#include <linux/config.h>
#include <linux/kernel.h>
+#include <linux/syscalls.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/percpu.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
+#include <linux/capability.h>
#include <linux/blkdev.h>
#include <linux/file.h>
#include <linux/quotaops.h>
#include <linux/bio.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
-#include <asm/bitops.h>
+#include <linux/bitops.h>
+#include <linux/mpage.h>
+#include <linux/bit_spinlock.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)
-/*
- * Hashed waitqueue_head's for wait_on_buffer()
- */
-#define BH_WAIT_TABLE_ORDER 7
-static struct bh_wait_queue_head {
- wait_queue_head_t wqh;
-} ____cacheline_aligned_in_smp bh_wait_queue_heads[1<<BH_WAIT_TABLE_ORDER];
-
inline void
init_buffer(struct buffer_head *bh, bh_end_io_t *handler, void *private)
{
bh->b_private = private;
}
-/*
- * Return the address of the waitqueue_head to be used for this
- * buffer_head
- */
-wait_queue_head_t *bh_waitq_head(struct buffer_head *bh)
+static int sync_buffer(void *word)
{
- return &bh_wait_queue_heads[hash_ptr(bh, BH_WAIT_TABLE_ORDER)].wqh;
+ struct block_device *bd;
+ struct buffer_head *bh
+ = container_of(word, struct buffer_head, b_state);
+
+ smp_mb();
+ bd = bh->b_bdev;
+ if (bd)
+ blk_run_address_space(bd->bd_inode->i_mapping);
+ io_schedule();
+ return 0;
}
-EXPORT_SYMBOL(bh_waitq_head);
-void wake_up_buffer(struct buffer_head *bh)
+void fastcall __lock_buffer(struct buffer_head *bh)
{
- wait_queue_head_t *wq = bh_waitq_head(bh);
-
- smp_mb();
- if (waitqueue_active(wq))
- wake_up_all(wq);
+ wait_on_bit_lock(&bh->b_state, BH_Lock, sync_buffer,
+ TASK_UNINTERRUPTIBLE);
}
-EXPORT_SYMBOL(wake_up_buffer);
+EXPORT_SYMBOL(__lock_buffer);
void fastcall unlock_buffer(struct buffer_head *bh)
{
clear_buffer_locked(bh);
smp_mb__after_clear_bit();
- wake_up_buffer(bh);
+ wake_up_bit(&bh->b_state, BH_Lock);
}
/*
*/
void __wait_on_buffer(struct buffer_head * bh)
{
- wait_queue_head_t *wqh = bh_waitq_head(bh);
- DEFINE_WAIT(wait);
-
- do {
- prepare_to_wait(wqh, &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);
- io_schedule();
- }
- } while (buffer_locked(bh));
- finish_wait(wqh, &wait);
-}
-
-static void
-__set_page_buffers(struct page *page, struct buffer_head *head)
-{
- page_cache_get(page);
- SetPagePrivate(page);
- page->private = (unsigned long)head;
+ wait_on_bit(&bh->b_state, BH_Lock, sync_buffer, TASK_UNINTERRUPTIBLE);
}
static void
__clear_page_buffers(struct page *page)
{
ClearPagePrivate(page);
- page->private = 0;
+ set_page_private(page, 0);
page_cache_release(page);
}
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",
{
int ret = 0;
- if (bdev) {
- int err;
-
- ret = filemap_fdatawrite(bdev->bd_inode->i_mapping);
- err = filemap_fdatawait(bdev->bd_inode->i_mapping);
- if (!ret)
- ret = err;
- }
+ if (bdev)
+ ret = filemap_write_and_wait(bdev->bd_inode->i_mapping);
return ret;
}
EXPORT_SYMBOL(sync_blockdev);
sb = get_super(bdev);
if (sb && !(sb->s_flags & MS_RDONLY)) {
sb->s_frozen = SB_FREEZE_WRITE;
- wmb();
+ smp_wmb();
sync_inodes_sb(sb, 0);
DQUOT_SYNC(sb);
sync_inodes_sb(sb, 1);
sb->s_frozen = SB_FREEZE_TRANS;
- wmb();
+ smp_wmb();
sync_blockdev(sb->s_bdev);
if (sb->s_op->unlockfs)
sb->s_op->unlockfs(sb);
sb->s_frozen = SB_UNFROZEN;
- wmb();
+ smp_wmb();
wake_up(&sb->s_wait_unfrozen);
drop_super(sb);
}
*/
static void do_sync(unsigned long wait)
{
- wakeup_bdflush(0);
+ wakeup_pdflush(0);
sync_inodes(0); /* All mappings, inodes and their blockdevs */
DQUOT_SYNC(NULL);
sync_supers(); /* Write the superblocks */
{
struct inode * inode = dentry->d_inode;
struct super_block * sb;
- int ret;
+ int ret, err;
/* sync the inode to buffers */
- write_inode_now(inode, 0);
+ ret = write_inode_now(inode, 0);
/* sync the superblock to buffers */
sb = inode->i_sb;
unlock_super(sb);
/* .. finally sync the buffers to disk */
- ret = sync_blockdev(sb->s_bdev);
+ err = sync_blockdev(sb->s_bdev);
+ if (!ret)
+ ret = err;
return ret;
}
-asmlinkage long sys_fsync(unsigned int fd)
+static long do_fsync(unsigned int fd, int datasync)
{
struct file * file;
struct address_space *mapping;
if (!file)
goto out;
- mapping = file->f_mapping;
-
ret = -EINVAL;
if (!file->f_op || !file->f_op->fsync) {
/* Why? We can still call filemap_fdatawrite */
goto out_putf;
}
- /* We need to protect against concurrent writers.. */
- down(&mapping->host->i_sem);
+ mapping = file->f_mapping;
+
current->flags |= PF_SYNCWRITE;
ret = filemap_fdatawrite(mapping);
- err = file->f_op->fsync(file, file->f_dentry, 0);
+
+ /*
+ * We need to protect against concurrent writers,
+ * which could cause livelocks in fsync_buffers_list
+ */
+ mutex_lock(&mapping->host->i_mutex);
+ err = file->f_op->fsync(file, file->f_dentry, datasync);
if (!ret)
ret = err;
+ mutex_unlock(&mapping->host->i_mutex);
err = filemap_fdatawait(mapping);
if (!ret)
ret = err;
current->flags &= ~PF_SYNCWRITE;
- up(&mapping->host->i_sem);
out_putf:
fput(file);
return ret;
}
-asmlinkage long sys_fdatasync(unsigned int fd)
+asmlinkage long sys_fsync(unsigned int fd)
{
- struct file * file;
- struct address_space *mapping;
- int ret, err;
-
- ret = -EBADF;
- file = fget(fd);
- if (!file)
- goto out;
-
- ret = -EINVAL;
- if (!file->f_op || !file->f_op->fsync)
- goto out_putf;
-
- mapping = file->f_mapping;
-
- down(&mapping->host->i_sem);
- current->flags |= PF_SYNCWRITE;
- ret = filemap_fdatawrite(mapping);
- err = file->f_op->fsync(file, file->f_dentry, 1);
- if (!ret)
- ret = err;
- err = filemap_fdatawait(mapping);
- if (!ret)
- ret = err;
- current->flags &= ~PF_SYNCWRITE;
- up(&mapping->host->i_sem);
+ return do_fsync(fd, 0);
+}
-out_putf:
- fput(file);
-out:
- return ret;
+asmlinkage long sys_fdatasync(unsigned int fd)
+{
+ return do_fsync(fd, 1);
}
/*
* private_lock is contended then so is mapping->tree_lock).
*/
static struct buffer_head *
-__find_get_block_slow(struct block_device *bdev, sector_t block, int unused)
+__find_get_block_slow(struct block_device *bdev, sector_t block)
{
struct inode *bd_inode = bdev->bd_inode;
struct address_space *bd_mapping = bd_inode->i_mapping;
struct buffer_head *bh;
struct buffer_head *head;
struct page *page;
+ int all_mapped = 1;
index = block >> (PAGE_CACHE_SHIFT - bd_inode->i_blkbits);
page = find_get_page(bd_mapping, index);
get_bh(bh);
goto out_unlock;
}
+ if (!buffer_mapped(bh))
+ all_mapped = 0;
bh = bh->b_this_page;
} while (bh != head);
- printk("__find_get_block_slow() failed. "
- "block=%llu, b_blocknr=%llu\n",
- (unsigned long long)block, (unsigned long long)bh->b_blocknr);
- printk("b_state=0x%08lx, b_size=%u\n", bh->b_state, bh->b_size);
- printk("device blocksize: %d\n", 1 << bd_inode->i_blkbits);
+ /* we might be here because some of the buffers on this page are
+ * not mapped. This is due to various races between
+ * file io on the block device and getblk. It gets dealt with
+ * elsewhere, don't buffer_error if we had some unmapped buffers
+ */
+ if (all_mapped) {
+ printk("__find_get_block_slow() failed. "
+ "block=%llu, b_blocknr=%llu\n",
+ (unsigned long long)block, (unsigned long long)bh->b_blocknr);
+ printk("b_state=0x%08lx, b_size=%u\n", bh->b_state, bh->b_size);
+ printk("device blocksize: %d\n", 1 << bd_inode->i_blkbits);
+ }
out_unlock:
spin_unlock(&bd_mapping->private_lock);
page_cache_release(page);
struct zone **zones;
pg_data_t *pgdat;
- wakeup_bdflush(1024);
+ wakeup_pdflush(1024);
yield();
for_each_pgdat(pgdat) {
- zones = pgdat->node_zonelists[GFP_NOFS&GFP_ZONEMASK].zones;
+ zones = pgdat->node_zonelists[gfp_zone(GFP_NOFS)].zones;
if (*zones)
- try_to_free_pages(zones, GFP_NOFS, 0);
+ try_to_free_pages(zones, GFP_NOFS);
}
}
*/
static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
{
- static spinlock_t page_uptodate_lock = SPIN_LOCK_UNLOCKED;
unsigned long flags;
+ struct buffer_head *first;
struct buffer_head *tmp;
struct page *page;
int page_uptodate = 1;
set_buffer_uptodate(bh);
} else {
clear_buffer_uptodate(bh);
- buffer_io_error(bh);
+ if (printk_ratelimit())
+ buffer_io_error(bh);
SetPageError(page);
}
* two buffer heads end IO at almost the same time and both
* decide that the page is now completely done.
*/
- spin_lock_irqsave(&page_uptodate_lock, flags);
+ first = page_buffers(page);
+ local_irq_save(flags);
+ bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
clear_buffer_async_read(bh);
unlock_buffer(bh);
tmp = bh;
}
tmp = tmp->b_this_page;
} while (tmp != bh);
- spin_unlock_irqrestore(&page_uptodate_lock, flags);
+ bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
+ local_irq_restore(flags);
/*
* If none of the buffers had errors and they are all
return;
still_busy:
- spin_unlock_irqrestore(&page_uptodate_lock, flags);
+ bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
+ local_irq_restore(flags);
return;
}
void end_buffer_async_write(struct buffer_head *bh, int uptodate)
{
char b[BDEVNAME_SIZE];
- static spinlock_t page_uptodate_lock = SPIN_LOCK_UNLOCKED;
unsigned long flags;
+ struct buffer_head *first;
struct buffer_head *tmp;
struct page *page;
SetPageError(page);
}
- spin_lock_irqsave(&page_uptodate_lock, flags);
+ first = page_buffers(page);
+ local_irq_save(flags);
+ bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
+
clear_buffer_async_write(bh);
unlock_buffer(bh);
tmp = bh->b_this_page;
}
tmp = tmp->b_this_page;
}
- spin_unlock_irqrestore(&page_uptodate_lock, flags);
+ bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
+ local_irq_restore(flags);
end_page_writeback(page);
return;
still_busy:
- spin_unlock_irqrestore(&page_uptodate_lock, flags);
+ bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
+ local_irq_restore(flags);
return;
}
* 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
*/
/**
* sync_mapping_buffers - write out and wait upon a mapping's "associated"
* buffers
- * @buffer_mapping - the mapping which backs the buffers' data
- * @mapping - the mapping which wants those buffers written
+ * @mapping: the mapping which wants those buffers written
*
* Starts I/O against the buffers at mapping->private_list, and waits upon
* that I/O.
*
- * Basically, this is a convenience function for fsync(). @buffer_mapping is
- * the blockdev which "owns" the buffers and @mapping is a file or directory
- * which needs those buffers to be written for a successful fsync().
+ * Basically, this is a convenience function for fsync().
+ * @mapping is a file or directory which needs those buffers to be written for
+ * a successful fsync().
*/
int sync_mapping_buffers(struct address_space *mapping)
{
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);
spin_unlock(&mapping->private_lock);
if (!TestSetPageDirty(page)) {
- spin_lock_irq(&mapping->tree_lock);
+ write_lock_irq(&mapping->tree_lock);
if (page->mapping) { /* Race with truncate? */
- if (!mapping->backing_dev_info->memory_backed)
+ if (mapping_cap_account_dirty(mapping))
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);
+ write_unlock_irq(&mapping->tree_lock);
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
* 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;
* contents - it is a noop if I/O is still in
* flight on potentially older contents.
*/
- wait_on_buffer(bh);
- ll_rw_block(WRITE, 1, &bh);
+ ll_rw_block(SWRITE, 1, &bh);
brelse(bh);
spin_lock(lock);
}
* The retry flag is used to differentiate async IO (paging, swapping)
* which may not fail from ordinary buffer allocations.
*/
-static struct buffer_head *
-create_buffers(struct page * page, unsigned long size, int retry)
+struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
+ int retry)
{
struct buffer_head *bh, *head;
long offset;
bh->b_state = 0;
atomic_set(&bh->b_count, 0);
+ bh->b_private = NULL;
bh->b_size = size;
/* Link the buffer to its page */
set_bh_page(bh, page, offset);
- bh->b_end_io = NULL;
+ init_buffer(bh, NULL, NULL);
}
return head;
/*
free_more_memory();
goto try_again;
}
+EXPORT_SYMBOL_GPL(alloc_page_buffers);
static inline void
link_dev_buffers(struct page *page, struct buffer_head *head)
bh = bh->b_this_page;
} while (bh);
tail->b_this_page = head;
- __set_page_buffers(page, head);
+ attach_page_buffers(page, head);
}
/*
{
struct buffer_head *head = page_buffers(page);
struct buffer_head *bh = head;
- unsigned int b_state;
-
- b_state = 1 << BH_Mapped;
- if (PageUptodate(page))
- b_state |= 1 << BH_Uptodate;
+ int uptodate = PageUptodate(page);
do {
- if (!(bh->b_state & (1 << BH_Mapped))) {
+ if (!buffer_mapped(bh)) {
init_buffer(bh, NULL, NULL);
bh->b_bdev = bdev;
bh->b_blocknr = block;
- bh->b_state = b_state;
+ if (uptodate)
+ set_buffer_uptodate(bh);
+ set_buffer_mapped(bh);
}
block++;
bh = bh->b_this_page;
if (page_has_buffers(page)) {
bh = page_buffers(page);
- if (bh->b_size == size)
+ if (bh->b_size == size) {
+ init_page_buffers(page, bdev, block, size);
return page;
+ }
if (!try_to_free_buffers(page))
goto failed;
}
/*
* Allocate some buffers for this page
*/
- bh = create_buffers(page, size, 0);
+ bh = alloc_page_buffers(page, size, 0);
if (!bh)
goto failed;
* some of those buffers may be aliases of filesystem data.
* grow_dev_page() will go BUG() if this happens.
*/
-static inline int
+static int
grow_buffers(struct block_device *bdev, sector_t block, int size)
{
struct page *page;
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++;
} while ((size << sizebits) < PAGE_SIZE);
index = block >> sizebits;
- block = index << sizebits;
+ /*
+ * Check for a block which wants to lie outside our maximum possible
+ * pagecache index. (this comparison is done using sector_t types).
+ */
+ if (unlikely(index != block >> sizebits)) {
+ char b[BDEVNAME_SIZE];
+
+ printk(KERN_ERR "%s: requested out-of-range block %llu for "
+ "device %s\n",
+ __FUNCTION__, (unsigned long long)block,
+ bdevname(bdev, b));
+ return -EIO;
+ }
+ block = index << sizebits;
/* Create a page with the proper size buffers.. */
page = grow_dev_page(bdev, block, index, size);
if (!page)
return 1;
}
-struct buffer_head *
+static 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;
+ int ret;
bh = __find_get_block(bdev, block, size);
if (bh)
return bh;
- if (!grow_buffers(bdev, block, size))
+ ret = grow_buffers(bdev, block, size);
+ if (ret < 0)
+ return NULL;
+ if (ret == 0)
free_more_memory();
}
}
/**
* mark_buffer_dirty - mark a buffer_head as needing writeout
+ * @bh: the buffer_head to mark dirty
*
* mark_buffer_dirty() will set the dirty bit against the buffer, then set its
* backing page dirty, then tag the page as dirty in its address_space's radix
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()
/*
* Look up the bh in this cpu's LRU. If it's there, move it to the head.
*/
-static inline struct buffer_head *
+static struct buffer_head *
lookup_bh_lru(struct block_device *bdev, sector_t block, int size)
{
struct buffer_head *ret = NULL;
struct buffer_head *bh = lookup_bh_lru(bdev, block, size);
if (bh == NULL) {
- bh = __find_get_block_slow(bdev, block, size);
+ bh = __find_get_block_slow(bdev, block);
if (bh)
bh_lru_install(bh);
}
{
struct buffer_head *bh = __find_get_block(bdev, block, size);
+ might_sleep();
if (bh == NULL)
bh = __getblk_slow(bdev, block, size);
return bh;
void __breadahead(struct block_device *bdev, sector_t block, int size)
{
struct buffer_head *bh = __getblk(bdev, block, size);
- ll_rw_block(READA, 1, &bh);
- brelse(bh);
+ if (likely(bh)) {
+ ll_rw_block(READA, 1, &bh);
+ brelse(bh);
+ }
}
EXPORT_SYMBOL(__breadahead);
/**
* __bread() - reads a specified block and returns the bh
+ * @bdev: the block_device to read from
* @block: number of block
* @size: size (in bytes) to read
*
{
struct buffer_head *bh = __getblk(bdev, block, size);
- if (!buffer_uptodate(bh))
+ if (likely(bh) && !buffer_uptodate(bh))
bh = __bread_slow(bh);
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)
{
/*
* Called when truncating a buffer on a page completely.
*/
-static inline void discard_buffer(struct buffer_head * bh)
+static void discard_buffer(struct buffer_head * bh)
{
lock_buffer(bh);
clear_buffer_dirty(bh);
*
* NOTE: @gfp_mask may go away, and this function may become non-blocking.
*/
-int try_to_release_page(struct page *page, int gfp_mask)
+int try_to_release_page(struct page *page, gfp_t gfp_mask)
{
struct address_space * const mapping = page->mapping;
}
EXPORT_SYMBOL(block_invalidatepage);
+int do_invalidatepage(struct page *page, unsigned long offset)
+{
+ int (*invalidatepage)(struct page *, unsigned long);
+ invalidatepage = page->mapping->a_ops->invalidatepage;
+ if (invalidatepage == NULL)
+ invalidatepage = block_invalidatepage;
+ return (*invalidatepage)(page, offset);
+}
+
/*
* We attach and possibly dirty the buffers atomically wrt
* __set_page_dirty_buffers() via private_lock. try_to_free_buffers
{
struct buffer_head *bh, *head, *tail;
- head = create_buffers(page, blocksize, 1);
+ head = alloc_page_buffers(page, blocksize, 1);
bh = head;
do {
bh->b_state |= b_state;
bh = bh->b_this_page;
} while (bh != head);
}
- __set_page_buffers(page, head);
+ attach_page_buffers(page, head);
spin_unlock(&page->mapping->private_lock);
}
EXPORT_SYMBOL(create_empty_buffers);
{
struct buffer_head *old_bh;
- old_bh = __find_get_block_slow(bdev, block, 0);
+ might_sleep();
+
+ old_bh = __find_get_block_slow(bdev, block);
if (old_bh) {
clear_buffer_dirty(old_bh);
wait_on_buffer(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)
* handle that here by just cleaning them.
*/
- block = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
head = page_buffers(page);
bh = head;
} while (bh != head);
do {
- get_bh(bh);
if (!buffer_mapped(bh))
continue;
/*
}
} while ((bh = bh->b_this_page) != head);
- BUG_ON(PageWriteback(page));
- set_page_writeback(page); /* Keeps try_to_free_buffers() away */
- unlock_page(page);
-
/*
- * The page may come unlocked any time after the *first* submit_bh()
- * call. Be careful with its buffers.
+ * 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);
+
do {
struct buffer_head *next = bh->b_this_page;
if (buffer_async_write(bh)) {
submit_bh(WRITE, bh);
nr_underway++;
}
- put_bh(bh);
bh = next;
} while (bh != head);
+ unlock_page(page);
err = 0;
done:
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 = head;
/* Recovery: lock and submit the mapped buffers */
do {
- get_bh(bh);
if (buffer_mapped(bh) && buffer_dirty(bh)) {
lock_buffer(bh);
mark_buffer_async_write(bh);
submit_bh(WRITE, bh);
nr_underway++;
}
- put_bh(bh);
bh = next;
} while (bh != head);
goto done;
if (!buffer_mapped(bh)) {
err = get_block(inode, block, bh, 1);
if (err)
- goto out;
+ break;
if (buffer_new(bh)) {
- clear_buffer_new(bh);
unmap_underlying_metadata(bh->b_bdev,
bh->b_blocknr);
if (PageUptodate(page)) {
while(wait_bh > wait) {
wait_on_buffer(*--wait_bh);
if (!buffer_uptodate(*wait_bh))
- return -EIO;
+ err = -EIO;
}
- return 0;
-out:
+ if (!err) {
+ bh = head;
+ do {
+ if (buffer_new(bh))
+ clear_buffer_new(bh);
+ } while ((bh = bh->b_this_page) != head);
+ return 0;
+ }
+ /* Error case: */
/*
* Zero out any newly allocated blocks to avoid exposing stale
* data. If BH_New is set, we know that the block was newly
int nr, i;
int fully_mapped = 1;
- if (!PageLocked(page))
- PAGE_BUG(page);
+ BUG_ON(!PageLocked(page));
blocksize = 1 << inode->i_blkbits;
if (!page_has_buffers(page))
create_empty_buffers(page, blocksize, 0);
continue;
if (!buffer_mapped(bh)) {
+ int err = 0;
+
fully_mapped = 0;
if (iblock < lblock) {
- if (get_block(inode, iblock, bh, 0))
+ err = get_block(inode, iblock, bh, 0);
+ if (err)
SetPageError(page);
}
if (!buffer_mapped(bh)) {
memset(kaddr + i * blocksize, 0, blocksize);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
- set_buffer_uptodate(bh);
+ if (!err)
+ set_buffer_uptodate(bh);
continue;
}
/*
* truncates. Uses prepare/commit_write to allow the filesystem to
* deal with the hole.
*/
-int generic_cont_expand(struct inode *inode, loff_t size)
+static int __generic_cont_expand(struct inode *inode, loff_t size,
+ pgoff_t index, unsigned int offset)
{
struct address_space *mapping = inode->i_mapping;
struct page *page;
- unsigned long index, offset, limit;
+ unsigned long limit;
int err;
err = -EFBIG;
- limit = current->rlim[RLIMIT_FSIZE].rlim_cur;
+ limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
if (limit != RLIM_INFINITY && size > (loff_t)limit) {
send_sig(SIGXFSZ, current, 0);
goto out;
if (size > inode->i_sb->s_maxbytes)
goto out;
- offset = (size & (PAGE_CACHE_SIZE-1)); /* Within page */
-
- /* ugh. in prepare/commit_write, if from==to==start of block, we
- ** skip the prepare. make sure we never send an offset for the start
- ** of a block
- */
- if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) {
- offset++;
- }
- index = size >> PAGE_CACHE_SHIFT;
err = -ENOMEM;
page = grab_cache_page(mapping, index);
if (!page)
goto out;
err = mapping->a_ops->prepare_write(NULL, page, offset, offset);
- if (!err) {
- err = mapping->a_ops->commit_write(NULL, page, offset, offset);
+ if (err) {
+ /*
+ * ->prepare_write() may have instantiated a few blocks
+ * outside i_size. Trim these off again.
+ */
+ unlock_page(page);
+ page_cache_release(page);
+ vmtruncate(inode, inode->i_size);
+ goto out;
}
+
+ err = mapping->a_ops->commit_write(NULL, page, offset, offset);
+
unlock_page(page);
page_cache_release(page);
if (err > 0)
return err;
}
+int generic_cont_expand(struct inode *inode, loff_t size)
+{
+ pgoff_t index;
+ unsigned int offset;
+
+ offset = (size & (PAGE_CACHE_SIZE - 1)); /* Within page */
+
+ /* ugh. in prepare/commit_write, if from==to==start of block, we
+ ** skip the prepare. make sure we never send an offset for the start
+ ** of a block
+ */
+ if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) {
+ /* caller must handle this extra byte. */
+ offset++;
+ }
+ index = size >> PAGE_CACHE_SHIFT;
+
+ return __generic_cont_expand(inode, size, index, offset);
+}
+
+int generic_cont_expand_simple(struct inode *inode, loff_t size)
+{
+ loff_t pos = size - 1;
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ unsigned int offset = (pos & (PAGE_CACHE_SIZE - 1)) + 1;
+
+ /* prepare/commit_write can handle even if from==to==start of block. */
+ return __generic_cont_expand(inode, size, index, offset);
+}
+
/*
* For moronic filesystems that do not allow holes in file.
* We may have to extend the file.
memset(kaddr+zerofrom, 0, PAGE_CACHE_SIZE-zerofrom);
flush_dcache_page(new_page);
kunmap_atomic(kaddr, KM_USER0);
- __block_commit_write(inode, new_page,
- zerofrom, PAGE_CACHE_SIZE);
+ generic_commit_write(NULL, new_page, zerofrom, PAGE_CACHE_SIZE);
unlock_page(new_page);
page_cache_release(new_page);
}
__block_commit_write(inode,page,from,to);
/*
* No need to use i_size_read() here, the i_size
- * cannot change under us because we hold i_sem.
+ * cannot change under us because we hold i_mutex.
*/
if (pos > inode->i_size) {
i_size_write(inode, pos);
}
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;
}
EXPORT_SYMBOL(nobh_commit_write);
+/*
+ * nobh_writepage() - based on block_full_write_page() except
+ * that it tries to operate without attaching bufferheads to
+ * the page.
+ */
+int nobh_writepage(struct page *page, get_block_t *get_block,
+ struct writeback_control *wbc)
+{
+ struct inode * const inode = page->mapping->host;
+ loff_t i_size = i_size_read(inode);
+ const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+ unsigned offset;
+ void *kaddr;
+ int ret;
+
+ /* Is the page fully inside i_size? */
+ if (page->index < end_index)
+ goto out;
+
+ /* Is the page fully outside i_size? (truncate in progress) */
+ offset = i_size & (PAGE_CACHE_SIZE-1);
+ if (page->index >= end_index+1 || !offset) {
+ /*
+ * The page may have dirty, unmapped buffers. For example,
+ * they may have been added in ext3_writepage(). Make them
+ * freeable here, so the page does not leak.
+ */
+#if 0
+ /* Not really sure about this - do we need this ? */
+ if (page->mapping->a_ops->invalidatepage)
+ page->mapping->a_ops->invalidatepage(page, offset);
+#endif
+ unlock_page(page);
+ return 0; /* don't care */
+ }
+
+ /*
+ * 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
+ * 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."
+ */
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+out:
+ ret = mpage_writepage(page, get_block, wbc);
+ if (ret == -EAGAIN)
+ ret = __block_write_full_page(inode, page, get_block, wbc);
+ return ret;
+}
+EXPORT_SYMBOL(nobh_writepage);
+
/*
* This function assumes that ->prepare_write() uses nobh_prepare_write().
*/
pgoff_t index = from >> PAGE_CACHE_SHIFT;
unsigned offset = from & (PAGE_CACHE_SIZE-1);
unsigned blocksize;
- pgoff_t iblock;
+ sector_t iblock;
unsigned length, pos;
struct inode *inode = mapping->host;
struct page *page;
return 0;
length = blocksize - length;
- iblock = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ iblock = (sector_t)index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
page = grab_cache_page(mapping, index);
err = -ENOMEM;
* they may have been added in ext3_writepage(). Make them
* freeable here, so the page does not leak.
*/
- block_invalidatepage(page, 0);
+ do_invalidatepage(page, 0);
unlock_page(page);
return 0; /* don't care */
}
/*
* 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;
}
/**
* ll_rw_block: low-level access to block devices (DEPRECATED)
- * @rw: whether to %READ or %WRITE or maybe %READA (readahead)
+ * @rw: whether to %READ or %WRITE or %SWRITE or maybe %READA (readahead)
* @nr: number of &struct buffer_heads in the array
* @bhs: array of pointers to &struct buffer_head
*
- * ll_rw_block() takes an array of pointers to &struct buffer_heads,
- * and requests an I/O operation on them, either a %READ or a %WRITE.
- * The third %READA option is described in the documentation for
- * generic_make_request() which ll_rw_block() calls.
+ * ll_rw_block() takes an array of pointers to &struct buffer_heads, and
+ * requests an I/O operation on them, either a %READ or a %WRITE. The third
+ * %SWRITE is like %WRITE only we make sure that the *current* data in buffers
+ * are sent to disk. The fourth %READA option is described in the documentation
+ * for generic_make_request() which ll_rw_block() calls.
*
* This function drops any buffer that it cannot get a lock on (with the
- * BH_Lock state bit), any buffer that appears to be clean when doing a
- * write request, and any buffer that appears to be up-to-date when doing
- * read request. Further it marks as clean buffers that are processed for
- * writing (the buffer cache won't assume that they are actually clean until
- * the buffer gets unlocked).
+ * BH_Lock state bit) unless SWRITE is required, any buffer that appears to be
+ * clean when doing a write request, and any buffer that appears to be
+ * up-to-date when doing read request. Further it marks as clean buffers that
+ * are processed for writing (the buffer cache won't assume that they are
+ * actually clean until the buffer gets unlocked).
*
* ll_rw_block sets b_end_io to simple completion handler that marks
* the buffer up-to-date (if approriate), unlocks the buffer and wakes
for (i = 0; i < nr; i++) {
struct buffer_head *bh = bhs[i];
- if (test_set_buffer_locked(bh))
+ if (rw == SWRITE)
+ lock_buffer(bh);
+ else if (test_set_buffer_locked(bh))
continue;
- get_bh(bh);
- if (rw == WRITE) {
- bh->b_end_io = end_buffer_write_sync;
+ if (rw == WRITE || rw == SWRITE) {
if (test_clear_buffer_dirty(bh)) {
+ bh->b_end_io = end_buffer_write_sync;
+ get_bh(bh);
submit_bh(WRITE, bh);
continue;
}
} else {
- bh->b_end_io = end_buffer_read_sync;
if (!buffer_uptodate(bh)) {
+ bh->b_end_io = end_buffer_read_sync;
+ get_bh(bh);
submit_bh(rw, bh);
continue;
}
}
unlock_buffer(bh);
- put_bh(bh);
}
}
/*
* 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 {
- if (buffer_write_io_error(bh))
+ if (buffer_write_io_error(bh) && page->mapping)
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;
}
return 0;
}
+/*
+ * Migration function for pages with buffers. This function can only be used
+ * if the underlying filesystem guarantees that no other references to "page"
+ * exist.
+ */
+#ifdef CONFIG_MIGRATION
+int buffer_migrate_page(struct page *newpage, struct page *page)
+{
+ struct address_space *mapping = page->mapping;
+ struct buffer_head *bh, *head;
+ int rc;
+
+ if (!mapping)
+ return -EAGAIN;
+
+ if (!page_has_buffers(page))
+ return migrate_page(newpage, page);
+
+ head = page_buffers(page);
+
+ rc = migrate_page_remove_references(newpage, page, 3);
+ if (rc)
+ return rc;
+
+ bh = head;
+ do {
+ get_bh(bh);
+ lock_buffer(bh);
+ bh = bh->b_this_page;
+
+ } while (bh != head);
+
+ ClearPagePrivate(page);
+ set_page_private(newpage, page_private(page));
+ set_page_private(page, 0);
+ put_page(page);
+ get_page(newpage);
+
+ bh = head;
+ do {
+ set_bh_page(bh, newpage, bh_offset(bh));
+ bh = bh->b_this_page;
+
+ } while (bh != head);
+
+ SetPagePrivate(newpage);
+
+ migrate_page_copy(newpage, page);
+
+ bh = head;
+ do {
+ unlock_buffer(bh);
+ put_bh(bh);
+ bh = bh->b_this_page;
+
+ } while (bh != head);
+
+ return 0;
+}
+EXPORT_SYMBOL(buffer_migrate_page);
+#endif
+
/*
* Buffer-head allocation
*/
buffer_heads_over_limit = (tot > max_buffer_heads);
}
-struct buffer_head *alloc_buffer_head(int gfp_flags)
+struct buffer_head *alloc_buffer_head(gfp_t gfp_flags)
{
struct buffer_head *ret = kmem_cache_alloc(bh_cachep, gfp_flags);
if (ret) {
- preempt_disable();
- __get_cpu_var(bh_accounting).nr++;
+ get_cpu_var(bh_accounting).nr++;
recalc_bh_state();
- preempt_enable();
+ put_cpu_var(bh_accounting);
}
return ret;
}
{
BUG_ON(!list_empty(&bh->b_assoc_buffers));
kmem_cache_free(bh_cachep, bh);
- preempt_disable();
- __get_cpu_var(bh_accounting).nr--;
+ get_cpu_var(bh_accounting).nr--;
recalc_bh_state();
- preempt_enable();
+ put_cpu_var(bh_accounting);
}
EXPORT_SYMBOL(free_buffer_head);
void __init buffer_init(void)
{
- int i;
int nrpages;
bh_cachep = kmem_cache_create("buffer_head",
sizeof(struct buffer_head), 0,
- 0, init_buffer_head, NULL);
- for (i = 0; i < ARRAY_SIZE(bh_wait_queue_heads); i++)
- init_waitqueue_head(&bh_wait_queue_heads[i].wqh);
+ SLAB_RECLAIM_ACCOUNT|SLAB_PANIC, init_buffer_head, NULL);
/*
* Limit the bh occupancy to 10% of ZONE_NORMAL
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);
+EXPORT_SYMBOL(generic_cont_expand_simple);
EXPORT_SYMBOL(init_buffer);
EXPORT_SYMBOL(invalidate_bdev);
EXPORT_SYMBOL(ll_rw_block);