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authorTheodore Ts'o <tytso@mit.edu>2014-12-27 04:58:21 (GMT)
committerTheodore Ts'o <tytso@mit.edu>2014-12-27 04:58:21 (GMT)
commit011fa99404bea3f5d897c4983f6bd51170e3b18f (patch)
tree09233f55cd3aa55cf779f684cd1968cc36a08437 /fs/ext4
parent50db71abc529c48b21f4c3034d3cff27cfb25795 (diff)
downloadlinux-011fa99404bea3f5d897c4983f6bd51170e3b18f.tar.xz
ext4: prevent online resize with backup superblock
Prevent BUG or corrupted file systems after the following: mkfs.ext4 /dev/vdc 100M mount -t ext4 -o sb=40961 /dev/vdc /vdc resize2fs /dev/vdc We previously prevented online resizing using the old resize ioctl. Move the code to ext4_resize_begin(), so the check applies for all of the resize ioctl's. Reported-by: Maxim Malkov <malkov@ispras.ru> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/resize.c24
1 files changed, 12 insertions, 12 deletions
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index bf76f40..8a8ec62 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -24,6 +24,18 @@ int ext4_resize_begin(struct super_block *sb)
return -EPERM;
/*
+ * If we are not using the primary superblock/GDT copy don't resize,
+ * because the user tools have no way of handling this. Probably a
+ * bad time to do it anyways.
+ */
+ if (EXT4_SB(sb)->s_sbh->b_blocknr !=
+ le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
+ ext4_warning(sb, "won't resize using backup superblock at %llu",
+ (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
+ return -EPERM;
+ }
+
+ /*
* We are not allowed to do online-resizing on a filesystem mounted
* with error, because it can destroy the filesystem easily.
*/
@@ -758,18 +770,6 @@ static int add_new_gdb(handle_t *handle, struct inode *inode,
"EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
gdb_num);
- /*
- * If we are not using the primary superblock/GDT copy don't resize,
- * because the user tools have no way of handling this. Probably a
- * bad time to do it anyways.
- */
- if (EXT4_SB(sb)->s_sbh->b_blocknr !=
- le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
- ext4_warning(sb, "won't resize using backup superblock at %llu",
- (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
- return -EPERM;
- }
-
gdb_bh = sb_bread(sb, gdblock);
if (!gdb_bh)
return -EIO;