Re: gfs2_dir_read_data(): fix uninitialized variable usage

From: Steven Whitehouse
Date: Thu Oct 19 2006 - 11:11:56 EST


Hi,

This one is now in the GFS2 tree too. Thanks,

Steve.

On Thu, 2006-10-19 at 16:02 +0200, Adrian Bunk wrote:
> In the "if (extlen)" case, "bh" was used uninitialized.
>
> This patch changes the code to what seems to have been intended.
>
> Spotted by the Coverity checker.
>
> This patch also removes a pointless "bh = NULL" asignment (the variable
> is never accessed again after this point).
>
> Signed-off-by: Adrian Bunk <bunk@xxxxxxxxx>
>
> --- linux-2.6/fs/gfs2/dir.c.old 2006-10-19 15:33:52.000000000 +0200
> +++ linux-2.6/fs/gfs2/dir.c 2006-10-19 15:35:44.000000000 +0200
> @@ -301,54 +301,52 @@ static int gfs2_dir_read_data(struct gfs
> while (copied < size) {
> unsigned int amount;
> struct buffer_head *bh;
> int new;
>
> amount = size - copied;
> if (amount > sdp->sd_sb.sb_bsize - o)
> amount = sdp->sd_sb.sb_bsize - o;
>
> if (!extlen) {
> new = 0;
> error = gfs2_extent_map(&ip->i_inode, lblock, &new,
> &dblock, &extlen);
> if (error || !dblock)
> goto fail;
> BUG_ON(extlen < 1);
> if (!ra)
> extlen = 1;
> bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
> - }
> - if (!bh) {
> + } else {
> error = gfs2_meta_read(ip->i_gl, dblock, DIO_WAIT, &bh);
> if (error)
> goto fail;
> }
> error = gfs2_metatype_check(sdp, bh, GFS2_METATYPE_JD);
> if (error) {
> brelse(bh);
> goto fail;
> }
> dblock++;
> extlen--;
> memcpy(buf, bh->b_data + o, amount);
> brelse(bh);
> - bh = NULL;
> buf += amount;
> copied += amount;
> lblock++;
> o = sizeof(struct gfs2_meta_header);
> }
>
> return copied;
> fail:
> return (copied) ? copied : error;
> }
>
> static inline int __gfs2_dirent_find(const struct gfs2_dirent *dent,
> const struct qstr *name, int ret)
> {
> if (dent->de_inum.no_addr != 0 &&
> be32_to_cpu(dent->de_hash) == name->hash &&
> be16_to_cpu(dent->de_name_len) == name->len &&
> memcmp(dent+1, name->name, name->len) == 0)
> return ret;
>

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