direct IO fixes
PATCH 10/12 direct IO fixes
Some direct IO fixes from Badari Pulavarty.
- off-by-one in the bounds checking in blkdev_get_blocks().
- When adding more blocks into a bio_vec, account for the current offset into that bio_vec.
- Fix a total ballsup in the code which calculates the total number of pages which are about to be put under IO.
block_dev.c | 2 +- direct-io.c | 7 ++++--- 2 files changed, 5 insertions, 4 deletions
fs/direct-io.c renamed from fs/direct-io.c~direct_io-fixes +4 -3
@@ -489,7 +489,7 @@ int do_direct_IO(struct dio *dio)/* Work out how much disk we can add to this page */ this_chunk_blocks = dio->blocks_available; - u = (PAGE_SIZE - dio->bvec->bv_len) >> blkbits; + u = (PAGE_SIZE - (dio->bvec->bv_offset + dio->bvec->bv_len)) >> blkbits;if (this_chunk_blocks > u) this_chunk_blocks = u; u = dio->final_block_in_request - dio->block_in_file;
@@ -567,10 +567,11 @@ generic_direct_IO(int rw, struct inode * dio.curr_page =0 ; bytes = count; dio.total_pages =0 ; -if (offset &PAGE_SIZE ) { +if (user_addr & (PAGE_SIZE -1 )) { dio.total_pages++; - bytes -=PAGE_SIZE - (offset & ~(PAGE_SIZE -1 )); + bytes -=PAGE_SIZE - (user_addr & (PAGE_SIZE -1 )); } + dio.total_pages += (bytes +PAGE_SIZE -1 ) /PAGE_SIZE ; dio.curr_user_address = user_addr;
fs/block_dev.c renamed from fs/block_dev.c~direct_io-fixes +1 -1
@@ -105,7 +105,7 @@ static int blkdev_get_blocks(struct inode *inode, sector_t iblock, unsigned long max_blocks, struct buffer_head *bh, int create) { - if ((iblock + max_blocks) >= max_block(inode->i_bdev)) + if ((iblock + max_blocks) > max_block(inode->i_bdev)) return -EIO; bh->b_bdev = inode->i_bdev;
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