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| author | Theodore Ts'o <tytso@mit.edu> | 2020-10-02 14:47:25 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2020-10-02 14:47:25 -0400 |
| commit | 21bad2b6797f387756af4480d338c0b877c86ba0 (patch) | |
| tree | 4f3ae1d5f0df1eb64c0992ecd70b0c3647cc6551 | |
| parent | b1a780ed7bc909026eab3f7318b2eafcff7d3c67 (diff) | |
| download | e2fsprogs-21bad2b6797f387756af4480d338c0b877c86ba0.tar.gz | |
resize2fs: prevent block group descriptors from overflowing the first bg
For 1k block file systems, resizing a file system larger than
1073610752 blocks will result in the size of the block group
descriptors to be so large that it will overlap with the backup
superblock in block group #1. This problem can be reproduced via:
mke2fs -t ext4 /tmp/foo.img 200M
resize2fs /tmp/foo.img 1T
e2fsck -f /tmp/foo.img
https://github.com/tytso/e2fsprogs/issues/50
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | resize/main.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/resize/main.c b/resize/main.c index a0c31c069..5e771d2ac 100644 --- a/resize/main.c +++ b/resize/main.c @@ -269,6 +269,8 @@ int main (int argc, char ** argv) long sysval; int len, mount_flags; char *mtpt, *undo_file = NULL; + dgrp_t new_group_desc_count; + unsigned long new_desc_blocks; #ifdef ENABLE_NLS setlocale(LC_MESSAGES, ""); @@ -528,6 +530,18 @@ int main (int argc, char ** argv) exit(1); } } + new_group_desc_count = ext2fs_div64_ceil(new_size - + fs->super->s_first_data_block, + EXT2_BLOCKS_PER_GROUP(fs->super)); + new_desc_blocks = ext2fs_div_ceil(new_group_desc_count, + EXT2_DESC_PER_BLOCK(fs->super)); + if ((new_desc_blocks + fs->super->s_first_data_block) > + EXT2_BLOCKS_PER_GROUP(fs->super)) { + com_err(program_name, 0, + _("New size results in too many block group " + "descriptors.\n")); + exit(1); + } if (!force && new_size < min_size) { com_err(program_name, 0, |