Cc: linux-ext4@xxxxxxxxxxxxxxx
Cc: Linux Filesystems <linux-fsdevel@xxxxxxxxxxxxxxx>
Convert ext4 to use write_begin()/write_end() methods.
Signed-off-by: Badari Pulavarty <pbadari@xxxxxxxxxx>
fs/ext4/inode.c | 147 +++++++++++++++++++++++++++++++++++---------------------
1 file changed, 93 insertions(+), 54 deletions(-)
Index: linux-2.6/fs/ext4/inode.c
===================================================================
--- linux-2.6.orig/fs/ext4/inode.c
+++ linux-2.6/fs/ext4/inode.c
@@ -1146,34 +1146,50 @@ static int do_journal_get_write_access(h
return ext4_journal_get_write_access(handle, bh);
}
-static int ext4_prepare_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
+static int ext4_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
{
- struct inode *inode = page->mapping->host;
+ struct inode *inode = mapping->host;
int ret, needed_blocks = ext4_writepage_trans_blocks(inode);
handle_t *handle;
int retries = 0;
+ struct page *page;
+ pgoff_t index;
+ unsigned from, to;
+
+ index = pos >> PAGE_CACHE_SHIFT;
+ from = pos & (PAGE_CACHE_SIZE - 1);
+ to = from + len;
retry:
- handle = ext4_journal_start(inode, needed_blocks);
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- goto out;
+ page = __grab_cache_page(mapping, index);
+ if (!page)
+ return -ENOMEM;
+ *pagep = page;
+
+ handle = ext4_journal_start(inode, needed_blocks);
+ if (IS_ERR(handle)) {
+ unlock_page(page);
+ page_cache_release(page);
+ ret = PTR_ERR(handle);
+ goto out;
}
- if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
- ret = nobh_prepare_write(page, from, to, ext4_get_block);
- else
- ret = block_prepare_write(page, from, to, ext4_get_block);
- if (ret)
- goto prepare_write_failed;
- if (ext4_should_journal_data(inode)) {
+ ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+ ext4_get_block);
+
+ if (!ret && ext4_should_journal_data(inode)) {
ret = walk_page_buffers(handle, page_buffers(page),
from, to, NULL, do_journal_get_write_access);
}
-prepare_write_failed:
- if (ret)
+
+ if (ret) {
ext4_journal_stop(handle);
+ unlock_page(page);
+ page_cache_release(page);
+ }
+
if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
goto retry;
out:
@@ -1185,12 +1201,12 @@ int ext4_journal_dirty_data(handle_t *ha
int err = jbd2_journal_dirty_data(handle, bh);
if (err)
ext4_journal_abort_handle(__FUNCTION__, __FUNCTION__,
- bh, handle,err);
+ bh, handle, err);
return err;
}
-/* For commit_write() in data=journal mode */
-static int commit_write_fn(handle_t *handle, struct buffer_head *bh)
+/* For write_end() in data=journal mode */
+static int write_end_fn(handle_t *handle, struct buffer_head *bh)
{
if (!buffer_mapped(bh) || buffer_freed(bh))
return 0;
@@ -1205,78 +1221,100 @@ static int commit_write_fn(handle_t *han
* ext4 never places buffers on inode->i_mapping->private_list. metadata
* buffers are managed internally.
*/
-static int ext4_ordered_commit_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
+static int ext4_ordered_write_end(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
{
handle_t *handle = ext4_journal_current_handle();
- struct inode *inode = page->mapping->host;
+ struct inode *inode = file->f_mapping->host;
+ unsigned from, to;
int ret = 0, ret2;
+ from = pos & (PAGE_CACHE_SIZE - 1);
+ to = from + len;
+
ret = walk_page_buffers(handle, page_buffers(page),
from, to, NULL, ext4_journal_dirty_data);
if (ret == 0) {
/*
- * generic_commit_write() will run mark_inode_dirty() if i_size
+ * generic_write_end() will run mark_inode_dirty() if i_size
* changes. So let's piggyback the i_disksize mark_inode_dirty
* into that.
*/
loff_t new_i_size;
- new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+ new_i_size = pos + copied;
if (new_i_size > EXT4_I(inode)->i_disksize)
EXT4_I(inode)->i_disksize = new_i_size;
- ret = generic_commit_write(file, page, from, to);
+ copied = generic_write_end(file, mapping, pos, len, copied,
+ page, fsdata);
+ if (copied < 0)
+ ret = copied;
+ } else {
+ unlock_page(page);
+ page_cache_release(page);
}
ret2 = ext4_journal_stop(handle);
if (!ret)
ret = ret2;
- return ret;
+ return ret ? ret : copied;
}
-static int ext4_writeback_commit_write(struct file *file, struct page *page,
- unsigned from, unsigned to)
+static int ext4_writeback_write_end(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
{
handle_t *handle = ext4_journal_current_handle();
- struct inode *inode = page->mapping->host;
+ struct inode *inode = file->f_mapping->host;
int ret = 0, ret2;
loff_t new_i_size;
- new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+ new_i_size = pos + copied;
if (new_i_size > EXT4_I(inode)->i_disksize)
EXT4_I(inode)->i_disksize = new_i_size;
- if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
- ret = nobh_commit_write(file, page, from, to);
- else
- ret = generic_commit_write(file, page, from, to);
+ copied = generic_write_end(file, mapping, pos, len, copied,
+ page, fsdata);
+ if (copied < 0)
+ ret = copied;
ret2 = ext4_journal_stop(handle);
if (!ret)
ret = ret2;
- return ret;
+ return ret ? ret : copied;
}
-static int ext4_journalled_commit_write(struct file *file,
- struct page *page, unsigned from, unsigned to)
+static int ext4_journalled_write_end(struct file *file,
+ struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
{
handle_t *handle = ext4_journal_current_handle();
- struct inode *inode = page->mapping->host;
+ struct inode *inode = mapping->host;
int ret = 0, ret2;
int partial = 0;
- loff_t pos;
+ unsigned from, to;
- /*
- * Here we duplicate the generic_commit_write() functionality
- */
- pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+ from = pos & (PAGE_CACHE_SIZE - 1);
+ to = from + len;
+
+ if (copied < len) {
+ if (!PageUptodate(page))
+ copied = 0;
+ page_zero_new_buffers(page, from+copied, to);
+ }
ret = walk_page_buffers(handle, page_buffers(page), from,
- to, &partial, commit_write_fn);
+ to, &partial, write_end_fn);
if (!partial)
SetPageUptodate(page);
- if (pos > inode->i_size)
- i_size_write(inode, pos);
+ unlock_page(page);
+ page_cache_release(page);
+ if (pos+copied > inode->i_size)
+ i_size_write(inode, pos+copied);
EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
if (inode->i_size > EXT4_I(inode)->i_disksize) {
EXT4_I(inode)->i_disksize = inode->i_size;
@@ -1284,10 +1322,11 @@ static int ext4_journalled_commit_write(
if (!ret)
ret = ret2;
}
+
ret2 = ext4_journal_stop(handle);
if (!ret)
ret = ret2;
- return ret;
+ return ret ? ret : copied;
}
/*
@@ -1545,7 +1584,7 @@ static int ext4_journalled_writepage(str
PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
err = walk_page_buffers(handle, page_buffers(page), 0,
- PAGE_CACHE_SIZE, NULL, commit_write_fn);
+ PAGE_CACHE_SIZE, NULL, write_end_fn);
if (ret == 0)
ret = err;
EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
@@ -1705,8 +1744,8 @@ static const struct address_space_operat
.readpages = ext4_readpages,
.writepage = ext4_ordered_writepage,
.sync_page = block_sync_page,
- .prepare_write = ext4_prepare_write,
- .commit_write = ext4_ordered_commit_write,
+ .write_begin = ext4_write_begin,
+ .write_end = ext4_ordered_write_end,
.bmap = ext4_bmap,
.invalidatepage = ext4_invalidatepage,
.releasepage = ext4_releasepage,
@@ -1719,8 +1758,8 @@ static const struct address_space_operat
.readpages = ext4_readpages,
.writepage = ext4_writeback_writepage,
.sync_page = block_sync_page,
- .prepare_write = ext4_prepare_write,
- .commit_write = ext4_writeback_commit_write,
+ .write_begin = ext4_write_begin,
+ .write_end = ext4_writeback_write_end,
.bmap = ext4_bmap,
.invalidatepage = ext4_invalidatepage,
.releasepage = ext4_releasepage,
@@ -1733,8 +1772,8 @@ static const struct address_space_operat
.readpages = ext4_readpages,
.writepage = ext4_journalled_writepage,
.sync_page = block_sync_page,
- .prepare_write = ext4_prepare_write,
- .commit_write = ext4_journalled_commit_write,
+ .write_begin = ext4_write_begin,
+ .write_end = ext4_journalled_write_end,
.set_page_dirty = ext4_journalled_set_page_dirty,
.bmap = ext4_bmap,
.invalidatepage = ext4_invalidatepage,
--
-
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