.dentry = lookup_hash(&nd);
|
||||
path.mnt = nd.path.mnt;
|
||||
|
||||
do_last:
|
||||
error = PTR_ERR(path.dentry);
|
||||
if (IS_ERR(path.dentry)) {
|
||||
path->dentry = lookup_hash(nd);
|
||||
path->mnt = nd->path.mnt;
|
||||
|
||||
error = PTR_ERR(path->dentry);
|
||||
if (IS_ERR(path->dentry)) {
|
||||
mutex_unlock(&dir->d_inode->i_mutex);
|
||||
goto exit;
|
||||
}
|
||||
|
||||
if (IS_ERR(nd.intent.open.file)) {
|
||||
error = PTR_ERR(nd.intent.open.file);
|
||||
if (IS_ERR(nd->intent.open.file)) {
|
||||
error = PTR_ERR(nd->intent.open.file);
|
||||
goto exit_mutex_unlock;
|
||||
}
|
||||
|
||||
/* Negative dentry, just create the file */
|
||||
if (!path.dentry->d_inode) {
|
||||
if (!path->dentry->d_inode) {
|
||||
/*
|
||||
* This write is needed to ensure that a
|
||||
* ro->rw transition does not occur between
|
||||
|
|
@ -1720,18 +1694,16 @@ do_last:
|
|||
* a permanent write count is taken through
|
||||
* the 'struct file' in nameidata_to_filp().
|
||||
*/
|
||||
error = mnt_want_write(nd.path.mnt);
|
||||
error = mnt_want_write(nd->path.mnt);
|
||||
if (error)
|
||||
goto exit_mutex_unlock;
|
||||
error = __open_namei_create(&nd, &path, open_flag, mode);
|
||||
error = __open_namei_create(nd, path, open_flag, mode);
|
||||
if (error) {
|
||||
mnt_drop_write(nd.path.mnt);
|
||||
mnt_drop_write(nd->path.mnt);
|
||||
goto exit;
|
||||
}
|
||||
filp = nameidata_to_filp(&nd);
|
||||
mnt_drop_write(nd.path.mnt);
|
||||
if (nd.root.mnt)
|
||||
path_put(&nd.root);
|
||||
filp = nameidata_to_filp(nd);
|
||||
mnt_drop_write(nd->path.mnt);
|
||||
if (!IS_ERR(filp)) {
|
||||
error = ima_file_check(filp, acc_mode);
|
||||
if (error) {
|
||||
|
|
@ -1746,150 +1718,181 @@ do_last:
|
|||
* It already exists.
|
||||
*/
|
||||
mutex_unlock(&dir->d_inode->i_mutex);
|
||||
audit_inode(pathname, path.dentry);
|
||||
audit_inode(pathname, path->dentry);
|
||||
|
||||
error = -EEXIST;
|
||||
if (flag & O_EXCL)
|
||||
if (open_flag & O_EXCL)
|
||||
goto exit_dput;
|
||||
|
||||
if (__follow_mount(&path)) {
|
||||
if (__follow_mount(path)) {
|
||||
error = -ELOOP;
|
||||
if (flag & O_NOFOLLOW)
|
||||
if (open_flag & O_NOFOLLOW)
|
||||
goto exit_dput;
|
||||
}
|
||||
|
||||
error = -ENOENT;
|
||||
if (!path.dentry->d_inode)
|
||||
if (!path->dentry->d_inode)
|
||||
goto exit_dput;
|
||||
if (path.dentry->d_inode->i_op->follow_link)
|
||||
goto do_link;
|
||||
|
||||
path_to_nameidata(&path, &nd);
|
||||
if (path->dentry->d_inode->i_op->follow_link)
|
||||
return NULL;
|
||||
|
||||
path_to_nameidata(path, nd);
|
||||
error = -EISDIR;
|
||||
if (S_ISDIR(path.dentry->d_inode->i_mode))
|
||||
if (S_ISDIR(path->dentry->d_inode->i_mode))
|
||||
goto exit;
|
||||
ok:
|
||||
/*
|
||||
* Consider:
|
||||
* 1. may_open() truncates a file
|
||||
* 2. a rw->ro mount transition occurs
|
||||
* 3. nameidata_to_filp() fails due to
|
||||
* the ro mount.
|
||||
* That would be inconsistent, and should
|
||||
* be avoided. Taking this mnt write here
|
||||
* ensures that (2) can not occur.
|
||||
*/
|
||||
will_truncate = open_will_truncate(flag, nd.path.dentry->d_inode);
|
||||
if (will_truncate) {
|
||||
error = mnt_want_write(nd.path.mnt);
|
||||
if (error)
|
||||
goto exit;
|
||||
}
|
||||
error = may_open(&nd.path, acc_mode, open_flag);
|
||||
if (error) {
|
||||
if (will_truncate)
|
||||
mnt_drop_write(nd.path.mnt);
|
||||
goto exit;
|
||||
}
|
||||
filp = nameidata_to_filp(&nd);
|
||||
if (!IS_ERR(filp)) {
|
||||
error = ima_file_check(filp, acc_mode);
|
||||
if (error) {
|
||||
fput(filp);
|
||||
filp = ERR_PTR(error);
|
||||
}
|
||||
}
|
||||
if (!IS_ERR(filp)) {
|
||||
if (acc_mode & MAY_WRITE)
|
||||
vfs_dq_init(nd.path.dentry->d_inode);
|
||||
|
||||
if (will_truncate) {
|
||||
error = handle_truncate(&nd.path);
|
||||
if (error) {
|
||||
fput(filp);
|
||||
filp = ERR_PTR(error);
|
||||
}
|
||||
}
|
||||
}
|
||||
/*
|
||||
* It is now safe to drop the mnt write
|
||||
* because the filp has had a write taken
|
||||
* on its behalf.
|
||||
*/
|
||||
if (will_truncate)
|
||||
mnt_drop_write(nd.path.mnt);
|
||||
if (nd.root.mnt)
|
||||
path_put(&nd.root);
|
||||
filp = finish_open(nd, open_flag, acc_mode);
|
||||
return filp;
|
||||
|
||||
exit_mutex_unlock:
|
||||
mutex_unlock(&dir->d_inode->i_mutex);
|
||||
exit_dput:
|
||||
path_put_conditional(&path, &nd);
|
||||
path_put_conditional(path, nd);
|
||||
exit:
|
||||
if (!IS_ERR(nd->intent.open.file))
|
||||
release_open_intent(nd);
|
||||
path_put(&nd->path);
|
||||
return ERR_PTR(error);
|
||||
}
|
||||
|
||||
/*
|
||||
* Note that the low bits of the passed in "open_flag"
|
||||
* are not the same as in the local variable "flag". See
|
||||
* open_to_namei_flags() for more details.
|
||||
*/
|
||||
struct file *do_filp_open(int dfd, const char *pathname,
|
||||
int open_flag, int mode, int acc_mode)
|
||||
{
|
||||
struct file *filp;
|
||||
struct nameidata nd;
|
||||
int error;
|
||||
struct path path;
|
||||
int count = 0;
|
||||
int flag = open_to_namei_flags(open_flag);
|
||||
int force_reval = 0;
|
||||
int want_dir = open_flag & O_DIRECTORY;
|
||||
|
||||
if (!(open_flag & O_CREAT))
|
||||
mode = 0;
|
||||
|
||||
/*
|
||||
* O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only
|
||||
* check for O_DSYNC if the need any syncing at all we enforce it's
|
||||
* always set instead of having to deal with possibly weird behaviour
|
||||
* for malicious applications setting only __O_SYNC.
|
||||
*/
|
||||
if (open_flag & __O_SYNC)
|
||||
open_flag |= O_DSYNC;
|
||||
|
||||
if (!acc_mode)
|
||||
acc_mode = MAY_OPEN | ACC_MODE(open_flag);
|
||||
|
||||
/* O_TRUNC implies we need access checks for write permissions */
|
||||
if (open_flag & O_TRUNC)
|
||||
acc_mode |= MAY_WRITE;
|
||||
|
||||
/* Allow the LSM permission hook to distinguish append
|
||||
access from general write access. */
|
||||
if (open_flag & O_APPEND)
|
||||
acc_mode |= MAY_APPEND;
|
||||
|
||||
/* find the parent */
|
||||
reval:
|
||||
error = path_init(dfd, pathname, LOOKUP_PARENT, &nd);
|
||||
if (error)
|
||||
return ERR_PTR(error);
|
||||
if (force_reval)
|
||||
nd.flags |= LOOKUP_REVAL;
|
||||
|
||||
current->total_link_count = 0;
|
||||
error = link_path_walk(pathname, &nd);
|
||||
if (error) {
|
||||
filp = ERR_PTR(error);
|
||||
goto out;
|
||||
}
|
||||
if (unlikely(!audit_dummy_context()) && (open_flag & O_CREAT))
|
||||
audit_inode(pathname, nd.path.dentry);
|
||||
|
||||
/*
|
||||
* We have the parent and last component.
|
||||
*/
|
||||
|
||||
error = -ENFILE;
|
||||
filp = get_empty_filp();
|
||||
if (filp == NULL)
|
||||
goto exit_parent;
|
||||
nd.intent.open.file = filp;
|
||||
filp->f_flags = open_flag;
|
||||
nd.intent.open.flags = flag;
|
||||
nd.intent.open.create_mode = mode;
|
||||
nd.flags &= ~LOOKUP_PARENT;
|
||||
nd.flags |= LOOKUP_OPEN;
|
||||
if (open_flag & O_CREAT) {
|
||||
nd.flags |= LOOKUP_CREATE;
|
||||
if (open_flag & O_EXCL)
|
||||
nd.flags |= LOOKUP_EXCL;
|
||||
}
|
||||
filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname, &want_dir);
|
||||
while (unlikely(!filp)) { /* trailing symlink */
|
||||
struct path holder;
|
||||
struct inode *inode = path.dentry->d_inode;
|
||||
void *cookie;
|
||||
error = -ELOOP;
|
||||
/* S_ISDIR part is a temporary automount kludge */
|
||||
if ((open_flag & O_NOFOLLOW) && !S_ISDIR(inode->i_mode))
|
||||
goto exit_dput;
|
||||
if (count++ == 32)
|
||||
goto exit_dput;
|
||||
/*
|
||||
* This is subtle. Instead of calling do_follow_link() we do
|
||||
* the thing by hands. The reason is that this way we have zero
|
||||
* link_count and path_walk() (called from ->follow_link)
|
||||
* honoring LOOKUP_PARENT. After that we have the parent and
|
||||
* last component, i.e. we are in the same situation as after
|
||||
* the first path_walk(). Well, almost - if the last component
|
||||
* is normal we get its copy stored in nd->last.name and we will
|
||||
* have to putname() it when we are done. Procfs-like symlinks
|
||||
* just set LAST_BIND.
|
||||
*/
|
||||
nd.flags |= LOOKUP_PARENT;
|
||||
error = security_inode_follow_link(path.dentry, &nd);
|
||||
if (error)
|
||||
goto exit_dput;
|
||||
error = __do_follow_link(&path, &nd, &cookie);
|
||||
if (unlikely(error)) {
|
||||
/* nd.path had been dropped */
|
||||
if (!IS_ERR(cookie) && inode->i_op->put_link)
|
||||
inode->i_op->put_link(path.dentry, &nd, cookie);
|
||||
path_put(&path);
|
||||
release_open_intent(&nd);
|
||||
filp = ERR_PTR(error);
|
||||
goto out;
|
||||
}
|
||||
holder = path;
|
||||
nd.flags &= ~LOOKUP_PARENT;
|
||||
filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname, &want_dir);
|
||||
if (inode->i_op->put_link)
|
||||
inode->i_op->put_link(holder.dentry, &nd, cookie);
|
||||
path_put(&holder);
|
||||
}
|
||||
out:
|
||||
if (nd.root.mnt)
|
||||
path_put(&nd.root);
|
||||
if (filp == ERR_PTR(-ESTALE) && !force_reval) {
|
||||
force_reval = 1;
|
||||
goto reval;
|
||||
}
|
||||
return filp;
|
||||
|
||||
exit_dput:
|
||||
path_put_conditional(&path, &nd);
|
||||
if (!IS_ERR(nd.intent.open.file))
|
||||
release_open_intent(&nd);
|
||||
exit_parent:
|
||||
if (nd.root.mnt)
|
||||
path_put(&nd.root);
|
||||
path_put(&nd.path);
|
||||
return ERR_PTR(error);
|
||||
|
||||
do_link:
|
||||
error = -ELOOP;
|
||||
if (flag & O_NOFOLLOW)
|
||||
goto exit_dput;
|
||||
/*
|
||||
* This is subtle. Instead of calling do_follow_link() we do the
|
||||
* thing by hands. The reason is that this way we have zero link_count
|
||||
* and path_walk() (called from ->follow_link) honoring LOOKUP_PARENT.
|
||||
* After that we have the parent and last component, i.e.
|
||||
* we are in the same situation as after the first path_walk().
|
||||
* Well, almost - if the last component is normal we get its copy
|
||||
* stored in nd->last.name and we will have to putname() it when we
|
||||
* are done. Procfs-like symlinks just set LAST_BIND.
|
||||
*/
|
||||
nd.flags |= LOOKUP_PARENT;
|
||||
error = security_inode_follow_link(path.dentry, &nd);
|
||||
if (error)
|
||||
goto exit_dput;
|
||||
error = __do_follow_link(&path, &nd);
|
||||
path_put(&path);
|
||||
if (error) {
|
||||
/* Does someone understand code flow here? Or it is only
|
||||
* me so stupid? Anathema to whoever designed this non-sense
|
||||
* with "intent.open".
|
||||
*/
|
||||
release_open_intent(&nd);
|
||||
if (nd.root.mnt)
|
||||
path_put(&nd.root);
|
||||
if (error == -ESTALE && !force_reval) {
|
||||
force_reval = 1;
|
||||
goto reval;
|
||||
}
|
||||
return ERR_PTR(error);
|
||||
}
|
||||
nd.flags &= ~LOOKUP_PARENT;
|
||||
if (nd.last_type == LAST_BIND)
|
||||
goto ok;
|
||||
error = -EISDIR;
|
||||
if (nd.last_type != LAST_NORM)
|
||||
goto exit;
|
||||
if (nd.last.name[nd.last.len]) {
|
||||
__putname(nd.last.name);
|
||||
goto exit;
|
||||
}
|
||||
error = -ELOOP;
|
||||
if (count++==32) {
|
||||
__putname(nd.last.name);
|
||||
goto exit;
|
||||
}
|
||||
dir = nd.path.dentry;
|
||||
mutex_lock(&dir->d_inode->i_mutex);
|
||||
path.dentry = lookup_hash(&nd);
|
||||
path.mnt = nd.path.mnt;
|
||||
__putname(nd.last.name);
|
||||
goto do_last;
|
||||
filp = ERR_PTR(error);
|
||||
goto out;
|
||||
}
|
||||
|
||||
/**
|
||||
|
|
|
|||
Loading…
Reference in a new issue