Commit bf5fc093c5 refactored
btrfs_ioctl_space_info() and introduced several security issues.
space_args.space_slots is an unsigned 64-bit type controlled by a
possibly unprivileged caller. The comparison as a signed int type
allows providing values that are treated as negative and cause the
subsequent allocation size calculation to wrap, or be truncated to 0.
By providing a size that's truncated to 0, kmalloc() will return
ZERO_SIZE_PTR. It's also possible to provide a value smaller than the
slot count. The subsequent loop ignores the allocation size when
copying data in, resulting in a heap overflow or write to ZERO_SIZE_PTR.
The fix changes the slot count type and comparison typecast to u64,
which prevents truncation or signedness errors, and also ensures that we
don't copy more data than we've allocated in the subsequent loop. Note
that zero-size allocations are no longer possible since there is already
an explicit check for space_args.space_slots being 0 and truncation of
this value is no longer an issue.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Mark the cloned backref_node as checked in clone_backref_node()
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Btrfs tracks uptodate state in an rbtree as well as in the
page bits. This is supposed to enable us to use block sizes other than
the page size, but there are a few parts still missing before that
completely works.
But, our readpage routine trusts this additional range based tracking
of uptodateness, much in the same way the buffer head up to date bits
are trusted for the other filesystems.
The problem is that sometimes we need to allocate memory in order to
split records in the rbtree, even when we are just clearing bits. This
can be difficult when our clearing function is called GFP_ATOMIC, which
can happen in the releasepage path.
So, what happens today looks like this:
releasepage called with GFP_ATOMIC
btrfs_releasepage calls clear_extent_bit
clear_extent_bit fails to allocate ram, leaving the up to date bit set
btrfs_releasepage returns success
The end result is the page being gone, but btrfs thinking the range is
up to date. Later on if someone tries to read that same page, the
btrfs readpage code will return immediately thinking the page is already
up to date.
This commit fixes things to fail the releasepage when we can't clear the
extent state bits. It covers both data pages and metadata tree blocks.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
There is a race where btrfs_releasepage can drop the
page->private contents just as alloc_extent_buffer is setting
up pages for metadata. Because of how the Btrfs page flags work,
this results in us skipping the crc on the page during IO.
This patch sovles the race by waiting until after the extent buffer
is inserted into the radix tree before it sets page private.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
take offset of start position into account when calculating page count.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
As this function is called in some error paths while not
removing the module, the __exit attribute prevents the kernel
image from linking when btrfs is compiled in statically.
Signed-off-by: Alexey Charkov <alchark@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When btrfs_alloc_path() fails, btrfs_free_path() need not be called.
Therefore, it changes the branch ahead.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This has been resulting in a BUT_ON(ret) after btrfs_reserve_extent in
btrfs_cow_file_range. The reason is we don't actually calculate the bytes_super
for a block group until we go to cache it, which means that the space_info can
hand out reservations for space that it doesn't actually have, and we can run
out of data space. This is also a problem if you are using space caching since
we don't ever calculate bytes_super for the block groups. So instead everytime
we read a block group call exclude_super_stripes, which calculates the
bytes_super for the block group so it can be left out of the space_info. Then
whenever caching completes we just call free_excluded_extents so that the super
excluded extents are freed up. Also if we are unmounting and we hit any block
groups that haven't been cached we still need to call free_excluded_extents to
make sure things are cleaned up properly. Thanks,
Reported-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When we're cleaning up the tree log we need to be able to remove free space from
the block group. The problem is if that free space spans bitmaps we would not
find the space since we're looking for too many bytes. So make sure the amount
of bytes we search for is limited to either the number of bytes we want, or the
number of bytes left in the bitmap. This was tested by a user who was hitting
the BUG() after search_bitmap. With this patch he can now mount his fs.
Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The error check of btrfs_start_transaction() is added, and the mistake
of the error check on several places is corrected.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Because NULL is returned when the memory allocation fails,
it is checked whether it is NULL.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This one isn't really an uninit variable, but for pretty
obscure reasons. Let's make it clearly correct.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
btrfs_sync_log returns -EAGAIN when we need full transaction commits
instead of small log commits, but sometimes we were dropping the return
value.
In practice, we check for this a few different ways, but this is still a
bug that can leave off full log commits when we really need them.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Xfstests 224 will just sit there and spin for ever until eventually we give up
flushing delalloc and exit. On my box this took several hours. I could not
interrupt this process either, even though we use INTERRUPTIBLE. So do 2 things
1) Keep us from looping over and over again without reclaiming anything
2) If we get interrupted exit the loop
I tested this and the test now exits in a reasonable amount of time, and can be
interrupted with ctrl+c. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Instead of doing a BUG_ON(1) in prepare_pages if grab_cache_page() fails, just
loop through the pages we've already grabbed and unlock and release them, then
return -ENOMEM like we should. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Got a report of a box panicing because we got a NULL eb in read_extent_buffer.
His fs was borked and btrfs_search_path returned EIO, but we don't check for
errors so the box paniced. Yes I know this will just make something higher up
the stack panic, but that's a problem for future Josef. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We call use_block_rsv right before we make an allocation in order to make sure
we have enough space. Now normally people have called btrfs_start_transaction()
with the appropriate amount of space that we need, so we just use some of that
pre-reserved space and move along happily. The problem is where people use
btrfs_join_transaction(), which doesn't actually reserve any space. So we try
and reserve space here, but we cannot flush delalloc, so this forces us to
return -ENOSPC when in reality we have plenty of space. The most common symptom
is seeing a bunch of "couldn't dirty inode" messages in syslog. With
xfstests 224 we end up falling back to start_transaction and then doing all the
flush delalloc stuff which causes to hang for a very long time.
So instead steal from the global reserve, which is what this is meant for
anyway. With this patch and the other 2 I have sent xfstests 224 now passes
successfully. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When we do btrfs_block_rsv_release, if global_block_rsv is not full we will
release all the extra bytes to global_block_rsv, even if it's only a little
short of the amount of space that we need to reserve. This causes us to starve
ourselves of reservable space during the transaction which will force us to
shrink delalloc bytes and commit the transaction more often than we should. So
instead just add the amount of bytes we need to add to the global reserve so
reserved == size, and then add the rest back into the space_info for general
use. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When running xfstests 224 I kept getting ENOSPC when trying to remove the files,
and this is because we were returning ret from check_path_shared while it was
uninitalized, which isn't right. Fix this to return 0 properly, and now
xfstests 224 doesn't freak out when it tries to clean itself up. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
btrfs_start_ioctl_transaction() returns ERR_PTR(), not NULL.
So, it is necessary to use IS_ERR() to check the return value.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The error check of btrfs_join_transaction()/btrfs_join_transaction_nolock()
is added, and the mistake of the error check in several places is
corrected.
For more stable Btrfs, I think that we should reduce BUG_ON().
But, I think that long time is necessary for this.
So, I propose this patch as a short-term solution.
With this patch:
- To more stable Btrfs, the part that should be corrected is clarified.
- The panic isn't done by the NULL pointer reference etc. (even if
BUG_ON() is increased temporarily)
- The error code is returned in the place where the error can be easily
returned.
As a long-term plan:
- BUG_ON() is reduced by using the forced-readonly framework, etc.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
After the conditional that precedes the following code, inode may be an
ERR_PTR value. This can eg result from a memory allocation failure via the
call to btrfs_iget, and thus does not imply that root is different than
sub_root. Thus, an IS_ERR check is added to ensure that there is no
dereference of inode in this case.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@r@
identifier f;
@@
f(...) { ... return ERR_PTR(...); }
@@
identifier r.f, fld;
expression x;
statement S1,S2;
@@
x = f(...)
... when != IS_ERR(x)
(
if (IS_ERR(x) ||...) S1 else S2
|
*x->fld
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
To make btrfs more stable, add several missing necessary memory allocation
checks, and when no memory, return proper errno.
We've checked that some of those -ENOMEM errors will be returned to
userspace, and some will be catched by BUG_ON() in the upper callers,
and none will be ignored silently.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
btrfs_submit_compressed_read() is lack of memory allocation checks and
corresponding error route.
After this fix, if it comes to "no memory" case, errno will be returned
to userland step by step, and tell users this operation cannot go on.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Suppose:
- the source extent is: [0, 100]
- the src offset is 10
- the clone length is 90
- the dest offset is 0
This statement:
new_key.offset = key.offset + destoff - off
will produce such an extent for the dest file:
[ino, BTRFS_EXTENT_DATA_KEY, -10]
, which is obviously wrong.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
fixup, which is allocated when starting page write to fix up the
extent without ORDERED bit set, should be freed after this work
is done.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
We must save and free the original kstrdup()'ed pointer
because strsep() modifies its first argument.
Signed-off-by: Tero Roponen <tero.roponen@gmail.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
We missed a memory deallocation in commit 450ba0ea.
If an existing super block is found at mount and there is no
error condition then the pre-allocated tree_root and fs_info
are no not used and are not freeded.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
After returing extents from a cluster to the block group, some
extents in the block group may be mergeable.
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
When adding a new extent, we'll firstly see if we can merge
this extent to the left or/and right extent. Extract this as
a helper try_merge_free_space().
As a side effect, we fix a small bug that if the new extent
has non-bitmap left entry but is unmergeble, we'll directly
link the extent without trying to drop it into bitmap.
This also prepares for the next patch.
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
When allocating extent entry from a cluster, we should update
the free_space and free_extents fields of the block group.
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
If there's no more free space in a bitmap, we should free it.
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Remove some duplicated code.
This prepares for the next patch.
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
If a block group is smaller than 1GB, the extent entry threadhold
calculation will always set the threshold to 0.
So as free space gets fragmented, btrfs will switch to use bitmap
to manage free space, but then will never switch back to extents
due to this bug.
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
This patch comes from "Forced readonly mounts on errors" ideas.
As we know, this is the first step in being more fault tolerant of disk
corruptions instead of just using BUG() statements.
The major content:
- add a framework for generating errors that should result in filesystems
going readonly.
- keep FS state in disk super block.
- make sure that all of resource will be freed and released at umount time.
- make sure that fter FS is forced readonly on error, there will be no more
disk change before FS is corrected. For this, we should stop write operation.
After this patch is applied, the conversion from BUG() to such a framework can
happen incrementally.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Filesystem rebalancing (BTRFS_IOC_BALANCE) affects the entire
filesystem and may run uninterruptibly for a long time. This does not
seem to be something that an unprivileged user should be able to do.
Reported-by: Aron Xu <happyaron.xu@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
If we run low on space we could get a bunch of warnings out of
btrfs_block_rsv_check, but this is mostly just called via the transaction code
to see if we need to end the transaction, it expects to see failures, so let's
not WARN and freak everybody out for no reason. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
In btrfs_read_fs_root_no_radix(), 'root' is not freed if
btrfs_search_slot() returns error.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Hi,
In fs/btrfs/inode.c::fixup_tree_root_location() we have this code:
...
if (!path) {
err = -ENOMEM;
goto out;
}
...
out:
btrfs_free_path(path);
return err;
btrfs_free_path() passes its argument on to other functions and some of
them end up dereferencing the pointer.
In the code above that pointer is clearly NULL, so btrfs_free_path() will
eventually cause a NULL dereference.
There are many ways to cut this cake (fix the bug). The one I chose was to
make btrfs_free_path() deal gracefully with NULL pointers. If you
disagree, feel free to come up with an alternative patch.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
I happened to pass swap partition as root partition in cmdline,
then kernel panic and tell me about "Cannot open root device".
It is not correct, in fact it is a fs type mismatch instead of 'no device'.
Eventually I found btrfs mounting failed with -EIO, it should be -EINVAL.
The logic in init/do_mounts.c:
for (p = fs_names; *p; p += strlen(p)+1) {
int err = do_mount_root(name, p, flags, root_mount_data);
switch (err) {
case 0:
goto out;
case -EACCES:
flags |= MS_RDONLY;
goto retry;
case -EINVAL:
continue;
}
print "Cannot open root device"
panic
}
SO fs type after btrfs will have no chance to mount
Here fix the return value as -EINVAL
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
It seems to me that we leak the memory allocated to 'value' in
btrfs_get_acl() if the call to posix_acl_from_xattr() fails.
Here's a patch that attempts to correct that problem.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When we store data by raid profile in btrfs with two or more different size
disks, df command shows there is some free space in the filesystem, but the
user can not write any data in fact, df command shows the wrong free space
information of btrfs.
# mkfs.btrfs -d raid1 /dev/sda9 /dev/sda10
# btrfs-show
Label: none uuid: a95cd49e-6e33-45b8-8741-a36153ce4b64
Total devices 2 FS bytes used 28.00KB
devid 1 size 5.01GB used 2.03GB path /dev/sda9
devid 2 size 10.00GB used 2.01GB path /dev/sda10
# btrfs device scan /dev/sda9 /dev/sda10
# mount /dev/sda9 /mnt
# dd if=/dev/zero of=tmpfile0 bs=4K count=9999999999
(fill the filesystem)
# sync
# df -TH
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda9 btrfs 17G 8.6G 5.4G 62% /mnt
# btrfs-show
Label: none uuid: a95cd49e-6e33-45b8-8741-a36153ce4b64
Total devices 2 FS bytes used 3.99GB
devid 1 size 5.01GB used 5.01GB path /dev/sda9
devid 2 size 10.00GB used 4.99GB path /dev/sda10
It is because btrfs cannot allocate chunks when one of the pairing disks has
no space, the free space on the other disks can not be used for ever, and should
be subtracted from the total space, but btrfs doesn't subtract this space from
the total. It is strange to the user.
This patch fixes it by calcing the free space that can be used to allocate
chunks.
Implementation:
1. get all the devices free space, and align them by stripe length.
2. sort the devices by the free space.
3. check the free space of the devices,
3.1. if it is not zero, and then check the number of the devices that has
more free space than this device,
if the number of the devices is beyond the min stripe number, the free
space can be used, and add into total free space.
if the number of the devices is below the min stripe number, we can not
use the free space, the check ends.
3.2. if the free space is zero, check the next devices, goto 3.1
This implementation is just likely fake chunk allocation.
After appling this patch, df can show correct space information:
# df -TH
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda9 btrfs 17G 8.6G 0 100% /mnt
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
With this patch, we change the handling method when we can not get enough free
extents with default size.
Implementation:
1. Look up the suitable free extent on each device and keep the search result.
If not find a suitable free extent, keep the max free extent
2. If we get enough suitable free extents with default size, chunk allocation
succeeds.
3. If we can not get enough free extents, but the number of the extent with
default size is >= min_stripes, we just change the mapping information
(reduce the number of stripes in the extent map), and chunk allocation
succeeds.
4. If the number of the extent with default size is < min_stripes, sort the
devices by its max free extent's size descending
5. Use the size of the max free extent on the (num_stripes - 1)th device as the
stripe size to allocate the device space
By this way, the chunk allocator can allocate chunks as large as possible when
the devices' space is not enough and make full use of the devices.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
- make it return the start position and length of the max free space when it can
not find a suitable free space.
- make it more readability
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
There are two tiny problem:
- One is When we check the chunk size is greater than the max chunk size or not,
we should take mirrors into account, but the original code didn't.
- The other is btrfs shouldn't use the size of the residual free space as the
length of of a dup chunk when doing chunk allocation. It is because the device
space that a dup chunk needs is twice as large as the chunk size, if we use
the size of the residual free space as the length of a dup chunk, we can not
get enough free space. Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Dan Rosenberg