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authorJan Kara <jack@suse.cz>2011-05-24 00:23:34 +0200
committerAl Viro <viro@zeniv.linux.org.uk>2011-05-26 07:26:44 -0400
commit24da4fab5a617ecbf0f0c64e7ba7703383faa411 (patch)
tree28f62d2e0e69b11765f021db53c327b56f741576
parent7c6e984dfca8ff5b04d359a59b24f39a691b87d3 (diff)
vfs: Create __block_page_mkwrite() helper passing error values back
Create __block_page_mkwrite() helper which does all what block_page_mkwrite() does except that it passes back errors from __block_write_begin / block_commit_write calls. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/buffer.c37
-rw-r--r--include/linux/buffer_head.h14
2 files changed, 34 insertions, 17 deletions
diff --git a/fs/buffer.c b/fs/buffer.c
index a08bb8e61c6f..f6ad8f9b8fa5 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2332,23 +2332,22 @@ EXPORT_SYMBOL(block_commit_write);
* beyond EOF, then the page is guaranteed safe against truncation until we
* unlock the page.
*/
-int
-block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
- get_block_t get_block)
+int __block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
+ get_block_t get_block)
{
struct page *page = vmf->page;
struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
unsigned long end;
loff_t size;
- int ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
+ int ret;
lock_page(page);
size = i_size_read(inode);
if ((page->mapping != inode->i_mapping) ||
(page_offset(page) > size)) {
- /* page got truncated out from underneath us */
- unlock_page(page);
- goto out;
+ /* We overload EFAULT to mean page got truncated */
+ ret = -EFAULT;
+ goto out_unlock;
}
/* page is wholly or partially inside EOF */
@@ -2361,18 +2360,22 @@ block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
if (!ret)
ret = block_commit_write(page, 0, end);
- if (unlikely(ret)) {
- unlock_page(page);
- if (ret == -ENOMEM)
- ret = VM_FAULT_OOM;
- else /* -ENOSPC, -EIO, etc */
- ret = VM_FAULT_SIGBUS;
- } else
- ret = VM_FAULT_LOCKED;
-
-out:
+ if (unlikely(ret < 0))
+ goto out_unlock;
+ return 0;
+out_unlock:
+ unlock_page(page);
return ret;
}
+EXPORT_SYMBOL(__block_page_mkwrite);
+
+int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
+ get_block_t get_block)
+{
+ int ret = __block_page_mkwrite(vma, vmf, get_block);
+
+ return block_page_mkwrite_return(ret);
+}
EXPORT_SYMBOL(block_page_mkwrite);
/*
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index f5df23561b96..2bf6a9136a94 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -217,8 +217,22 @@ int cont_write_begin(struct file *, struct address_space *, loff_t,
get_block_t *, loff_t *);
int generic_cont_expand_simple(struct inode *inode, loff_t size);
int block_commit_write(struct page *page, unsigned from, unsigned to);
+int __block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
+ get_block_t get_block);
int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
get_block_t get_block);
+/* Convert errno to return value from ->page_mkwrite() call */
+static inline int block_page_mkwrite_return(int err)
+{
+ if (err == 0)
+ return VM_FAULT_LOCKED;
+ if (err == -EFAULT)
+ return VM_FAULT_NOPAGE;
+ if (err == -ENOMEM)
+ return VM_FAULT_OOM;
+ /* -ENOSPC, -EDQUOT, -EIO ... */
+ return VM_FAULT_SIGBUS;
+}
sector_t generic_block_bmap(struct address_space *, sector_t, get_block_t *);
int block_truncate_page(struct address_space *, loff_t, get_block_t *);
int nobh_write_begin(struct address_space *, loff_t, unsigned, unsigned,