xfs: Introduce error injection to reduce maximum inode fork extent count

Source kernel commit: f9fa87169d2bc1bf55ab42bb6085114378c53b86

This commit adds XFS_ERRTAG_REDUCE_MAX_IEXTENTS error tag which enables
userspace programs to test "Inode fork extent count overflow detection"
by reducing maximum possible inode fork extent count to 10.

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/io/inject.c b/io/inject.c
index 352d27ce5d1c07fb875909c1d832e28d0d1d90d5..9e3d5ad49d3f8fc107ff90744ed5ccf6f4164c24 100644 (file)
--- a/io/inject.c
+++ b/io/inject.c
@@ -55,6 +55,7 @@ error_tag(char *name)
                { XFS_ERRTAG_FORCE_SUMMARY_RECALC,      "bad_summary" },
                { XFS_ERRTAG_IUNLINK_FALLBACK,          "iunlink_fallback" },
                { XFS_ERRTAG_BUF_IOERROR,               "buf_ioerror" },
+               { XFS_ERRTAG_REDUCE_MAX_IEXTENTS,       "reduce_max_iextents" },
                { XFS_ERRTAG_MAX,                       NULL }
        };
        int     count;

diff --git a/libxfs/xfs_errortag.h b/libxfs/xfs_errortag.h
index 53b305dea381563d7291d48bde418e171dc38786..1c56fcceeea65ba97b0edac3bd80e5d3b99e1983 100644 (file)
--- a/libxfs/xfs_errortag.h
+++ b/libxfs/xfs_errortag.h
@@ -56,7 +56,8 @@
 #define XFS_ERRTAG_FORCE_SUMMARY_RECALC                        33
 #define XFS_ERRTAG_IUNLINK_FALLBACK                    34
 #define XFS_ERRTAG_BUF_IOERROR                         35
-#define XFS_ERRTAG_MAX                                 36
+#define XFS_ERRTAG_REDUCE_MAX_IEXTENTS                 36
+#define XFS_ERRTAG_MAX                                 37
 
 /*
  * Random factors for above tags, 1 means always, 2 means 1/2 time, etc.
@@ -97,5 +98,6 @@
 #define XFS_RANDOM_FORCE_SUMMARY_RECALC                        1
 #define XFS_RANDOM_IUNLINK_FALLBACK                    (XFS_RANDOM_DEFAULT/10)
 #define XFS_RANDOM_BUF_IOERROR                         XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_REDUCE_MAX_IEXTENTS                 1
 
 #endif /* __XFS_ERRORTAG_H_ */

diff --git a/libxfs/xfs_inode_fork.c b/libxfs/xfs_inode_fork.c
index 83866cd21133bc12ddff3fb2154e6c0455fad33e..1802586c11db290ed7bb667e6383eb9883bdbe4f 100644 (file)
--- a/libxfs/xfs_inode_fork.c
+++ b/libxfs/xfs_inode_fork.c
@@ -22,6 +22,7 @@
 #include "xfs_dir2_priv.h"
 #include "xfs_attr_leaf.h"
 #include "xfs_types.h"
+#include "xfs_errortag.h"
 
 kmem_zone_t *xfs_ifork_zone;
 
@@ -743,6 +744,9 @@ xfs_iext_count_may_overflow(
 
        max_exts = (whichfork == XFS_ATTR_FORK) ? MAXAEXTNUM : MAXEXTNUM;
 
+       if (XFS_TEST_ERROR(false, ip->i_mount, XFS_ERRTAG_REDUCE_MAX_IEXTENTS))
+               max_exts = 10;
+
        nr_exts = ifp->if_nextents + nr_to_add;
        if (nr_exts < ifp->if_nextents || nr_exts > max_exts)
                return -EFBIG;