fs: Enable bmap() function to properly return errors
By now, bmap() will either return the physical block number related to
the requested file offset or 0 in case of error or the requested offset
maps into a hole.
This patch makes the needed changes to enable bmap() to proper return
errors, using the return value as an error return, and now, a pointer
must be passed to bmap() to be filled with the mapped physical block.
It will change the behavior of bmap() on return:
- negative value in case of error
- zero on success or map fell into a hole
In case of a hole, the *block will be zero too
Since this is a prep patch, by now, the only error return is -EINVAL if
->bmap doesn't exist.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/mm/page_io.c b/mm/page_io.c
index 3a198de..76965be 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -177,8 +177,9 @@ int generic_swapfile_activate(struct swap_info_struct *sis,
cond_resched();
- first_block = bmap(inode, probe_block);
- if (first_block == 0)
+ first_block = probe_block;
+ ret = bmap(inode, &first_block);
+ if (ret || !first_block)
goto bad_bmap;
/*
@@ -193,9 +194,11 @@ int generic_swapfile_activate(struct swap_info_struct *sis,
block_in_page++) {
sector_t block;
- block = bmap(inode, probe_block + block_in_page);
- if (block == 0)
+ block = probe_block + block_in_page;
+ ret = bmap(inode, &block);
+ if (ret || !block)
goto bad_bmap;
+
if (block != first_block + block_in_page) {
/* Discontiguity */
probe_block++;