We can race with readdir and the RCU path walking stuff.  This is because we
clear the need lookup flag before actually instantiating the inode.  This will
lead the RCU path walk stuff to find a dentry it thinks is valid without a
d_inode attached.  So instead unhash the dentry when we first start the lookup,
and then clear the flag after we've instantiated the dentry so we're garunteed
to either try the slow lookup, or have the d_inode set properly.
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Since the d_off in the first dirent for "." (that originates from
the 4th argument "offset" of filldir() for the 2nd dirent for "..")
is wrongly assigned in btrfs_real_readdir(), telldir returns same
offset for different locations.

 | # mkfs.btrfs /dev/sdb1
 | # mount /dev/sdb1 fs0
 | # cd fs0
 | # touch file0 file1
 | # ../test
 | telldir: 0
 | readdir: d_off = 2, d_name = "."
 | telldir: 2
 | readdir: d_off = 2, d_name = ".."
 | telldir: 2
 | readdir: d_off = 3, d_name = "file0"
 | telldir: 3
 | readdir: d_off = 2147483647, d_name = "file1"
 | telldir: 2147483647

To fix this problem, pass filp->f_pos (which is loff_t) instead.

 | # ../test
 | telldir: 0
 | readdir: d_off = 1, d_name = "."
 | telldir: 1
 | readdir: d_off = 2, d_name = ".."
 | telldir: 2
 | readdir: d_off = 3, d_name = "file0"
 :

At the moment the "offset" for "." is unused because there is no
preceding dirent, however it is better to pass filp->f_pos to follow
grammatical usage.
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

If we write some data into the data hole of the file(no preallocation for this
hole), Btrfs will allocate some disk space, and update nbytes of the inode, but
the other element--disk_i_size needn't be updated. At this condition, we must
update inode metadata though disk_i_size is not changed(btrfs_ordered_update_i_size()
return 1).

 # mkfs.btrfs /dev/sdb1
 # mount /dev/sdb1 /mnt
 # touch /mnt/a
 # truncate -s 856002 /mnt/a
 # dd if=/dev/zero of=/mnt/a bs=4K count=1 conv=nocreat,notrunc
 # umount /mnt
 # btrfsck /dev/sdb1
 root 5 inode 257 errors 400
 found 32768 bytes used err is 1
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The function - btrfs_cont_expand() forgot to close the transaction handle before
it jump out the while loop. Fix it.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

iput() shouldn't be called for inodes in I_NEW state.
We need to mark inode as constructed first.

WARNING: at fs/inode.c:1309 iput+0x20b/0x210()
Call Trace:
 [<ffffffff8103e7ba>] warn_slowpath_common+0x7a/0xb0
 [<ffffffff8103e805>] warn_slowpath_null+0x15/0x20
 [<ffffffff810eaf0b>] iput+0x20b/0x210
 [<ffffffff811b96fb>] btrfs_iget+0x1eb/0x4a0
 [<ffffffff811c3ad6>] btrfs_run_defrag_inodes+0x136/0x210
 [<ffffffff811ad55f>] cleaner_kthread+0x17f/0x1a0
 [<ffffffff81035b7d>] ? sub_preempt_count+0x9d/0xd0
 [<ffffffff811ad3e0>] ? transaction_kthread+0x280/0x280
 [<ffffffff8105af86>] kthread+0x96/0xa0
 [<ffffffff814336d4>] kernel_thread_helper+0x4/0x10
 [<ffffffff8105aef0>] ? kthread_worker_fn+0x190/0x190
 [<ffffffff814336d0>] ? gs_change+0xb/0xb
Signed-off-by: NSergei Trofimovich <slyfox@gentoo.org>
CC: Konstantin Khlebnikov <khlebnikov@openvz.org>
Tested-by: NDavid Sterba <dsterba@suse.cz>
CC: Josef Bacik <josef@redhat.com>
CC: Chris Mason <chris.mason@oracle.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This patch tightens the read-only access checks in btrfs_permission to
 match the constraints in inode_permission. Currently, even though the
 device node itself will be unmodified, read-write access to device nodes
 is denied to when the device node resides on a read-only subvolume or a
 is a file that has been marked read-only by the btrfs conversion utility.

 With this patch applied, the check only affects regular files,
 directories, and symlinks. It also restructures the code a bit so that
 we don't duplicate the MAY_WRITE check for both tests.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The set/clear bit and the extent split/merge hooks only ever return 0.

 Changing them to return void simplifies the error handling cases later.

 This patch changes the hook prototypes, the single implementation of each,
 and the functions that call them to return void instead.

 Since all four of these hooks execute under a spinlock, they're necessarily
 simple.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We passed the wrong value to btrfs_force_ra(). Fix this by changing
the argument of btrfs_force_ra() from last_index to nr_page.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When btrfs_unlink_inode() and btrfs_orphan_add() in btrfs_unlink()
are error, the error code is returned to the caller instead of
BUG_ON().
Signed-off-by: NTsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

In btrfs we have 2 indexes for inodes.  One is for readdir, it's in this nice
sequential order and works out brilliantly for readdir.  However if you use ls,
it usually stat's each file it gets from readdir.  This is where the second
index comes in, which is based on a hash of the name of the file.  So then the
lookup has to lookup this index, and then lookup the inode.  The index lookup is
going to be in random order (since its based on the name hash), which gives us
less than stellar performance.  Since we know the inode location from the
readdir index, I create a dummy dentry and copy the location key into
dentry->d_fsdata.  Then on lookup if we have d_fsdata we use that location to
lookup the inode, avoiding looking up the other directory index.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Now that we are using regular file crcs for the free space cache,
we can deadlock if we try to read the free_space_inode while we are
updating the crc tree.

This commit fixes things by using the commit_root to read the crcs.  This is
safe because we the free space cache file would already be loaded if
that block group had been changed in the current transaction.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The extent_buffers have a very complex interface where
we use HIGHMEM for metadata and try to cache a kmap mapping
to access the memory.

The next commit adds reader/writer locks, and concurrent use
of this kmap cache would make it even more complex.

This commit drops the ability to use HIGHMEM with extent buffers,
and rips out all of the related code.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

So I had this brilliant idea to use atomic counters for outstanding and reserved
extents, but this turned out to be a bad idea.  Consider this where we have 1
outstanding extent and 1 reserved extent

Reserver				Releaser
					atomic_dec(outstanding) now 0
atomic_read(outstanding)+1 get 1
atomic_read(reserved) get 1
don't actually reserve anything because
they are the same
					atomic_cmpxchg(reserved, 1, 0)
atomic_inc(outstanding)
atomic_add(0, reserved)
					free reserved space for 1 extent

Then the reserver now has no actual space reserved for it, and when it goes to
finish the ordered IO it won't have enough space to do it's allocation and you
get those lovely warnings.
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

grab_cache_page will use mapping_gfp_mask(), which for all inodes is set to
GFP_HIGHUSER_MOVABLE.  So instead use find_or_create_page in all cases where we
need GFP_NOFS so we don't deadlock.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Replace the ->check_acl method with a ->get_acl method that simply reads an
ACL from disk after having a cache miss.  This means we can replace the ACL
checking boilerplate code with a single implementation in namei.c.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

->d_parent is locked and stable there...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and simplify the living hell out of callers
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

not used by the instances anymore.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

redundant; all callers get it duplicated in mask & MAY_NOT_BLOCK and none of
them removes that bit.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

its value depends only on inode and does not change; we might as
well store it in ->i_op->check_acl and be done with that.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

btrfs_iget() also needed an update so that errors from btrfs_locked_inode()
are caught and bubbled back up.
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

I moved the path allocation up a few lines to the top of the function so
that we couldn't get into the state where we've dropped delayed items and
the extent cache but fail due to -ENOMEM.
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

This patch fixes many callers of btrfs_alloc_path() which BUG_ON allocation
failure. All the sites that are fixed in this patch were checked by me to
be fairly trivial to fix because of at least one of two criteria:

 - Callers of the function catch errors from it already so bubbling the
   error up will be handled.
 - Callers of the function might BUG_ON any nonzero return code in which
   case there is no behavior changed (but we still got to remove a BUG_ON)

The following functions were updated:

btrfs_lookup_extent, alloc_reserved_tree_block, btrfs_remove_block_group,
btrfs_lookup_csums_range, btrfs_csum_file_blocks, btrfs_mark_extent_written,
btrfs_inode_by_name, btrfs_new_inode, btrfs_symlink,
insert_reserved_file_extent, and run_delalloc_nocow
Signed-off-by: NMark Fasheh <mfasheh@suse.com>

We need to make sure the data relocation inode doesn't go through
the delayed metadata updates, otherwise we get an oops during balance:

kernel BUG at fs/btrfs/relocation.c:4303!
[SNIP]
Call Trace:
 [<ffffffffa03143fd>] ? update_ref_for_cow+0x22d/0x330 [btrfs]
 [<ffffffffa0314951>] __btrfs_cow_block+0x451/0x5e0 [btrfs]
 [<ffffffffa031355d>] ? read_block_for_search+0x14d/0x4d0 [btrfs]
 [<ffffffffa0314beb>] btrfs_cow_block+0x10b/0x240 [btrfs]
 [<ffffffffa031acae>] btrfs_search_slot+0x49e/0x7a0 [btrfs]
 [<ffffffffa032d8af>] btrfs_lookup_inode+0x2f/0xa0 [btrfs]
 [<ffffffff8147bf0e>] ? mutex_lock+0x1e/0x50
 [<ffffffffa0380cf1>] btrfs_update_delayed_inode+0x71/0x160 [btrfs]
 [<ffffffffa037ff27>] ? __btrfs_release_delayed_node+0x67/0x190 [btrfs]
 [<ffffffffa0381cf8>] btrfs_run_delayed_items+0xe8/0x120 [btrfs]
 [<ffffffffa03365e0>] btrfs_commit_transaction+0x250/0x850 [btrfs]
 [<ffffffff810f91d9>] ? find_get_pages+0x39/0x130
 [<ffffffffa0336cd5>] ? join_transaction+0x25/0x250 [btrfs]
 [<ffffffff81081de0>] ? wake_up_bit+0x40/0x40
 [<ffffffffa03785fa>] prepare_to_relocate+0xda/0xf0 [btrfs]
 [<ffffffffa037f2bb>] relocate_block_group+0x4b/0x620 [btrfs]
 [<ffffffffa0334cf5>] ? btrfs_clean_old_snapshots+0x35/0x150 [btrfs]
 [<ffffffffa037fa43>] btrfs_relocate_block_group+0x1b3/0x2e0 [btrfs]
 [<ffffffffa0368ec0>] ? btrfs_tree_unlock+0x50/0x50 [btrfs]
 [<ffffffffa035e39b>] btrfs_relocate_chunk+0x8b/0x670 [btrfs]
 [<ffffffffa031303d>] ? btrfs_set_path_blocking+0x3d/0x50 [btrfs]
 [<ffffffffa03577d8>] ? read_extent_buffer+0xd8/0x1d0 [btrfs]
 [<ffffffffa031bea1>] ? btrfs_previous_item+0xb1/0x150 [btrfs]
 [<ffffffffa03577d8>] ? read_extent_buffer+0xd8/0x1d0 [btrfs]
 [<ffffffffa035f5aa>] btrfs_balance+0x21a/0x2b0 [btrfs]
 [<ffffffffa0368898>] btrfs_ioctl+0x798/0xd20 [btrfs]
 [<ffffffff8111e358>] ? handle_mm_fault+0x148/0x270
 [<ffffffff814809e8>] ? do_page_fault+0x1d8/0x4b0
 [<ffffffff81160d6a>] do_vfs_ioctl+0x9a/0x540
 [<ffffffff811612b1>] sys_ioctl+0xa1/0xb0
 [<ffffffff81484ec2>] system_call_fastpath+0x16/0x1b
[SNIP]
RIP  [<ffffffffa037c1cc>] btrfs_reloc_cow_block+0x22c/0x270 [btrfs]
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When iputting the inode, We may leave the delayed nodes if they have some
delayed items that have not been dealt with. So when the inode is read again,
we must look up the relative delayed node, and use the information in it to
initialize the inode. Or we will get inconsonant inode information, it may
cause that the same directory index number is allocated again, and hit the
following oops:

[ 5447.554187] err add delayed dir index item(name: pglog_0.965_0) into the
insertion tree of the delayed node(root id: 262, inode id: 258, errno: -17)
[ 5447.569766] ------------[ cut here ]------------
[ 5447.575361] kernel BUG at fs/btrfs/delayed-inode.c:1301!
[SNIP]
[ 5447.790721] Call Trace:
[ 5447.793191]  [<ffffffffa0641c4e>] btrfs_insert_dir_item+0x189/0x1bb [btrfs]
[ 5447.800156]  [<ffffffffa0651a45>] btrfs_add_link+0x12b/0x191 [btrfs]
[ 5447.806517]  [<ffffffffa0651adc>] btrfs_add_nondir+0x31/0x58 [btrfs]
[ 5447.812876]  [<ffffffffa0651d6a>] btrfs_create+0xf9/0x197 [btrfs]
[ 5447.818961]  [<ffffffff8111f840>] vfs_create+0x72/0x92
[ 5447.824090]  [<ffffffff8111fa8c>] do_last+0x22c/0x40b
[ 5447.829133]  [<ffffffff8112076a>] path_openat+0xc0/0x2ef
[ 5447.834438]  [<ffffffff810c58e2>] ? __perf_event_task_sched_out+0x24/0x44
[ 5447.841216]  [<ffffffff8103ecdd>] ? perf_event_task_sched_out+0x59/0x67
[ 5447.847846]  [<ffffffff81121a79>] do_filp_open+0x3d/0x87
[ 5447.853156]  [<ffffffff811e126c>] ? strncpy_from_user+0x43/0x4d
[ 5447.859072]  [<ffffffff8111f1f5>] ? getname_flags+0x2e/0x80
[ 5447.864636]  [<ffffffff8111f179>] ? do_getname+0x14b/0x173
[ 5447.870112]  [<ffffffff8111f1b7>] ? audit_getname+0x16/0x26
[ 5447.875682]  [<ffffffff8112b1ab>] ? spin_lock+0xe/0x10
[ 5447.880882]  [<ffffffff81112d39>] do_sys_open+0x69/0xae
[ 5447.886153]  [<ffffffff81112db1>] sys_open+0x20/0x22
[ 5447.891114]  [<ffffffff813b9aab>] system_call_fastpath+0x16/0x1b

Fix it by reusing the old delayed node.
Reported-by: NJim Schutt <jaschut@sandia.gov>
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Tested-by: NJim Schutt <jaschut@sandia.gov>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When we create a new inode, we aren't filling in the
field that records the transaction that last changed this
inode.

If we then go to fsync that inode, it will be skipped because the field
isn't filled in.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The delayed ref patch accidently removed the btrfs_free_path in
btrfs_unlink_subvol, this puts it back and means we don't leak a path.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

The WARN_ON() in start_transaction() was triggered while balancing.

The cause is btrfs_relocate_chunk() started a transaction and
then called iput() on the inode that stores free space cache,
and iput() called btrfs_start_transaction() again.
Reported-by: NTsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Reviewed-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When encountering an EIO while reading from a nodatasum extent, we
insert an error record into the inode's failure tree.
btrfs_readpage_end_io_hook returns early for nodatasum inodes. We'd
better clear the failure tree in that case, otherwise the kernel
complains about

	BUG extent_state: Objects remaining on kmem_cache_close()

on rmmod.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

wrap checking of filesystem 'closing' flag and fix a few missing memory
barriers.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

Tell the filesystem if we just updated timestamp (I_DIRTY_SYNC) or
anything else, so that the filesystem can track internally if it
needs to push out a transaction for fdatasync or not.

This is just the prototype change with no user for it yet.  I plan
to push large XFS changes for the next merge window, and getting
this trivial infrastructure in this window would help a lot to avoid
tree interdependencies.

Also remove incorrect comments that ->dirty_inode can't block.  That
has been changed a long time ago, and many implementations rely on it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This will detect small random writes into files and
queue the up for an auto defrag process.  It isn't well suited to
database workloads yet, but works for smaller files such as rpm, sqlite
or bdb databases.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Btrfs has no problems with lingering references to unlinked directory
inodes.

CC: Chris Mason <chris.mason@oracle.com>
CC: linux-btrfs@vger.kernel.org
Signed-off-by: NSage Weil <sage@newdream.net>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Only a few file systems need this.  Start by pushing it down into each
rename method (except gfs2 and xfs) so that it can be dealt with on a
per-fs basis.
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSage Weil <sage@newdream.net>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Only a few file systems need this.  Start by pushing it down into each
fs rmdir method (except gfs2 and xfs) so it can be dealt with on a per-fs
basis.

This does not change behavior for any in-tree file systems.
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSage Weil <sage@newdream.net>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Btrfs_alloc_path should be matched with btrfs_free_path in error-handling code.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
local idexpression struct btrfs_path * x;
expression ra,rb;
position p1,p2;
@@

x = btrfs_alloc_path@p1(...)
...  when != btrfs_free_path(x,...)
     when != if (...) { ... btrfs_free_path(x,...) ...}
     when != x = ra
if(...) { ... when != x = rb
     when forall
     when != btrfs_free_path(x,...)
 \(return <+...x...+>; \| return@p2...; \) }

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

cocci.print_main("alloc",p1)
cocci.print_secs("return",p2)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Currently, btrfs_truncate_item and btrfs_extend_item returns only 0.
So, the check by BUG_ON in the caller is unnecessary.
Signed-off-by: NTsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Signed-off-by: NSergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: NChris Mason <chris.mason@oracle.com>