diff options
Diffstat (limited to 'fs/buffer.c')
| -rw-r--r-- | fs/buffer.c | 70 |
1 files changed, 59 insertions, 11 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index 3586fb05c8c..c017a2dfb90 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -46,8 +46,7 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list); #define BH_ENTRY(list) list_entry((list), struct buffer_head, b_assoc_buffers) -inline void -init_buffer(struct buffer_head *bh, bh_end_io_t *handler, void *private) +void init_buffer(struct buffer_head *bh, bh_end_io_t *handler, void *private) { bh->b_end_io = handler; bh->b_private = private; @@ -555,7 +554,7 @@ void emergency_thaw_all(void) */ int sync_mapping_buffers(struct address_space *mapping) { - struct address_space *buffer_mapping = mapping->assoc_mapping; + struct address_space *buffer_mapping = mapping->private_data; if (buffer_mapping == NULL || list_empty(&mapping->private_list)) return 0; @@ -588,10 +587,10 @@ void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode) struct address_space *buffer_mapping = bh->b_page->mapping; mark_buffer_dirty(bh); - if (!mapping->assoc_mapping) { - mapping->assoc_mapping = buffer_mapping; + if (!mapping->private_data) { + mapping->private_data = buffer_mapping; } else { - BUG_ON(mapping->assoc_mapping != buffer_mapping); + BUG_ON(mapping->private_data != buffer_mapping); } if (!bh->b_assoc_map) { spin_lock(&buffer_mapping->private_lock); @@ -788,7 +787,7 @@ void invalidate_inode_buffers(struct inode *inode) if (inode_has_buffers(inode)) { struct address_space *mapping = &inode->i_data; struct list_head *list = &mapping->private_list; - struct address_space *buffer_mapping = mapping->assoc_mapping; + struct address_space *buffer_mapping = mapping->private_data; spin_lock(&buffer_mapping->private_lock); while (!list_empty(list)) @@ -811,7 +810,7 @@ int remove_inode_buffers(struct inode *inode) if (inode_has_buffers(inode)) { struct address_space *mapping = &inode->i_data; struct list_head *list = &mapping->private_list; - struct address_space *buffer_mapping = mapping->assoc_mapping; + struct address_space *buffer_mapping = mapping->private_data; spin_lock(&buffer_mapping->private_lock); while (!list_empty(list)) { @@ -850,13 +849,10 @@ try_again: if (!bh) goto no_grow; - bh->b_bdev = NULL; bh->b_this_page = head; bh->b_blocknr = -1; head = bh; - bh->b_state = 0; - atomic_set(&bh->b_count, 0); bh->b_size = size; /* Link the buffer to its page */ @@ -2893,6 +2889,55 @@ static void end_bio_bh_io_sync(struct bio *bio, int err) bio_put(bio); } +/* + * This allows us to do IO even on the odd last sectors + * of a device, even if the bh block size is some multiple + * of the physical sector size. + * + * We'll just truncate the bio to the size of the device, + * and clear the end of the buffer head manually. + * + * Truly out-of-range accesses will turn into actual IO + * errors, this only handles the "we need to be able to + * do IO at the final sector" case. + */ +static void guard_bh_eod(int rw, struct bio *bio, struct buffer_head *bh) +{ + sector_t maxsector; + unsigned bytes; + + maxsector = i_size_read(bio->bi_bdev->bd_inode) >> 9; + if (!maxsector) + return; + + /* + * If the *whole* IO is past the end of the device, + * let it through, and the IO layer will turn it into + * an EIO. + */ + if (unlikely(bio->bi_sector >= maxsector)) + return; + + maxsector -= bio->bi_sector; + bytes = bio->bi_size; + if (likely((bytes >> 9) <= maxsector)) + return; + + /* Uhhuh. We've got a bh that straddles the device size! */ + bytes = maxsector << 9; + + /* Truncate the bio.. */ + bio->bi_size = bytes; + bio->bi_io_vec[0].bv_len = bytes; + + /* ..and clear the end of the buffer for reads */ + if ((rw & RW_MASK) == READ) { + void *kaddr = kmap_atomic(bh->b_page); + memset(kaddr + bh_offset(bh) + bytes, 0, bh->b_size - bytes); + kunmap_atomic(kaddr); + } +} + int submit_bh(int rw, struct buffer_head * bh) { struct bio *bio; @@ -2929,6 +2974,9 @@ int submit_bh(int rw, struct buffer_head * bh) bio->bi_end_io = end_bio_bh_io_sync; bio->bi_private = bh; + /* Take care of bh's that straddle the end of the device */ + guard_bh_eod(rw, bio, bh); + bio_get(bio); submit_bio(rw, bio); |