Messages in this thread Patch in this message | | | Date | Thu, 24 Apr 2003 10:51:19 +0530 | From | Suparna Bhattacharya <> | Subject | [PATCH 6/7] Filesystem AIO rdwr - async bread |
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On Thu, Apr 24, 2003 at 10:22:22AM +0530, Suparna Bhattacharya wrote: > Here is a revised version of the filesystem AIO patches > for 2.5.68. > > 06bread_wq.patch : Async bread implementation >
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
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