Commit 5a00f3cc authored by Steven Whitehouse's avatar Steven Whitehouse
Browse files

GFS2: Only do one directory search on create 



Creation of a new inode requires a directory search in order to ensure
that we are not trying to create an inode with the same name as an
existing one. This was hidden away inside the create_ok() function.

In the case that there was an existing inode, and a lookup can be
substituted for a create (which is the case with regular files
when the O_EXCL flag is not in use) then we were doing a second
lookup in order to return the inode.

This patch merges these two lookups into one. This can be done by
passing a flag to gfs2_dir_search() to tell it to just return -EEXIST
in the cases where we don't actually want to look up the inode.

Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent a9aefd70

fs/gfs2/dir.c

+13 −10
Original line number Diff line number Diff line
@@ -1555,9 +1555,9 @@ out: 


/**

 * gfs2_dir_search - Search a directory

 * @dip: The GFS2 inode

 * @filename:

 * @inode:

 * @dip: The GFS2 dir inode

 * @name: The name we are looking up

 * @fail_on_exist: Fail if the name exists rather than looking it up

 *

 * This routine searches a directory for a file or another directory.

 * Assumes a glock is held on dip.
@@ -1565,22 +1565,25 @@ out: 
 * Returns: errno

 */



struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name)

struct inode *gfs2_dir_search(struct inode *dir, const struct qstr *name,

			      bool fail_on_exist)

{

	struct buffer_head *bh;

	struct gfs2_dirent *dent;

	struct inode *inode;

	u64 addr, formal_ino;

	u16 dtype;



	dent = gfs2_dirent_search(dir, name, gfs2_dirent_find, &bh);

	if (dent) {

		if (IS_ERR(dent))

			return ERR_CAST(dent);

		inode = gfs2_inode_lookup(dir->i_sb, 

				be16_to_cpu(dent->de_type),

				be64_to_cpu(dent->de_inum.no_addr),

				be64_to_cpu(dent->de_inum.no_formal_ino), 0);

		dtype = be16_to_cpu(dent->de_type);

		addr = be64_to_cpu(dent->de_inum.no_addr);

		formal_ino = be64_to_cpu(dent->de_inum.no_formal_ino);

		brelse(bh);

		return inode;

		if (fail_on_exist)

			return ERR_PTR(-EEXIST);

		return gfs2_inode_lookup(dir->i_sb, dtype, addr, formal_ino, 0);

	}

	return ERR_PTR(-ENOENT);

}

fs/gfs2/dir.h

+2 −1
Original line number Diff line number Diff line
@@ -18,7 +18,8 @@ struct gfs2_inode; 
struct gfs2_inum;



extern struct inode *gfs2_dir_search(struct inode *dir,

				     const struct qstr *filename);

				     const struct qstr *filename,

				     bool fail_on_exist);

extern int gfs2_dir_check(struct inode *dir, const struct qstr *filename,

			  const struct gfs2_inode *ip);

extern int gfs2_dir_add(struct inode *inode, const struct qstr *filename,

fs/gfs2/inode.c

+10 −17
Original line number Diff line number Diff line
@@ -313,7 +313,7 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name, 
			goto out;

	}



	inode = gfs2_dir_search(dir, name);

	inode = gfs2_dir_search(dir, name, false);

	if (IS_ERR(inode))

		error = PTR_ERR(inode);

out:
@@ -346,17 +346,6 @@ static int create_ok(struct gfs2_inode *dip, const struct qstr *name, 
	if (!dip->i_inode.i_nlink)

		return -ENOENT;



	error = gfs2_dir_check(&dip->i_inode, name, NULL);

	switch (error) {

	case -ENOENT:

		error = 0;

		break;

	case 0:

		return -EEXIST;

	default:

		return error;

	}



	if (dip->i_entries == (u32)-1)

		return -EFBIG;

	if (S_ISDIR(mode) && dip->i_inode.i_nlink == (u32)-1)
@@ -584,14 +573,18 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry, 
		goto fail;



	error = create_ok(dip, name, mode);

	if ((error == -EEXIST) && S_ISREG(mode) && !excl) {

		inode = gfs2_lookupi(dir, &dentry->d_name, 0);

	if (error)

		goto fail_gunlock;



	inode = gfs2_dir_search(dir, &dentry->d_name, !S_ISREG(mode) || excl);

	error = PTR_ERR(inode);

	if (!IS_ERR(inode)) {

		gfs2_glock_dq_uninit(ghs);

		d_instantiate(dentry, inode);

		return PTR_RET(inode);

	}

	if (error)

		return 0;

	} else if (error != -ENOENT) {

		goto fail_gunlock;

	}



	arq = error = gfs2_diradd_alloc_required(dir, name);

	if (error < 0)

CRA Git | Maintained and supported by SUSTech CRA and CCSE