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vfs: Create __block_page_mkwrite() helper passing error values back

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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>
This commit is contained in:
Jan Kara 2011-05-24 00:23:34 +02:00 committed by Al Viro
parent 7c6e984dfc
commit 24da4fab5a
2 changed files with 34 additions and 17 deletions
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37
fs/buffer.c
View File

@ -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);
/*

14
include/linux/buffer_head.h
View File

@ -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,