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-rw-r--r--fs/buffer.c180
1 files changed, 36 insertions, 144 deletions
diff --git a/fs/buffer.c b/fs/buffer.c
index d54812b198e9..50efa339e051 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1833,9 +1833,10 @@ void page_zero_new_buffers(struct page *page, unsigned from, unsigned to)
}
EXPORT_SYMBOL(page_zero_new_buffers);
-static int __block_prepare_write(struct inode *inode, struct page *page,
- unsigned from, unsigned to, get_block_t *get_block)
+int block_prepare_write(struct page *page, unsigned from, unsigned to,
+ get_block_t *get_block)
{
+ struct inode *inode = page->mapping->host;
unsigned block_start, block_end;
sector_t block;
int err = 0;
@@ -1908,10 +1909,13 @@ static int __block_prepare_write(struct inode *inode, struct page *page,
if (!buffer_uptodate(*wait_bh))
err = -EIO;
}
- if (unlikely(err))
+ if (unlikely(err)) {
page_zero_new_buffers(page, from, to);
+ ClearPageUptodate(page);
+ }
return err;
}
+EXPORT_SYMBOL(block_prepare_write);
static int __block_commit_write(struct inode *inode, struct page *page,
unsigned from, unsigned to)
@@ -1948,90 +1952,41 @@ static int __block_commit_write(struct inode *inode, struct page *page,
return 0;
}
-/*
- * Filesystems implementing the new truncate sequence should use the
- * _newtrunc postfix variant which won't incorrectly call vmtruncate.
- * The filesystem needs to handle block truncation upon failure.
- */
-int block_write_begin_newtrunc(struct file *file, struct address_space *mapping,
- loff_t pos, unsigned len, unsigned flags,
- struct page **pagep, void **fsdata,
- get_block_t *get_block)
+int __block_write_begin(struct page *page, loff_t pos, unsigned len,
+ get_block_t *get_block)
{
- struct inode *inode = mapping->host;
- int status = 0;
- struct page *page;
- pgoff_t index;
- unsigned start, end;
- int ownpage = 0;
-
- index = pos >> PAGE_CACHE_SHIFT;
- start = pos & (PAGE_CACHE_SIZE - 1);
- end = start + len;
-
- page = *pagep;
- if (page == NULL) {
- ownpage = 1;
- page = grab_cache_page_write_begin(mapping, index, flags);
- if (!page) {
- status = -ENOMEM;
- goto out;
- }
- *pagep = page;
- } else
- BUG_ON(!PageLocked(page));
-
- status = __block_prepare_write(inode, page, start, end, get_block);
- if (unlikely(status)) {
- ClearPageUptodate(page);
+ unsigned start = pos & (PAGE_CACHE_SIZE - 1);
- if (ownpage) {
- unlock_page(page);
- page_cache_release(page);
- *pagep = NULL;
- }
- }
-
-out:
- return status;
+ return block_prepare_write(page, start, start + len, get_block);
}
-EXPORT_SYMBOL(block_write_begin_newtrunc);
+EXPORT_SYMBOL(__block_write_begin);
/*
* block_write_begin takes care of the basic task of block allocation and
* bringing partial write blocks uptodate first.
*
- * If *pagep is not NULL, then block_write_begin uses the locked page
- * at *pagep rather than allocating its own. In this case, the page will
- * not be unlocked or deallocated on failure.
+ * The filesystem needs to handle block truncation upon failure.
*/
-int block_write_begin(struct file *file, struct address_space *mapping,
- loff_t pos, unsigned len, unsigned flags,
- struct page **pagep, void **fsdata,
- get_block_t *get_block)
+int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
+ unsigned flags, struct page **pagep, get_block_t *get_block)
{
- int ret;
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ struct page *page;
+ int status;
- ret = block_write_begin_newtrunc(file, mapping, pos, len, flags,
- pagep, fsdata, get_block);
+ page = grab_cache_page_write_begin(mapping, index, flags);
+ if (!page)
+ return -ENOMEM;
- /*
- * prepare_write() may have instantiated a few blocks
- * outside i_size. Trim these off again. Don't need
- * i_size_read because we hold i_mutex.
- *
- * Filesystems which pass down their own page also cannot
- * call into vmtruncate here because it would lead to lock
- * inversion problems (*pagep is locked). This is a further
- * example of where the old truncate sequence is inadequate.
- */
- if (unlikely(ret) && *pagep == NULL) {
- loff_t isize = mapping->host->i_size;
- if (pos + len > isize)
- vmtruncate(mapping->host, isize);
+ status = __block_write_begin(page, pos, len, get_block);
+ if (unlikely(status)) {
+ unlock_page(page);
+ page_cache_release(page);
+ page = NULL;
}
- return ret;
+ *pagep = page;
+ return status;
}
EXPORT_SYMBOL(block_write_begin);
@@ -2351,7 +2306,7 @@ out:
* For moronic filesystems that do not allow holes in file.
* We may have to extend the file.
*/
-int cont_write_begin_newtrunc(struct file *file, struct address_space *mapping,
+int cont_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata,
get_block_t *get_block, loff_t *bytes)
@@ -2363,7 +2318,7 @@ int cont_write_begin_newtrunc(struct file *file, struct address_space *mapping,
err = cont_expand_zero(file, mapping, pos, bytes);
if (err)
- goto out;
+ return err;
zerofrom = *bytes & ~PAGE_CACHE_MASK;
if (pos+len > *bytes && zerofrom & (blocksize-1)) {
@@ -2371,44 +2326,10 @@ int cont_write_begin_newtrunc(struct file *file, struct address_space *mapping,
(*bytes)++;
}
- *pagep = NULL;
- err = block_write_begin_newtrunc(file, mapping, pos, len,
- flags, pagep, fsdata, get_block);
-out:
- return err;
-}
-EXPORT_SYMBOL(cont_write_begin_newtrunc);
-
-int cont_write_begin(struct file *file, struct address_space *mapping,
- loff_t pos, unsigned len, unsigned flags,
- struct page **pagep, void **fsdata,
- get_block_t *get_block, loff_t *bytes)
-{
- int ret;
-
- ret = cont_write_begin_newtrunc(file, mapping, pos, len, flags,
- pagep, fsdata, get_block, bytes);
- if (unlikely(ret)) {
- loff_t isize = mapping->host->i_size;
- if (pos + len > isize)
- vmtruncate(mapping->host, isize);
- }
-
- return ret;
+ return block_write_begin(mapping, pos, len, flags, pagep, get_block);
}
EXPORT_SYMBOL(cont_write_begin);
-int block_prepare_write(struct page *page, unsigned from, unsigned to,
- get_block_t *get_block)
-{
- struct inode *inode = page->mapping->host;
- int err = __block_prepare_write(inode, page, from, to, get_block);
- if (err)
- ClearPageUptodate(page);
- return err;
-}
-EXPORT_SYMBOL(block_prepare_write);
-
int block_commit_write(struct page *page, unsigned from, unsigned to)
{
struct inode *inode = page->mapping->host;
@@ -2510,11 +2431,11 @@ static void attach_nobh_buffers(struct page *page, struct buffer_head *head)
}
/*
- * Filesystems implementing the new truncate sequence should use the
- * _newtrunc postfix variant which won't incorrectly call vmtruncate.
+ * On entry, the page is fully not uptodate.
+ * On exit the page is fully uptodate in the areas outside (from,to)
* The filesystem needs to handle block truncation upon failure.
*/
-int nobh_write_begin_newtrunc(struct file *file, struct address_space *mapping,
+int nobh_write_begin(struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata,
get_block_t *get_block)
@@ -2547,8 +2468,8 @@ int nobh_write_begin_newtrunc(struct file *file, struct address_space *mapping,
unlock_page(page);
page_cache_release(page);
*pagep = NULL;
- return block_write_begin_newtrunc(file, mapping, pos, len,
- flags, pagep, fsdata, get_block);
+ return block_write_begin(mapping, pos, len, flags, pagep,
+ get_block);
}
if (PageMappedToDisk(page))
@@ -2654,35 +2575,6 @@ out_release:
return ret;
}
-EXPORT_SYMBOL(nobh_write_begin_newtrunc);
-
-/*
- * On entry, the page is fully not uptodate.
- * On exit the page is fully uptodate in the areas outside (from,to)
- */
-int nobh_write_begin(struct file *file, struct address_space *mapping,
- loff_t pos, unsigned len, unsigned flags,
- struct page **pagep, void **fsdata,
- get_block_t *get_block)
-{
- int ret;
-
- ret = nobh_write_begin_newtrunc(file, mapping, pos, len, flags,
- pagep, fsdata, get_block);
-
- /*
- * prepare_write() may have instantiated a few blocks
- * outside i_size. Trim these off again. Don't need
- * i_size_read because we hold i_mutex.
- */
- if (unlikely(ret)) {
- loff_t isize = mapping->host->i_size;
- if (pos + len > isize)
- vmtruncate(mapping->host, isize);
- }
-
- return ret;
-}
EXPORT_SYMBOL(nobh_write_begin);
int nobh_write_end(struct file *file, struct address_space *mapping,