Pre-req for the filesystem specific async get block
patches.
Regards
Suparna
06bread_wq.patch
................
fs/buffer.c | 54 +++++++++++++++++++++++++++++++++++++-------
include/linux/buffer_head.h | 30 ++++++++++++++++++++++--
2 files changed, 73 insertions(+), 11 deletions(-)
diff -ur -X /home/kiran/dontdiff linux-2.5.68/fs/buffer.c linux-aio-2568/fs/buffer.c
--- linux-2.5.68/fs/buffer.c Mon Apr 21 23:30:33 2003
+++ linux-aio-2568/fs/buffer.c Mon Apr 21 17:26:58 2003
@@ -118,23 +118,35 @@
* from becoming locked again - you have to lock it yourself
* if you want to preserve its state.
*/
-void __wait_on_buffer(struct buffer_head * bh)
+int __wait_on_buffer_wq(struct buffer_head * bh, wait_queue_t *wait)
{
wait_queue_head_t *wqh = bh_waitq_head(bh);
- DEFINE_WAIT(wait);
+ DEFINE_WAIT(local_wait);
+
+ if (!wait)
+ wait = &local_wait;
if (atomic_read(&bh->b_count) == 0 &&
(!bh->b_page || !PageLocked(bh->b_page)))
buffer_error();
do {
- prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
+ prepare_to_wait(wqh, wait, TASK_UNINTERRUPTIBLE);
if (buffer_locked(bh)) {
blk_run_queues();
+ if (!is_sync_wait(wait)) {
+ return -EIOCBRETRY;
+ }
io_schedule();
}
} while (buffer_locked(bh));
- finish_wait(wqh, &wait);
+ finish_wait(wqh, wait);
+ return 0;
+}
+
+void __wait_on_buffer(struct buffer_head * bh)
+{
+ __wait_on_buffer_wq(bh, NULL);
}
static void
@@ -1190,9 +1202,12 @@
__brelse(bh);
}
-static struct buffer_head *__bread_slow(struct buffer_head *bh)
+static struct buffer_head *__bread_slow_wq(struct buffer_head *bh,
+ wait_queue_t *wait)
{
- lock_buffer(bh);
+ if (-EIOCBRETRY == lock_buffer_wq(bh, wait))
+ return ERR_PTR(-EIOCBRETRY);
+
if (buffer_uptodate(bh)) {
unlock_buffer(bh);
return bh;
@@ -1202,7 +1217,8 @@
get_bh(bh);
bh->b_end_io = end_buffer_io_sync;
submit_bh(READ, bh);
- wait_on_buffer(bh);
+ if (-EIOCBRETRY == wait_on_buffer_wq(bh, wait))
+ return ERR_PTR(-EIOCBRETRY);
if (buffer_uptodate(bh))
return bh;
}
@@ -1210,6 +1226,11 @@
return NULL;
}
+static inline struct buffer_head *__bread_slow(struct buffer_head *bh)
+{
+ return __bread_slow_wq(bh, NULL);
+}
+
/*
* Per-cpu buffer LRU implementation. To reduce the cost of __find_get_block().
* The bhs[] array is sorted - newest buffer is at bhs[0]. Buffers have their
@@ -1384,6 +1405,18 @@
bh = __bread_slow(bh);
return bh;
}
+
+
+struct buffer_head *
+__bread_wq(struct block_device *bdev, sector_t block, int size,
+ wait_queue_t *wait)
+{
+ struct buffer_head *bh = __getblk(bdev, block, size);
+
+ if (!buffer_uptodate(bh))
+ bh = __bread_slow_wq(bh, wait);
+ return bh;
+}
EXPORT_SYMBOL(__bread);
/*
@@ -1822,8 +1855,11 @@
clear_buffer_new(bh);
if (!buffer_mapped(bh)) {
err = get_block(inode, block, bh, 1);
- if (err)
+ if (err) {
+ if (-EIOCBRETRY == err)
+ pr_debug("get_block queued\n");
goto out;
+ }
if (buffer_new(bh)) {
clear_buffer_new(bh);
unmap_underlying_metadata(bh->b_bdev,
@@ -1865,6 +1901,8 @@
* If we issued read requests - let them complete.
*/
while(wait_bh > wait) {
+ if (!is_sync_wait(current->io_wait))
+ printk("block_prepare_write: wait on buffer\n");
wait_on_buffer(*--wait_bh);
if (!buffer_uptodate(*wait_bh))
return -EIO;
diff -ur -X /home/kiran/dontdiff linux-2.5.68/include/linux/buffer_head.h linux-aio-2568/include/linux/buffer_head.h
--- linux-2.5.68/include/linux/buffer_head.h Fri Apr 11 21:10:51 2003
+++ linux-aio-2568/include/linux/buffer_head.h Wed Apr 16 16:31:12 2003
@@ -162,6 +162,7 @@
void __invalidate_buffers(kdev_t dev, int);
int sync_blockdev(struct block_device *bdev);
void __wait_on_buffer(struct buffer_head *);
+int __wait_on_buffer_wq(struct buffer_head *, wait_queue_t *wait);
wait_queue_head_t *bh_waitq_head(struct buffer_head *bh);
void wake_up_buffer(struct buffer_head *bh);
int fsync_bdev(struct block_device *);
@@ -172,6 +173,8 @@
void __brelse(struct buffer_head *);
void __bforget(struct buffer_head *);
struct buffer_head *__bread(struct block_device *, sector_t block, int size);
+struct buffer_head *__bread_wq(struct block_device *, sector_t block,
+ int size, wait_queue_t *wait);
struct buffer_head *alloc_buffer_head(void);
void free_buffer_head(struct buffer_head * bh);
void FASTCALL(unlock_buffer(struct buffer_head *bh));
@@ -229,13 +232,13 @@
static inline void brelse(struct buffer_head *bh)
{
- if (bh)
+ if (bh && !IS_ERR(bh))
__brelse(bh);
}
static inline void bforget(struct buffer_head *bh)
{
- if (bh)
+ if (bh && !IS_ERR(bh))
__bforget(bh);
}
@@ -246,7 +249,12 @@
}
static inline struct buffer_head *
-sb_getblk(struct super_block *sb, sector_t block)
+sb_bread_wq(struct super_block *sb, sector_t block, wait_queue_t *wait)
+{
+ return __bread_wq(sb->s_bdev, block, sb->s_blocksize, wait);
+}
+
+static inline struct buffer_head *sb_getblk(struct super_block *sb, sector_t block)
{
return __getblk(sb->s_bdev, block, sb->s_blocksize);
}
@@ -276,10 +284,26 @@
__wait_on_buffer(bh);
}
+static inline int wait_on_buffer_wq(struct buffer_head *bh, wait_queue_t *wait)
+{
+ if (buffer_locked(bh))
+ return __wait_on_buffer_wq(bh, wait);
+
+ return 0;
+}
+
static inline void lock_buffer(struct buffer_head *bh)
{
while (test_set_buffer_locked(bh))
__wait_on_buffer(bh);
}
+static inline int lock_buffer_wq(struct buffer_head *bh, wait_queue_t *wait)
+{
+ if (test_set_buffer_locked(bh))
+ return __wait_on_buffer_wq(bh, wait);
+
+ return 0;
+}
+
#endif /* _LINUX_BUFFER_HEAD_H */
-- Suparna Bhattacharya (suparna@in.ibm.com) Linux Technology Center IBM Software Labs, India- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/