What bugzilla does this address?
Kevin
On Tue, 2007-07-24 at 14:11 +0100, Steven Whitehouse wrote:
> Hi,
>
> This fixes an oops which was occurring during glock dumping due to the
> seq file code not taking a reference to the glock. Also this fixes a
> memory leak which occurred in certain cases, in turn preventing the
> filesystem from unmounting.
>
> Steve.
>
> ----------------------------------------------------------------------
> diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
> index d403fd7..e4bc8ae 100644
> --- a/fs/gfs2/glock.c
> +++ b/fs/gfs2/glock.c
> @@ -46,7 +46,6 @@ struct glock_iter {
> int hash; /* hash bucket index */
> struct gfs2_sbd *sdp; /* incore superblock */
> struct gfs2_glock *gl; /* current glock struct */
> - struct hlist_head *hb_list; /* current hash bucket ptr */
> struct seq_file *seq; /* sequence file for debugfs */
> char string[512]; /* scratch space */
> };
> @@ -1990,47 +1989,38 @@ int __init gfs2_glock_init(void)
>
> static int gfs2_glock_iter_next(struct glock_iter *gi)
> {
> + struct gfs2_glock *gl;
> +
> read_lock(gl_lock_addr(gi->hash));
> - while (1) {
> - if (!gi->hb_list) { /* If we don't have a hash bucket yet */
> - gi->hb_list = &gl_hash_table[gi->hash].hb_list;
> - if (hlist_empty(gi->hb_list)) {
> - read_unlock(gl_lock_addr(gi->hash));
> - gi->hash++;
> - read_lock(gl_lock_addr(gi->hash));
> - gi->hb_list = NULL;
> - if (gi->hash >= GFS2_GL_HASH_SIZE) {
> - read_unlock(gl_lock_addr(gi->hash));
> - return 1;
> - }
> - else
> - continue;
> - }
> - if (!hlist_empty(gi->hb_list)) {
> - gi->gl = list_entry(gi->hb_list->first,
> - struct gfs2_glock,
> - gl_list);
> - }
> - } else {
> - if (gi->gl->gl_list.next == NULL) {
> - read_unlock(gl_lock_addr(gi->hash));
> - gi->hash++;
> - read_lock(gl_lock_addr(gi->hash));
> - gi->hb_list = NULL;
> - continue;
> - }
> - gi->gl = list_entry(gi->gl->gl_list.next,
> - struct gfs2_glock, gl_list);
> - }
> + gl = gi->gl;
> + if (gl) {
> + gi->gl = hlist_entry(gl->gl_list.next, struct gfs2_glock,
> + gl_list);
> if (gi->gl)
> - break;
> + gfs2_glock_hold(gi->gl);
> }
> read_unlock(gl_lock_addr(gi->hash));
> + if (gl)
> + gfs2_glock_put(gl);
> +
> + while(gi->gl == NULL) {
> + gi->hash++;
> + if (gi->hash >= GFS2_GL_HASH_SIZE)
> + return 1;
> + read_lock(gl_lock_addr(gi->hash));
> + gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
> + struct gfs2_glock, gl_list);
> + if (gi->gl)
> + gfs2_glock_hold(gi->gl);
> + read_unlock(gl_lock_addr(gi->hash));
> + }
> return 0;
> }
>
> static void gfs2_glock_iter_free(struct glock_iter *gi)
> {
> + if (gi->gl)
> + gfs2_glock_put(gi->gl);
> kfree(gi);
> }
>
> @@ -2044,12 +2034,17 @@ static struct glock_iter *gfs2_glock_iter_init(struct
> gfs2_sbd *sdp)
>
> gi->sdp = sdp;
> gi->hash = 0;
> - gi->gl = NULL;
> - gi->hb_list = NULL;
> gi->seq = NULL;
> memset(gi->string, 0, sizeof(gi->string));
>
> - if (gfs2_glock_iter_next(gi)) {
> + read_lock(gl_lock_addr(gi->hash));
> + gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
> + struct gfs2_glock, gl_list);
> + if (gi->gl)
> + gfs2_glock_hold(gi->gl);
> + read_unlock(gl_lock_addr(gi->hash));
> +
> + if (!gi->gl && gfs2_glock_iter_next(gi)) {
> gfs2_glock_iter_free(gi);
> return NULL;
> }
> @@ -2066,7 +2061,7 @@ static void *gfs2_glock_seq_start(struct seq_file
> *file, loff_t *pos)
> if (!gi)
> return NULL;
>
> - while (n--) {
> + while(n--) {
> if (gfs2_glock_iter_next(gi)) {
> gfs2_glock_iter_free(gi);
> return NULL;
> @@ -2093,7 +2088,9 @@ static void *gfs2_glock_seq_next(struct seq_file *file,
> void *iter_ptr,
>
> static void gfs2_glock_seq_stop(struct seq_file *file, void *iter_ptr)
> {
> - /* nothing for now */
> + struct glock_iter *gi = iter_ptr;
> + if (gi)
> + gfs2_glock_iter_free(gi);
> }
>
> static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr)
>
>
