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authorBenjamin Marzinski <bmarzins@redhat.com>2007-03-23 12:05:12 +0300
committerSteven Whitehouse <swhiteho@redhat.com>2007-05-01 12:10:50 +0400
commit6883562588bc6c70776ecc396ee7eda36c2c8da9 (patch)
treec683994d1f805914fc18f3247cc86cc011a9aa0b
parentf35ac346bc48b2086aa94f031baf1f6237a89de6 (diff)
downloadlinux-6883562588bc6c70776ecc396ee7eda36c2c8da9.tar.xz
[GFS2] Fix log entry list corruption
When glock_lo_add and rg_lo_add attempt to add an element to the log, they check to see if has already been added before locking the log. If another process adds that element to the log in this window between the check and locking the log, the element will be added to the list twice. This causes the log element list to become corrupted in such a way that the log element can never be successfully removed from the list. This patch pulls the list_empty() check inside the log lock, to remove this window. Signed-off-by: Benjamin E. Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
-rw-r--r--fs/gfs2/lops.c20
1 files changed, 11 insertions, 9 deletions
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 16bb4b4561ae..f82d84d05d23 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -33,16 +33,17 @@ static void glock_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
tr->tr_touched = 1;
- if (!list_empty(&le->le_list))
- return;
-
gl = container_of(le, struct gfs2_glock, gl_le);
if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(gl)))
return;
- gfs2_glock_hold(gl);
- set_bit(GLF_DIRTY, &gl->gl_flags);
gfs2_log_lock(sdp);
+ if (!list_empty(&le->le_list)){
+ gfs2_log_unlock(sdp);
+ return;
+ }
+ gfs2_glock_hold(gl);
+ set_bit(GLF_DIRTY, &gl->gl_flags);
sdp->sd_log_num_gl++;
list_add(&le->le_list, &sdp->sd_log_le_gl);
gfs2_log_unlock(sdp);
@@ -415,13 +416,14 @@ static void rg_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)
tr->tr_touched = 1;
- if (!list_empty(&le->le_list))
- return;
-
rgd = container_of(le, struct gfs2_rgrpd, rd_le);
- gfs2_rgrp_bh_hold(rgd);
gfs2_log_lock(sdp);
+ if (!list_empty(&le->le_list)){
+ gfs2_log_unlock(sdp);
+ return;
+ }
+ gfs2_rgrp_bh_hold(rgd);
sdp->sd_log_num_rg++;
list_add(&le->le_list, &sdp->sd_log_le_rg);
gfs2_log_unlock(sdp);