On Tue, 2007-01-09 at 07:56 -0600, Dave Kleikamp wrote:
> On Tue, 2007-01-09 at 15:02 +0530, Srinivasa Ds wrote:
> > Tomasz Kvarsin wrote:
> > > This I got during boot with 2.6.20-rc4:
> > > =============================================
> > > [ INFO: possible recursive locking detected ]
>
> ...
>
> > So below patch should fix this problem,please test this. Let me know
> > your comments on this.
>
> I'm sure there are several other places in the jfs code that need the
> same treatment. I've put this off too long already. I'll get a
> comprehensive lock annotation patch out today, starting with this one.
Okay,
Here it is. I'd appreciate it if anyone who has looked into the lockdep
annotations would give this a sanity check.
Thanks,
Shaggy
JFS: Add lockdep annotations
Yeah, it's about time.
Signed-off-by: Dave Kleikamp <[email protected]>
diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c
index f571911..e285022 100644
--- a/fs/jfs/inode.c
+++ b/fs/jfs/inode.c
@@ -182,9 +182,9 @@ int jfs_get_block(struct inode *ip, sector_t lblock,
* Take appropriate lock on inode
*/
if (create)
- IWRITE_LOCK(ip);
+ IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
else
- IREAD_LOCK(ip);
+ IREAD_LOCK(ip, RDWRLOCK_NORMAL);
if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
(!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
@@ -359,7 +359,7 @@ void jfs_truncate(struct inode *ip)
nobh_truncate_page(ip->i_mapping, ip->i_size);
- IWRITE_LOCK(ip);
+ IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
jfs_truncate_nolock(ip, ip->i_size);
IWRITE_UNLOCK(ip);
}
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 23546c8..82b0544 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -337,7 +337,7 @@ int dbFree(struct inode *ip, s64 blkno, s64 nblocks)
struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
- IREAD_LOCK(ipbmap);
+ IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
/* block to be freed better be within the mapsize. */
if (unlikely((blkno == 0) || (blkno + nblocks > bmp->db_mapsize))) {
@@ -733,7 +733,7 @@ int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results)
* allocation group size, try to allocate anywhere.
*/
if (l2nb > bmp->db_agl2size) {
- IWRITE_LOCK(ipbmap);
+ IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
rc = dbAllocAny(bmp, nblocks, l2nb, results);
@@ -774,7 +774,7 @@ int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results)
* the hint using a tiered strategy.
*/
if (nblocks <= BPERDMAP) {
- IREAD_LOCK(ipbmap);
+ IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
/* get the buffer for the dmap containing the hint.
*/
@@ -844,7 +844,7 @@ int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results)
/* try to satisfy the allocation request with blocks within
* the same allocation group as the hint.
*/
- IWRITE_LOCK(ipbmap);
+ IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
if ((rc = dbAllocAG(bmp, agno, nblocks, l2nb, results)) != -ENOSPC)
goto write_unlock;
@@ -856,7 +856,7 @@ int dbAlloc(struct inode *ip, s64 hint, s64 nblocks, s64 * results)
* Let dbNextAG recommend a preferred allocation group
*/
agno = dbNextAG(ipbmap);
- IWRITE_LOCK(ipbmap);
+ IWRITE_LOCK(ipbmap, RDWRLOCK_DMAP);
/* Try to allocate within this allocation group. if that fails, try to
* allocate anywhere in the map.
@@ -900,7 +900,7 @@ int dbAllocExact(struct inode *ip, s64 blkno, int nblocks)
s64 lblkno;
struct metapage *mp;
- IREAD_LOCK(ipbmap);
+ IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
/*
* validate extent request:
@@ -1050,7 +1050,7 @@ static int dbExtend(struct inode *ip, s64 blkno, s64 nblocks, s64 addnblocks)
*/
extblkno = lastblkno + 1;
- IREAD_LOCK(ipbmap);
+ IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
/* better be within the file system */
bmp = sbi->bmap;
@@ -3116,7 +3116,7 @@ int dbAllocBottomUp(struct inode *ip, s64 blkno, s64 nblocks)
struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
- IREAD_LOCK(ipbmap);
+ IREAD_LOCK(ipbmap, RDWRLOCK_DMAP);
/* block to be allocated better be within the mapsize. */
ASSERT(nblocks <= bmp->db_mapsize - blkno);
diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c
index 53f63b4..aa5124b 100644
--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -331,7 +331,7 @@ int diRead(struct inode *ip)
/* read the iag */
imap = JFS_IP(ipimap)->i_imap;
- IREAD_LOCK(ipimap);
+ IREAD_LOCK(ipimap, RDWRLOCK_IMAP);
rc = diIAGRead(imap, iagno, &mp);
IREAD_UNLOCK(ipimap);
if (rc) {
@@ -920,7 +920,7 @@ int diFree(struct inode *ip)
/* Obtain read lock in imap inode. Don't release it until we have
* read all of the IAG's that we are going to.
*/
- IREAD_LOCK(ipimap);
+ IREAD_LOCK(ipimap, RDWRLOCK_IMAP);
/* read the iag.
*/
@@ -1415,7 +1415,7 @@ int diAlloc(struct inode *pip, bool dir, struct inode *ip)
AG_LOCK(imap, agno);
/* Get read lock on imap inode */
- IREAD_LOCK(ipimap);
+ IREAD_LOCK(ipimap, RDWRLOCK_IMAP);
/* get the iag number and read the iag */
iagno = INOTOIAG(inum);
@@ -1808,7 +1808,7 @@ static int diAllocIno(struct inomap * imap, int agno, struct inode *ip)
return -ENOSPC;
/* obtain read lock on imap inode */
- IREAD_LOCK(imap->im_ipimap);
+ IREAD_LOCK(imap->im_ipimap, RDWRLOCK_IMAP);
/* read the iag at the head of the list.
*/
@@ -1946,7 +1946,7 @@ static int diAllocExt(struct inomap * imap, int agno, struct inode *ip)
} else {
/* read the iag.
*/
- IREAD_LOCK(imap->im_ipimap);
+ IREAD_LOCK(imap->im_ipimap, RDWRLOCK_IMAP);
if ((rc = diIAGRead(imap, iagno, &mp))) {
IREAD_UNLOCK(imap->im_ipimap);
jfs_error(ip->i_sb, "diAllocExt: error reading iag");
@@ -2509,7 +2509,7 @@ diNewIAG(struct inomap * imap, int *iagnop, int agno, struct metapage ** mpp)
*/
/* acquire inode map lock */
- IWRITE_LOCK(ipimap);
+ IWRITE_LOCK(ipimap, RDWRLOCK_IMAP);
if (ipimap->i_size >> L2PSIZE != imap->im_nextiag + 1) {
IWRITE_UNLOCK(ipimap);
@@ -2648,7 +2648,7 @@ diNewIAG(struct inomap * imap, int *iagnop, int agno, struct metapage ** mpp)
}
/* obtain read lock on map */
- IREAD_LOCK(ipimap);
+ IREAD_LOCK(ipimap, RDWRLOCK_IMAP);
/* read the iag */
if ((rc = diIAGRead(imap, iagno, &mp))) {
@@ -2779,7 +2779,7 @@ diUpdatePMap(struct inode *ipimap,
return -EIO;
}
/* read the iag */
- IREAD_LOCK(ipimap);
+ IREAD_LOCK(ipimap, RDWRLOCK_IMAP);
rc = diIAGRead(imap, iagno, &mp);
IREAD_UNLOCK(ipimap);
if (rc)
diff --git a/fs/jfs/jfs_incore.h b/fs/jfs/jfs_incore.h
index 9400558..8f453ef 100644
--- a/fs/jfs/jfs_incore.h
+++ b/fs/jfs/jfs_incore.h
@@ -109,9 +109,11 @@ struct jfs_inode_info {
#define JFS_ACL_NOT_CACHED ((void *)-1)
-#define IREAD_LOCK(ip) down_read(&JFS_IP(ip)->rdwrlock)
+#define IREAD_LOCK(ip, subclass) \
+ down_read_nested(&JFS_IP(ip)->rdwrlock, subclass)
#define IREAD_UNLOCK(ip) up_read(&JFS_IP(ip)->rdwrlock)
-#define IWRITE_LOCK(ip) down_write(&JFS_IP(ip)->rdwrlock)
+#define IWRITE_LOCK(ip, subclass) \
+ down_write_nested(&JFS_IP(ip)->rdwrlock, subclass)
#define IWRITE_UNLOCK(ip) up_write(&JFS_IP(ip)->rdwrlock)
/*
@@ -127,6 +129,29 @@ enum cflags {
COMMIT_Synclist, /* metadata pages on group commit synclist */
};
+/*
+ * commit_mutex nesting subclasses:
+ */
+enum commit_mutex_class
+{
+ COMMIT_MUTEX_PARENT,
+ COMMIT_MUTEX_CHILD,
+ COMMIT_MUTEX_SECOND_PARENT, /* Renaming */
+ COMMIT_MUTEX_VICTIM /* Inode being unlinked due to rename */
+};
+
+/*
+ * rdwrlock subclasses:
+ * The dmap inode may be locked while a normal inode or the imap inode are
+ * locked.
+ */
+enum rdwrlock_class
+{
+ RDWRLOCK_NORMAL,
+ RDWRLOCK_IMAP,
+ RDWRLOCK_DMAP
+};
+
#define set_cflag(flag, ip) set_bit(flag, &(JFS_IP(ip)->cflag))
#define clear_cflag(flag, ip) clear_bit(flag, &(JFS_IP(ip)->cflag))
#define test_cflag(flag, ip) test_bit(flag, &(JFS_IP(ip)->cflag))
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index a6a8c16..7ab4756 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -104,8 +104,8 @@ static int jfs_create(struct inode *dip, struct dentry *dentry, int mode,
tid = txBegin(dip->i_sb, 0);
- mutex_lock(&JFS_IP(dip)->commit_mutex);
- mutex_lock(&JFS_IP(ip)->commit_mutex);
+ mutex_lock_nested(&JFS_IP(dip)->commit_mutex, COMMIT_MUTEX_PARENT);
+ mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
rc = jfs_init_acl(tid, ip, dip);
if (rc)
@@ -238,8 +238,8 @@ static int jfs_mkdir(struct inode *dip, struct dentry *dentry, int mode)
tid = txBegin(dip->i_sb, 0);
- mutex_lock(&JFS_IP(dip)->commit_mutex);
- mutex_lock(&JFS_IP(ip)->commit_mutex);
+ mutex_lock_nested(&JFS_IP(dip)->commit_mutex, COMMIT_MUTEX_PARENT);
+ mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
rc = jfs_init_acl(tid, ip, dip);
if (rc)
@@ -365,8 +365,8 @@ static int jfs_rmdir(struct inode *dip, struct dentry *dentry)
tid = txBegin(dip->i_sb, 0);
- mutex_lock(&JFS_IP(dip)->commit_mutex);
- mutex_lock(&JFS_IP(ip)->commit_mutex);
+ mutex_lock_nested(&JFS_IP(dip)->commit_mutex, COMMIT_MUTEX_PARENT);
+ mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
iplist[0] = dip;
iplist[1] = ip;
@@ -483,12 +483,12 @@ static int jfs_unlink(struct inode *dip, struct dentry *dentry)
if ((rc = get_UCSname(&dname, dentry)))
goto out;
- IWRITE_LOCK(ip);
+ IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
tid = txBegin(dip->i_sb, 0);
- mutex_lock(&JFS_IP(dip)->commit_mutex);
- mutex_lock(&JFS_IP(ip)->commit_mutex);
+ mutex_lock_nested(&JFS_IP(dip)->commit_mutex, COMMIT_MUTEX_PARENT);
+ mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
iplist[0] = dip;
iplist[1] = ip;
@@ -802,8 +802,8 @@ static int jfs_link(struct dentry *old_dentry,
tid = txBegin(ip->i_sb, 0);
- mutex_lock(&JFS_IP(dir)->commit_mutex);
- mutex_lock(&JFS_IP(ip)->commit_mutex);
+ mutex_lock_nested(&JFS_IP(dir)->commit_mutex, COMMIT_MUTEX_PARENT);
+ mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
/*
* scan parent directory for entry/freespace
@@ -913,8 +913,8 @@ static int jfs_symlink(struct inode *dip, struct dentry *dentry,
tid = txBegin(dip->i_sb, 0);
- mutex_lock(&JFS_IP(dip)->commit_mutex);
- mutex_lock(&JFS_IP(ip)->commit_mutex);
+ mutex_lock_nested(&JFS_IP(dip)->commit_mutex, COMMIT_MUTEX_PARENT);
+ mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
rc = jfs_init_security(tid, ip, dip);
if (rc)
@@ -1127,7 +1127,7 @@ static int jfs_rename(struct inode *old_dir, struct dentry *old_dentry,
goto out3;
}
} else if (new_ip) {
- IWRITE_LOCK(new_ip);
+ IWRITE_LOCK(new_ip, RDWRLOCK_NORMAL);
/* Init inode for quota operations. */
DQUOT_INIT(new_ip);
}
@@ -1137,13 +1137,21 @@ static int jfs_rename(struct inode *old_dir, struct dentry *old_dentry,
*/
tid = txBegin(new_dir->i_sb, 0);
- mutex_lock(&JFS_IP(new_dir)->commit_mutex);
- mutex_lock(&JFS_IP(old_ip)->commit_mutex);
+ /*
+ * How do we know the locking is safe from deadlocks?
+ * The vfs does the hard part for us. Any time we are taking nested
+ * commit_mutexes, the vfs already has i_mutex held on the parent.
+ * Here, the vfs has already taken i_mutex on both old_dir and new_dir.
+ */
+ mutex_lock_nested(&JFS_IP(new_dir)->commit_mutex, COMMIT_MUTEX_PARENT);
+ mutex_lock_nested(&JFS_IP(old_ip)->commit_mutex, COMMIT_MUTEX_CHILD);
if (old_dir != new_dir)
- mutex_lock(&JFS_IP(old_dir)->commit_mutex);
+ mutex_lock_nested(&JFS_IP(old_dir)->commit_mutex,
+ COMMIT_MUTEX_SECOND_PARENT);
if (new_ip) {
- mutex_lock(&JFS_IP(new_ip)->commit_mutex);
+ mutex_lock_nested(&JFS_IP(new_ip)->commit_mutex,
+ COMMIT_MUTEX_VICTIM);
/*
* Change existing directory entry to new inode number
*/
@@ -1357,8 +1365,8 @@ static int jfs_mknod(struct inode *dir, struct dentry *dentry,
tid = txBegin(dir->i_sb, 0);
- mutex_lock(&JFS_IP(dir)->commit_mutex);
- mutex_lock(&JFS_IP(ip)->commit_mutex);
+ mutex_lock_nested(&JFS_IP(dir)->commit_mutex, COMMIT_MUTEX_PARENT);
+ mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);
rc = jfs_init_acl(tid, ip, dir);
if (rc)
--
David Kleikamp
IBM Linux Technology Center
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