From a488edc914aa1d766a4e2c982b5ae03d5657ec1b Mon Sep 17 00:00:00 2001
From: Dave Kleikamp <shaggy@austin.ibm.com>
Date: Tue, 14 Mar 2006 13:44:00 -0600
Subject: [PATCH] [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>
---
fs/jfs/jfs_dmap.c | 7 ++-----
fs/jfs/jfs_imap.c | 6 ++----
2 files changed, 4 insertions(+), 9 deletions(-)
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 2967b73934151..79b5404db100a 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -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. */
diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c
index 31b4aa13dd4b9..4efa0d0eec394 100644
--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -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);
}
--
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