Unverified Commit 2b108260 authored by Konstantin Komarov's avatar Konstantin Komarov
Browse files

fs/ntfs3: atomic_open implementation 



Added ntfs_atomic_open function.
Relaxed locking in ntfs_create_inode.

Signed-off-by: default avatarKonstantin Komarov <almaz.alexandrovich@paragon-software.com>
parent 07f4aa9d

fs/ntfs3/inode.c

+20 −4
Original line number Diff line number Diff line
@@ -1184,6 +1184,18 @@ ntfs_create_reparse_buffer(struct ntfs_sb_info *sbi, const char *symname, 
	return ERR_PTR(err);

}



/*

 * ntfs_create_inode

 *

 * Helper function for:

 * - ntfs_create

 * - ntfs_mknod

 * - ntfs_symlink

 * - ntfs_mkdir

 * - ntfs_atomic_open

 * 

 * NOTE: if fnd != NULL (ntfs_atomic_open) then @dir is locked

 */

struct inode *ntfs_create_inode(struct user_namespace *mnt_userns,

				struct inode *dir, struct dentry *dentry,

				const struct cpu_str *uni, umode_t mode,
@@ -1213,6 +1225,7 @@ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns, 
	struct REPARSE_DATA_BUFFER *rp = NULL;

	bool rp_inserted = false;



	if (!fnd)

		ni_lock_dir(dir_ni);



	dir_root = indx_get_root(&dir_ni->dir, dir_ni, NULL, NULL);
@@ -1583,6 +1596,7 @@ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns, 
		goto out6;



	/* Unlock parent directory before ntfs_init_acl. */

	if (!fnd)

		ni_unlock(dir_ni);



	inode->i_generation = le16_to_cpu(rec->seq);
@@ -1643,6 +1657,7 @@ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns, 
out7:



	/* Undo 'indx_insert_entry'. */

	if (!fnd)

		ni_lock_dir(dir_ni);

	indx_delete_entry(&dir_ni->dir, dir_ni, new_de + 1,

			  le16_to_cpu(new_de->key_size), sbi);
@@ -1671,6 +1686,7 @@ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns, 


out1:

	if (err) {

		if (!fnd)

			ni_unlock(dir_ni);

		return ERR_PTR(err);

	}

fs/ntfs3/namei.c

+100 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/fs.h>

#include <linux/nls.h>

#include <linux/ctype.h>

#include <linux/posix_acl.h>



#include "debug.h"

#include "ntfs.h"
@@ -334,6 +335,104 @@ static int ntfs_rename(struct user_namespace *mnt_userns, struct inode *dir, 
	return err;

}



/*

 * ntfs_atomic_open

 *

 * inode_operations::atomic_open

 */

static int ntfs_atomic_open(struct inode *dir, struct dentry *dentry,

			    struct file *file, u32 flags, umode_t mode)

{

	int err;

	struct inode *inode;

	struct ntfs_fnd *fnd = NULL;

	struct ntfs_inode *ni = ntfs_i(dir);

	struct dentry *d = NULL;

	struct cpu_str *uni = __getname();

	bool locked = false;



	if (!uni)

		return -ENOMEM;



	err = ntfs_nls_to_utf16(ni->mi.sbi, dentry->d_name.name,

				dentry->d_name.len, uni, NTFS_NAME_LEN,

				UTF16_HOST_ENDIAN);

	if (err < 0)

		goto out;



#ifdef CONFIG_NTFS3_FS_POSIX_ACL

	if (IS_POSIXACL(dir)) {

		/* 

		 * Load in cache current acl to avoid ni_lock(dir):

		 * ntfs_create_inode -> ntfs_init_acl -> posix_acl_create ->

		 * ntfs_get_acl -> ntfs_get_acl_ex -> ni_lock

		 */

		struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT);



		if (IS_ERR(p)) {

			err = PTR_ERR(p);

			goto out;

		}

		posix_acl_release(p);

	}

#endif



	if (d_in_lookup(dentry)) {

		ni_lock_dir(ni);

		locked = true;

		fnd = fnd_get();

		if (!fnd) {

			err = -ENOMEM;

			goto out1;

		}



		d = d_splice_alias(dir_search_u(dir, uni, fnd), dentry);

		if (IS_ERR(d)) {

			err = PTR_ERR(d);

			d = NULL;

			goto out2;

		}



		if (d)

			dentry = d;

	}



	if (!(flags & O_CREAT) || d_really_is_positive(dentry)) {

		err = finish_no_open(file, d);

		goto out2;

	}



	file->f_mode |= FMODE_CREATED;



	/*

	 * fnd contains tree's path to insert to.

	 * If fnd is not NULL then dir is locked.

	 */



	/*

	 * Unfortunately I don't know how to get here correct 'struct nameidata *nd'

	 * or 'struct user_namespace *mnt_userns'.

	 * See atomic_open in fs/namei.c.

	 * This is why xfstest/633 failed.

	 * Looks like ntfs_atomic_open must accept 'struct user_namespace *mnt_userns' as argument.

	 */



	inode = ntfs_create_inode(&init_user_ns, dir, dentry, uni, mode, 0,

				  NULL, 0, fnd);

	err = IS_ERR(inode) ? PTR_ERR(inode)

			    : finish_open(file, dentry, ntfs_file_open);

	dput(d);



out2:

	fnd_put(fnd);

out1:

	if (locked)

		ni_unlock(ni);

out:

	__putname(uni);

	return err;

}



struct dentry *ntfs3_get_parent(struct dentry *child)

{

	struct inode *inode = d_inode(child);
@@ -500,6 +599,7 @@ const struct inode_operations ntfs_dir_inode_operations = { 
	.setattr	= ntfs3_setattr,

	.getattr	= ntfs_getattr,

	.listxattr	= ntfs_listxattr,

	.atomic_open	= ntfs_atomic_open,

	.fiemap		= ntfs_fiemap,

};