if (!acl)
return -EAGAIN;
/* no ->get_acl() calls in RCU mode... */
- if (acl == ACL_NOT_CACHED)
+ if (is_uncached_acl(acl))
return -ECHILD;
return posix_acl_permission(inode, acl, mask & ~MAY_NOT_BLOCK);
}
struct dentry *dir,
unsigned int flags)
{
- struct dentry *dentry;
- inode_lock(dir->d_inode);
- dentry = d_lookup(dir, name);
- if (unlikely(dentry)) {
+ struct dentry *dentry = ERR_PTR(-ENOENT), *old;
+ struct inode *inode = dir->d_inode;
+ DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+
+ inode_lock_shared(inode);
+ /* Don't go there if it's already dead */
+ if (unlikely(IS_DEADDIR(inode)))
+ goto out;
+again:
+ dentry = d_alloc_parallel(dir, name, &wq);
+ if (IS_ERR(dentry))
+ goto out;
+ if (unlikely(!d_in_lookup(dentry))) {
if ((dentry->d_flags & DCACHE_OP_REVALIDATE) &&
!(flags & LOOKUP_NO_REVAL)) {
int error = d_revalidate(dentry, flags);
if (unlikely(error <= 0)) {
- if (!error)
+ if (!error) {
d_invalidate(dentry);
+ dput(dentry);
+ goto again;
+ }
dput(dentry);
dentry = ERR_PTR(error);
}
}
- if (dentry) {
- inode_unlock(dir->d_inode);
- return dentry;
+ } else {
+ old = inode->i_op->lookup(inode, dentry, flags);
+ d_lookup_done(dentry);
+ if (unlikely(old)) {
+ dput(dentry);
+ dentry = old;
}
}
- dentry = d_alloc(dir, name);
- if (unlikely(!dentry)) {
- inode_unlock(dir->d_inode);
- return ERR_PTR(-ENOMEM);
- }
- dentry = lookup_real(dir->d_inode, dentry, flags);
- inode_unlock(dir->d_inode);
+out:
+ inode_unlock_shared(inode);
return dentry;
}
return NULL;
}
- mutex_lock(&p1->d_inode->i_sb->s_vfs_rename_mutex);
+ mutex_lock(&p1->d_sb->s_vfs_rename_mutex);
p = d_ancestor(p2, p1);
if (p) {
inode_unlock(p1->d_inode);
if (p1 != p2) {
inode_unlock(p2->d_inode);
- mutex_unlock(&p1->d_inode->i_sb->s_vfs_rename_mutex);
+ mutex_unlock(&p1->d_sb->s_vfs_rename_mutex);
}
}
EXPORT_SYMBOL(unlock_rename);
return flag;
}
-static int may_o_create(struct path *dir, struct dentry *dentry, umode_t mode)
+static int may_o_create(const struct path *dir, struct dentry *dentry, umode_t mode)
{
int error = security_path_mknod(dir, dentry, mode, 0);
if (error)
static int atomic_open(struct nameidata *nd, struct dentry *dentry,
struct path *path, struct file *file,
const struct open_flags *op,
- bool got_write, bool need_lookup,
+ int open_flag, umode_t mode,
int *opened)
{
+ struct dentry *const DENTRY_NOT_SET = (void *) -1UL;
struct inode *dir = nd->path.dentry->d_inode;
- unsigned open_flag = open_to_namei_flags(op->open_flag);
- umode_t mode;
int error;
- int acc_mode;
- int create_error = 0;
- struct dentry *const DENTRY_NOT_SET = (void *) -1UL;
- bool excl;
-
- BUG_ON(dentry->d_inode);
-
- /* Don't create child dentry for a dead directory. */
- if (unlikely(IS_DEADDIR(dir))) {
- error = -ENOENT;
- goto out;
- }
- mode = op->mode;
- if ((open_flag & O_CREAT) && !IS_POSIXACL(dir))
- mode &= ~current_umask();
-
- excl = (open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT);
- if (excl)
+ if (!(~open_flag & (O_EXCL | O_CREAT))) /* both O_EXCL and O_CREAT */
open_flag &= ~O_TRUNC;
- /*
- * Checking write permission is tricky, bacuse we don't know if we are
- * going to actually need it: O_CREAT opens should work as long as the
- * file exists. But checking existence breaks atomicity. The trick is
- * to check access and if not granted clear O_CREAT from the flags.
- *
- * Another problem is returing the "right" error value (e.g. for an
- * O_EXCL open we want to return EEXIST not EROFS).
- */
- if (((open_flag & (O_CREAT | O_TRUNC)) ||
- (open_flag & O_ACCMODE) != O_RDONLY) && unlikely(!got_write)) {
- if (!(open_flag & O_CREAT)) {
- /*
- * No O_CREATE -> atomicity not a requirement -> fall
- * back to lookup + open
- */
- goto no_open;
- } else if (open_flag & (O_EXCL | O_TRUNC)) {
- /* Fall back and fail with the right error */
- create_error = -EROFS;
- goto no_open;
- } else {
- /* No side effects, safe to clear O_CREAT */
- create_error = -EROFS;
- open_flag &= ~O_CREAT;
- }
- }
-
- if (open_flag & O_CREAT) {
- error = may_o_create(&nd->path, dentry, mode);
- if (error) {
- create_error = error;
- if (open_flag & O_EXCL)
- goto no_open;
- open_flag &= ~O_CREAT;
- }
- }
-
if (nd->flags & LOOKUP_DIRECTORY)
open_flag |= O_DIRECTORY;
file->f_path.dentry = DENTRY_NOT_SET;
file->f_path.mnt = nd->path.mnt;
- error = dir->i_op->atomic_open(dir, dentry, file, open_flag, mode,
- opened);
- if (error < 0) {
- if (create_error && error == -ENOENT)
- error = create_error;
- goto out;
- }
-
- if (error) { /* returned 1, that is */
+ error = dir->i_op->atomic_open(dir, dentry, file,
+ open_to_namei_flags(open_flag),
+ mode, opened);
+ d_lookup_done(dentry);
+ if (!error) {
+ /*
+ * We didn't have the inode before the open, so check open
+ * permission here.
+ */
+ int acc_mode = op->acc_mode;
+ if (*opened & FILE_CREATED) {
+ WARN_ON(!(open_flag & O_CREAT));
+ fsnotify_create(dir, dentry);
+ acc_mode = 0;
+ }
+ error = may_open(&file->f_path, acc_mode, open_flag);
+ if (WARN_ON(error > 0))
+ error = -EINVAL;
+ } else if (error > 0) {
if (WARN_ON(file->f_path.dentry == DENTRY_NOT_SET)) {
error = -EIO;
- goto out;
- }
- if (file->f_path.dentry) {
- dput(dentry);
- dentry = file->f_path.dentry;
- }
- if (*opened & FILE_CREATED)
- fsnotify_create(dir, dentry);
- if (!dentry->d_inode) {
- WARN_ON(*opened & FILE_CREATED);
- if (create_error) {
- error = create_error;
- goto out;
- }
} else {
- if (excl && !(*opened & FILE_CREATED)) {
- error = -EEXIST;
- goto out;
+ if (file->f_path.dentry) {
+ dput(dentry);
+ dentry = file->f_path.dentry;
}
+ if (*opened & FILE_CREATED)
+ fsnotify_create(dir, dentry);
+ path->dentry = dentry;
+ path->mnt = nd->path.mnt;
+ return 1;
}
- goto looked_up;
- }
-
- /*
- * We didn't have the inode before the open, so check open permission
- * here.
- */
- acc_mode = op->acc_mode;
- if (*opened & FILE_CREATED) {
- WARN_ON(!(open_flag & O_CREAT));
- fsnotify_create(dir, dentry);
- acc_mode = 0;
}
- error = may_open(&file->f_path, acc_mode, open_flag);
- if (error)
- fput(file);
-
-out:
dput(dentry);
return error;
-
-no_open:
- if (need_lookup) {
- dentry = lookup_real(dir, dentry, nd->flags);
- if (IS_ERR(dentry))
- return PTR_ERR(dentry);
- }
- if (create_error && !dentry->d_inode) {
- error = create_error;
- goto out;
- }
-looked_up:
- path->dentry = dentry;
- path->mnt = nd->path.mnt;
- return 1;
}
/*
{
struct dentry *dir = nd->path.dentry;
struct inode *dir_inode = dir->d_inode;
+ int open_flag = op->open_flag;
struct dentry *dentry;
- int error;
- bool need_lookup = false;
+ int error, create_error = 0;
+ umode_t mode = op->mode;
+ DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+
+ if (unlikely(IS_DEADDIR(dir_inode)))
+ return -ENOENT;
*opened &= ~FILE_CREATED;
- dentry = lookup_dcache(&nd->last, dir, nd->flags);
- if (IS_ERR(dentry))
- return PTR_ERR(dentry);
+ dentry = d_lookup(dir, &nd->last);
+ for (;;) {
+ if (!dentry) {
+ dentry = d_alloc_parallel(dir, &nd->last, &wq);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
+ }
+ if (d_in_lookup(dentry))
+ break;
- if (!dentry) {
- dentry = d_alloc(dir, &nd->last);
- if (unlikely(!dentry))
- return -ENOMEM;
- need_lookup = true;
- } else if (dentry->d_inode) {
+ if (!(dentry->d_flags & DCACHE_OP_REVALIDATE))
+ break;
+
+ error = d_revalidate(dentry, nd->flags);
+ if (likely(error > 0))
+ break;
+ if (error)
+ goto out_dput;
+ d_invalidate(dentry);
+ dput(dentry);
+ dentry = NULL;
+ }
+ if (dentry->d_inode) {
/* Cached positive dentry: will open in f_op->open */
goto out_no_open;
}
- if ((nd->flags & LOOKUP_OPEN) && dir_inode->i_op->atomic_open) {
- return atomic_open(nd, dentry, path, file, op, got_write,
- need_lookup, opened);
+ /*
+ * Checking write permission is tricky, bacuse we don't know if we are
+ * going to actually need it: O_CREAT opens should work as long as the
+ * file exists. But checking existence breaks atomicity. The trick is
+ * to check access and if not granted clear O_CREAT from the flags.
+ *
+ * Another problem is returing the "right" error value (e.g. for an
+ * O_EXCL open we want to return EEXIST not EROFS).
+ */
+ if (open_flag & O_CREAT) {
+ if (!IS_POSIXACL(dir->d_inode))
+ mode &= ~current_umask();
+ if (unlikely(!got_write)) {
+ create_error = -EROFS;
+ open_flag &= ~O_CREAT;
+ if (open_flag & (O_EXCL | O_TRUNC))
+ goto no_open;
+ /* No side effects, safe to clear O_CREAT */
+ } else {
+ create_error = may_o_create(&nd->path, dentry, mode);
+ if (create_error) {
+ open_flag &= ~O_CREAT;
+ if (open_flag & O_EXCL)
+ goto no_open;
+ }
+ }
+ } else if ((open_flag & (O_TRUNC|O_WRONLY|O_RDWR)) &&
+ unlikely(!got_write)) {
+ /*
+ * No O_CREATE -> atomicity not a requirement -> fall
+ * back to lookup + open
+ */
+ goto no_open;
}
- if (need_lookup) {
- BUG_ON(dentry->d_inode);
+ if (dir_inode->i_op->atomic_open) {
+ error = atomic_open(nd, dentry, path, file, op, open_flag,
+ mode, opened);
+ if (unlikely(error == -ENOENT) && create_error)
+ error = create_error;
+ return error;
+ }
- dentry = lookup_real(dir_inode, dentry, nd->flags);
- if (IS_ERR(dentry))
- return PTR_ERR(dentry);
+no_open:
+ if (d_in_lookup(dentry)) {
+ struct dentry *res = dir_inode->i_op->lookup(dir_inode, dentry,
+ nd->flags);
+ d_lookup_done(dentry);
+ if (unlikely(res)) {
+ if (IS_ERR(res)) {
+ error = PTR_ERR(res);
+ goto out_dput;
+ }
+ dput(dentry);
+ dentry = res;
+ }
}
/* Negative dentry, just create the file */
- if (!dentry->d_inode && (op->open_flag & O_CREAT)) {
- umode_t mode = op->mode;
- if (!IS_POSIXACL(dir->d_inode))
- mode &= ~current_umask();
- /*
- * This write is needed to ensure that a
- * rw->ro 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 finish_open().
- */
- if (!got_write) {
- error = -EROFS;
- goto out_dput;
- }
+ if (!dentry->d_inode && (open_flag & O_CREAT)) {
*opened |= FILE_CREATED;
- error = security_path_mknod(&nd->path, dentry, mode, 0);
- if (error)
+ audit_inode_child(dir_inode, dentry, AUDIT_TYPE_CHILD_CREATE);
+ if (!dir_inode->i_op->create) {
+ error = -EACCES;
goto out_dput;
- error = vfs_create(dir->d_inode, dentry, mode,
- nd->flags & LOOKUP_EXCL);
+ }
+ error = dir_inode->i_op->create(dir_inode, dentry, mode,
+ open_flag & O_EXCL);
if (error)
goto out_dput;
+ fsnotify_create(dir_inode, dentry);
+ }
+ if (unlikely(create_error) && !dentry->d_inode) {
+ error = create_error;
+ goto out_dput;
}
out_no_open:
path->dentry = dentry;
}
retry_lookup:
- if (op->open_flag & (O_CREAT | O_TRUNC | O_WRONLY | O_RDWR)) {
+ if (open_flag & (O_CREAT | O_TRUNC | O_WRONLY | O_RDWR)) {
error = mnt_want_write(nd->path.mnt);
if (!error)
got_write = true;
* dropping this one anyway.
*/
}
- inode_lock(dir->d_inode);
+ if (open_flag & O_CREAT)
+ inode_lock(dir->d_inode);
+ else
+ inode_lock_shared(dir->d_inode);
error = lookup_open(nd, &path, file, op, got_write, opened);
- inode_unlock(dir->d_inode);
+ if (open_flag & O_CREAT)
+ inode_unlock(dir->d_inode);
+ else
+ inode_unlock_shared(dir->d_inode);
if (error <= 0) {
if (error)
return error;
}
audit_inode(nd->name, nd->path.dentry, 0);
- if (unlikely(d_is_symlink(nd->path.dentry)) && !(open_flag & O_PATH)) {
- error = -ELOOP;
- goto out;
- }
error = -EISDIR;
if ((open_flag & O_CREAT) && d_is_dir(nd->path.dentry))
goto out;
got_write = true;
}
finish_open_created:
- if (likely(!(open_flag & O_PATH))) {
- error = may_open(&nd->path, acc_mode, open_flag);
- if (error)
- goto out;
- }
+ error = may_open(&nd->path, acc_mode, open_flag);
+ if (error)
+ goto out;
BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */
error = vfs_open(&nd->path, file, current_cred());
if (!error) {
}
opened:
error = open_check_o_direct(file);
- if (error)
- goto exit_fput;
- error = ima_file_check(file, op->acc_mode, *opened);
- if (error)
- goto exit_fput;
-
- if (will_truncate) {
+ if (!error)
+ error = ima_file_check(file, op->acc_mode, *opened);
+ if (!error && will_truncate)
error = handle_truncate(file);
- if (error)
- goto exit_fput;
- }
out:
+ if (unlikely(error) && (*opened & FILE_OPENED))
+ fput(file);
if (unlikely(error > 0)) {
WARN_ON(1);
error = -EINVAL;
path_put(&save_parent);
return error;
-exit_fput:
- fput(file);
- goto out;
-
stale_open:
/* If no saved parent or already retried then can't retry */
if (!save_parent.dentry || retried)
return error;
}
+static int do_o_path(struct nameidata *nd, unsigned flags, struct file *file)
+{
+ struct path path;
+ int error = path_lookupat(nd, flags, &path);
+ if (!error) {
+ audit_inode(nd->name, path.dentry, 0);
+ error = vfs_open(&path, file, current_cred());
+ path_put(&path);
+ }
+ return error;
+}
+
static struct file *path_openat(struct nameidata *nd,
const struct open_flags *op, unsigned flags)
{
goto out2;
}
+ if (unlikely(file->f_flags & O_PATH)) {
+ error = do_o_path(nd, flags, file);
+ if (!error)
+ opened |= FILE_OPENED;
+ goto out2;
+ }
+
s = path_init(nd, flags);
if (IS_ERR(s)) {
put_filp(file);
switch (mode & S_IFMT) {
case 0: case S_IFREG:
error = vfs_create(path.dentry->d_inode,dentry,mode,true);
+ if (!error)
+ ima_post_path_mknod(dentry);
break;
case S_IFCHR: case S_IFBLK:
error = vfs_mknod(path.dentry->d_inode,dentry,mode,
out:
return len;
}
-EXPORT_SYMBOL(readlink_copy);
/*
* A helper for ->readlink(). This should be used *ONLY* for symlinks that
projects / cascardo / linux.git / blobdiff