From 6e1db88d536adcbbfe562b2d4b7d6425784fff12 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 4 Jun 2010 11:29:57 +0200 Subject: [PATCH] introduce __block_write_begin Split up the block_write_begin implementation - __block_write_begin is a new trivial wrapper for block_prepare_write that always takes an already allocated page and can be either called from block_write_begin or filesystem code that already has a page allocated. Remove the handling of already allocated pages from block_write_begin after switching all callers that do it to __block_write_begin. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- fs/buffer.c | 69 ++++++++++++++----------------------- fs/ext2/dir.c | 3 +- fs/ext3/inode.c | 3 +- fs/ext4/inode.c | 11 +++--- fs/minix/inode.c | 3 +- fs/nilfs2/dir.c | 3 +- fs/reiserfs/inode.c | 3 +- fs/sysv/itree.c | 3 +- fs/ufs/inode.c | 3 +- include/linux/buffer_head.h | 2 ++ 10 files changed, 39 insertions(+), 64 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index 14529ec759b9..c319c49da511 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) @@ -1948,6 +1952,15 @@ static int __block_commit_write(struct inode *inode, struct page *page, return 0; } +int __block_write_begin(struct page *page, loff_t pos, unsigned len, + get_block_t *get_block) +{ + unsigned start = pos & (PAGE_CACHE_SIZE - 1); + + return block_prepare_write(page, start, start + len, get_block); +} +EXPORT_SYMBOL(__block_write_begin); + /* * Filesystems implementing the new truncate sequence should use the * _newtrunc postfix variant which won't incorrectly call vmtruncate. @@ -1958,41 +1971,22 @@ int block_write_begin_newtrunc(struct file *file, struct address_space *mapping, struct page **pagep, void **fsdata, get_block_t *get_block) { - struct inode *inode = mapping->host; - int status = 0; + pgoff_t index = pos >> PAGE_CACHE_SHIFT; struct page *page; - pgoff_t index; - unsigned start, end; - int ownpage = 0; + int status; - 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)); + page = grab_cache_page_write_begin(mapping, index, flags); + if (!page) + return -ENOMEM; - status = __block_prepare_write(inode, page, start, end, get_block); + status = __block_write_begin(page, pos, len, get_block); if (unlikely(status)) { - ClearPageUptodate(page); - - if (ownpage) { - unlock_page(page); - page_cache_release(page); - *pagep = NULL; - } + unlock_page(page); + page_cache_release(page); + page = NULL; } -out: + *pagep = page; return status; } EXPORT_SYMBOL(block_write_begin_newtrunc); @@ -2379,17 +2373,6 @@ out: } 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; diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c index 6b946bae11cf..764109886ec0 100644 --- a/fs/ext2/dir.c +++ b/fs/ext2/dir.c @@ -450,8 +450,7 @@ ino_t ext2_inode_by_name(struct inode *dir, struct qstr *child) static int ext2_prepare_chunk(struct page *page, loff_t pos, unsigned len) { - return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0, - &page, NULL, ext2_get_block); + return __block_write_begin(page, pos, len, ext2_get_block); } /* Releases the page */ diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index a66f3fe33672..5c6f07eefa4a 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -1196,8 +1196,7 @@ retry: ret = PTR_ERR(handle); goto out; } - ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, - ext3_get_block); + ret = __block_write_begin(page, pos, len, ext3_get_block); if (ret) goto write_begin_failed; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index d6a7701018a6..3da3c9646e5e 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1578,11 +1578,9 @@ retry: *pagep = page; if (ext4_should_dioread_nolock(inode)) - ret = block_write_begin(file, mapping, pos, len, flags, pagep, - fsdata, ext4_get_block_write); + ret = __block_write_begin(page, pos, len, ext4_get_block_write); else - ret = block_write_begin(file, mapping, pos, len, flags, pagep, - fsdata, ext4_get_block); + ret = __block_write_begin(page, pos, len, ext4_get_block); if (!ret && ext4_should_journal_data(inode)) { ret = walk_page_buffers(handle, page_buffers(page), @@ -1593,7 +1591,7 @@ retry: unlock_page(page); page_cache_release(page); /* - * block_write_begin may have instantiated a few blocks + * __block_write_begin may have instantiated a few blocks * outside i_size. Trim these off again. Don't need * i_size_read because we hold i_mutex. * @@ -3185,8 +3183,7 @@ retry: } *pagep = page; - ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, - ext4_da_get_block_prep); + ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep); if (ret < 0) { unlock_page(page); ext4_journal_stop(handle); diff --git a/fs/minix/inode.c b/fs/minix/inode.c index f4abe45229bb..6b29e73f0ca6 100644 --- a/fs/minix/inode.c +++ b/fs/minix/inode.c @@ -359,8 +359,7 @@ static int minix_readpage(struct file *file, struct page *page) int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len) { - return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0, - &page, NULL, minix_get_block); + return __block_write_begin(page, pos, len, minix_get_block); } static int minix_write_begin(struct file *file, struct address_space *mapping, diff --git a/fs/nilfs2/dir.c b/fs/nilfs2/dir.c index fc2bcfa599a3..d14e3b94d81f 100644 --- a/fs/nilfs2/dir.c +++ b/fs/nilfs2/dir.c @@ -83,8 +83,7 @@ static unsigned nilfs_last_byte(struct inode *inode, unsigned long page_nr) static int nilfs_prepare_chunk(struct page *page, unsigned from, unsigned to) { loff_t pos = page_offset(page) + from; - return block_write_begin_newtrunc(NULL, page->mapping, pos, to - from, - 0, &page, NULL, nilfs_get_block); + return __block_write_begin(page, pos, to - from, nilfs_get_block); } static void nilfs_commit_chunk(struct page *page, diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c index 4c1fb548ab64..045729f5674a 100644 --- a/fs/reiserfs/inode.c +++ b/fs/reiserfs/inode.c @@ -2585,8 +2585,7 @@ static int reiserfs_write_begin(struct file *file, old_ref = th->t_refcount; th->t_refcount++; } - ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, - reiserfs_get_block); + ret = __block_write_begin(page, pos, len, reiserfs_get_block); if (ret && reiserfs_transaction_running(inode->i_sb)) { struct reiserfs_transaction_handle *th = current->journal_info; /* this gets a little ugly. If reiserfs_get_block returned an diff --git a/fs/sysv/itree.c b/fs/sysv/itree.c index 4068f485cfd6..82a005c3d7eb 100644 --- a/fs/sysv/itree.c +++ b/fs/sysv/itree.c @@ -461,8 +461,7 @@ static int sysv_readpage(struct file *file, struct page *page) int sysv_prepare_chunk(struct page *page, loff_t pos, unsigned len) { - return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0, - &page, NULL, get_block); + return __block_write_begin(page, pos, len, get_block); } static int sysv_write_begin(struct file *file, struct address_space *mapping, diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c index a9555b1ffd28..45ce32391f8f 100644 --- a/fs/ufs/inode.c +++ b/fs/ufs/inode.c @@ -560,8 +560,7 @@ static int ufs_readpage(struct file *file, struct page *page) int ufs_prepare_chunk(struct page *page, loff_t pos, unsigned len) { - return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0, - &page, NULL, ufs_getfrag_block); + return __block_write_begin(page, pos, len, ufs_getfrag_block); } static int ufs_write_begin(struct file *file, struct address_space *mapping, diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 7638647f0424..accc9f81bb63 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -209,6 +209,8 @@ int block_write_begin_newtrunc(struct file *, struct address_space *, int block_write_begin(struct file *, struct address_space *, loff_t, unsigned, unsigned, struct page **, void **, get_block_t*); +int __block_write_begin(struct page *page, loff_t pos, unsigned len, + get_block_t *get_block); int block_write_end(struct file *, struct address_space *, loff_t, unsigned, unsigned, struct page *, void *); -- 2.20.1