diff options
| author | Andrew Morton <akpm@osdl.org> | 2007-02-03 01:14:01 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-03 11:26:06 -0800 |
| commit | b2e895dbd80c420bfc0937c3729b4afe073b3848 (patch) | |
| tree | d03f686831405c190ce80c895e5dea3fb17d09fc | |
| parent | 8560a10e16faccafdc2e26c4873bf4edfbbf651e (diff) | |
[PATCH] revert blockdev direct io back to 2.6.19 version
Andrew Vasquez is reporting as-iosched oopses and a 65% throughput
slowdown due to the recent special-casing of direct-io against
blockdevs. We don't know why either of these things are occurring.
The patch minimally reverts us back to the 2.6.19 code for a 2.6.20
release.
Cc: Andrew Vasquez <andrew.vasquez@qlogic.com>
Cc: Ken Chen <kenchen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/block_dev.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index d9bdf2b3ade..fc7028b685f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -129,6 +129,46 @@ blkdev_get_block(struct inode *inode, sector_t iblock, return 0; } +static int +blkdev_get_blocks(struct inode *inode, sector_t iblock, + struct buffer_head *bh, int create) +{ + sector_t end_block = max_block(I_BDEV(inode)); + unsigned long max_blocks = bh->b_size >> inode->i_blkbits; + + if ((iblock + max_blocks) > end_block) { + max_blocks = end_block - iblock; + if ((long)max_blocks <= 0) { + if (create) + return -EIO; /* write fully beyond EOF */ + /* + * It is a read which is fully beyond EOF. We return + * a !buffer_mapped buffer + */ + max_blocks = 0; + } + } + + bh->b_bdev = I_BDEV(inode); + bh->b_blocknr = iblock; + bh->b_size = max_blocks << inode->i_blkbits; + if (max_blocks) + set_buffer_mapped(bh); + return 0; +} + +static ssize_t +blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, + loff_t offset, unsigned long nr_segs) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file->f_mapping->host; + + return blockdev_direct_IO_no_locking(rw, iocb, inode, I_BDEV(inode), + iov, offset, nr_segs, blkdev_get_blocks, NULL); +} + +#if 0 static int blk_end_aio(struct bio *bio, unsigned int bytes_done, int error) { struct kiocb *iocb = bio->bi_private; @@ -323,6 +363,7 @@ backout: return PTR_ERR(page); goto completion; } +#endif static int blkdev_writepage(struct page *page, struct writeback_control *wbc) { |