This patch fixes a tiny race in unaligned aio+dio that leads to a hang.
Commit a11f7e63c59810a81494d4c4b028af707d4c7ca4 serialized unaligned
aio+dio writes. However the serialize code in end_io() was not
differentiating between writes and reads and thus allowing reads to
interfere with the serialization accounting for writes. This patch
seperates the handler functions to avoid this issue.
Signed-off-by: Sunil Mushran <sunil.mush...@oracle.com>
---
fs/ocfs2/aops.c | 44 ++++++++++++++++++++++++++++++++------------
1 files changed, 32 insertions(+), 12 deletions(-)
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 78b68af..3783ba3 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -558,20 +558,15 @@ bail:
}
/*
- * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're
- * particularly interested in the aio/dio case. We use the rw_lock DLM lock
- * to protect io on one node from truncation on another.
+ * ocfs2_dio_end_io_[read|write] is called by the dio core when a dio is
+ * finished. We're particularly interested in the aio/dio case. We use
+ * the rw_lock DLM lock to protect io on one node from truncation on another.
*/
-static void ocfs2_dio_end_io(struct kiocb *iocb,
- loff_t offset,
- ssize_t bytes,
- void *private,
- int ret,
- bool is_async)
+static void ocfs2_dio_end_io(struct kiocb *iocb, loff_t offset, ssize_t bytes,
+ void *private, int ret, bool is_async, int rw)
{
struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
int level;
- wait_queue_head_t *wq = ocfs2_ioend_wq(inode);
/* this io's submitter should not have unlocked this before we could */
BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
@@ -579,7 +574,9 @@ static void ocfs2_dio_end_io(struct kiocb *iocb,
if (ocfs2_iocb_is_sem_locked(iocb))
ocfs2_iocb_clear_sem_locked(iocb);
- if (ocfs2_iocb_is_unaligned_aio(iocb)) {
+ if (rw == WRITE && ocfs2_iocb_is_unaligned_aio(iocb)) {
+ wait_queue_head_t *wq = ocfs2_ioend_wq(inode);
+
ocfs2_iocb_clear_unaligned_aio(iocb);
if (atomic_dec_and_test(&OCFS2_I(inode)->ip_unaligned_aio) &&
@@ -598,6 +595,23 @@ static void ocfs2_dio_end_io(struct kiocb *iocb,
inode_dio_done(inode);
}
+static void ocfs2_dio_end_io_write(struct kiocb *iocb, loff_t offset,
+ ssize_t bytes, void *private, int ret,
+ bool is_async)
+{
+
+ return ocfs2_dio_end_io(iocb, offset, bytes, private, ret,
+ is_async, WRITE);
+}
+
+static void ocfs2_dio_end_io_read(struct kiocb *iocb, loff_t offset,
+ ssize_t bytes, void *private, int ret,
+ bool is_async)
+{
+ return ocfs2_dio_end_io(iocb, offset, bytes, private, ret,
+ is_async, READ);
+}
+
/*
* ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen
* from ext3. PageChecked() bits have been removed as OCFS2 does not
@@ -627,6 +641,7 @@ static ssize_t ocfs2_direct_IO(int rw,
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
+ dio_iodone_t *end_io;
/*
* Fallback to buffered I/O if we see an inode without
@@ -639,10 +654,15 @@ static ssize_t ocfs2_direct_IO(int rw,
if (i_size_read(inode) <= offset)
return 0;
+ if (rw == WRITE)
+ end_io = ocfs2_dio_end_io_write;
+ else
+ end_io = ocfs2_dio_end_io_read;
+
return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
iov, offset, nr_segs,
ocfs2_direct_IO_get_blocks,
- ocfs2_dio_end_io, NULL, 0);
+ end_io, NULL, 0);
}
static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
--
1.7.7.6
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