xfs: push corruption -> ESTALE conversion to xfs_nfs_get_inode()

In xfs_imap_to_bp(), we convert a -EFSCORRUPTED error to -EINVAL if
we are doing an untrusted lookup. This is done because we need
failed filehandle lookups to report -ESTALE to the caller, and it
does this by converting -EINVAL and -ENOENT errors to -ESTALE.

The squashing of EFSCORRUPTED in imap_to_bp makes it impossible for
for xfs_iget(UNTRUSTED) callers to determine the difference between
"inode does not exist" and "corruption detected during lookup". We
realy need that distinction in places calling xfS_iget(UNTRUSTED),
so move the filehandle error case handling all the way out to
xfs_nfs_get_inode() where it is needed.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

2 files changed, 12 insertions, 8 deletions

diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
index eecf654b4188..88ae2bba755a 100644
--- a/fs/xfs/libxfs/xfs_inode_buf.c
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -201,11 +201,6 @@ xfs_imap_to_bp(
                         ASSERT(buf_flags & XBF_TRYLOCK);
                         return error;
                 }
-
-                if (error == -EFSCORRUPTED &&
-                    (iget_flags & XFS_IGET_UNTRUSTED))
-                        return -EINVAL;
-
                 xfs_warn(mp, "%s: xfs_trans_read_buf() returned error %d.",
                         __func__, error);
                 return error;
diff --git a/fs/xfs/xfs_export.c b/fs/xfs/xfs_export.c
index eed698aa9f16..af540b41ea75 100644
--- a/fs/xfs/xfs_export.c
+++ b/fs/xfs/xfs_export.c
@@ -140,15 +140,24 @@ xfs_nfs_get_inode(
          */
         error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
         if (error) {
+
                 /*
                  * EINVAL means the inode cluster doesn't exist anymore.
-                 * This implies the filehandle is stale, so we should
-                 * translate it here.
+                 * EFSCORRUPTED means the metadata pointing to the inode cluster
+                 * or the inode cluster itself is corrupt.  This implies the
+                 * filehandle is stale, so we should translate it here.
                  * We don't use ESTALE directly down the chain to not
                  * confuse applications using bulkstat that expect EINVAL.
                  */
-                if (error == -EINVAL || error == -ENOENT)
+                switch (error) {
+                case -EINVAL:
+                case -ENOENT:
+                case -EFSCORRUPTED:
                         error = -ESTALE;
+                        break;
+                default:
+                        break;
+                }
                 return ERR_PTR(error);
         }