[PATCH 1/2 linux-next] fs/affs: bugfix: enable writes on OFS disks

From: Fabian Frederick
Date: Mon Apr 24 2017 - 16:13:20 EST


We called unconditionally affs_bread_ino() with create 0 resulting in
"error (device ...): get_block(): strange block request 0"
when trying to write on AFFS OFS format.

This patch adds create parameter to that function.
0 for affs_readpage_ofs()
1 for affs_write_begin_ofs()

Bug was found here:
https://bugzilla.kernel.org/show_bug.cgi?id=114961

Signed-off-by: Fabian Frederick <fabf@xxxxxxxxx>
---
fs/affs/file.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/affs/file.c b/fs/affs/file.c
index 0deec9c..e5c5de6 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -499,7 +499,7 @@ affs_getemptyblk_ino(struct inode *inode, int block)
}

static int
-affs_do_readpage_ofs(struct page *page, unsigned to)
+affs_do_readpage_ofs(struct page *page, unsigned to, int create)
{
struct inode *inode = page->mapping->host;
struct super_block *sb = inode->i_sb;
@@ -518,7 +518,7 @@ affs_do_readpage_ofs(struct page *page, unsigned to)
boff = tmp % bsize;

while (pos < to) {
- bh = affs_bread_ino(inode, bidx, 0);
+ bh = affs_bread_ino(inode, bidx, create);
if (IS_ERR(bh))
return PTR_ERR(bh);
tmp = min(bsize - boff, to - pos);
@@ -620,7 +620,7 @@ affs_readpage_ofs(struct file *file, struct page *page)
memset(page_address(page) + to, 0, PAGE_SIZE - to);
}

- err = affs_do_readpage_ofs(page, to);
+ err = affs_do_readpage_ofs(page, to, 0);
if (!err)
SetPageUptodate(page);
unlock_page(page);
@@ -657,7 +657,7 @@ static int affs_write_begin_ofs(struct file *file, struct address_space *mapping
return 0;

/* XXX: inefficient but safe in the face of short writes */
- err = affs_do_readpage_ofs(page, PAGE_SIZE);
+ err = affs_do_readpage_ofs(page, PAGE_SIZE, 1);
if (err) {
unlock_page(page);
put_page(page);
--
2.9.3