Teach e2fsck to (re)construct extent trees. This enables us to do
either of the following: compress a highly sparse extent tree into
fewer ETB blocks; or convert a ext3-style block mapped file to an
extent file. The reconstruction is performed during pass 1E or 3A,
as detailed below.
For files that are already extent based, this algorithm will
automatically run (pending user approval) if pass1 determines either
(1) that a whole level of extent tree will fit into a higher level of
the tree; (2) that the size of any level can be reduced by at least
one ETB block; or (3) the extent tree is unnecessarily deep. It will
not run at all if errors are found and the user declines to fix the
errors.
The option "-E bmap2extent" can be used to force e2fsck to convert all
block map files to extent trees, and to rebuild all extent files'
extent trees. After conversion, files larger than 12 blocks should be
defragmented to eliminate empty holes where a block lives.
The extent tree constructor is pretty dumb -- it creates a list of
leaf extents (adjacent extents are collapsed), marks all indirect
blocks / ETB blocks free, installs a new extent tree root in the
inode, then loads the leaf extents into the tree.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
e2fsck pass1 is modified to use the block group data prefetch function
to try to fetch the inode tables into the pagecache before it is
needed. We iterate through the blockgroups until we have enough inode
tables that need reading such that we can issue readahead; then we sit
and wait until the last inode table block read of the last group to
start fetching the next bunch.
pass2 is modified to use the dirblock prefetching function to prefetch
the list of directory blocks that are assembled in pass1. We use the
"iterate a subset of a dblist" and avoid copying the dblist. Directory
blocks are fetched incrementally as we walk through the directory
block list. In previous iterations of this patch we would free the
directory blocks after processing, but the performance hit to e2fsck
itself wasn't worth it. Furthermore, it is anticipated that most
users will then mount the FS and start using the directories, so they
may as well remain in the page cache.
pass4 is modified to prefetch the block and inode bitmaps in
anticipation of pass 5, because pass4 is entirely CPU bound.
In general, these mechanisms can decrease fsck time by 10-40%, if the
host system has sufficient memory and the storage system can provide a
lot of IOPs. Pretty much any storage system capable of handling
multiple IOs in-flight at any time will see a fairly large performance
boost. (Single-issue USB mass storage disks seem to suffer badly.)
By default, the readahead buffer size will be set to the size of a block
group's inode table (which is 2MiB for a regular ext4 FS). The -E
readahead_kb= option can be given to specify the amount of memory to
use for readahead or zero to disable it entirely; or an option can be
given in e2fsck.conf.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This patch adds to e2fsck the ability to pre-fetch metadata into the
page cache in the hopes of speeding up fsck runs. There are two new
functions -- the first allows a caller to readahead a list of blocks,
and the second is a helper function that uses that first mechanism to
load group data (bitmaps, inode tables).
These new e2fsck routines require the addition of a dblist API to
allow us to iterate a subset of a dblist. This will enable
incremental directory block readahead in e2fsck pass 2.
There's also a function to estimate the readahead given a FS.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When there's a problem accessing the EA part of an inline data symlink
and we want to truncate the symlink back to 60 characters (hoping the
user can re-establish the link later on, apparently) be sure to turn
off the inline data flag to convert the symlink back to a regular fast
symlink.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Once we've "fixed" the filesystem, try mounting and modifying it to see
if we can break the kernel.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The s_lpf_ino field is intended to store the location of the lost and
found directory if the root directory becomes encrypted (which is not
yet supported). The s_encryption_level field is designed to allow
support for future changes in the on-disk ext4 encryption format while
this feature under development, without having to burn a large number
of bits in the incompat feature flag.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The compression patches were an out-of-kernel patch set that was (a)
only available for ext2, (b) something that was never could be
stablized due to file system corruption, and (c) the most recent
patches were for 3.1, last updated in 2011.
The history of the compression patches has been a bit checkered.
There is a long history here at http://e2compr.sourceforge.net which
lists the perspective of the people working on it from the e2compr
side.
From the ext2/3/4 mainline developers' perspective, initial
compression support was added to e2fsprogs in 2000 (in the Linux 2.2
era), but due to stability concerns the kernel patches were never
merged into the mainline kernel. While there were some sporadic
efforts to try to get the ext2 compression patches working in the 2.4
and 2.6 era, by that time mainline work had moved on to ext4, and the
e2compr approach could only work with 32-bit block numbers and
indirect mapped files.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Previously we were using a weird hybrid CBC/CTS. Switch things so we
are using straight CTS; this corresponds to changes made in the latest
ext4 encryption patches.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The ext2fs_digest_encode() function was broken for any input which was
a multiple of 3. Previously we never hit that case, so we never
noticed it was busted. Also fix up the unit test so future problems
like this get noticed quickly.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Add missing new lib/ext2fs source files that were added for encryption
support. Also move configuration #define's from individual Android.mk
to the android_config.h file, since we've moved away from specifying
configuration #define's on the command-line upstream.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The kernel never updates the extended attribute hash value for
attributes stored in the inode. However, fsck has always checked this
value (if it's nonzero) and will complain if the hash doesn't match
the xattr. Therefore, always zero the hash value when writing to
in-ibody xattrs to avoid creating "corrupt" attribute errors
downstream.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
fix_problem() returning 1 means to fix the fs error, so do that.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If ext2fs_new_block2() is called without a specific block map, we
should call the alloc_block hook before checking fs->block_map. This
helps us to avoid a bug in e2fsck where we need to allocate a block
but instead of consulting block_found_map, we use the FS bitmaps,
which (prior to pass 5) could be wrong.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Plumb a new call into the IO manager to support translating
ext2fs_zero_blocks calls into the equivalent FALLOC_FL_ZERO_RANGE
fallocate flag primitive when possible. This patch provides _only_
support for file-based images.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This allows us to print a message warning the user that there is
something funny going on with their hardware clock (probably time zone
issues caused by trying to be compatible with legacy OS's such as
Windows), without triggering a full file system check.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Previously, e4crypt required the user to manually specify the salt
used for their passphrase. This was user unfriendly to say the least.
The e4crypt program can now request the salt using an ioctl, which
will automatically generate the salt if necessary, and keep it in the
ext4 superblock.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This patch adds new e4crypt tool for encryption management in the ext4
filesystem.
Signed-off-by: Ildar Muslukhov <muslukhovi@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Add const annotation to the input pointers; also run the tst_sha256
and tst_sha512 unit tests on a "make check".
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Use memcmp() instead of strncmp() since encrypted directory names can
contain NUL characters. For non-encrypted directories, we've already
checked for the case of NUL characters in file names, so it's safe to
use memcmp() here in all cases.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Teach ext2fs_inodes_has_valid_blocks2() that encrypted symlinks always
use an external block (i.e., we never try to store the symlink in the
i_blocks[] array if it is encrypted).
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The Android.mk files were taken from the Android AOSP sources, and
updated for the 1.43 next branch. The intention is that this will
allow the repository which is currently located in external/e2fsprogs
with one which is based off of the upstream e2fsprogs. Right now
external/e2fsprogs was not created using "git clone", so it means that
git merges don't work. After the external/e2fsprogs Android
repository is replaced, with one based off the upstream repository,
Android will be able to synchronize with the upstream repository by
pulling and merging from upstream, and then running the script
"./util/gen-android-files" to update any generated files. (This is
necessary because in the Android build system, the Android.mk files
are rather stylized and don't make it easy to run arbitrary shell
scripts during the build phase.)
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The C preprocessing symbol NDEBUG is also defined (differently) by
Android's build files, and this was causing compilation failures. So
change assert() to dict_assert() and manually define it instead of
relying on the NDEBUG and <assert.h> semantics.
Also make sure the necessary debugging functions are available is
DICT_NODEBUG is not defined, so that dict.c will correctly build with
and without DICT_NODEBUG.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Provide a mechanism for a user to switch fsck into '-y' mode if they
start an interactive session and then get tired of pressing 'y' in
response to numerous prompts.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The bug fix in f66e6ce4446: "libext2fs: avoid buffer overflow if
s_first_meta_bg is too big" had a typo in the fix for
ext2fs_closefs(). In practice most of the security exposure was from
the openfs path, since this meant if there was a carefully crafted
file system, buffer overrun would be triggered when the file system was
opened.
However, if corrupted file system didn't trip over some corruption
check, and then the file system was modified via tune2fs or debugfs,
such that the superblock was marked dirty and then written out via the
closefs() path, it's possible that the buffer overrun could be
triggered when the file system is closed.
Also clear up a signed vs unsigned warning while we're at it.
Thanks to Nick Kralevich <nnk@google.com> for asking me to look at
compiler warning in the code in question, which led me to notice the
bug in f66e6ce444.
Addresses: CVE-2015-1572
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If the directory processing code ends up pointing to a directory entry
that's so close to the end of the block that there's not even space
for a rec_len/name_len, just substitute dummy values that will force
e2fsck to extend the previous entry to cover the remaining space. We
can't use the helper methods to extract rec_len because that's reading
off the end of the buffer.
This isn't an issue with non-inline directories because the directory
check buffer is zero-extended so that fsck won't blow up.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Strengthen the checks that guess if the inode we're looking at is an
inline directory. The current check sweeps up any inline inode if
its length is a multiple of four; now we'll at least try to see if
there's the beginning of a valid directory entry.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The design of inline directories (apparently) calls for the i_block[]
region and the EA regions to be treated as if they were two separate
blocks of dirents. Effectively this means that it is impossible for a
directory entry to straddle both areas. e2fsck doesn't enforce this,
so teach it to do so. e2fslib already knows to do this....
Cc: Zheng Liu <gnehzuil.liu@gmail.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Decrement the bad count *after* we've shown that (a) we can allocate a
replacement block and (b) remap the file block. Unfortunately,
the only way to tell if the remapping succeeded is to wait until the
next clone_file_block() call or block_iterate3() returns.
Otherwise, there's a corruption error: we decrease the badcount once in
preparation to remap, then the remap fails (either we can't find a
replacement block or we have to split the extent tree and can't find a
new extent block), so we delete the file, which decreases the badcount
on the block a second time. Later on e2fsck will think that it's
straightened out all the duplicate blocks, which isn't true.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
An earlier patch tried to detect indirect blocks that conflicted with
critical FS metadata for the purpose of preventing corrections being
made to those indirect blocks. Unfortunately, that patch cannot
handle more than one conflicting *ind block per file; therefore, use
the ref_block parameter to test the metadata block map to decide if
we need to avoid fixing the *ind block when we're iterating the
block's entries. (We have to iterate the block to capture any blocks
that the block points to, as they could be in use.)
As a side note, in 1B we'll reallocate all those conflicting *ind
blocks and restart fsck, so the contents will be checked eventually.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When we recreate the journal, don't say that the FS "is now ext3
again", since we could be fixing a damaged ext4 FS journal, which does
not magically convert the FS back to ext3.
[ Use "journaled" instead of "journalled", and also fix the message we
print when deleting the journal --Ted ]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If e2fsck encounters a read error on a block past the end of the
filesystem, don't bother trying to "rewrite" the block. We might
still want to re-try the read to capture FS data marooned past the end
of the filesystem, but in that case e2fsck ought to move the block
back inside the filesystem.
This enables e2fuzz to detect writes past the end of the FS due to
software bugs.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If we decide to clear a special inode because of bad mappings, we need
to zero the i_block array. The clearing routine depends on setting
i_links_count to zero to keep us from re-checking the block maps,
but that field isn't checked for special inodes. Therefore, if we
haven't erased the mappings, check_blocks will restart fsck and fsck
will try to check the blocks again, leading to an infinite loop.
(This seems easy to trigger if the bootloader inode extent map is
corrupted.)
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If the user tries to enable or disable the 64bit feature via tune2fs,
tell them how to use resize2fs to effect the conversion.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>