On Mon, 26 Jan 2015 11:20:47 +0800 Joseph Qi <joseph...@huawei.com> wrote:
> In ocfs2_orphan_del it uses dynamic stack allocation for orphan entry
> name. Fix it by using dynamic heap allocation.
>
> ...
>
> --- a/fs/ocfs2/namei.c
> +++ b/fs/ocfs2/namei.c
> @@ -2298,18 +2298,22 @@ int ocfs2_orphan_del(struct ocfs2_super *osb,
> {
> int namelen = dio ? OCFS2_DIO_ORPHAN_PREFIX_LEN + OCFS2_ORPHAN_NAMELEN :
> OCFS2_ORPHAN_NAMELEN;
> - char name[namelen + 1];
> + char *name;
> struct ocfs2_dinode *orphan_fe;
> int status = 0;
> struct ocfs2_dir_lookup_result lookup = { NULL, };
>
> + name = kmalloc(namelen + 1, GFP_NOFS);
> + if (!name)
> + goto leave;
> +
> if (dio) {
> status = snprintf(name, OCFS2_DIO_ORPHAN_PREFIX_LEN + 1, "%s",
> OCFS2_DIO_ORPHAN_PREFIX);
> if (status != OCFS2_DIO_ORPHAN_PREFIX_LEN) {
> status = -EINVAL;
> mlog_errno(status);
> - return status;
> + goto leave;
> }
>
> status = ocfs2_blkno_stringify(OCFS2_I(inode)->ip_blkno,
> @@ -2357,6 +2361,7 @@ int ocfs2_orphan_del(struct ocfs2_super *osb,
> ocfs2_journal_dirty(handle, orphan_dir_bh);
>
> leave:
> + kfree(name);
> ocfs2_free_dir_lookup_result(&lookup);
>
> if (status)
I think I prefer my fix:
---
a/fs/ocfs2/namei.c~ocfs2-add-functions-to-add-and-remove-inode-in-orphan-dir-fix
+++ a/fs/ocfs2/namei.c
@@ -2296,8 +2296,7 @@ int ocfs2_orphan_del(struct ocfs2_super
struct buffer_head *orphan_dir_bh,
bool dio)
{
- int namelen = dio ? OCFS2_DIO_ORPHAN_PREFIX_LEN + OCFS2_ORPHAN_NAMELEN :
- OCFS2_ORPHAN_NAMELEN;
+ const int namelen = OCFS2_DIO_ORPHAN_PREFIX_LEN + OCFS2_ORPHAN_NAMELEN;
char name[namelen + 1];
struct ocfs2_dinode *orphan_fe;
int status = 0;
It means we use 20 bytes of stack all the time, instead of
sometimes-20, sometimes-16.
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