ext4: avoid declaring fs inconsistent due to invalid file handles
If we receive a file handle, either from NFS or open_by_handle_at(2),
and it points at an inode which has not been initialized, and the file
system has metadata checksums enabled, we shouldn't try to get the
inode, discover the checksum is invalid, and then declare the file
system as being inconsistent.
This can be reproduced by creating a test file system via "mke2fs -t
ext4 -O metadata_csum /tmp/foo.img 8M", mounting it, cd'ing into that
directory, and then running the following program.
#define _GNU_SOURCE
#include <fcntl.h>
struct handle {
struct file_handle fh;
unsigned char fid[MAX_HANDLE_SZ];
};
int main(int argc, char **argv)
{
struct handle h = {{8, 1 }, { 12, }};
open_by_handle_at(AT_FDCWD, &h.fh, O_RDONLY);
return 0;
}
Google-Bug-Id: 120690101
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index bc8ee0c..48421de 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1637,7 +1637,7 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
"No reserved GDT blocks, can't resize");
return -EPERM;
}
- inode = ext4_iget(sb, EXT4_RESIZE_INO);
+ inode = ext4_iget(sb, EXT4_RESIZE_INO, EXT4_IGET_SPECIAL);
if (IS_ERR(inode)) {
ext4_warning(sb, "Error opening resize inode");
return PTR_ERR(inode);
@@ -1965,7 +1965,8 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
}
if (!resize_inode)
- resize_inode = ext4_iget(sb, EXT4_RESIZE_INO);
+ resize_inode = ext4_iget(sb, EXT4_RESIZE_INO,
+ EXT4_IGET_SPECIAL);
if (IS_ERR(resize_inode)) {
ext4_warning(sb, "Error opening resize inode");
return PTR_ERR(resize_inode);