#include <linux/cpu.h>
#include <asm/bitops.h>
+static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
static void invalidate_bh_lrus(void);
#define BH_ENTRY(list) list_entry((list), struct buffer_head, b_assoc_buffers)
+struct bh_wait_queue {
+ struct buffer_head *bh;
+ wait_queue_t wait;
+};
+
+#define __DEFINE_BH_WAIT(name, b, f) \
+ struct bh_wait_queue name = { \
+ .bh = b, \
+ .wait = { \
+ .task = current, \
+ .flags = f, \
+ .func = bh_wake_function, \
+ .task_list = \
+ LIST_HEAD_INIT(name.wait.task_list),\
+ }, \
+ }
+#define DEFINE_BH_WAIT(name, bh) __DEFINE_BH_WAIT(name, bh, 0)
+#define DEFINE_BH_WAIT_EXCLUSIVE(name, bh) \
+ __DEFINE_BH_WAIT(name, bh, WQ_FLAG_EXCLUSIVE)
+
/*
* Hashed waitqueue_head's for wait_on_buffer()
*/
smp_mb();
if (waitqueue_active(wq))
- wake_up_all(wq);
+ __wake_up(wq, TASK_INTERRUPTIBLE|TASK_UNINTERRUPTIBLE, 1, bh);
}
EXPORT_SYMBOL(wake_up_buffer);
+static int bh_wake_function(wait_queue_t *wait, unsigned mode,
+ int sync, void *key)
+{
+ struct buffer_head *bh = key;
+ struct bh_wait_queue *wq;
+
+ wq = container_of(wait, struct bh_wait_queue, wait);
+ if (wq->bh != bh || buffer_locked(bh))
+ return 0;
+ else
+ return autoremove_wake_function(wait, mode, sync, key);
+}
+
+static void sync_buffer(struct buffer_head *bh)
+{
+ struct block_device *bd;
+
+ smp_mb();
+ bd = bh->b_bdev;
+ if (bd)
+ blk_run_address_space(bd->bd_inode->i_mapping);
+}
+
+void fastcall __lock_buffer(struct buffer_head *bh)
+{
+ wait_queue_head_t *wqh = bh_waitq_head(bh);
+ DEFINE_BH_WAIT_EXCLUSIVE(wait, bh);
+
+ do {
+ prepare_to_wait_exclusive(wqh, &wait.wait,
+ TASK_UNINTERRUPTIBLE);
+ if (buffer_locked(bh)) {
+ sync_buffer(bh);
+ io_schedule();
+ }
+ } while (test_set_buffer_locked(bh));
+ finish_wait(wqh, &wait.wait);
+}
+EXPORT_SYMBOL(__lock_buffer);
+
void fastcall unlock_buffer(struct buffer_head *bh)
{
clear_buffer_locked(bh);
void __wait_on_buffer(struct buffer_head * bh)
{
wait_queue_head_t *wqh = bh_waitq_head(bh);
- DEFINE_WAIT(wait);
+ DEFINE_BH_WAIT(wait, bh);
do {
- prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
+ prepare_to_wait(wqh, &wait.wait, TASK_UNINTERRUPTIBLE);
if (buffer_locked(bh)) {
- struct block_device *bd;
- smp_mb();
- bd = bh->b_bdev;
- if (bd)
- blk_run_address_space(bd->bd_inode->i_mapping);
+ sync_buffer(bh);
io_schedule();
}
} while (buffer_locked(bh));
- finish_wait(wqh, &wait);
+ finish_wait(wqh, &wait.wait);
}
static void
if (uptodate) {
set_buffer_uptodate(bh);
} else {
- if (printk_ratelimit()) {
+ if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
buffer_io_error(bh);
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
* PageLocked prevents anyone from starting writeback of a page which is
* under read I/O (PageWriteback is only ever set against a locked page).
*/
-void mark_buffer_async_read(struct buffer_head *bh)
+static void mark_buffer_async_read(struct buffer_head *bh)
{
bh->b_end_io = end_buffer_async_read;
set_buffer_async_read(bh);
}
-EXPORT_SYMBOL(mark_buffer_async_read);
void mark_buffer_async_write(struct buffer_head *bh)
{
* b_inode back.
*/
-void buffer_insert_list(spinlock_t *lock,
- struct buffer_head *bh, struct list_head *list)
-{
- spin_lock(lock);
- list_move_tail(&bh->b_assoc_buffers, list);
- spin_unlock(lock);
-}
-
/*
* The buffer's backing address_space's private_lock must be held
*/
if (mapping->assoc_mapping != buffer_mapping)
BUG();
}
- if (list_empty(&bh->b_assoc_buffers))
- buffer_insert_list(&buffer_mapping->private_lock,
- bh, &mapping->private_list);
+ if (list_empty(&bh->b_assoc_buffers)) {
+ spin_lock(&buffer_mapping->private_lock);
+ list_move_tail(&bh->b_assoc_buffers,
+ &mapping->private_list);
+ spin_unlock(&buffer_mapping->private_lock);
+ }
}
EXPORT_SYMBOL(mark_buffer_dirty_inode);
if (page->mapping) { /* Race with truncate? */
if (!mapping->backing_dev_info->memory_backed)
inc_page_state(nr_dirty);
- radix_tree_tag_set(&mapping->page_tree, page->index,
+ radix_tree_tag_set(&mapping->page_tree,
+ page_index(page),
PAGECACHE_TAG_DIRTY);
}
spin_unlock_irq(&mapping->tree_lock);
* the osync code to catch these locked, dirty buffers without requeuing
* any newly dirty buffers for write.
*/
-int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
+static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
{
struct buffer_head *bh;
struct list_head tmp;
pgoff_t index;
int sizebits;
- /* Size must be multiple of hard sectorsize */
- if (size & (bdev_hardsect_size(bdev)-1))
- BUG();
- if (size < 512 || size > PAGE_SIZE)
- BUG();
-
sizebits = -1;
do {
sizebits++;
struct buffer_head *
__getblk_slow(struct block_device *bdev, sector_t block, int size)
{
+ /* Size must be multiple of hard sectorsize */
+ if (unlikely(size & (bdev_hardsect_size(bdev)-1) ||
+ (size < 512 || size > PAGE_SIZE))) {
+ printk(KERN_ERR "getblk(): invalid block size %d requested\n",
+ size);
+ printk(KERN_ERR "hardsect size: %d\n",
+ bdev_hardsect_size(bdev));
+
+ dump_stack();
+ return NULL;
+ }
+
for (;;) {
struct buffer_head * bh;
struct buffer_head *bhs[BH_LRU_SIZE];
};
-static DEFINE_PER_CPU(struct bh_lru, bh_lrus) = {{0}};
+static DEFINE_PER_CPU(struct bh_lru, bh_lrus) = {{ NULL }};
#ifdef CONFIG_SMP
#define bh_lru_lock() local_irq_disable()
{
struct buffer_head *bh = __find_get_block(bdev, block, size);
+ might_sleep();
if (bh == NULL)
bh = __getblk_slow(bdev, block, size);
return bh;
EXPORT_SYMBOL(__bread);
/*
- * invalidate_bh_lrus() is called rarely - at unmount. Because it is only for
- * unmount it only needs to ensure that all buffers from the target device are
- * invalidated on return and it doesn't need to worry about new buffers from
- * that device being added - the unmount code has to prevent that.
+ * invalidate_bh_lrus() is called rarely - but not only at unmount.
+ * This doesn't race because it runs in each cpu either in irq
+ * or with preempt disabled.
*/
static void invalidate_bh_lru(void *arg)
{
{
struct buffer_head *old_bh;
+ might_sleep();
+
old_bh = __find_get_block_slow(bdev, block, 0);
if (old_bh) {
clear_buffer_dirty(old_bh);
* state inside lock_buffer().
*
* If block_write_full_page() is called for regular writeback
- * (called_for_sync() is false) then it will redirty a page which has a locked
- * buffer. This only can happen if someone has written the buffer directly,
- * with submit_bh(). At the address_space level PageWriteback prevents this
- * contention from occurring.
+ * (wbc->sync_mode == WB_SYNC_NONE) then it will redirty a page which has a
+ * locked buffer. This only can happen if someone has written the buffer
+ * directly, with submit_bh(). At the address_space level PageWriteback
+ * prevents this contention from occurring.
*/
static int __block_write_full_page(struct inode *inode, struct page *page,
get_block_t *get_block, struct writeback_control *wbc)
}
} while ((bh = bh->b_this_page) != head);
+ /*
+ * The page and its buffers are protected by PageWriteback(), so we can
+ * drop the bh refcounts early.
+ */
BUG_ON(PageWriteback(page));
- set_page_writeback(page); /* Keeps try_to_free_buffers() away */
+ set_page_writeback(page);
unlock_page(page);
- /*
- * The page may come unlocked any time after the *first* submit_bh()
- * call. Be careful with its buffers.
- */
do {
struct buffer_head *next = bh->b_this_page;
if (buffer_async_write(bh)) {
if (uptodate)
SetPageUptodate(page);
end_page_writeback(page);
+ /*
+ * The page and buffer_heads can be released at any time from
+ * here on.
+ */
wbc->pages_skipped++; /* We didn't write this page */
}
return err;
}
bh->b_state = map_bh.b_state;
atomic_set(&bh->b_count, 0);
- bh->b_this_page = 0;
+ bh->b_this_page = NULL;
bh->b_page = page;
bh->b_blocknr = map_bh.b_blocknr;
bh->b_size = blocksize;
/*
* The page straddles i_size. It must be zeroed out on each and every
- * writepage invocation because it may be mmapped. "A file is mapped
+ * writepage invokation because it may be mmapped. "A file is mapped
* in multiples of the page size. For a file that is not a multiple of
* the page size, the remaining memory is zeroed when mapped, and
* writes to that region are not written out to the file."
if (bio->bi_size)
return 1;
+ if (err == -EOPNOTSUPP) {
+ set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+ set_bit(BH_Eopnotsupp, &bh->b_state);
+ }
+
bh->b_end_io(bh, test_bit(BIO_UPTODATE, &bio->bi_flags));
bio_put(bio);
return 0;
}
-void submit_bh(int rw, struct buffer_head * bh)
+int submit_bh(int rw, struct buffer_head * bh)
{
struct bio *bio;
+ int ret = 0;
BUG_ON(!buffer_locked(bh));
BUG_ON(!buffer_mapped(bh));
BUG_ON(!bh->b_end_io);
- /* Only clear out a write error when rewriting */
- if (test_set_buffer_req(bh) && rw == WRITE)
+ if (buffer_ordered(bh) && (rw == WRITE))
+ rw = WRITE_BARRIER;
+
+ /*
+ * Only clear out a write error when rewriting, should this
+ * include WRITE_SYNC as well?
+ */
+ if (test_set_buffer_req(bh) && (rw == WRITE || rw == WRITE_BARRIER))
clear_buffer_write_io_error(bh);
/*
bio->bi_end_io = end_bio_bh_io_sync;
bio->bi_private = bh;
+ bio_get(bio);
submit_bio(rw, bio);
+
+ if (bio_flagged(bio, BIO_EOPNOTSUPP))
+ ret = -EOPNOTSUPP;
+
+ bio_put(bio);
+ return ret;
}
/**
/*
* For a data-integrity writeout, we need to wait upon any in-progress I/O
- * and then start new I/O and then wait upon it.
+ * and then start new I/O and then wait upon it. The caller must have a ref on
+ * the buffer_head.
*/
-void sync_dirty_buffer(struct buffer_head *bh)
+int sync_dirty_buffer(struct buffer_head *bh)
{
+ int ret = 0;
+
WARN_ON(atomic_read(&bh->b_count) < 1);
lock_buffer(bh);
if (test_clear_buffer_dirty(bh)) {
get_bh(bh);
bh->b_end_io = end_buffer_write_sync;
- submit_bh(WRITE, bh);
+ ret = submit_bh(WRITE, bh);
wait_on_buffer(bh);
+ if (buffer_eopnotsupp(bh)) {
+ clear_buffer_eopnotsupp(bh);
+ ret = -EOPNOTSUPP;
+ }
+ if (!ret && !buffer_uptodate(bh))
+ ret = -EIO;
} else {
unlock_buffer(bh);
}
+ return ret;
}
/*
{
struct buffer_head *head = page_buffers(page);
struct buffer_head *bh;
- int was_uptodate = 1;
bh = head;
do {
set_bit(AS_EIO, &page->mapping->flags);
if (buffer_busy(bh))
goto failed;
- if (!buffer_uptodate(bh) && !buffer_req(bh))
- was_uptodate = 0;
bh = bh->b_this_page;
} while (bh != head);
int block_sync_page(struct page *page)
{
struct address_space *mapping;
+
smp_mb();
- mapping = page->mapping;
- blk_run_address_space(mapping);
+ mapping = page_mapping(page);
+ if (mapping)
+ blk_run_backing_dev(mapping->backing_dev_info, page);
return 0;
}
bh_cachep = kmem_cache_create("buffer_head",
sizeof(struct buffer_head), 0,
- 0, init_buffer_head, NULL);
+ SLAB_PANIC, init_buffer_head, NULL);
for (i = 0; i < ARRAY_SIZE(bh_wait_queue_heads); i++)
init_waitqueue_head(&bh_wait_queue_heads[i].wqh);
EXPORT_SYMBOL(block_sync_page);
EXPORT_SYMBOL(block_truncate_page);
EXPORT_SYMBOL(block_write_full_page);
-EXPORT_SYMBOL(buffer_insert_list);
EXPORT_SYMBOL(cont_prepare_write);
EXPORT_SYMBOL(end_buffer_async_write);
EXPORT_SYMBOL(end_buffer_read_sync);
EXPORT_SYMBOL(end_buffer_write_sync);
EXPORT_SYMBOL(file_fsync);
EXPORT_SYMBOL(fsync_bdev);
-EXPORT_SYMBOL(fsync_buffers_list);
EXPORT_SYMBOL(generic_block_bmap);
EXPORT_SYMBOL(generic_commit_write);
EXPORT_SYMBOL(generic_cont_expand);
git://git.onelab.eu / linux-2.6.git / blobdiff