btrfs currently handles most errors with BUG_ON. This patch is a work-in-
progress but aims to handle most errors other than internal logic
errors and ENOMEM more gracefully.
This iteration prevents most crashes but can run into lockups with
the page lock on occasion when the timing "works out."
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
btrfs_alloc_chunk() unconditionally BUGs on any error returned from
__finish_chunk_alloc() so there's no need for two BUG_ON lines. Remove the
one from __finish_chunk_alloc().
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
We BUG_ON() error from add_extent_mapping(), but that error looks pretty
easy to bubble back up - as far as I can tell there have not been any
permanent modifications to fs state at that point.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
The only caller of btrfs_alloc_dev_extent() is __btrfs_alloc_chunk() which
already bugs on any error returned. We can remove the BUG_ON's in
btrfs_alloc_dev_extent() then since __btrfs_alloc_chunk() will "catch" them
anyway.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
balace_level() seems to deal with missing tree nodes by BUG_ON(). Instead,
we can easily just set the file system readonly and bubble -EROFS back up
the stack.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
__btrfs_cow_block(), the only caller of update_ref_for_cow() will BUG_ON()
any error return. Instead, we can go read-only fs as update_ref_for_cow()
manipulates disk data in a way which doesn't look like it's easily rolled
back.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
update_ref_for_cow() will BUG_ON() after it's call to
btrfs_lookup_extent_info() if no existing references are found. Since refs
are computed directly from disk, this should be treated as a corruption
instead of a logic error.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
All callers of __finish_chunk_alloc() BUG_ON() return value, so it's trivial
for us to always bubble up any errors caught in __finish_chunk_alloc() to be
caught there.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Unfortunately it isn't enough to just exit here - the kzalloc() happens in a
loop and the allocated items are added to a linked list whose head is passed
in from the caller.
To fix the BUG_ON() and also provide the semantic that the list passed in is
only modified on success, I create function-local temporary list that we add
items too. If no error is met, that list is spliced to the callers at the
end of the function. Otherwise the list will be walked and all items freed
before the error value is returned.
I did a simple test on this patch by forcing an error at the kzalloc() point
and verifying that when this hits (git clone seemed to exercise this), the
function throws the proper error. Unfortunately but predictably, we later
hit a BUG_ON(ret) type line that still hasn't been fixed up ;)
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The only caller of update_ref_for_cow() is __btrfs_cow_block() which was
originally ignoring any return values. update_ref_for_cow() however doesn't
look like a candidate to become a void function - there are a few places
where errors can occur.
So instead I changed update_ref_for_cow() to bubble all errors up (instead
of BUG_ON). __btrfs_cow_block() was then updated to catch and BUG_ON() any
errors from update_ref_for_cow(). The end effect is that we have no change
in behavior, but about 8 different places where a BUG_ON(ret) was removed.
Obviously a future patch will have to address the BUG_ON() in
__btrfs_cow_block().
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
This is called from only one place - create_subvol() which passes errors
safely back out to it's caller, btrfs_mksubvol where they are handled.
Additionally, btrfs_create_subvol_root() itself bug's needlessly from error
return of btrfs_update_inode(). Since create_subvol() was fixed to catch
errors we can bubble this one up too.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Commit cb1b69f4 (Btrfs: forced readonly when btrfs_drop_snapshot() fails)
made btrfs_drop_snapshot return void because there were no callers checking
the return value. That is the wrong order to handle error propogation since
the caller will have no idea that an error has occured and continue on
as if nothing went wrong.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
set_extent_bit can do exclusive locking but only when called by lock_extent*,
Drop the exclusive bits argument except when called by lock_extent.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
lock_extent and unlock_extent are always called with GFP_NOFS, drop the
argument and use GFP_NOFS consistently.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
This patch pushes kmalloc errors up to the caller and BUGs in the caller.
The BUG_ON for duplicate reloc tree root insertion is replaced with a
panic explaining the issue.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
This pushes failures from the submit_bio_hook callbacks,
btrfs_submit_bio_hook and btree_submit_bio_hook into the callers, including
callers of submit_one_bio where it catches the failures with BUG_ON.
It also pushes up through the ->readpage_io_failed_hook to
end_bio_extent_writepage where the error is already caught with BUG_ON.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
In submit_extent_page, there's a visually noisy if statement that, in
the midst of other conditions, does the tree dependency for tree->ops
and tree->ops->merge_bio_hook before calling it, and then another
condition afterwards. If an error is returned from merge_bio_hook,
there's no way to catch it. It's considered a routine "1" return
value instead of a failure.
This patch factors out the dependency check into a new local merge_bio
routine and BUG's on an error. The if statement is less noisy as a side-
effect.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
btrfs_submit_bio_hook currently calls btrfs_bio_wq_end_io in either case
of an if statement that determines one of the arguments.
This patch moves the function call outside of the if statement and uses it
to only determine the different argument. This allows us to catch an
error in one place in a more visually obvious way.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
btrfs_update_root BUG's when it can't alloc a path, yet it can recover
from a search error. This patch returns -ENOMEM instead.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
find_and_setup_root BUGs when it encounters an error from
btrfs_find_last_root, which can occur if a path can't be allocated.
This patch pushes it up to its callers where it is already handled.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
There is only one caller of clear_extent_bit that checks the return value
and it only checks if it's negative. Since there are no users of the
returned bits functionality of clear_extent_bit, stop returning it
and avoid complicating error handling.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
The only error condition in clean_tree_block is an accounting bug.
Returning without modifying dirty_metadata_bytes and as if the cleaning
as been performed may cause problems later so it should panic instead.
It should probably be a BUG_ON but we have btrfs_panic now.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Correctness fix: The kfree calls in the add_delayed_* functions free
the node that's passed into it, but the node is a member of another
structure. It works because it's always the first member of the
containing structure, but it should really be using the containing
structure itself.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
The ordered data and relocation trees have BUG_ONs to protect against
bad tree operations.
This patch replaces them with a panic that will report the problem.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
The *_state functions can only return 0 or -EEXIST. This patch addresses
the cases where those functions returning -EEXIST represent a locking
failure. It handles them by panicking with an appropriate error message.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
As part of the effort to eliminate BUG_ON as an error handling
technique, we need to determine which errors are actual logic errors,
which are on-disk corruption, and which are normal runtime errors
e.g. -ENOMEM.
Annotating these error cases is helpful to understand and report them.
This patch adds a btrfs_panic() routine that will either panic
or BUG depending on the new -ofatal_errors={panic,bug} mount option.
Since there are still so many BUG_ONs, it defaults to BUG for now but I
expect that to change once the error handling effort has made
significant progress.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Commit 28d82dc1c4 ("epoll: limit paths") that I did to limit the
number of possible wakeup paths in epoll is causing a few applications
to longer work (dovecot for one).
The original patch is really about limiting the amount of epoll nesting
(since epoll fds can be attached to other fds). Thus, we probably can
allow an unlimited number of paths of depth 1. My current patch limits
it at 1000. And enforce the limits on paths that have a greater depth.
This is captured in: https://bugzilla.redhat.com/show_bug.cgi?id=681578
Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge some more email patches from Andrew Morton:
"A couple of nilfs fixes"
* emailed from Andrew Morton <akpm@linux-foundation.org>:
nilfs2: fix NULL pointer dereference in nilfs_load_super_block()
nilfs2: clamp ns_r_segments_percentage to [1, 99]
ns_r_segments_percentage is read from the disk. Bogus or malicious
value could cause integer overflow and malfunction due to meaningless
disk usage calculation. This patch reports error when mounting such
bogus volumes.
Signed-off-by: Haogang Chen <haogangchen@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When writing files to afs I sometimes hit a BUG:
kernel BUG at fs/afs/rxrpc.c:179!
With a backtrace of:
afs_free_call
afs_make_call
afs_fs_store_data
afs_vnode_store_data
afs_write_back_from_locked_page
afs_writepages_region
afs_writepages
The cause is:
ASSERT(skb_queue_empty(&call->rx_queue));
Looking at a tcpdump of the session the abort happens because we
are exceeding our disk quota:
rx abort fs reply store-data error diskquota exceeded (32)
So the abort error is valid. We hit the BUG because we haven't
freed all the resources for the call.
By freeing any skbs in call->rx_queue before calling afs_free_call
we avoid hitting leaking memory and avoid hitting the BUG.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A read of a large file on an afs mount failed:
# cat junk.file > /dev/null
cat: junk.file: Bad message
Looking at the trace, call->offset wrapped since it is only an
unsigned short. In afs_extract_data:
_enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count);
...
if (call->offset < count) {
if (last) {
_leave(" = -EBADMSG [%d < %zu]", call->offset, count);
return -EBADMSG;
}
Which matches the trace:
[cat ] ==> afs_extract_data({65132},{524},1,,65536)
[cat ] <== afs_extract_data() = -EBADMSG [0 < 65536]
call->offset went from 65132 to 0. Fix this by making call->offset an
unsigned int.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull block fixes from Jens Axboe:
"Been sitting on this for a while, but lets get this out the door.
This fixes various important bugs for 3.3 final, along with a few more
trivial ones. Please pull!"
* 'for-linus' of git://git.kernel.dk/linux-block:
block: fix ioc leak in put_io_context
block, sx8: fix pointer math issue getting fw version
Block: use a freezable workqueue for disk-event polling
drivers/block/DAC960: fix -Wuninitialized warning
drivers/block/DAC960: fix DAC960_V2_IOCTL_Opcode_T -Wenum-compare warning
block: fix __blkdev_get and add_disk race condition
block: Fix setting bio flags in drivers (sd_dif/floppy)
block: Fix NULL pointer dereference in sd_revalidate_disk
block: exit_io_context() should call elevator_exit_icq_fn()
block: simplify ioc_release_fn()
block: replace icq->changed with icq->flags
Pull CIFS fixes from Steve French.
* git://git.samba.org/sfrench/cifs-2.6:
CIFS: Do not kmalloc under the flocks spinlock
cifs: possible memory leak in xattr.
complete_walk() returns either ECHILD or ESTALE. do_last() turns this into
ECHILD unconditionally. If not in RCU mode, this error will reach userspace
which is complete nonsense.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
complete_walk() already puts nd->path, no need to do it again at cleanup time.
This would result in Oopses if triggered, apparently the codepath is not too
well exercised.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
udf_release_file() can be called from munmap() path with mmap_sem held. Thus
we cannot take i_mutex there because that ranks above mmap_sem. Luckily,
i_mutex is not needed in udf_release_file() anymore since protection by
i_data_sem is enough to protect from races with write and truncate.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
9a7aa12f39 introduced additional logic around setting the i_mutex
lockdep class for directory inodes. The idea was that some filesystems
may want their own special lockdep class for different directory
inodes and calling unlock_new_inode() should not clobber one of
those special classes.
I believe that the added conditional, around the *negated* return value
of lockdep_match_class(), caused directory inodes to be placed in the
wrong lockdep class.
inode_init_always() sets the i_mutex lockdep class with i_mutex_key for
all inodes. If the filesystem did not change the class during inode
initialization, then the conditional mentioned above was false and the
directory inode was incorrectly left in the non-directory lockdep class.
If the filesystem did set a special lockdep class, then the conditional
mentioned above was true and that class was clobbered with
i_mutex_dir_key.
This patch removes the negation from the conditional so that the i_mutex
lockdep class is properly set for directory inodes. Special classes are
preserved and directory inodes with unmodified classes are set with
i_mutex_dir_key.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Current code has put_ioctx() called asynchronously from aio_fput_routine();
that's done *after* we have killed the request that used to pin ioctx,
so there's nothing to stop io_destroy() waiting in wait_for_all_aios()
from progressing. As the result, we can end up with async call of
put_ioctx() being the last one and possibly happening during exit_mmap()
or elf_core_dump(), neither of which expects stray munmap() being done
to them...
We do need to prevent _freeing_ ioctx until aio_fput_routine() is done
with that, but that's all we care about - neither io_destroy() nor
exit_aio() will progress past wait_for_all_aios() until aio_fput_routine()
does really_put_req(), so the ioctx teardown won't be done until then
and we don't care about the contents of ioctx past that point.
Since actual freeing of these suckers is RCU-delayed, we don't need to
bump ioctx refcount when request goes into list for async removal.
All we need is rcu_read_lock held just over the ->ctx_lock-protected
area in aio_fput_routine().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Have ioctx_alloc() return an extra reference, so that caller would drop it
on success and not bother with re-grabbing it on failure exit. The current
code is obviously broken - io_destroy() from another thread that managed
to guess the address io_setup() would've returned would free ioctx right
under us; gets especially interesting if aio_context_t * we pass to
io_setup() points to PROT_READ mapping, so put_user() fails and we end
up doing io_destroy() on kioctx another thread has just got freed...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull btrfs updates from Chris Mason:
"I have two additional and btrfs fixes in my for-linus branch. One is
a casting error that leads to memory corruption on i386 during scrub,
and the other fixes a corner case in the backref walking code (also
triggered by scrub)."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix casting error in scrub reada code
btrfs: fix locking issues in find_parent_nodes()
Reorganize the code to make the memory already allocated before
spinlock'ed loop.
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Memory is allocated irrespective of whether CIFS_ACL is configured
or not. But free is happenning only if CIFS_ACL is set. This is a
possible memory leak scenario.
Fix is:
Allocate and free memory only if CIFS_ACL is configured.
Signed-off-by: Santosh Nayak <santoshprasadnayak@gmail.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Pull CIFS fixes from Steve French
* git://git.samba.org/sfrench/cifs-2.6:
cifs: fix dentry refcount leak when opening a FIFO on lookup
CIFS: Fix mkdir/rmdir bug for the non-POSIX case
Merge the emailed seties of 19 patches from Andrew Morton
* akpm:
rapidio/tsi721: fix queue wrapping bug in inbound doorbell handler
memcg: fix mapcount check in move charge code for anonymous page
mm: thp: fix BUG on mm->nr_ptes
alpha: fix 32/64-bit bug in futex support
memcg: fix GPF when cgroup removal races with last exit
debugobjects: Fix selftest for static warnings
floppy/scsi: fix setting of BIO flags
memcg: fix deadlock by inverting lrucare nesting
drivers/rtc/rtc-r9701.c: fix crash in r9701_remove()
c2port: class_create() returns an ERR_PTR
pps: class_create() returns an ERR_PTR, not NULL
hung_task: fix the broken rcu_lock_break() logic
vfork: kill PF_STARTING
coredump_wait: don't call complete_vfork_done()
vfork: make it killable
vfork: introduce complete_vfork_done()
aio: wake up waiters when freeing unused kiocbs
kprobes: return proper error code from register_kprobe()
kmsg_dump: don't run on non-error paths by default
Now that CLONE_VFORK is killable, coredump_wait() no longer needs
complete_vfork_done(). zap_threads() should find and kill all tasks with
the same ->mm, this includes our parent if ->vfork_done is set.
mm_release() becomes the only caller, unexport complete_vfork_done().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jeff Mahoney