akpm at linux-foundation.org
2016-Mar-23 20:12 UTC
[Ocfs2-devel] [patch 10/25] ocfs2: take ip_alloc_sem in ocfs2_dio_get_block & ocfs2_dio_end_io_write
From: Ryan Ding <ryan.ding at oracle.com>
Subject: ocfs2: take ip_alloc_sem in ocfs2_dio_get_block &
ocfs2_dio_end_io_write
Take ip_alloc_sem to prevent concurrent access to extent tree, which may
cause the extent tree in an unstable state.
Signed-off-by: Ryan Ding <ryan.ding at oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi at oracle.com>
Cc: Joseph Qi <joseph.qi at huawei.com>
Cc: Mark Fasheh <mfasheh at suse.de>
Cc: Joel Becker <jlbec at evilplan.org>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
---
fs/ocfs2/aops.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff -puN
fs/ocfs2/aops.c~ocfs2-take-ip_alloc_sem-in-ocfs2_dio_get_block-ocfs2_dio_end_io_write
fs/ocfs2/aops.c
---
a/fs/ocfs2/aops.c~ocfs2-take-ip_alloc_sem-in-ocfs2_dio_get_block-ocfs2_dio_end_io_write
+++ a/fs/ocfs2/aops.c
@@ -2151,6 +2151,7 @@ static int ocfs2_dio_get_block(struct in
struct buffer_head *bh_result, int create)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
struct ocfs2_write_ctxt *wc;
struct ocfs2_write_cluster_desc *desc = NULL;
struct ocfs2_dio_write_ctxt *dwc = NULL;
@@ -2166,9 +2167,12 @@ static int ocfs2_dio_get_block(struct in
mlog(0, "get block of %lu at %llu:%u req %u\n",
inode->i_ino, pos, len, total_len);
+ down_read(&oi->ip_alloc_sem);
/* This is the fast path for re-write. */
ret = ocfs2_get_block(inode, iblock, bh_result, create);
+ up_read(&oi->ip_alloc_sem);
+
if (buffer_mapped(bh_result) &&
!buffer_new(bh_result) &&
ret == 0)
@@ -2206,6 +2210,8 @@ static int ocfs2_dio_get_block(struct in
goto out;
}
+ down_write(&oi->ip_alloc_sem);
+
if (first_get_block) {
if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
ret = ocfs2_zero_tail(inode, di_bh, pos);
@@ -2259,6 +2265,7 @@ static int ocfs2_dio_get_block(struct in
BUG_ON(ret != len);
ret = 0;
unlock:
+ up_write(&oi->ip_alloc_sem);
ocfs2_inode_unlock(inode, 1);
brelse(di_bh);
out:
@@ -2275,6 +2282,7 @@ static void ocfs2_dio_end_io_write(struc
struct ocfs2_cached_dealloc_ctxt dealloc;
struct ocfs2_extent_tree et;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
struct ocfs2_unwritten_extent *ue = NULL;
struct buffer_head *di_bh = NULL;
struct ocfs2_dinode *di;
@@ -2293,12 +2301,6 @@ static void ocfs2_dio_end_io_write(struc
!dwc->dw_orphaned)
goto out;
- ret = ocfs2_inode_lock(inode, &di_bh, 1);
- if (ret < 0) {
- mlog_errno(ret);
- goto out;
- }
-
/* ocfs2_file_write_iter will get i_mutex, so we need not lock if we
* are in that context. */
if (dwc->dw_writer_pid != task_pid_nr(current)) {
@@ -2306,6 +2308,14 @@ static void ocfs2_dio_end_io_write(struc
locked = 1;
}
+ ret = ocfs2_inode_lock(inode, &di_bh, 1);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ down_write(&oi->ip_alloc_sem);
+
/* Delete orphan before acquire i_mutex. */
if (dwc->dw_orphaned) {
BUG_ON(dwc->dw_writer_pid != task_pid_nr(current));
@@ -2359,6 +2369,7 @@ static void ocfs2_dio_end_io_write(struc
commit:
ocfs2_commit_trans(osb, handle);
unlock:
+ up_write(&oi->ip_alloc_sem);
ocfs2_inode_unlock(inode, 1);
brelse(di_bh);
out:
_