[v15,6/7] ext4: disable map_sync for async flush
diff mbox series

Message ID 20190705140328.20190-7-pagupta@redhat.com
State Not Applicable
Headers show
Series
  • virtio pmem driver
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Commit Message

Pankaj Gupta July 5, 2019, 2:03 p.m. UTC
Dont support 'MAP_SYNC' with non-DAX files and DAX files
with asynchronous dax_device. Virtio pmem provides
asynchronous host page cache flush mechanism. We don't
support 'MAP_SYNC' with virtio pmem and ext4.

Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/file.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

Comments

Theodore Y. Ts'o July 7, 2019, 4:34 p.m. UTC | #1
On Fri, Jul 05, 2019 at 07:33:27PM +0530, Pankaj Gupta wrote:
> Dont support 'MAP_SYNC' with non-DAX files and DAX files
> with asynchronous dax_device. Virtio pmem provides
> asynchronous host page cache flush mechanism. We don't
> support 'MAP_SYNC' with virtio pmem and ext4.
> 
> Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
> Reviewed-by: Jan Kara <jack@suse.cz>

Acked-by: Theodore Ts'o <tytso@mit.edu>

Patch
diff mbox series

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 98ec11f69cd4..dee549339e13 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -360,15 +360,17 @@  static const struct vm_operations_struct ext4_file_vm_ops = {
 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
 	struct inode *inode = file->f_mapping->host;
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	struct dax_device *dax_dev = sbi->s_daxdev;
 
-	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+	if (unlikely(ext4_forced_shutdown(sbi)))
 		return -EIO;
 
 	/*
-	 * We don't support synchronous mappings for non-DAX files. At least
-	 * until someone comes with a sensible use case.
+	 * We don't support synchronous mappings for non-DAX files and
+	 * for DAX files if underneath dax_device is not synchronous.
 	 */
-	if (!IS_DAX(file_inode(file)) && (vma->vm_flags & VM_SYNC))
+	if (!daxdev_mapping_supported(vma, dax_dev))
 		return -EOPNOTSUPP;
 
 	file_accessed(file);