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Commit e43ae79c authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Al Viro
Browse files

9p: implement i_op->atomic_open() 



Add an ->atomic_open implementation which replaces the atomic open+create
operation implemented via ->create.  No functionality is changed.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
CC: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 2d83bde9

fs/9p/vfs_inode.c

+102 −67
Original line number Diff line number Diff line
@@ -712,11 +712,14 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir, 
}



/**

 * v9fs_vfs_create - VFS hook to create files

 * v9fs_vfs_create - VFS hook to create a regular file

 *

 * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called

 * for mknod(2).

 *

 * @dir: directory inode that is being created

 * @dentry:  dentry that is being deleted

 * @mode: create permissions

 * @nd: path information

 *

 */
@@ -724,76 +727,19 @@ static int 
v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,

		struct nameidata *nd)

{

	int err;

	u32 perm;

	int flags;

	struct file *filp;

	struct v9fs_inode *v9inode;

	struct v9fs_session_info *v9ses;

	struct p9_fid *fid, *inode_fid;



	err = 0;

	fid = NULL;

	v9ses = v9fs_inode2v9ses(dir);

	perm = unixmode2p9mode(v9ses, mode);

	if (nd)

		flags = nd->intent.open.flags;

	else

		flags = O_RDWR;

	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);

	u32 perm = unixmode2p9mode(v9ses, mode);

	struct p9_fid *fid;



	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,

				v9fs_uflags2omode(flags,

						v9fs_proto_dotu(v9ses)));

	if (IS_ERR(fid)) {

		err = PTR_ERR(fid);

		fid = NULL;

		goto error;

	}

	/* P9_OEXCL? */

	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);

	if (IS_ERR(fid))

		return PTR_ERR(fid);



	v9fs_invalidate_inode_attr(dir);

	/* if we are opening a file, assign the open fid to the file */

	if (nd) {

		v9inode = V9FS_I(dentry->d_inode);

		mutex_lock(&v9inode->v_mutex);

		if (v9ses->cache && !v9inode->writeback_fid &&

		    ((flags & O_ACCMODE) != O_RDONLY)) {

			/*

			 * clone a fid and add it to writeback_fid

			 * we do it during open time instead of

			 * page dirty time via write_begin/page_mkwrite

			 * because we want write after unlink usecase

			 * to work.

			 */

			inode_fid = v9fs_writeback_fid(dentry);

			if (IS_ERR(inode_fid)) {

				err = PTR_ERR(inode_fid);

				mutex_unlock(&v9inode->v_mutex);

				goto error;

			}

			v9inode->writeback_fid = (void *) inode_fid;

		}

		mutex_unlock(&v9inode->v_mutex);

		filp = lookup_instantiate_filp(nd, dentry, generic_file_open);

		if (IS_ERR(filp)) {

			err = PTR_ERR(filp);

			goto error;

		}



		filp->private_data = fid;

#ifdef CONFIG_9P_FSCACHE

		if (v9ses->cache)

			v9fs_cache_inode_set_cookie(dentry->d_inode, filp);

#endif

	} else

	p9_client_clunk(fid);



	return 0;



error:

	if (fid)

		p9_client_clunk(fid);



	return err;

}



/**
@@ -910,6 +856,93 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, 
	return ERR_PTR(result);

}



static struct file *

v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,

		     struct opendata *od, unsigned flags, umode_t mode,

		     bool *created)

{

	int err;

	u32 perm;

	struct file *filp;

	struct v9fs_inode *v9inode;

	struct v9fs_session_info *v9ses;

	struct p9_fid *fid, *inode_fid;

	struct dentry *res = NULL;



	if (d_unhashed(dentry)) {

		res = v9fs_vfs_lookup(dir, dentry, NULL);

		if (IS_ERR(res))

			return ERR_CAST(res);



		if (res)

			dentry = res;

	}



	/* Only creates */

	if (!(flags & O_CREAT) || dentry->d_inode) {

		finish_no_open(od, res);

		return NULL;

	}



	err = 0;

	fid = NULL;

	v9ses = v9fs_inode2v9ses(dir);

	perm = unixmode2p9mode(v9ses, mode);

	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,

				v9fs_uflags2omode(flags,

						v9fs_proto_dotu(v9ses)));

	if (IS_ERR(fid)) {

		err = PTR_ERR(fid);

		fid = NULL;

		goto error;

	}



	v9fs_invalidate_inode_attr(dir);

	v9inode = V9FS_I(dentry->d_inode);

	mutex_lock(&v9inode->v_mutex);

	if (v9ses->cache && !v9inode->writeback_fid &&

	    ((flags & O_ACCMODE) != O_RDONLY)) {

		/*

		 * clone a fid and add it to writeback_fid

		 * we do it during open time instead of

		 * page dirty time via write_begin/page_mkwrite

		 * because we want write after unlink usecase

		 * to work.

		 */

		inode_fid = v9fs_writeback_fid(dentry);

		if (IS_ERR(inode_fid)) {

			err = PTR_ERR(inode_fid);

			mutex_unlock(&v9inode->v_mutex);

			goto error;

		}

		v9inode->writeback_fid = (void *) inode_fid;

	}

	mutex_unlock(&v9inode->v_mutex);

	filp = finish_open(od, dentry, generic_file_open);

	if (IS_ERR(filp)) {

		err = PTR_ERR(filp);

		goto error;

	}



	filp->private_data = fid;

#ifdef CONFIG_9P_FSCACHE

	if (v9ses->cache)

		v9fs_cache_inode_set_cookie(dentry->d_inode, filp);

#endif



	*created = true;

out:

	dput(res);

	return filp;



error:

	if (fid)

		p9_client_clunk(fid);



	filp = ERR_PTR(err);

	goto out;

}



/**

 * v9fs_vfs_unlink - VFS unlink hook to delete an inode

 * @i:  inode that is being unlinked
@@ -1488,6 +1521,7 @@ int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode) 
static const struct inode_operations v9fs_dir_inode_operations_dotu = {

	.create = v9fs_vfs_create,

	.lookup = v9fs_vfs_lookup,

	.atomic_open = v9fs_vfs_atomic_open,

	.symlink = v9fs_vfs_symlink,

	.link = v9fs_vfs_link,

	.unlink = v9fs_vfs_unlink,
@@ -1502,6 +1536,7 @@ static const struct inode_operations v9fs_dir_inode_operations_dotu = { 
static const struct inode_operations v9fs_dir_inode_operations = {

	.create = v9fs_vfs_create,

	.lookup = v9fs_vfs_lookup,

	.atomic_open = v9fs_vfs_atomic_open,

	.unlink = v9fs_vfs_unlink,

	.mkdir = v9fs_vfs_mkdir,

	.rmdir = v9fs_vfs_rmdir,

fs/9p/vfs_inode_dotl.c

+35 −17
Original line number Diff line number Diff line
@@ -230,17 +230,23 @@ int v9fs_open_to_dotl_flags(int flags) 
 * @dir: directory inode that is being created

 * @dentry:  dentry that is being deleted

 * @mode: create permissions

 * @nd: path information

 *

 */



static int

v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,

		struct nameidata *nd)

{

	return v9fs_vfs_mknod_dotl(dir, dentry, omode, 0);

}



static struct file *

v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,

			  struct opendata *od, unsigned flags, umode_t omode,

			  bool *created)

{

	int err = 0;

	gid_t gid;

	int flags;

	umode_t mode;

	char *name = NULL;

	struct file *filp;
@@ -251,19 +257,25 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode, 
	struct p9_fid *dfid, *ofid, *inode_fid;

	struct v9fs_session_info *v9ses;

	struct posix_acl *pacl = NULL, *dacl = NULL;

	struct dentry *res = NULL;



	v9ses = v9fs_inode2v9ses(dir);

	if (nd)

		flags = nd->intent.open.flags;

	else {

		/*

		 * create call without LOOKUP_OPEN is due

		 * to mknod of regular files. So use mknod

		 * operation.

		 */

		return v9fs_vfs_mknod_dotl(dir, dentry, omode, 0);

	if (d_unhashed(dentry)) {

		res = v9fs_vfs_lookup(dir, dentry, NULL);

		if (IS_ERR(res))

			return ERR_CAST(res);



		if (res)

			dentry = res;

	}



	/* Only creates */

	if (!(flags & O_CREAT) || dentry->d_inode) {

		finish_no_open(od, res);

		return NULL;

	}



	v9ses = v9fs_inode2v9ses(dir);



	name = (char *) dentry->d_name.name;

	p9_debug(P9_DEBUG_VFS, "name:%s flags:0x%x mode:0x%hx\n",

		 name, flags, omode);
@@ -272,7 +284,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode, 
	if (IS_ERR(dfid)) {

		err = PTR_ERR(dfid);

		p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);

		return err;

		goto err_return;

	}



	/* clone a fid to use for creation */
@@ -280,7 +292,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode, 
	if (IS_ERR(ofid)) {

		err = PTR_ERR(ofid);

		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);

		return err;

		goto err_return;

	}



	gid = v9fs_get_fsgid_for_create(dir);
@@ -345,7 +357,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode, 
	}

	mutex_unlock(&v9inode->v_mutex);

	/* Since we are opening a file, assign the open fid to the file */

	filp = lookup_instantiate_filp(nd, dentry, generic_file_open);

	filp = finish_open(od, dentry, generic_file_open);

	if (IS_ERR(filp)) {

		err = PTR_ERR(filp);

		goto err_clunk_old_fid;
@@ -355,7 +367,10 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode, 
	if (v9ses->cache)

		v9fs_cache_inode_set_cookie(inode, filp);

#endif

	return 0;

	*created = true;

out:

	dput(res);

	return filp;



error:

	if (fid)
@@ -364,7 +379,9 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode, 
	if (ofid)

		p9_client_clunk(ofid);

	v9fs_set_create_acl(NULL, &dacl, &pacl);

	return err;

err_return:

	filp = ERR_PTR(err);

	goto out;

}



/**
@@ -982,6 +999,7 @@ int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode) 


const struct inode_operations v9fs_dir_inode_operations_dotl = {

	.create = v9fs_vfs_create_dotl,

	.atomic_open = v9fs_vfs_atomic_open_dotl,

	.lookup = v9fs_vfs_lookup,

	.link = v9fs_vfs_link_dotl,

	.symlink = v9fs_vfs_symlink_dotl,