3 files changed, 29 insertions, 30 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index ce615d12fb44..a2e1cb8a568b 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -397,7 +397,8 @@ STATIC int				/* error (positive) */
 xfs_zero_last_block(
         struct xfs_inode        *ip,
         xfs_fsize_t             offset,
-        xfs_fsize_t             isize)
+        xfs_fsize_t             isize,
+        bool                    *did_zeroing)
 {
         struct xfs_mount        *mp = ip->i_mount;
         xfs_fileoff_t           last_fsb = XFS_B_TO_FSBT(mp, isize);
@@ -425,6 +426,7 @@ xfs_zero_last_block(
         zero_len = mp->m_sb.sb_blocksize - zero_offset;
         if (isize + zero_len > offset)
                 zero_len = offset - isize;
+        *did_zeroing = true;
         return xfs_iozero(ip, isize, zero_len);
 }
 
@@ -443,7 +445,8 @@ int					/* error (positive) */
 xfs_zero_eof(
         struct xfs_inode        *ip,
         xfs_off_t               offset,         /* starting I/O offset */
-        xfs_fsize_t             isize)          /* current inode size */
+        xfs_fsize_t             isize,          /* current inode size */
+        bool                    *did_zeroing)
 {
         struct xfs_mount        *mp = ip->i_mount;
         xfs_fileoff_t           start_zero_fsb;
@@ -465,7 +468,7 @@ xfs_zero_eof(
          * We only zero a part of that block so it is handled specially.
          */
         if (XFS_B_FSB_OFFSET(mp, isize) != 0) {
-                error = xfs_zero_last_block(ip, offset, isize);
+                error = xfs_zero_last_block(ip, offset, isize, did_zeroing);
                 if (error)
                         return error;
         }
@@ -525,6 +528,7 @@ xfs_zero_eof(
                 if (error)
                         return error;
 
+                *did_zeroing = true;
                 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
                 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
         }
@@ -567,13 +571,15 @@ restart:
          * having to redo all checks before.
          */
         if (*pos > i_size_read(inode)) {
+                bool    zero = false;
+
                 if (*iolock == XFS_IOLOCK_SHARED) {
                         xfs_rw_iunlock(ip, *iolock);
                         *iolock = XFS_IOLOCK_EXCL;
                         xfs_rw_ilock(ip, *iolock);
                         goto restart;
                 }
-                error = xfs_zero_eof(ip, *pos, i_size_read(inode));
+                error = xfs_zero_eof(ip, *pos, i_size_read(inode), &zero);
                 if (error)
                         return error;
         }
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 86cd6b39bed7..a1cd55f3f351 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -384,10 +384,11 @@ enum xfs_prealloc_flags {
         XFS_PREALLOC_INVISIBLE  = (1 << 4),
 };
 
-int             xfs_update_prealloc_flags(struct xfs_inode *,
-                        enum xfs_prealloc_flags);
-int             xfs_zero_eof(struct xfs_inode *, xfs_off_t, xfs_fsize_t);
-int             xfs_iozero(struct xfs_inode *, loff_t, size_t);
+int     xfs_update_prealloc_flags(struct xfs_inode *ip,
+                                  enum xfs_prealloc_flags flags);
+int     xfs_zero_eof(struct xfs_inode *ip, xfs_off_t offset,
+                     xfs_fsize_t isize, bool *did_zeroing);
+int     xfs_iozero(struct xfs_inode *ip, loff_t pos, size_t count);
 
 
 #define IHOLD(ip) \
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index d919ad7b16bf..e53a90331422 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -751,6 +751,7 @@ xfs_setattr_size(
         int                     error;
         uint                    lock_flags = 0;
         uint                    commit_flags = 0;
+        bool                    did_zeroing = false;
 
         trace_xfs_setattr(ip);
 
@@ -794,20 +795,16 @@ xfs_setattr_size(
                 return error;
 
         /*
-         * Now we can make the changes.  Before we join the inode to the
-         * transaction, take care of the part of the truncation that must be
-         * done without the inode lock.  This needs to be done before joining
-         * the inode to the transaction, because the inode cannot be unlocked
-         * once it is a part of the transaction.
+         * File data changes must be complete before we start the transaction to
+         * modify the inode.  This needs to be done before joining the inode to
+         * the transaction because the inode cannot be unlocked once it is a
+         * part of the transaction.
+         *
+         * Start with zeroing any data block beyond EOF that we may expose on
+         * file extension.
          */
         if (newsize > oldsize) {
-                /*
-                 * Do the first part of growing a file: zero any data in the
-                 * last block that is beyond the old EOF.  We need to do this
-                 * before the inode is joined to the transaction to modify
-                 * i_size.
-                 */
-                error = xfs_zero_eof(ip, newsize, oldsize);
+                error = xfs_zero_eof(ip, newsize, oldsize, &did_zeroing);
                 if (error)
                         return error;
         }
@@ -817,23 +814,18 @@ xfs_setattr_size(
          * any previous writes that are beyond the on disk EOF and the new
          * EOF that have not been written out need to be written here.  If we
          * do not write the data out, we expose ourselves to the null files
-         * problem.
-         *
-         * Only flush from the on disk size to the smaller of the in memory
-         * file size or the new size as that's the range we really care about
-         * here and prevents waiting for other data not within the range we
-         * care about here.
+         * problem. Note that this includes any block zeroing we did above;
+         * otherwise those blocks may not be zeroed after a crash.
          */
-        if (oldsize != ip->i_d.di_size && newsize > ip->i_d.di_size) {
+        if (newsize > ip->i_d.di_size &&
+            (oldsize != ip->i_d.di_size || did_zeroing)) {
                 error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
                                                       ip->i_d.di_size, newsize);
                 if (error)
                         return error;
         }
 
-        /*
-         * Wait for all direct I/O to complete.
-         */
+        /* Now wait for all direct I/O to complete. */
         inode_dio_wait(inode);
 
         /*