ext2fs_extent_replace: Support uninit extents and check validity of e_len

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/lib/ext2fs/ext2_err.et.in b/lib/ext2fs/ext2_err.et.in
index 9047a8f..d72bbd2 100644 (file)
--- a/lib/ext2fs/ext2_err.et.in
+++ b/lib/ext2fs/ext2_err.et.in
@@ -407,4 +407,7 @@ ec  EXT2_ET_EXTENT_NOT_FOUND,
 ec     EXT2_ET_EXTENT_NOT_SUPPORTED,
        "Operation not supported for inodes containing extents"
 
+ec     EXT2_ET_EXTENT_INVALID_LENGTH,
+       "Extent length is invalid"
+
        end

diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c
index b76abdc..b669e29 100644 (file)
--- a/lib/ext2fs/extent.c
+++ b/lib/ext2fs/extent.c
@@ -663,7 +663,16 @@ errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle,
                ex->ee_block = ext2fs_cpu_to_le32(extent->e_lblk);
                ex->ee_start = ext2fs_cpu_to_le32(extent->e_pblk & 0xFFFFFFFF);
                ex->ee_start_hi = ext2fs_cpu_to_le16(extent->e_pblk >> 32);
-               ex->ee_len = ext2fs_cpu_to_le16(extent->e_len);
+               if (extent->e_flags & EXT2_EXTENT_FLAGS_UNINIT) {
+                       if (extent->e_len > EXT_UNINIT_MAX_LEN)
+                               return EXT2_ET_EXTENT_INVALID_LENGTH;
+                       ex->ee_len = ext2fs_cpu_to_le16(extent->e_len +
+                                                       EXT_INIT_MAX_LEN);
+               } else {
+                       if (extent->e_len > EXT_INIT_MAX_LEN)
+                               return EXT2_ET_EXTENT_INVALID_LENGTH;
+                       ex->ee_len = ext2fs_cpu_to_le16(extent->e_len);
+               }
        } else {
                ix = path->curr;
 
@@ -970,6 +979,14 @@ void do_replace_node(int argc, char *argv[])
        if (check_fs_read_write(argv[0]))
                return;
 
+       extent.e_flags = 0;
+
+       if (!strcmp(argv[1], "--uninit")) {
+               argc--;
+               argv++;
+               extent.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
+       }
+
        if (argc != 4) {
                fprintf(stderr, "usage: %s <lblk> <len> <pblk>\n", argv[0]);
                return;
@@ -1011,10 +1028,22 @@ void do_insert_node(int argc, char *argv[])
 
        cmd = argv[0];
 
-       if (argc > 2 && !strcmp(argv[1], "--after")) {
-               argc--;
-               argv++;
-               flags |= EXT2_EXTENT_INSERT_AFTER;
+       extent.e_flags = 0;
+
+       while (argc > 2) {
+               if (!strcmp(argv[1], "--after")) {
+                       argc--;
+                       argv++;
+                       flags |= EXT2_EXTENT_INSERT_AFTER;
+                       continue;
+               }
+               if (!strcmp(argv[1], "--uninit")) {
+                       argc--;
+                       argv++;
+                       extent.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
+                       continue;
+               }
+               break;
        }
 
        if (argc != 4) {