[PATCH] JFS: Take logsync lock before testing mp->lsn

This fixes a race where lsn could be cleared before taking the lock

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Dave Kleikamp 2006-03-14 13:44:00 -06:00 committed by Linus Torvalds
parent 0f511ea706
commit a488edc914
2 changed files with 4 additions and 9 deletions

View file

@ -532,10 +532,10 @@ dbUpdatePMap(struct inode *ipbmap,
lastlblkno = lblkno;
LOGSYNC_LOCK(log, flags);
if (mp->lsn != 0) {
/* inherit older/smaller lsn */
logdiff(diffp, mp->lsn, log);
LOGSYNC_LOCK(log, flags);
if (difft < diffp) {
mp->lsn = lsn;
@ -548,20 +548,17 @@ dbUpdatePMap(struct inode *ipbmap,
logdiff(diffp, mp->clsn, log);
if (difft > diffp)
mp->clsn = tblk->clsn;
LOGSYNC_UNLOCK(log, flags);
} else {
mp->log = log;
mp->lsn = lsn;
/* insert bp after tblock in logsync list */
LOGSYNC_LOCK(log, flags);
log->count++;
list_add(&mp->synclist, &tblk->synclist);
mp->clsn = tblk->clsn;
LOGSYNC_UNLOCK(log, flags);
}
LOGSYNC_UNLOCK(log, flags);
}
/* write the last buffer. */

View file

@ -2844,11 +2844,11 @@ diUpdatePMap(struct inode *ipimap,
*/
lsn = tblk->lsn;
log = JFS_SBI(tblk->sb)->log;
LOGSYNC_LOCK(log, flags);
if (mp->lsn != 0) {
/* inherit older/smaller lsn */
logdiff(difft, lsn, log);
logdiff(diffp, mp->lsn, log);
LOGSYNC_LOCK(log, flags);
if (difft < diffp) {
mp->lsn = lsn;
/* move mp after tblock in logsync list */
@ -2860,17 +2860,15 @@ diUpdatePMap(struct inode *ipimap,
logdiff(diffp, mp->clsn, log);
if (difft > diffp)
mp->clsn = tblk->clsn;
LOGSYNC_UNLOCK(log, flags);
} else {
mp->log = log;
mp->lsn = lsn;
/* insert mp after tblock in logsync list */
LOGSYNC_LOCK(log, flags);
log->count++;
list_add(&mp->synclist, &tblk->synclist);
mp->clsn = tblk->clsn;
LOGSYNC_UNLOCK(log, flags);
}
LOGSYNC_UNLOCK(log, flags);
write_metapage(mp);
return (0);
}