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-rw-r--r--fs/buffer.c91
1 files changed, 59 insertions, 32 deletions
diff --git a/fs/buffer.c b/fs/buffer.c
index 5287be18633b..3dc712f29d2d 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -26,6 +26,7 @@
#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>
@@ -153,14 +154,8 @@ int sync_blockdev(struct block_device *bdev)
{
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);
@@ -358,11 +353,11 @@ static long do_fsync(unsigned int fd, int datasync)
* We need to protect against concurrent writers,
* which could cause livelocks in fsync_buffers_list
*/
- down(&mapping->host->i_sem);
+ mutex_lock(&mapping->host->i_mutex);
err = file->f_op->fsync(file, file->f_dentry, datasync);
if (!ret)
ret = err;
- up(&mapping->host->i_sem);
+ mutex_unlock(&mapping->host->i_mutex);
err = filemap_fdatawait(mapping);
if (!ret)
ret = err;
@@ -1032,7 +1027,7 @@ try_again:
/* Link the buffer to its page */
set_bh_page(bh, page, offset);
- bh->b_end_io = NULL;
+ init_buffer(bh, NULL, NULL);
}
return head;
/*
@@ -1170,7 +1165,7 @@ 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;
@@ -1396,7 +1391,7 @@ static void bh_lru_install(struct buffer_head *bh)
/*
* 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;
@@ -1546,7 +1541,7 @@ EXPORT_SYMBOL(set_bh_page);
/*
* 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);
@@ -1768,7 +1763,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
* 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;
@@ -2160,11 +2155,12 @@ int block_read_full_page(struct page *page, get_block_t *get_block)
* 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;
@@ -2176,24 +2172,24 @@ int generic_cont_expand(struct inode *inode, loff_t size)
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)
@@ -2202,6 +2198,36 @@ out:
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.
@@ -2313,7 +2339,7 @@ int generic_commit_write(struct file *file, struct page *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);
@@ -2610,7 +2636,7 @@ int block_truncate_page(struct address_space *mapping,
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;
@@ -2626,7 +2652,7 @@ int block_truncate_page(struct address_space *mapping,
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;
@@ -3145,6 +3171,7 @@ EXPORT_SYMBOL(fsync_bdev);
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);