Commit Graph

49313 Commits

Author SHA1 Message Date
David Sterba
3fb99303c6 btrfs: scrub: embed scrub_wr_ctx into scrub context
The structure scrub_wr_ctx is not used anywhere just the scrub context,
we can move the members there. The tgtdev is renamed so it's more clear
that it belongs to the "wr" part.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
David Sterba
25cc1226c1 btrfs: scrub: use fs_info::sectorsize and drop it from scrub context
As we now have the node/block sizes in fs_info, we can use them and can
drop the local copies.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Yonghong Song
04a87e3472 Btrfs: add statx support
Return enhanced file attributes from the btrfs, including:
  (1). inode creation time as stx_btime, and
  (2). Certain BTRFS_INODE_xxx flags are mapped to stx_attributes flags.

Example output:
	[root@localhost ~]# cat t.sh
	touch t
	chattr +aic t
	~/linux/samples/statx/test-statx t
	chattr -aic t
	touch t
	echo "========================================"
	~/linux/samples/statx/test-statx t
	/bin/rm t
	[root@localhost ~]# ./t.sh
	statx(t) = 0
	results=fff
  	  Size: 0               Blocks: 0          IO Block: 4096    regular file
	Device: 00:1c           Inode: 63962       Links: 1
	Access: (0644/-rw-r--r--)  Uid:     0   Gid:     0
	Access: 2017-05-11 16:03:13.999856591-0700
	Modify: 2017-05-11 16:03:13.999856591-0700
	Change: 2017-05-11 16:03:14.000856663-0700
 	 Birth: 2017-05-11 16:03:13.999856591-0700
	Attributes: 0000000000000034 (........ ........ ........ ........ ........ ........ ........ .-ai.c..)
	========================================
	statx(t) = 0
	results=fff
	  Size: 0               Blocks: 0          IO Block: 4096    regular file
	Device: 00:1c           Inode: 63962       Links: 1
	Access: (0644/-rw-r--r--)  Uid:     0   Gid:     0
	Access: 2017-05-11 16:03:14.006857097-0700
	Modify: 2017-05-11 16:03:14.006857097-0700
	Change: 2017-05-11 16:03:14.006857097-0700
 	Birth: 2017-05-11 16:03:13.999856591-0700
	Attributes: 0000000000000000 (........ ........ ........ ........ ........ ........ ........ .---.-..)
	[root@localhost ~]#

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Timofey Titovets
036b0217ad Btrfs: lzo: fix typo in error message after failed deflate
Fix copy paste typo in debug message for lzo.c, lzo is not deflate.

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Jeff Layton
3189ff7786 btrfs: btrfs_wait_tree_block_writeback can be void return
Nothing checks its return value.

Is it safe to skip checking return value of btrfs_wait_tree_block_writeback?

Liu Bo: I think yes, it's used in walk_log_tree which is called in two
places, free_log_tree and log replay.  For free_log_tree, it waits for
any running writeback of the extent buffer under freeing to finish in
case we need to access the eb pointer from page->private, and it's OK to
not check the return value, while for log replay, it's doesn't wait
because wc->wait is not set. So neither cares about the writeback error.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
[ added more explanation to changelog, from Liu Bo ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Nikolay Borisov
118c701e20 btrfs: remove __BTRFS_LEAF_DATA_SIZE
__BTRFS_LAF_DATA_SIZE is used only by BTRFS_LEAF_DATA_SIZE. Make the
latter subsume the former.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Nikolay Borisov
3d9ec8c49a btrfs: rename btrfs_leaf_data to BTRFS_LEAF_DATA_OFFSET
Commit 5f39d397df ("Btrfs: Create extent_buffer interface
for large blocksizes") refactored btrfs_leaf_data function to take
extent_buffer rather than struct btrfs_leaf. However, as it turns out the
parameter being passed is never used. Furthermore this function no longer
returns the leaf data but rather the offset to it. So rename the function
to BTRFS_LEAF_DATA_OFFSET to make it consistent with other BTRFS_LEAF_*
helpers and turn it into a macro.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
[ removed () from the macro ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Anand Jain
e1ddce71d6 btrfs: reduce arguments for decompress_bio ops
struct compressed_bio pointer can be used instead.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Anand Jain
8140dc30a4 btrfs: btrfs_decompress_bio() could accept compressed_bio instead
Instead of sending each argument of struct compressed_bio, send
the compressed_bio itself.

Also by having struct compressed_bio in btrfs_decompress_bio()
it would help tracing.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Nikolay Borisov
d2006e6d28 btrfs: Refactor update_space_info
Following the factoring out of the creation code udpate_space_info can
only be called for already-existing space_info structs. As such it
cannot fail.  Remove superfluous error handling and make the function
return void.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Nikolay Borisov
2be12ef79f btrfs: Separate space_info create/update
Currently the struct space_info creation code is intermixed in the
udpate_space_info function. There are well-defined points at which the
we actually want to create brand-new space_info structs (e.g. during
mount of the filesystem as well as sometimes when adding/initialising
new chunks). In such cases update_space_info is called with 0 as the
bytes parameter. All of this makes for spaghetti code.

Fix it by factoring out the creation code in a separate
create_space_info structure. This also allows to simplify the internals.
Also remove BUG_ON from do_alloc_chunk since the callers handle errors.
Furthermore it will make the update_space_info function not fail,
allowing us to remove error handling in callers. This will come in a
follow up patch.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Liu Bo
555ba411aa Btrfs: let btrfs_print_leaf print more about block group
This adds chunk_objectid and flags, with flags we can recognize whether
the block group is about data or metadata.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Liu Bo
28785f70ef Btrfs: skip commit transaction if we don't have enough pinned bytes
We commit transaction in order to reclaim space from pinned bytes because
it could process delayed refs, and in may_commit_transaction(), we check
first if pinned bytes are enough for the required space, we then check if
that plus bytes reserved for delayed insert are enough for the required
space.

This changes the code to the above logic.

Fixes: b150a4f10d ("Btrfs: use a percpu to keep track of possibly pinned bytes")
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reported-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
David Sterba
4e2814ef04 btrfs: scrub: simplify cleanup of wr_ctx in scrub_free_ctx
We don't need to take the mutex and zero out wr_cur_bio, as this is
called after the scrub finished.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
David Sterba
e241ddeb9c btrfs: scrub: inline helper scrub_free_wr_ctx
The helper scrub_free_wr_ctx is used only once and fits into
scrub_free_ctx as it continues sctx shutdown, no need to keep it
separate.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
David Sterba
8fcdac3f20 btrfs: scrub: inline helper scrub_setup_wr_ctx
The helper scrub_setup_wr_ctx is used only once and fits into
scrub_setup_ctx as it continues intialization, no need to keep it
separate.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Jeff Mahoney
c1c4919b11 btrfs: remove root usage from can_overcommit
can_overcommit using the root to determine the allocation profile
is the only use of a root in the call graph below reserve_metadata_bytes.

It turns out that we only need to know whether the allocation is for
the chunk root or not -- and we can pass that around as a bool instead.

This allows us to pull root usage out of the reservation path all the
way up to reserve_metadata_bytes itself, which uses it only to compare
against fs_info->chunk_root to set the bool.  In turn, this eliminates
a bunch of races where we use a particular root too early in the mount
process.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Jeff Mahoney
1b86826d12 btrfs: cleanup root usage by btrfs_get_alloc_profile
There are two places where we don't already know what kind of alloc
profile we need before calling btrfs_get_alloc_profile, but we need
access to a root everywhere we call it.

This patch adds helpers for btrfs_{data,metadata,system}_alloc_profile()
and relegates btrfs_system_alloc_profile to a static for use in those
two cases.  The next patch will eliminate one of those.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
David Sterba
e03733da5a btrfs: fix bool type in btrfs_page_exists_in_range
We use only a simple bool indicator, int is not a problem here.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
David Sterba
c9fed2bb61 btrfs: remove unused member list from btrfs_end_io_wq
The end io work queue items have been tracked by the work queues since
"Btrfs: Add async worker threads for pre and post IO checksumming"
(8b71284292) (2008).

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
David Sterba
ee4ea69852 btrfs: remove unused members dir_path from recorded_ref
The two members do not seem to be used since the initial commit.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
David Sterba
b297c9f68f btrfs: remove unused member list from async_submit_bio
The list used to track checksums in the early version (2.6.29), but I
was able not pinpoint the commit that stopped using it. Everything
apparently works without it for a long time.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
David Sterba
106204f191 btrfs: remove unused member err from reada_extent
Seems to be unused since the initial commit, we ignore readahead errors
anyway, the full read will handle that if necessary.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Sahil Kang
0bef71093d btrfs: Remove unnecessary branching in free-space-tree.c
Both btrfs_create_free_space_tree and btrfs_clear_free_space_tree
contain:

  if (ret)
          return ret;

  return 0;

The if statement is only false when ret equals zero, and since we return
zero in such cases, we can safely remove the branching.

Signed-off-by: Sahil Kang <sahil.kang@asilaycomputing.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Liu Bo
e477094f0d Btrfs: hardcode GFP_NOFS for btrfs_bio_clone_partial
We only pass GFP_NOFS to btrfs_bio_clone_partial, so lets hardcode it.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Arnd Bergmann
3c91ee6964 Btrfs: work around maybe-uninitialized warning
A rewrite of btrfs_submit_direct_hook appears to have introduced a warning:

fs/btrfs/inode.c: In function 'btrfs_submit_direct_hook':
fs/btrfs/inode.c:8467:14: error: 'bio' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Where the 'bio' variable was previously initialized unconditionally, it
is now set in the "while (submit_len > 0)" loop that would never execute
if submit_len is zero.

Assuming this cannot happen in practice, we can avoid the warning
by simply replacing the while{} loop with a do{}while() loop so
the compiler knows that it will always be entered at least once.

Fixes changes introduced in "Btrfs: use bio_clone_bioset_partial to
simplify DIO submit".

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Liu Bo
3892ac9086 Btrfs: unify naming of btrfs_io_bio
All dio endio functions are using io_bio for struct btrfs_io_bio, this
makes btrfs_submit_direct to follow this convention.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Liu Bo
11b5616516 Btrfs: check-integrity use bvec_iter
Some check-integrity code depends on bio->bi_vcnt, this changes it to use
bio segments because some bios passing here may not have a reliable
bi_vcnt.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Liu Bo
629ebf4fad Btrfs: record error if one block has failed to retry
In the nocsum case of dio read endio, it returns immediately if an error
gets returned when repairing, which leaves the rest blocks unrepaired.  The
behavior is different from how buffered read endio works in the same case.
This changes it to record error only and go on repairing the rest blocks.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Liu Bo
17347cec15 Btrfs: change how we iterate bios in endio
Since dio submit has used bio_clone_fast, the submitted bio may not have a
reliable bi_vcnt, for the bio vector iterations in checksum related
functions, bio->bi_iter is not modified yet and it's safe to use
bio_for_each_segment, while for those bio vector iterations in dio read's
endio, we now save a copy of bvec_iter in struct btrfs_io_bio when cloning
bios and use the helper __bio_for_each_segment with the saved bvec_iter to
access each bvec.

Also for dio reads which don't get split, we also need to save a copy of
bio iterator in btrfs_bio_clone to let __bio_for_each_segments to access
each bvec in dio read's endio.  Note that it doesn't affect other calls of
btrfs_bio_clone() because they don't need to use this iterator.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Liu Bo
725130bac5 Btrfs: use bio_clone_bioset_partial to simplify DIO submit
Currently when mapping bio to limit bio to a single stripe length, we
split bio by adding page to bio one by one, but later we don't modify
the vector of bio at all, thus we can use bio_clone_fast to use the
original bio vector directly.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Liu Bo
2f8e914042 Btrfs: new helper btrfs_bio_clone_partial
This adds a new helper btrfs_bio_clone_partial, it'll allocate a cloned
bio that only owns a part of the original bio's data.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Liu Bo
015c1bd9f1 Btrfs: use bio_clone_fast to clone our bio
For raid1 and raid10, we clone the original bio to the bios which are then
sent to different disks.

Right now we use bio_clone_bioset to create a clone bio with iterating
bi_io_vec to initialize it.  This changes it to use bio_clone_fast()
which creates a clone bio but only copies the bi_io_vec pointer
instead of iterating bi_io_vec.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Josef Bacik
7870d0822b Btrfs: don't pass the inode through clean_io_failure
Instead pass around the failure tree and the io tree.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Josef Bacik
6ec656bc0f btrfs: remove inode argument from repair_io_failure
Once we remove the btree_inode we won't have an inode to pass anymore,
just pass the fs_info directly and the inum since we use that to print
out the repair message.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Josef Bacik
c6100a4b4e Btrfs: replace tree->mapping with tree->private_data
For extent_io tree's we have carried the address_mapping of the inode
around in the io tree in order to pull the inode back out for calling
into various tree ops hooks.  This works fine when everything that has
an extent_io_tree has an inode.  But we are going to remove the
btree_inode, so we need to change this.  Instead just have a generic
void * for private data that we can initialize with, and have all the
tree ops use that instead.  This had a lot of cascading changes but
should be relatively straightforward.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor reordering of the callback prototypes ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Sargun Dhillon
2723480a0f btrfs: Add quota_override knob into sysfs
This patch adds the read-write attribute quota_override into sysfs.
Any process which has CAP_SYS_RESOURCE can set this flag to on, and
once it is set to true, processes with CAP_SYS_RESOURCE can exceed
the quota.

Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor changelog edits ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Sargun Dhillon
f29efe2921 btrfs: add quota override flag to enable quota override for CAP_SYS_RESOURCE
This patch introduces the quota override flag to btrfs_fs_info, and a
change to quota limit checking code to temporarily allow for quota to be
overridden for processes with CAP_SYS_RESOURCE.

It's useful for administrative programs, such as log rotation, that may
need to temporarily use more disk space in order to free up a greater
amount of overall disk space without yielding more disk space to the
rest of userland.

Eventually, we may want to add the idea of an operator-specific quota,
operator reserved space, or something else to allow for administrative
override, but this is perhaps the simplest solution.

Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor changelog edits ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Nikolay Borisov
a5ed45f822 btrfs: Convert fs_info->free_chunk_space to atomic64_t
The ->free_chunk_space variable is used to track the unallocated space
and access to it is protected by a spinlock, which is not used for
anything else.  Make the code a bit self-explanatory by switching the
variable to an atomic64_t type and kill the spinlock.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
[ not a performance critical code, use of atomic type is ok ]
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Anand Jain
401b41e5a8 btrfs: add framework to handle device flush error as a volume
This adds comments to the flush error handling part of the code, and
hopes to maintain the same logic with a framework which can be used to
handle the errors at the volume level.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Daichou
6b349dfe80 Btrfs: remove obsolete FIXMEs in qgroup ioctls
These FIXMEs were already addressed in 2013. All functions check for
qgroup existence:

* btrfs_add_qgroup_relation
* btrfs_ioctl_qgroup_create
* btrfs_limit_qgroup
* btrfs_del_qgroup_relation

Signed-off-by: Daichou <tommy0705c@gmail.com>
[ enhance and reformat changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Dan Carpenter
97d038562a Btrfs: remove an unused variable
"item" is never used.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:57 +02:00
Fabian Frederick
977ec79271 btrfs: kmap() can't fail
Remove NULL test on kmap() as it will always return a valid pointer.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:57 +02:00
Hugh Dickins
1be7107fbe mm: larger stack guard gap, between vmas
Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.

This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.

Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.

One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications.  For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).

Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.

Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.

Original-patch-by: Oleg Nesterov <oleg@redhat.com>
Original-patch-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-19 21:50:20 +08:00
Linus Torvalds
6e20350659 A fix for an old ceph ->fh_to_* bug from Luis and two timestamp
fixups from Zheng, prompted by the ongoing y2038 work.
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Merge tag 'ceph-for-4.12-rc6' of git://github.com/ceph/ceph-client

Pull ceph fixes from Ilya Dryomov:
 "A fix for an old ceph ->fh_to_* bug from Luis and two timestamp fixups
  from Zheng, prompted by the ongoing y2038 work"

* tag 'ceph-for-4.12-rc6' of git://github.com/ceph/ceph-client:
  ceph: unify inode i_ctime update
  ceph: use current_kernel_time() to get request time stamp
  ceph: check i_nlink while converting a file handle to dentry
2017-06-18 08:23:02 +09:00
Linus Torvalds
adc311034c Changes since last update:
- Fix some bogus ASSERT failures on CONFIG_SMP=n and CONFIG_XFS_DEBUG=y.
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Merge tag 'xfs-4.12-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs fix from Darrick Wong:
 "One more bugfix for you for 4.12-rc6 to fix something that came up in
  an earlier rc:

   - Fix some bogus ASSERT failures on CONFIG_SMP=n and CONFIG_XFS_DEBUG=y"

* tag 'xfs-4.12-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: fix spurious spin_is_locked() assert failures on non-smp kernels
2017-06-17 17:34:41 +09:00
Linus Torvalds
c8636b90a0 Merge branch 'ufs-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull ufs fixes from Al Viro:
 "Fix assorted ufs bugs: a couple of deadlocks, fs corruption in
  truncate(), oopsen on tail unpacking and truncate when racing with
  vmscan, mild fs corruption (free blocks stats summary buggered, *BSD
  fsck would complain and fix), several instances of broken logics
  around reserved blocks (starting with "check almost never triggers
  when it should" and then there are issues with sufficiently large
  UFS2)"

[ Note: ufs hasn't gotten any loving in a long time, because nobody
  really seems to use it. These ufs fixes are triggered by people
  actually caring now, not some sudden influx of new bugs.  - Linus ]

* 'ufs-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ufs_truncate_blocks(): fix the case when size is in the last direct block
  ufs: more deadlock prevention on tail unpacking
  ufs: avoid grabbing ->truncate_mutex if possible
  ufs_get_locked_page(): make sure we have buffer_heads
  ufs: fix s_size/s_dsize users
  ufs: fix reserved blocks check
  ufs: make ufs_freespace() return signed
  ufs: fix logics in "ufs: make fsck -f happy"
2017-06-17 17:30:07 +09:00
Linus Torvalds
ccd3d905f7 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "A couple of fixes; a leak in mntns_install() caught by Andrei (this
  cycle regression) + d_invalidate() softlockup fix - that had been
  reported by a bunch of people lately, but the problem is pretty old"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: don't forget to put old mntns in mntns_install
  Hang/soft lockup in d_invalidate with simultaneous calls
2017-06-17 17:26:53 +09:00
Andrea Arcangeli
64c2b20301 userfaultfd: shmem: handle coredumping in handle_userfault()
Anon and hugetlbfs handle FOLL_DUMP set by get_dump_page() internally to
__get_user_pages().

shmem as opposed has no special FOLL_DUMP handling there so
handle_mm_fault() is invoked without mmap_sem and ends up calling
handle_userfault() that isn't expecting to be invoked without mmap_sem
held.

This makes handle_userfault() fail immediately if invoked through
shmem_vm_ops->fault during coredumping and solves the problem.

The side effect is a BUG_ON with no lock held triggered by the
coredumping process which exits.  Only 4.11 is affected, pre-4.11 anon
memory holes are skipped in __get_user_pages by checking FOLL_DUMP
explicitly against empty pagetables (mm/gup.c:no_page_table()).

It's zero cost as we already had a check for current->flags to prevent
futex to trigger userfaults during exit (PF_EXITING).

Link: http://lkml.kernel.org/r/20170615214838.27429-1-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: <stable@vger.kernel.org>	[4.11+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-17 06:37:05 +09:00
Linus Torvalds
ab2789b72d A fix from Nic for a race seen in production (including a stable tag).
And while I'm sending you this I'm also sneaking in a trivial new helper
 from Bart so that we don't need inter-tree dependencies for the next merge
 window.
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Merge tag 'configfs-for-4.12' of git://git.infradead.org/users/hch/configfs

Pull configfs updates from Christoph Hellwig:
 "A fix from Nic for a race seen in production (including a stable tag).

  And while I'm sending you this I'm also sneaking in a trivial new
  helper from Bart so that we don't need inter-tree dependencies for the
  next merge window"

* tag 'configfs-for-4.12' of git://git.infradead.org/users/hch/configfs:
  configfs: Introduce config_item_get_unless_zero()
  configfs: Fix race between create_link and configfs_rmdir
2017-06-16 18:45:47 +09:00