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Revert "gfs2: eliminate tr_num_revoke_rm"

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This reverts commit e955537e32.

Before patch e955537e32, tr_num_revoke tracked the number of revokes
added to the transaction, and tr_num_revoke_rm tracked how many
revokes were removed. But since revokes are queued off the sdp
(superblock) pointer, some transactions could remove more revokes
than they added. (e.g. revokes added by a different process).
Commit e955537e32 eliminated transaction variable tr_num_revoke_rm,
but in order to do so, it changed the accounting to always use
tr_num_revoke for its math. Since you can remove more revokes than
you add, tr_num_revoke could now become a negative value.
This negative value broke the assert in function gfs2_trans_end:

	if (gfs2_assert_withdraw(sdp, (nbuf <=3D tr->tr_blocks) &&
			       (tr->tr_num_revoke <=3D tr->tr_revokes)))

One way to fix this is to simply remove the tr_num_revoke clause
from the assert and allow the value to become negative. Andreas
didn't like that idea, so instead, we decided to revert e955537e32.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This commit is contained in:
Bob Peterson 2020-01-20 15:49:28 +01:00 committed by Andreas Gruenbacher
parent c04f2e0dd5
commit a31b4ec539
3 changed files with 6 additions and 4 deletions
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1
fs/gfs2/incore.h
View File

@ -503,6 +503,7 @@ struct gfs2_trans {
unsigned int tr_num_buf_rm;
unsigned int tr_num_databuf_rm;
unsigned int tr_num_revoke;
unsigned int tr_num_revoke_rm;
struct list_head tr_list;
struct list_head tr_databuf;

3
fs/gfs2/log.c
View File

@ -895,6 +895,7 @@ static void gfs2_merge_trans(struct gfs2_trans *old, struct gfs2_trans *new)
old->tr_num_buf_rm += new->tr_num_buf_rm;
old->tr_num_databuf_rm += new->tr_num_databuf_rm;
old->tr_num_revoke += new->tr_num_revoke;
old->tr_num_revoke_rm += new->tr_num_revoke_rm;
list_splice_tail_init(&new->tr_databuf, &old->tr_databuf);
list_splice_tail_init(&new->tr_buf, &old->tr_buf);
@ -916,7 +917,7 @@ static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
set_bit(TR_ATTACHED, &tr->tr_flags);
}
sdp->sd_log_committed_revoke += tr->tr_num_revoke;
sdp->sd_log_committed_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
reserved = calc_reserved(sdp);
maxres = sdp->sd_log_blks_reserved + tr->tr_reserved;
gfs2_assert_withdraw(sdp, maxres >= reserved);

6
fs/gfs2/trans.c
View File

@ -76,10 +76,10 @@ static void gfs2_print_trans(struct gfs2_sbd *sdp, const struct gfs2_trans *tr)
fs_warn(sdp, "blocks=%u revokes=%u reserved=%u touched=%u\n",
tr->tr_blocks, tr->tr_revokes, tr->tr_reserved,
test_bit(TR_TOUCHED, &tr->tr_flags));
fs_warn(sdp, "Buf %u/%u Databuf %u/%u Revoke %u\n",
fs_warn(sdp, "Buf %u/%u Databuf %u/%u Revoke %u/%u\n",
tr->tr_num_buf_new, tr->tr_num_buf_rm,
tr->tr_num_databuf_new, tr->tr_num_databuf_rm,
tr->tr_num_revoke);
tr->tr_num_revoke, tr->tr_num_revoke_rm);
}
void gfs2_trans_end(struct gfs2_sbd *sdp)
@ -264,7 +264,7 @@ void gfs2_trans_remove_revoke(struct gfs2_sbd *sdp, u64 blkno, unsigned int len)
if (bd->bd_gl)
gfs2_glock_remove_revoke(bd->bd_gl);
kmem_cache_free(gfs2_bufdata_cachep, bd);
tr->tr_num_revoke--;
tr->tr_num_revoke_rm++;
if (--n == 0)
break;
}