Linux 4.11 compat: vfs_getattr() takes 4 args

There are changes to vfs_getattr() in torvalds/linux@a528d35.  The new
interface is:

int vfs_getattr(const struct path *path, struct kstat *stat,
               u32 request_mask, unsigned int query_flags)

The request_mask argument indicates which field(s) the caller intends to
use.  Fields the caller does not specify via request_mask may be set in
the returned struct anyway, but their values may be approximate.

The query_flags argument indicates whether the filesystem must update
the attributes from the backing store.

This patch uses the query_flags which result in vfs_getattr behaving the same
as it did with the 2-argument version which the kernel provided before
Linux 4.11.

Members blksize and blocks are now always the same size regardless of
arch.  They match the size of the equivalent members in vnode_t.

The configure checks are modified to ensure that the appropriate
vfs_getattr() interface is used.

A more complete fix, removing the ZFS dependency on vfs_getattr()
entirely, is deferred as it is a much larger project.

Reviewed-by: Chunwei Chen <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Olaf Faaland <[email protected]>
Closes #608

1 files changed, 10 insertions, 3 deletions

diff --git a/module/spl/spl-vnode.c b/module/spl/spl-vnode.c
index cd276b5c8..0902e1161 100644
--- a/module/spl/spl-vnode.c
+++ b/module/spl/spl-vnode.c
@@ -153,7 +153,9 @@ vn_open(const char *path, uio_seg_t seg, int flags, int mode,
 	if (IS_ERR(fp))
 		return (-PTR_ERR(fp));
 
-#ifdef HAVE_2ARGS_VFS_GETATTR
+#if defined(HAVE_4ARGS_VFS_GETATTR)
+	rc = vfs_getattr(&fp->f_path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
+#elif defined(HAVE_2ARGS_VFS_GETATTR)
 	rc = vfs_getattr(&fp->f_path, &stat);
 #else
 	rc = vfs_getattr(fp->f_path.mnt, fp->f_dentry, &stat);
@@ -510,7 +512,10 @@ vn_getattr(vnode_t *vp, vattr_t *vap, int flags, void *x3, void *x4)
 
 	fp = vp->v_file;
 
-#ifdef HAVE_2ARGS_VFS_GETATTR
+#if defined(HAVE_4ARGS_VFS_GETATTR)
+	rc = vfs_getattr(&fp->f_path, &stat, STATX_BASIC_STATS,
+	    AT_STATX_SYNC_AS_STAT);
+#elif defined(HAVE_2ARGS_VFS_GETATTR)
 	rc = vfs_getattr(&fp->f_path, &stat);
 #else
 	rc = vfs_getattr(fp->f_path.mnt, fp->f_dentry, &stat);
@@ -708,7 +713,9 @@ vn_getf(int fd)
 	if (vp == NULL)
 		goto out_fget;
 
-#ifdef HAVE_2ARGS_VFS_GETATTR
+#if defined(HAVE_4ARGS_VFS_GETATTR)
+	rc = vfs_getattr(&lfp->f_path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
+#elif defined(HAVE_2ARGS_VFS_GETATTR)
 	rc = vfs_getattr(&lfp->f_path, &stat);
 #else
 	rc = vfs_getattr(lfp->f_path.mnt, lfp->f_dentry, &stat);