If btrfs_bio_alloc fails in submit_extent_page, submit_extent_page returns
without clearing the writeback bit of the failed page.

__extent_writepage_io, that is a caller of submit_extent_page,
does not clear the remaining writeback bit anywhere.
As a result, this will cause the hang at filemap_fdatawait_range,
because it waits the writeback bit to be cleared from the failed page.
So, we have to call end_page_writeback to clear the writeback bit.

For reproducing the hang, we inject a fault like

   if (should_failtest()) { // I define should_failtest()
        bio = NULL;
   }
   else {
        bio = btrfs_bio_alloc(...);
   }

in submit_extent_page.

We should also check whether page has the bit before end_page_writeback,
to avoid the conflict against the other end_page_writeback in bio_endio.
Thus, we add PageWriteback checks not only in __extent_writepage_io,
but also in write_one_eb too, because it misses the check.
Signed-off-by: NTakafumi Kubota <takafumi.kubota1012@sslab.ics.keio.ac.jp>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Commit "btrfs: ulist: Add ulist_del() function" (d4b80404)
removed some debugging code but left the structure defintions.
Reviewed-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Since we have a helper to set page bits, let lock_delalloc_pages and
__unlock_for_delalloc use it.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ changes to the helper separated from the following patch ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This introduces a new helper which can be used to process pages bits.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

run_delalloc_nocow has used trans in two places where they don't
actually need @trans.

For btrfs_lookup_file_extent, we search for file extents without COWing
anything, and for btrfs_cross_ref_exist, the only place where we need
@trans is deferencing it in order to get running_transaction which we
could easily get from the global fs_info.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All we need is @delayed_refs, all callers have get it ahead of calling
btrfs_find_delayed_ref_head since lock needs to be acquired firstly,
there is no reason to deference it again inside the function.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

@trans is not used at all, this removes it.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

@cached_state is no more required in __extent_writepage_io, also remove
the goto label.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Once a qgroup limit is exceeded, it's impossible to restore normal
operation to the subvolume without modifying the limit or removing
the subvolume.  This is a surprising situation for many users used
to the typical workflow with quotas on other file systems where it's
possible to remove files until the used space is back under the limit.

When we go to unlink a file and start the transaction, we'll hit
the qgroup limit while trying to reserve space for the items we'll
modify while removing the file.  We discussed last month how best
to handle this situation and agreed that there is no perfect solution.
The best principle-of-least-surprise solution is to handle it similarly
to how we already handle ENOSPC when unlinking, which is to allow
the operation to succeed with the expectation that it will ultimately
release space under most circumstances.

This patch modifies the transaction start path to select whether to
honor the qgroups limits.  btrfs_start_transaction_fallback_global_rsv
is the only caller that skips enforcement.  The reservation and tracking
still happens normally -- it just skips the enforcement step.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Reviewed-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Commit Btrfs: btrfs_page_mkwrite: Reserve space in sectorsized units"
(d0b7da88) did this, but btrfs_lookup_ordered_range expects a 'length'
rather than a 'page_end'.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NChandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Variable 'walk' in lock_stripe_add() is not used.  Remove it.
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This was originally a prep patch for changing the behavior on len=0, but
we went another direction with that. This still makes the function
slightly easier to follow.
Reviewed-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: NOmar Sandoval <osandov@fb.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

In a lot of places, it's unclear when it's safe to reuse a struct
btrfs_key after it has been passed to a helper function. Constify these
arguments wherever possible to make it obvious.
Signed-off-by: NOmar Sandoval <osandov@fb.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Dio writes can update i_size in btrfs_get_blocks_direct when it
writes to offset beyond EOF so that endio can update disk_i_size
correctly (because we don't udpate disk_i_size beyond i_size).

However, when truncating down a file, we firstly update i_size
and then wait for in-flight lockless dio reads/writes, according
to the above, i_size may have been changed in dio writes, and
file extents don't get truncated.

For lockless dio writes are always overwrites, i_size is not
supposed to be changed, so this adds a check to filter out this
case.

The race could be reproduced by fstests/generic/299 with patch
"Btrfs: fix btrfs_ordered_update_i_size to update disk_i_size properly"
 applied.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Since we have a good helper entry_end, use it for ordered extent.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ whitespace reformatting ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The comment about "page_mkwrite gets called every time the page is
dirtied" in btrfs_page_mkwrite is not correct, it only gets called the
first time the page gets dirtied after the page faults in.

However, we don't need to touch the code because it works well, although
the proper logic is to check if delalloc bits has been set and if so, go
free reserved space, if not, set the delalloc bits for dirty page range.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

btrfs_ordered_update_i_size can be called by truncate and endio, but
only endio takes ordered_extent which contains the completed IO.

while truncating down a file, if there are some in-flight IOs,
btrfs_ordered_update_i_size in endio will set disk_i_size to
@orig_offset that is zero.  If truncating-down fails somehow, we try to
recover in memory isize with this zero'd disk_i_size.

Fix it by only updating disk_i_size with @orig_offset when
btrfs_ordered_update_i_size is not called from endio while truncating
down and waiting for in-flight IOs completing their work before recover
in-memory size.

Besides fixing the above issue, add an assertion for last_size to double
check we truncate down to the desired size.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This goes as a separate patch because fixing that inside the patches
caused too many many conflicts.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NNikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>