Currently both xfs_rtpick_extent and xfs_rtallocate_extent call
xfs_trans_iget to grab and lock the rt bitmap inode, which results in a
deadlock since the removal of the lock recursion counters in commit
"xfs: simplify inode to transaction joining"
Fix this by acquiring and locking the inode in xfs_bmap_rtalloc before
calling into xfs_rtpick_extent and xfs_rtallocate_extent.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Alex Elder <aelder@xxxxxxx>
Signed-off-by: Kamal Dasu <kdasu.kdev@xxxxxxxxx>
---
fs/xfs/xfs_bmap.c | 11 +++++++++++
fs/xfs/xfs_rtalloc.c | 34 +++++++++++++---------------------
2 files changed, 24 insertions(+), 21 deletions(-)
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 4111cd3..9d9970b 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -2316,6 +2316,7 @@ xfs_bmap_rtalloc(
xfs_extlen_t prod = 0; /* product factor for allocators */
xfs_extlen_t ralen = 0; /* realtime allocation length */
xfs_extlen_t align; /* minimum allocation alignment */
+ xfs_inode_t *ip; /* bitmap incore inode */
xfs_rtblock_t rtb;
kdasu@kdasu-VirtualBox:~/linux-2.6$ more
0001-xfs-only-lock-the-rt-bitmap-inode-once-per-allocatio.patch
>From f59ab29cc191a5955c4d44c0b92a537f981184c2 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Date: Tue, 25 Jan 2011 09:06:19 +0000
Subject: [PATCH 1/4] xfs: only lock the rt bitmap inode once per allocation
Currently both xfs_rtpick_extent and xfs_rtallocate_extent call
xfs_trans_iget to grab and lock the rt bitmap inode, which results in a
deadlock since the removal of the lock recursion counters in commit
"xfs: simplify inode to transaction joining"
Fix this by acquiring and locking the inode in xfs_bmap_rtalloc before
calling into xfs_rtpick_extent and xfs_rtallocate_extent.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Alex Elder <aelder@xxxxxxx>
Signed-off-by: Kamal Dasu <kdasu.kdev@xxxxxxxxx>
---
fs/xfs/xfs_bmap.c | 11 +++++++++++
fs/xfs/xfs_rtalloc.c | 34 +++++++++++++---------------------
2 files changed, 24 insertions(+), 21 deletions(-)
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 4111cd3..9d9970b 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -2316,6 +2316,7 @@ xfs_bmap_rtalloc(
xfs_extlen_t prod = 0; /* product factor for allocators */
xfs_extlen_t ralen = 0; /* realtime allocation length */
xfs_extlen_t align; /* minimum allocation alignment */
+ xfs_inode_t *ip; /* bitmap incore inode */
xfs_rtblock_t rtb;
mp = ap->ip->i_mount;
@@ -2348,6 +2349,16 @@ xfs_bmap_rtalloc(
*/
if (ralen * mp->m_sb.sb_rextsize >= MAXEXTLEN)
ralen = MAXEXTLEN / mp->m_sb.sb_rextsize;
+
+ /*
+ * Lock out other modifications to the RT bitmap inode.
+ */
+ error = xfs_trans_iget(mp, ap->tp, mp->m_sb.sb_rbmino, 0,
+ XFS_ILOCK_EXCL, &ip);
+ if (error)
+ return error;
+ ASSERT(ip == mp->m_rbmip);
+
/*
* If it's an allocation to an empty file at offset 0,
* pick an extent that will space things out in the rt area.
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 12a1913..037fab1 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -2075,15 +2075,15 @@ xfs_rtallocate_extent(
xfs_extlen_t prod, /* extent product factor */
xfs_rtblock_t *rtblock) /* out: start block allocated */
{
+ xfs_mount_t *mp = tp->t_mountp;
int error; /* error value */
- xfs_inode_t *ip; /* inode for bitmap file */
- xfs_mount_t *mp; /* file system mount structure */
xfs_rtblock_t r; /* result allocated block */
xfs_fsblock_t sb; /* summary file block number */
xfs_buf_t *sumbp; /* summary file block buffer */
+ ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
ASSERT(minlen > 0 && minlen <= maxlen);
- mp = tp->t_mountp;
+
/*
* If prod is set then figure out what to do to minlen and maxlen.
*/
@@ -2099,12 +2099,7 @@ xfs_rtallocate_extent(
return 0;
}
}
- /*
- * Lock out other callers by grabbing the bitmap inode lock.
- */
- if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rbmino, 0,
- XFS_ILOCK_EXCL, &ip)))
- return error;
+
sumbp = NULL;
/*
* Allocate by size, or near another block, or exactly at some
block.
@@ -2123,11 +2118,12 @@ xfs_rtallocate_extent(
len, &sumbp, &sb, prod, &r);
break;
default:
+ error = EIO;
ASSERT(0);
}
- if (error) {
+ if (error)
return error;
- }
+
/*
* If it worked, update the superblock.
*/
@@ -2306,20 +2302,16 @@ xfs_rtpick_extent(
xfs_rtblock_t *pick) /* result rt extent */
{
xfs_rtblock_t b; /* result block */
- int error; /* error return value */
- xfs_inode_t *ip; /* bitmap incore inode */
int log2; /* log of sequence number */
__uint64_t resid; /* residual after log removed */
__uint64_t seq; /* sequence number of file creation
*/
__uint64_t *seqp; /* pointer to seqno in inode */
- if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rbmino, 0,
- XFS_ILOCK_EXCL, &ip)))
- return error;
+
sumbp = NULL;
/*
* Allocate by size, or near another block, or exactly at some
block.
@@ -2123,11 +2118,12 @@ xfs_rtallocate_extent(
len, &sumbp, &sb, prod, &r);
break;
default:
+ error = EIO;
ASSERT(0);
}
- if (error) {
+ if (error)
return error;
- }
+
/*
* If it worked, update the superblock.
*/
@@ -2306,20 +2302,16 @@ xfs_rtpick_extent(
xfs_rtblock_t *pick) /* result rt extent */
{
xfs_rtblock_t b; /* result block */
- int error; /* error return value */
- xfs_inode_t *ip; /* bitmap incore inode */
int log2; /* log of sequence number */
__uint64_t resid; /* residual after log removed */
__uint64_t seq; /* sequence number of file creation
*/
__uint64_t *seqp; /* pointer to seqno in inode */
- if ((error = xfs_trans_iget(mp, tp, mp->m_sb.sb_rbmino, 0,
- XFS_ILOCK_EXCL, &ip)))
- return error;
- ASSERT(ip == mp->m_rbmip);
- seqp = (__uint64_t *)&ip->i_d.di_atime;
- if (!(ip->i_d.di_flags & XFS_DIFLAG_NEWRTBM)) {
- ip->i_d.di_flags |= XFS_DIFLAG_NEWRTBM;
+ ASSERT(xfs_isilocked(mp->m_rbmip, XFS_ILOCK_EXCL));
+
+ seqp = (__uint64_t *)&mp->m_rbmip->i_d.di_atime;
+ if (!(mp->m_rbmip->i_d.di_flags & XFS_DIFLAG_NEWRTBM)) {
+ mp->m_rbmip->i_d.di_flags |= XFS_DIFLAG_NEWRTBM;
*seqp = 0;
}
seq = *seqp;
@@ -2335,7 +2327,7 @@ xfs_rtpick_extent(
b = mp->m_sb.sb_rextents - len;
}
*seqp = seq + 1;
- xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+ xfs_trans_log_inode(tp, mp->m_rbmip, XFS_ILOG_CORE);
*pick = b;
return 0;
}
--
1.7.5.4
--
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