The buffer read-overrun would be triggered by a printk format
starting with <N>, where N is a single digit.  NUL-terminate
after strncpy.  Use memcpy, not strncpy, since we know the
string we're copying fits in the destination buffer and
contains no NUL byte.
Signed-off-by: NJim Meyering <meyering@redhat.com>

Address some minor type issues identified by sparse checker.
Signed-off-by: NDaniel J Blueman <daniel@quora.org>

Changing 'mount -oremount,thread_pool=2 /' didn't make any effect:

maximum amount of worker threads is specified in 2 places:
- in 'strict btrfs_fs_info::thread_pool_size'
- in each worker struct: 'struct btrfs_workers::max_workers'

'mount -oremount' updated only 'btrfs_fs_info::thread_pool_size'.

Fix it by pushing new maximum value to all created worker structures
as well.

Cc: Josef Bacik <josef@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>
Reviewed-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NSergei Trofimovich <slyfox@gentoo.org>

We already do the btrfs_wait_ordered_range which will do this for us, so
just remove this call so we don't call it twice.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

In btrfs_wait_ordered_range we have been calling filemap_fdata_write() twice
because compression does strange things and then waiting.  Then we look up
ordered extents and if we find any we will always schedule_timeout(); once
and then loop back around and do it all again.  We will even check to see if
there is delalloc pages on this range and loop again.  So this patch gets
rid of the multipe fdata_write() calls and just does
filemap_write_and_wait().  In the case of compression we will still find the
ordered extents and start those individually if we need to so that is ok,
but in the normal buffered case we avoid all this weird overhead.

Then in the case of the schedule_timeout(1), we don't need it.  All callers
either 1) don't care, they just want to make sure what they just wrote maeks
it to disk or 2) are doing the lock()->lookup ordered->unlock->flush thing
in which case it will lock and check for ordered extents _anyway_ so get
back to them as quickly as possible.  The delaloc check is simply not
needed, this only catches the case where we write to the file again since
doing the filemap_write_and_wait() and if the caller truly cares about that
it will take care of everything itself.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

These warnings are bogus since we will always have at least one page in an
eb, but to make the compiler happy just set ret = 0 in these two cases.
Thanks,
Btrfs: fix compile warnings in extent_io.c

These warnings are bogus since we will always have at least one page in an
eb, but to make the compiler happy just set ret = 0 in these two cases.
Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

When running compilebench I noticed we were spending some time looking up
acls on new inodes, which shouldn't be happening since there were no acls.
This is because when we init acls on the inode after creating them we don't
cache the fact there are no acls if there aren't any.  Doing this adds a
little bit of a bump to my compilebench runs.  Thanks,
Btrfs: cache no acl on new inodes
Signed-off-by: NJosef Bacik <josef@redhat.com>

We've been keeping around the inode sequence number in hopes that somebody
would use it, but nobody uses it and people actually use i_version which
serves the same purpose, so use i_version where we used the incore inode's
sequence number and that way the sequence is updated properly across the
board, and not just in file write.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

It confuses Smatch that we use two names for the same lock.  Plus the
shorter name is nicer.  This doesn't change how the code works, it's
just a cleanup.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>

The integrity checker used to be coded for nodesize == leafsize ==
sectorsize == PAGE_CACHE_SIZE.
This is now changed to support sizes for nodesize and leafsize which are
N * PAGE_CACHE_SIZE.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

In tree_insert, var *entry is used in the loop only, and is useless
out of the loop. Remove the useless assignment after the loop.
Signed-off-by: NWang Sheng-Hui <shhuiw@gmail.com>

The return value of find_first_extent_bit is 1 or 0, no < 0.
And if found something, return 0; if nothing was found, return 1.
Fix the comment.
Signed-off-by: NWang Sheng-Hui <shhuiw@gmail.com>

num_extent_pages returns the number of pages in the specific range, not
the index of the last page in the eb range.

btrfs_release_extent_buffer_page is called with start_idx set 0 in current
codes, so it's not a problem yet. But the logic is indeed wrong.

Fix it here.
Signed-off-by: NWang Sheng-Hui <shhuiw@gmail.com>

No 'delete' arg is used for clear_state_bit.
Cleanup the comment.
Signed-off-by: NWang Sheng-Hui <shhuiw@gmail.com>

The code path should not reach there. Remove it.
Signed-off-by: NWang Sheng-Hui <shhuiw@gmail.com>

verify_parent_transid needs to lock the extent range to make
sure no IO is underway, and so it can safely clear the
uptodate bits if our checks fail.

But, a few callers are using it with spinlocks held.  Most
of the time, the generation numbers are going to match, and
we don't want to switch to a blocking lock just for the error
case.  This adds an atomic flag to verify_parent_transid,
and changes it to return EAGAIN if it needs to block to
properly verifiy things.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Fix that when scrub tries to repair an I/O or checksum error and one of
the devices containing the mirror is missing, it crashes in bio_add_page
because the bdev is a NULL pointer for missing devices.
Reported-by: NMarco L. Crociani <marco.crociani@gmail.com>
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Fix the size members of btrfs_ioctl_ino_path_args and
btrfs_ioctl_logical_ino_args. The user space btrfs-progs utilities used
__u64 and the kernel headers used __u32 before.
Signed-off-by: NAlexander Block <ablock84@googlemail.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

If we happen to alloc a extent buffer and then alloc a page and notice that
page is already attached to an extent buffer, we will only unlock it and
free our existing eb.  Any pages currently attached to that eb will be
properly freed, but we don't do the page_cache_release() on the page where
we noticed the other extent buffer which can cause us to leak pages and I
hope cause the weird issues we've been seeing in this area.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

add_root_to_dirty_list happens once at the very beginning of the
transaction, but it is still racey.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We're spending huge amounts of time on lock contention during
end_io processing because we unconditionally assume we are overwriting
an existing extent in the file for each IO.

This checks to see if we are outside i_size, and if so, it uses a
less expensive readonly search of the btree to look for existing
extents.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Btrfs has an optimization where it will preallocate dentries during
readdir to fill in enough information to open the inode without an extra
lookup.

But, we're calling d_alloc, which is doing GFP_KERNEL allocations, and
that leads to deadlocks because our readdir code has tree locks held.

For now, disable this optimization.  We'll fix the gfp mask in the next
merge window.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Fix out-of-space checking, addressing a warning and potential resource
leak when resizing the filesystem down while allocating blocks.
Signed-off-by: NDaniel J Blueman <daniel@quora.org>
Reviewed-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

may_commit_transaction() calls
        spin_lock(&space_info->lock);
        spin_lock(&delayed_rsv->lock);
and update_global_block_rsv() calls
        spin_lock(&block_rsv->lock);
        spin_lock(&sinfo->lock);

Lockdep complains about this at run time.
Everywhere except in update_global_block_rsv(), the space_info lock is
the outer lock, therefore the locking order in update_global_block_rsv()
is changed.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

I was seeing root_list corruption on unmount during fs resize in 3.4-rc4; add
correct locking to address this.
Signed-off-by: NDaniel J Blueman <daniel@quora.org>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

btrfs_map_block sets mirror_num, so that the repair code knows eventually
which device gave us the read error. For RAID10, mirror_num must be 1 or 2.
Before this fix mirror_num was incorrectly related to our stripe index.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

btrfs_start_delalloc_inodes will just walk the list of delalloc inodes and
start writing them out, but it doesn't splice the list or anything so as
long as somebody is doing work on the box you could end up in this section
_forever_.  So just remove it, it's not needed anyway since sync will start
writeback on all inodes anyway, all we need to do is wait for ordered
extents and then we can commit the transaction.  In my horrible torture test
sync goes from taking 4 minutes to about 1.5 minutes.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The bitfield member mount_opt was too small by one bit to hold the mount
option that enabled to include data extents in the integrity checker.
Since the same issue happened when the BTRFS_MOUNT_PANIC_ON_FATAL_ERROR
option was added (git rebase silently merges so that the increase of the
size of the bitfield member is lost), the bit limit was removed entirely.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

Each CRC or header error was counted twice, this is now fixed.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

When a filesystem is mounted with the degraded option, it is
possible that some of the devices are not there.
btrfs_ioctl_dev_info() crashs in this case because the device
name is a NULL pointer. This ioctl was only used for scrub.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>

It is basically a good thing if we are interruptible when waiting for
free space, but the generality in which it is implemented currently
leads to system calls being interruptible that are not documented this
way. For example git can't handle interrupted unlink(), leading to
corrupt repos under space pressure.
Instead we raise the bar to only be interruptible by SIGKILL.
Thanks to David Sterba for suggesting this.
Signed-off-by: NArne Jansen <sensille@gmx.net>

The caller expects this function to return with the lock held and
releases it immediately on error.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>

A user reported a panic where we were trying to fix a bad mirror but the
mirror number we were giving was 0, which is invalid.  This is because we
don't do the transid verification until after the read, so as far as the
read code is concerned the read was a success.  So instead store the mirror
we read from so that if there is some failure post read we know which mirror
to try next and which mirror needs to be fixed if we find a good copy of the
block.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

Free fs_devices as done in the error-handling code just below.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>

Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Josef Bacik <josef@redhat.com>
Signed-off-by: NSergei Trofimovich <slyfox@gentoo.org>

Fix a bug, where in case we need to adjust stripe_size so that the
length of the resulting chunk is less than or equal to max_chunk_size,
DUP chunks turn out to be only half as big as they could be.

Cc: Arne Jansen <sensille@gmx.net>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

iref_to_path and iterate_irefs both increment the eb's refcount to use it
after releasing the path. Both depend on consistent data remaining in the
extent buffer and need a read lock to protect it.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>

Avoid calling free_extent_buffer more than once when the iterator function
returns non-zero. The only code that uses this is scrub repair for corrupted
nodatasum blocks.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>

Make free_ipath() behave like most other freeing functions in the
kernel and gracefully do nothing when passed a NULL pointer.

Besides this making the bahaviour consistent with functions such as
kfree(), vfree(), btrfs_free_path() etc etc, it also fixes a real NULL
deref issue in fs/btrfs/ioctl.c::btrfs_ioctl_ino_to_path(). In that
function we have this code:

...
        ipath = init_ipath(size, root, path);
        if (IS_ERR(ipath)) {
                ret = PTR_ERR(ipath);
                ipath = NULL;
                goto out;
        }
...
out:
        btrfs_free_path(path);
        free_ipath(ipath);
...

If we ever take the true branch of that 'if' statement we'll end up
passing a NULL pointer to free_ipath() which will subsequently
dereference it and we'll go "Boom" :-(
This patch will avoid that.
Signed-off-by: NJesper Juhl <jj@chaosbits.net>

clear_extent_bit()
{
    next_node = rb_next(&state->rb_node);
    ...
    clear_state_bit(state);  <-- this may free next_node
    if (next_node) {
        state = rb_entry(next_node);
        ...
    }
}

clear_state_bit() calls merge_state() which may free the next node
of the passing extent_state, so clear_extent_bit() may end up
referencing freed memory.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>