4 files changed, 26 insertions, 3 deletions

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index a526f8d2dc6f..51757113a822 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1599,6 +1599,7 @@ xfs_setsize_buftarg(
         unsigned int            blocksize,
         unsigned int            sectorsize)
 {
+        /* Set up metadata sector size info */
         btp->bt_meta_sectorsize = sectorsize;
         btp->bt_meta_sectormask = sectorsize - 1;
 
@@ -1613,6 +1614,10 @@ xfs_setsize_buftarg(
                 return EINVAL;
         }
 
+        /* Set up device logical sector size mask */
+        btp->bt_logical_sectorsize = bdev_logical_block_size(btp->bt_bdev);
+        btp->bt_logical_sectormask = bdev_logical_block_size(btp->bt_bdev) - 1;
+
         return 0;
 }
 
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index d5d88dda4d31..995339534db6 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -88,6 +88,19 @@ typedef unsigned int xfs_buf_flags_t;
  */
 #define XFS_BSTATE_DISPOSE       (1 << 0)       /* buffer being discarded */
 
+/*
+ * The xfs_buftarg contains 2 notions of "sector size" -
+ *
+ * 1) The metadata sector size, which is the minimum unit and
+ *    alignment of IO which will be performed by metadata operations.
+ * 2) The device logical sector size
+ *
+ * The first is specified at mkfs time, and is stored on-disk in the
+ * superblock's sb_sectsize.
+ *
+ * The latter is derived from the underlying device, and controls direct IO
+ * alignment constraints.
+ */
 typedef struct xfs_buftarg {
         dev_t                   bt_dev;
         struct block_device     *bt_bdev;
@@ -95,6 +108,8 @@ typedef struct xfs_buftarg {
         struct xfs_mount        *bt_mount;
         unsigned int            bt_meta_sectorsize;
         size_t                  bt_meta_sectormask;
+        size_t                  bt_logical_sectorsize;
+        size_t                  bt_logical_sectormask;
 
         /* LRU control structures */
         struct shrinker         bt_shrinker;
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index d01745f748ac..2e7989e3a2d6 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -261,7 +261,8 @@ xfs_file_aio_read(
                 xfs_buftarg_t   *target =
                         XFS_IS_REALTIME_INODE(ip) ?
                                 mp->m_rtdev_targp : mp->m_ddev_targp;
-                if ((pos | size) & target->bt_meta_sectormask) {
+                /* DIO must be aligned to device logical sector size */
+                if ((pos | size) & target->bt_logical_sectormask) {
                         if (pos == i_size_read(inode))
                                 return 0;
                         return -XFS_ERROR(EINVAL);
@@ -641,9 +642,11 @@ xfs_file_dio_aio_write(
         struct xfs_buftarg      *target = XFS_IS_REALTIME_INODE(ip) ?
                                         mp->m_rtdev_targp : mp->m_ddev_targp;
 
-        if ((pos | count) & target->bt_meta_sectormask)
+        /* DIO must be aligned to device logical sector size */
+        if ((pos | count) & target->bt_logical_sectormask)
                 return -XFS_ERROR(EINVAL);
 
+        /* "unaligned" here means not aligned to a filesystem block */
         if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask))
                 unaligned_io = 1;
 
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 3dc60ed9572a..bcfe61202115 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1583,7 +1583,7 @@ xfs_file_ioctl(
                         XFS_IS_REALTIME_INODE(ip) ?
                         mp->m_rtdev_targp : mp->m_ddev_targp;
 
-                da.d_mem = da.d_miniosz = target->bt_meta_sectorsize;
+                da.d_mem =  da.d_miniosz = target->bt_logical_sectorsize;
                 da.d_maxiosz = INT_MAX & ~(da.d_miniosz - 1);
 
                 if (copy_to_user(arg, &da, sizeof(da)))