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GFS2: Only do one directory search on create

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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: Steven Whitehouse <swhiteho@redhat.com>
This commit is contained in:
Steven Whitehouse
2013-06-11 13:45:29 +01:00
parent a9aefd707c
commit 5a00f3cc97
3 changed files with 26 additions and 29 deletions
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29
fs/gfs2/inode.c
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@@ -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)
@@ -584,15 +573,19 @@ 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);
gfs2_glock_dq_uninit(ghs);
d_instantiate(dentry, inode);
return PTR_RET(inode);
}
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 0;
} else if (error != -ENOENT) {
goto fail_gunlock;
}
arq = error = gfs2_diradd_alloc_required(dir, name);
if (error < 0)
goto fail_gunlock;