ext4: use ext4_get_block_write() for DAX
authorMatthew Wilcox <willy@linux.intel.com>
Tue, 8 Sep 2015 21:59:11 +0000 (14:59 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 8 Sep 2015 22:35:28 +0000 (15:35 -0700)
DAX relies on the get_block function either zeroing newly allocated
blocks before they're findable by subsequent calls to get_block, or
marking newly allocated blocks as unwritten.  ext4_get_block() cannot
create unwritten extents, but ext4_get_block_write() can.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Reported-by: Andy Rudoff <andy.rudoff@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ext4/file.c

index 953d519e799c074f682c25d8e6b820cdead74c82..ca5302a256ead2140670f45d440c63134b26558b 100644 (file)
@@ -196,7 +196,7 @@ out:
 static void ext4_end_io_unwritten(struct buffer_head *bh, int uptodate)
 {
        struct inode *inode = bh->b_assoc_map->host;
-       /* XXX: breaks on 32-bit > 16GB. Is that even supported? */
+       /* XXX: breaks on 32-bit > 16TB. Is that even supported? */
        loff_t offset = (loff_t)(uintptr_t)bh->b_private << inode->i_blkbits;
        int err;
        if (!uptodate)
@@ -207,8 +207,7 @@ static void ext4_end_io_unwritten(struct buffer_head *bh, int uptodate)
 
 static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-       return dax_fault(vma, vmf, ext4_get_block, ext4_end_io_unwritten);
-                                       /* Is this the right get_block? */
+       return dax_fault(vma, vmf, ext4_get_block_write, ext4_end_io_unwritten);
 }
 
 static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
@@ -220,7 +219,8 @@ static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
 
 static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-       return dax_mkwrite(vma, vmf, ext4_get_block, ext4_end_io_unwritten);
+       return dax_mkwrite(vma, vmf, ext4_get_block_write,
+                               ext4_end_io_unwritten);
 }
 
 static const struct vm_operations_struct ext4_dax_vm_ops = {