From: Lachlan McIlroy <lachlan@sgi.com>
Date: Wed, 13 Aug 2008 06:51:57 +0000 (+1000)
Subject: [XFS] Use KM_NOFS for debug trace buffers
X-Git-Tag: v2.6.27-rc4~106^2~2
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=5695ef46ef02ba1c6658daa46e6879a2d4f52f5f;p=linux-2.6-omap-h63xx.git

[XFS] Use KM_NOFS for debug trace buffers

Use KM_NOFS to prevent recursion back into the filesystem which can cause
deadlocks.

In the case of xfs_iread() we hold the lock on the inode cluster buffer
while allocating memory for the trace buffers. If we recurse back into XFS
to flush data that may require a transaction to allocate extents which
needs log space. This can deadlock with the xfsaild thread which can't
push the tail of the log because it is trying to get the inode cluster
buffer lock.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31838a

Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
---

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index a0072d9315a..986061ae1b9 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -1795,7 +1795,7 @@ int __init
 xfs_buf_init(void)
 {
 #ifdef XFS_BUF_TRACE
-	xfs_buf_trace_buf = ktrace_alloc(XFS_BUF_TRACE_SIZE, KM_SLEEP);
+	xfs_buf_trace_buf = ktrace_alloc(XFS_BUF_TRACE_SIZE, KM_NOFS);
 #endif
 
 	xfs_buf_zone = kmem_zone_init_flags(sizeof(xfs_buf_t), "xfs_buf",
diff --git a/fs/xfs/quota/xfs_dquot.c b/fs/xfs/quota/xfs_dquot.c
index 32290578c66..f2705f2fd43 100644
--- a/fs/xfs/quota/xfs_dquot.c
+++ b/fs/xfs/quota/xfs_dquot.c
@@ -112,7 +112,7 @@ xfs_qm_dqinit(
 		complete(&dqp->q_flush);
 
 #ifdef XFS_DQUOT_TRACE
-		dqp->q_trace = ktrace_alloc(DQUOT_TRACE_SIZE, KM_SLEEP);
+		dqp->q_trace = ktrace_alloc(DQUOT_TRACE_SIZE, KM_NOFS);
 		xfs_dqtrace_entry(dqp, "DQINIT");
 #endif
 	} else {
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 215c36dee32..608c30c3f76 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -737,7 +737,7 @@ xfs_buf_item_init(
 	bip->bli_format.blf_len = (ushort)BTOBB(XFS_BUF_COUNT(bp));
 	bip->bli_format.blf_map_size = map_size;
 #ifdef XFS_BLI_TRACE
-	bip->bli_trace = ktrace_alloc(XFS_BLI_TRACE_SIZE, KM_SLEEP);
+	bip->bli_trace = ktrace_alloc(XFS_BLI_TRACE_SIZE, KM_NOFS);
 #endif
 
 #ifdef XFS_TRANS_DEBUG
diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c
index c38fd14fca2..f3bb75da384 100644
--- a/fs/xfs/xfs_filestream.c
+++ b/fs/xfs/xfs_filestream.c
@@ -400,7 +400,7 @@ xfs_filestream_init(void)
 	if (!item_zone)
 		return -ENOMEM;
 #ifdef XFS_FILESTREAMS_TRACE
-	xfs_filestreams_trace_buf = ktrace_alloc(XFS_FSTRM_KTRACE_SIZE, KM_SLEEP);
+	xfs_filestreams_trace_buf = ktrace_alloc(XFS_FSTRM_KTRACE_SIZE, KM_NOFS);
 #endif
 	return 0;
 }
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 41371c56f36..358511b85ce 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -835,22 +835,22 @@ xfs_iread(
 	 * Do this before xfs_iformat in case it adds entries.
 	 */
 #ifdef	XFS_INODE_TRACE
-	ip->i_trace = ktrace_alloc(INODE_TRACE_SIZE, KM_SLEEP);
+	ip->i_trace = ktrace_alloc(INODE_TRACE_SIZE, KM_NOFS);
 #endif
 #ifdef XFS_BMAP_TRACE
-	ip->i_xtrace = ktrace_alloc(XFS_BMAP_KTRACE_SIZE, KM_SLEEP);
+	ip->i_xtrace = ktrace_alloc(XFS_BMAP_KTRACE_SIZE, KM_NOFS);
 #endif
 #ifdef XFS_BMBT_TRACE
-	ip->i_btrace = ktrace_alloc(XFS_BMBT_KTRACE_SIZE, KM_SLEEP);
+	ip->i_btrace = ktrace_alloc(XFS_BMBT_KTRACE_SIZE, KM_NOFS);
 #endif
 #ifdef XFS_RW_TRACE
-	ip->i_rwtrace = ktrace_alloc(XFS_RW_KTRACE_SIZE, KM_SLEEP);
+	ip->i_rwtrace = ktrace_alloc(XFS_RW_KTRACE_SIZE, KM_NOFS);
 #endif
 #ifdef XFS_ILOCK_TRACE
-	ip->i_lock_trace = ktrace_alloc(XFS_ILOCK_KTRACE_SIZE, KM_SLEEP);
+	ip->i_lock_trace = ktrace_alloc(XFS_ILOCK_KTRACE_SIZE, KM_NOFS);
 #endif
 #ifdef XFS_DIR2_TRACE
-	ip->i_dir_trace = ktrace_alloc(XFS_DIR2_KTRACE_SIZE, KM_SLEEP);
+	ip->i_dir_trace = ktrace_alloc(XFS_DIR2_KTRACE_SIZE, KM_NOFS);
 #endif
 
 	/*
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 9c23864d4fd..1f6f780dbd3 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -160,7 +160,7 @@ void
 xlog_trace_iclog(xlog_in_core_t *iclog, uint state)
 {
 	if (!iclog->ic_trace)
-		iclog->ic_trace = ktrace_alloc(256, KM_SLEEP);
+		iclog->ic_trace = ktrace_alloc(256, KM_NOFS);
 	ktrace_enter(iclog->ic_trace,
 		     (void *)((unsigned long)state),
 		     (void *)((unsigned long)current_pid()),