Provide an API to set i_size in an inode and take care of all required
feature flag modifications. Refactor the code to use this new
function.
[ Moved the function to lib/ext2fs/blk_num.c, which is the rest of
these sorts of functions live, and renamed it to be
ext2fs_inode_size_set() instead of ext2fs_inode_set_size() to be
consistent with the other functions in in blk_num.c -- tytso ]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
In practice, it is **extremely** rare for users to try to use more
than the first backup superblock located at the beginning of block
group #1. (i.e., at block number 32768 for file systems with a 4k
block size). This new compat feature restricts the backup superblock
to block group #1 and the last block group in the file system.
Aside from reducing the overhead of the file system by a small number
of blocks, by eliminating the rest of the backup superblocks, it
allows us to have a much more flexible metadata layout. For example,
we can force all of the allocation bitmaps and inode table blocks to
the beginning of the disk, which allows most of the disk to be
exclusively used for contiguous data blocks.
This simplifies taking advantage of certain HDD specific features,
such as Shingled Magnetic Recording (aka Shingled Drives), and the
TCG's OPAL Storage Specification where having a simple mapping between
LBA block ranges and the data blocks used by the file system can make
life much simpler.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The DEFS line in MCONFIG had gotten so long that it exceeded 4k, and
this was starting to cause some tools heartburn. It also made "make
V=1" almost useless, since trying to following the individual commands
run by make was lost in the noise of all of the defines.
So fix this by putting the configure-generated defines in lib/config.h
and the directory pathnames to lib/dirpaths.h.
In addition, clean up some vestigal defines in configure.in and in the
Makefiles to further shorten the cc command lines.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Filesystems with a blocksize of 1024 have the superblock starting at
block #1. However, the first data block in the superblock is 0 to
simplify the cluster calculations. So we must compensate for this in
a number of places, mostly in the ext2fs library, but also in e2fsck.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Fix several types of compiler warnings (unused variables/labels),
uninitialized variables, etc that are hit with gcc -Wall.
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The top-level COPYING file states that the e2p and ext2fs libraries
are available under the LGPLv2. The files were incorrectly labelled.
Alex Thomas/Luster has been consulted wrt to the ext3_extents.h file;
the rest of the files were primarily authored by Theodore Ts'o.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
I noticed that neither the journal nor resize inodes have
i_extra_isize set post-mkfs; while this isn't likely
to be a big problem, I think the below patch tidies
it up.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Thanks to Max Lindner (lokimuh) for pointing this out.
I'm playing around a bit with ext2 and multi-user encryption and I
need space for my key management. So I set s_first_data_block to 4000
or something like that.
This way mke2fs segfaults when executing
ext2fs_create_resize_inode() because
blk_t goal = 3 + sb->s_reserved_gdt_blocks + fs->desc_blocks +
fs->inode_blocks_per_group;
will produce a integer underrun later and segfault then in the
ext2fs_test_bit assembler inline function.
when exchanging 3 with 2 + sb->s_first_data_block, mke2fs does not
segfault.
I'm not 100% sure if thats the correct way dealing with this issue
but I think its a proper solution.
Addresses-Sourceforge-Bug: #1935847
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This addresses a potential security vulnerability where an untrusted
filesystem can be corrupted in such a way that a program using
libext2fs will allocate a buffer which is far too small. This can
lead to either a crash or potentially a heap-based buffer overflow
crash. No known exploits exist, but main concern is where an
untrusted user who possesses privileged access in a guest Xen
environment could corrupt a filesystem which is then accessed by the
pygrub program, running as root in the dom0 host environment, thus
allowing the untrusted user to gain privileged access in the host OS.
Thanks to the McAfee AVERT Research group for reporting this issue.
Addresses CVE-2007-5497.
Signed-off-by: Rafal Wojtczuk <rafal_wojtczuk@mcafee.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If fs->now is non-zero, use that as the time instead of the system
time when setting various filesystem fields (last modified time, last
write time, etc.)
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
any debugging statements from within library code (always a bad idea), and
ext2fs_create_resize_inode() will return a proper error code if the
resize inode is corrupt, instead of returning -1.
res_gdt.c (list_backups), closefs.c (ext2fs_bg_has_super),
ext2fs.h: Move ext2fs_list_backups() to res_gdt.c, and
ext2fs_bg_has_super() back to closefs.c. There's no
reason for the new file, since list_backups() isn't being
used by any other functions, and can be made static, and
all users of the ext2fs filesystem will have to call
ext2fs_close() anyway.
Darrick J. Wong