set_root(nd);
while(1) {
- struct vfsmount *parent;
struct dentry *old = nd->path.dentry;
if (nd->path.dentry == nd->root.dentry &&
nd->path.mnt == nd->root.mnt) {
break;
}
- spin_lock(&dcache_lock);
if (nd->path.dentry != nd->path.mnt->mnt_root) {
- nd->path.dentry = dget(nd->path.dentry->d_parent);
- spin_unlock(&dcache_lock);
+ /* rare case of legitimate dget_parent()... */
+ nd->path.dentry = dget_parent(nd->path.dentry);
dput(old);
break;
}
- spin_unlock(&dcache_lock);
- spin_lock(&vfsmount_lock);
- parent = nd->path.mnt->mnt_parent;
- if (parent == nd->path.mnt) {
- spin_unlock(&vfsmount_lock);
+ if (!follow_up(&nd->path))
break;
- }
- mntget(parent);
- nd->path.dentry = dget(nd->path.mnt->mnt_mountpoint);
- spin_unlock(&vfsmount_lock);
- dput(old);
- mntput(nd->path.mnt);
- nd->path.mnt = parent;
}
follow_mount(&nd->path);
}
}
/*
+ * This is a temporary kludge to deal with "automount" symlinks; proper
+ * solution is to trigger them on follow_mount(), so that do_lookup()
+ * would DTRT. To be killed before 2.6.34-final.
+ */
+static inline int follow_on_final(struct inode *inode, unsigned lookup_flags)
+{
+ return inode && unlikely(inode->i_op->follow_link) &&
+ ((lookup_flags & LOOKUP_FOLLOW) || S_ISDIR(inode->i_mode));
+}
+
+/*
* Name resolution.
* This is the basic name resolution function, turning a pathname into
* the final dentry. We expect 'base' to be positive and a directory.
if (err)
break;
inode = next.dentry->d_inode;
- if ((lookup_flags & LOOKUP_FOLLOW)
- && inode && inode->i_op->follow_link) {
+ if (follow_on_final(inode, lookup_flags)) {
err = do_follow_link(&next, nd);
if (err)
goto return_err;
* An append-only file must be opened in append mode for writing.
*/
if (IS_APPEND(inode)) {
- if ((flag & FMODE_WRITE) && !(flag & O_APPEND))
+ if ((flag & O_ACCMODE) != O_RDONLY && !(flag & O_APPEND))
return -EPERM;
if (flag & O_TRUNC)
return -EPERM;
* what get passed to sys_open().
*/
static int __open_namei_create(struct nameidata *nd, struct path *path,
- int flag, int mode)
+ int open_flag, int mode)
{
int error;
struct dentry *dir = nd->path.dentry;
if (error)
return error;
/* Don't check for write permission, don't truncate */
- return may_open(&nd->path, 0, flag & ~O_TRUNC);
+ return may_open(&nd->path, 0, open_flag & ~O_TRUNC);
}
/*
return (flag & O_TRUNC);
}
+static struct file *finish_open(struct nameidata *nd,
+ int open_flag, int acc_mode)
+{
+ struct file *filp;
+ int will_truncate;
+ int error;
+
+ will_truncate = open_will_truncate(open_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);
+ 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)
+{
+ struct dentry *dir = nd->path.dentry;
+ struct file *filp;
+ int error;
+
+ if (nd->last_type == LAST_BIND)
+ goto ok;
+
+ error = -EISDIR;
+ if (nd->last_type != LAST_NORM || nd->last.name[nd->last.len])
+ goto exit;
+
+ mutex_lock(&dir->d_inode->i_mutex);
+
+ 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);
+ goto exit_mutex_unlock;
+ }
+
+ /* Negative dentry, just create the file */
+ if (!path->dentry->d_inode) {
+ /*
+ * This write is needed to ensure that a
+ * ro->rw transition does not occur between
+ * the time when the file is created and when
+ * a permanent write count is taken through
+ * the 'struct file' in nameidata_to_filp().
+ */
+ error = mnt_want_write(nd->path.mnt);
+ if (error)
+ goto exit_mutex_unlock;
+ error = __open_namei_create(nd, path, open_flag, mode);
+ if (error) {
+ mnt_drop_write(nd->path.mnt);
+ goto exit;
+ }
+ filp = nameidata_to_filp(nd);
+ mnt_drop_write(nd->path.mnt);
+ if (!IS_ERR(filp)) {
+ error = ima_file_check(filp, acc_mode);
+ if (error) {
+ fput(filp);
+ filp = ERR_PTR(error);
+ }
+ }
+ return filp;
+ }
+
+ /*
+ * It already exists.
+ */
+ mutex_unlock(&dir->d_inode->i_mutex);
+ audit_inode(pathname, path->dentry);
+
+ error = -EEXIST;
+ if (open_flag & O_EXCL)
+ goto exit_dput;
+
+ if (__follow_mount(path)) {
+ error = -ELOOP;
+ if (open_flag & O_NOFOLLOW)
+ goto exit_dput;
+ }
+
+ error = -ENOENT;
+ if (!path->dentry->d_inode)
+ goto exit_dput;
+
+ 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))
+ goto exit;
+ok:
+ 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);
+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
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;
acc_mode = MAY_OPEN | ACC_MODE(open_flag);
/* O_TRUNC implies we need access checks for write permissions */
- if (flag & O_TRUNC)
+ if (open_flag & O_TRUNC)
acc_mode |= MAY_WRITE;
/* Allow the LSM permission hook to distinguish append
access from general write access. */
- if (flag & O_APPEND)
+ if (open_flag & O_APPEND)
acc_mode |= MAY_APPEND;
/*
* The simplest case - just a plain lookup.
*/
- if (!(flag & O_CREAT)) {
+ if (!(open_flag & O_CREAT)) {
filp = get_empty_filp();
if (filp == NULL)
nd.intent.open.flags = flag;
nd.intent.open.create_mode = 0;
error = do_path_lookup(dfd, pathname,
- lookup_flags(flag)|LOOKUP_OPEN, &nd);
+ lookup_flags(open_flag)|LOOKUP_OPEN, &nd);
if (IS_ERR(nd.intent.open.file)) {
if (error == 0) {
error = PTR_ERR(nd.intent.open.file);
release_open_intent(&nd);
if (error)
return ERR_PTR(error);
- goto ok;
+ return finish_open(&nd, open_flag, acc_mode);
}
/*
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.
+ * We have the parent and last component.
*/
- error = -EISDIR;
- if (nd.last_type != LAST_NORM || nd.last.name[nd.last.len])
- goto exit_parent;
error = -ENFILE;
filp = get_empty_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)
+ if (open_flag & O_EXCL)
nd.flags |= LOOKUP_EXCL;
- 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)) {
- mutex_unlock(&dir->d_inode->i_mutex);
- goto exit;
- }
-
- 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) {
- /*
- * This write is needed to ensure that a
- * ro->rw transition does not occur between
- * the time when the file is created and when
- * a permanent write count is taken through
- * the 'struct file' in nameidata_to_filp().
- */
- error = mnt_want_write(nd.path.mnt);
- if (error)
- goto exit_mutex_unlock;
- error = __open_namei_create(&nd, &path, flag, mode);
- if (error) {
- 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);
- if (!IS_ERR(filp)) {
- error = ima_file_check(filp, acc_mode);
- if (error) {
- fput(filp);
- filp = ERR_PTR(error);
- }
- }
- return filp;
- }
-
- /*
- * It already exists.
- */
- mutex_unlock(&dir->d_inode->i_mutex);
- audit_inode(pathname, path.dentry);
-
- error = -EEXIST;
- if (flag & O_EXCL)
- goto exit_dput;
-
- if (__follow_mount(&path)) {
- error = -ELOOP;
- if (flag & O_NOFOLLOW)
- goto exit_dput;
- }
-
- error = -ENOENT;
- if (!path.dentry->d_inode)
- goto exit_dput;
- if (path.dentry->d_inode->i_op->follow_link)
+ filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
+ if (!filp)
goto do_link;
-
- path_to_nameidata(&path, &nd);
- error = -EISDIR;
- 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, 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);
return filp;
-exit_mutex_unlock:
- mutex_unlock(&dir->d_inode->i_mutex);
exit_dput:
path_put_conditional(&path, &nd);
-exit:
if (!IS_ERR(nd.intent.open.file))
release_open_intent(&nd);
exit_parent:
+ path_put(&nd.path);
if (nd.root.mnt)
path_put(&nd.root);
- path_put(&nd.path);
return ERR_PTR(error);
do_link:
error = -ELOOP;
- if (flag & O_NOFOLLOW)
+ if ((open_flag & O_NOFOLLOW) || count++ == 32)
goto exit_dput;
/*
* This is subtle. Instead of calling do_follow_link() we do the
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) {
+ filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
+ if (nd.last_type == LAST_NORM)
__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;
+ if (!filp)
+ goto do_link;
+ if (nd.root.mnt)
+ path_put(&nd.root);
+ return filp;
}
/**
error = -EBUSY;
else {
error = security_inode_unlink(dir, dentry);
- if (!error)
+ if (!error) {
error = dir->i_op->unlink(dir, dentry);
+ if (!error)
+ dentry->d_inode->i_flags |= S_DEAD;
+ }
}
mutex_unlock(&dentry->d_inode->i_mutex);
else
error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
if (!error) {
+ if (target)
+ target->i_flags |= S_DEAD;
if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
d_move(old_dentry, new_dentry);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff