A filesystem with errors is not allowed to being resized, otherwise,
it is easy to destroy the filesystem.
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Before this patch, parallel resizers are allowed and protected by a
mutex lock, actually, there is no need to support parallel resizer, so
this patch prevents parallel resizers by atmoic bit ops, like
lock_page() and unlock_page() do.

To do this, the patch removed the mutex lock s_resize_lock from struct
ext4_sb_info and added a unsigned long field named s_resize_flags
which inidicates if there is a resizer.
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

When journalling data for an inode (either because it is a symlink or
because the filesystem is mounted in data=journal mode), ext4_evict_inode()
can discard unwritten data by calling truncate_inode_pages(). This is
because we don't mark the buffer / page dirty when journalling data but only
add the buffer to the running transaction and thus mm does not know there
are still unwritten data.

Fix the problem by carefully tracking transaction containing inode's data,
committing this transaction, and writing uncheckpointed buffers when inode
should be reaped.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

The comment for ext4_ext_check_cache has a litte mistake.
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

The debug message in ext4_ext_insert_extent before moving extent
is incorrect (the "from xx to xx").
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

The argument "inode" in function ext4_ext_next_allocated_block looks useless,
so clean it.
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

ac_repeats isn't referenced in the mballoc code. So remove it.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

In ext4_mb_release, we use s_mb_buddies_generated++.  Although
the output is OK, but I don't think we need this extra ++.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

ext4_mb_load_buddy() calls ext4_get_group_info() for setting both
"grp" and "e4b->bd_info", but it could do "e4b->bd_info = grp".
Reported-by: Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

If eh_entries is equal to (or greater than) eh_max, the operation of
inserting new extent_idx will make number of entries overflow.
So check eh_entries before inserting the new extent_idx.

Although there is no bug case according the code (function
ext4_ext_insert_index is called by ext4_ext_split and ext4_ext_split
is called only if the index block has free space), the right logic
should be "lookup the capacity before insertion".
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

This patch avoids an extraneous lookup of the extent cache
in ext4_ext_map_blocks() when the flag
EXT4_GET_BLOCKS_PUNCH_OUT_EXT is absent.

The existing logic was performing the lookup but not making
use of the result. The patch simply reverses the order of evaluation
in the condition.

Since ext4_ext_in_cache() does not initialize newex on misses, bypassing
its invocation does not introduce any new issue in this regard.
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Eric Gouriou <egouriou@google.com>

This patch removes the extra parameter in ext4_ext_remove_space()
which is no longer needed.
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

This patch optimizes the punch hole operation by skipping the
tree walking code that is used by truncate.  Since punch hole
is done through map blocks, the path to the extent is already
known in this function, so we do not need to look it up again.
Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

If the stripe width was set to 1, then this patch will ignore
that stripe width and ext4 will act as if the stripe width
were 0 with respect to optimizing allocations.
Signed-off-by: Dan Ehrenberg <dehrenberg@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Previously, if a stripe width was provided, then it would be used
as the preallocation granularity, with no santiy checking and no
way to override this. Now, mb_prealloc_size defaults to the smallest
multiple of stripe size that is greater than or equal to the old
default mb_prealloc_size, and this can be overridden with the sysfs
interface.
Signed-off-by: Dan Ehrenberg <dehrenberg@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Compilation of ext4/namei.c brought up an error and warning messages
when compiled with -DDX_DEBUG
Signed-off-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

The comment from Al Viro about possible race in the ext4_orphan_add() is
not justified. There is no race possible as we always have either i_mutex
locked, or the inode can not be referenced from outside hence the
J_ASSERS should not be hit from the reason described in comment.

This commit replaces it with notion that we are holding i_mutex so it
should not be possible for i_nlink to be changed while waiting for
s_orphan_lock.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

If we meet with an error in ext4_mb_add_groupinfo, we kfree
sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)], but fail to
reset it to NULL. So the caller ext4_mb_init_backend will try to kfree
it again and causes a double free. So fix it by resetting it to NULL.

Some typo in comments of mballoc.c are also changed.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

In ext4_groupinfo_create_slab, we create ext4_groupinfo_caches within
ext4_grpinfo_slab_create_mutex, but set it outside the lock, and there
does exist some case that we may create it twice and causes a memory
leak.  So set it before we call mutex_unlock.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Optimize ext4_ext_insert_extent() by avoiding
ext4_ext_next_leaf_block() when the result is not used/needed.
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

If eh->eh_entries is smaller than eh->eh_max, the routine will
go to the "repeat" and then go to "has_space" directlly ,
since argument "depth" and "eh" are not even changed.

Therefore, goto "has_space" directly and remove redundant "repeat" tag.
Signed-off-by: Robin Dong <sanbai@taobao.com>

at ext4_trim_all_free() comment, there is no longer an @e4b parameter,
instead it is @group.
Reported-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

In ext4, when FITRIM is called every time, we iterate all the
groups and do trim one by one. It is a bit time wasting if the
group has been trimmed and there is no change since the last
trim.

So this patch adds a new flag in ext4_group_info->bb_state to
indicate that the group has been trimmed, and it will be cleared
if some blocks is freed(in release_blocks_on_commit). Another
trim_minlen is added in ext4_sb_info to record the last minlen
we use to trim the volume, so that if the caller provide a small
one, we will go on the trim regardless of the bb_state.

A simple test with my intel x25m ssd:
df -h shows:
/dev/sdb1              40G   21G   17G  56% /mnt/ext4
Block size:               4096

run the FITRIM with the following parameter:
range.start = 0;
range.len = UINT64_MAX;
range.minlen = 1048576;

without the patch:
[root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a
real	0m5.505s
user	0m0.000s
sys	0m1.224s
[root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a
real	0m5.359s
user	0m0.000s
sys	0m1.178s
[root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a
real	0m5.228s
user	0m0.000s
sys	0m1.151s

with the patch:
[root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a
real	0m5.625s
user	0m0.000s
sys	0m1.269s
[root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a
real	0m0.002s
user	0m0.000s
sys	0m0.001s
[root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a
real	0m0.002s
user	0m0.000s
sys	0m0.001s

A big improvement for the 2nd and 3rd run.

Even after I delete some big image files, it is still much
faster than iterating the whole disk.

[root@boyu-tm test]# time ./ftrim /mnt/ext4/a
real	0m1.217s
user	0m0.000s
sys	0m0.196s

Cc: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Add ext4_trim_extent and ext4_trim_all_free.
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

When we trim some free blocks in a group of ext4, we need to 
calculate the free blocks properly and check whether there are
enough freed blocks left for us to trim. Current solution will
only calculate free spaces if they are large for a trim which
isn't appropriate.

Let us see a small example:
a group has 1.5M free which are 300k, 300k, 300k, 300k, 300k.
And minblocks is 1M.  With current solution, we have to iterate
the whole group since these 300k will never be subtracted from
1.5M.  But actually we should exit after we find the first 2
free spaces since the left 3 chunks only sum up to 900K if we
subtract the first 600K although they can't be trimed.
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

In 0f0a25bf, we adjust 'len' with s_first_data_block - start, but
it could underflow in case blocksize=1K, fstrim_range.len=512 and
fstrim_range.start = 0. In this case, when we run the code:
len -= first_data_blk - start; len will be underflow to -1ULL.
In the end, although we are safe that last_group check later will limit
the trim to the whole volume, but that isn't what the user really want.

So this patch fix it. It also adds the check for 'start' like ext3 so that
we can break immediately if the start is invalid.

Cc: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

This will help debug who is responsible for starting a jbd2 transaction.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Using function calls in TP_printk causes perf heartburn, so print the
MAJOR/MINOR device numbers instead.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Upon corrupted inode or disk failures, we may fail after we already
allocate some blocks from the inode or take some blocks from the
inode's preallocation list, but before we successfully insert the
corresponding extent to the extent tree. In this case, we should free
any allocated blocks and discard the inode's preallocated blocks
because the entries in the inode's preallocation list may be in an
inconsistent state.
Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

The current implementation of ext4_free_blocks() always calls
dquot_free_block This looks quite sensible in the most cases: blocks
to be freed are associated with inode and were accounted in quota and
i_blocks some time ago.

However, there is a case when blocks to free were not accounted by the
time calling ext4_free_blocks() yet:

1. delalloc is on, write_begin pre-allocated some space in quota
2. write-back happens, ext4 allocates some blocks in ext4_ext_map_blocks()
3. then ext4_ext_map_blocks() gets an error (e.g.  ENOSPC) from
   ext4_ext_insert_extent() and calls ext4_free_blocks().

In this scenario, ext4_free_blocks() calls dquot_free_block() who, in
turn, decrements i_blocks for blocks which were not accounted yet (due
to delalloc) After clean umount, e2fsck reports something like:

> Inode 21, i_blocks is 5080, should be 5128.  Fix<y>?
because i_blocks was erroneously decremented as explained above.

The patch fixes the problem by passing the new flag
EXT4_FREE_BLOCKS_NO_QUOT_UPDATE to ext4_free_blocks(), to request
that the dquot_free_block() call be skipped.
Signed-off-by: Maxim Patlasov <maxim.patlasov@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

These days, bio_alloc() is guaranteed to never fail (as long as nvecs
is less than BIO_MAX_PAGES), so we don't need the loop around the
struct bio allocation.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Unused variables was deleted.
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

I found that ext4_ext_find_goal() and ext4_find_near()
share the same code for returning a coloured start block
based on i_block_group.

We can refactor this into a common function so that they
don't diverge in the future.

Thanks to adilger for suggesting the new function name.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

This patch moves functions from inode.c to indirect.c.
The moved functions are ext4_ind_* functions and their helpers.
Functions called from inode.c are declared extern.
Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Move two functions that will be needed by the indirect functions to be
moved to indirect.c as well as inode.c to truncate.h as inline
functions, so that we can avoid having duplicate copies of the
function (which can be a maintenance problem) without having to expose
them as globally functions.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

In preparation for moving the indirect functions to a separate file,
move __ext4_check_blockref() to block_validity.c and rename it to
ext4_check_blockref() which is exported as globally visible function.

Also, rename the cpp macro ext4_check_inode_blockref() to
ext4_ind_check_inode(), to make it clear that it is only valid for use
with non-extent mapped inodes.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

We are going to move all ext4_ind_* functions to indirect.c.
Before we do that, let's rename 2 functions called ext4_indirect_*
to ext4_ind_*, to keep to the naming convention.
Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

We are about to move all indirect inode functions to a new file.
Before we do that, let's split ext4_ind_truncate() out of ext4_truncate()
leaving only generic code in the latter, so we will be able to move
ext4_ind_truncate() to the new file.
Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

In function ext4_ext_insert_index when eh_entries of curp is
bigger than eh_max, error messages will be printed out, but the content
is about logical and ei_block, that's incorret.
Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

In journal checkpoint, we write the buffer and wait for its finish.
But in cfq, the async queue has a very low priority, and in our test,
if there are too many sync queues and every queue is filled up with
requests, the write request will be delayed for quite a long time and
all the tasks which are waiting for journal space will end with errors like:

INFO: task attr_set:3816 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
attr_set      D ffff880028393480     0  3816      1 0x00000000
 ffff8802073fbae8 0000000000000086 ffff8802140847c8 ffff8800283934e8
 ffff8802073fb9d8 ffffffff8103e456 ffff8802140847b8 ffff8801ed728080
 ffff8801db4bc080 ffff8801ed728450 ffff880028393480 0000000000000002
Call Trace:
 [<ffffffff8103e456>] ? __dequeue_entity+0x33/0x38
 [<ffffffff8103caad>] ? need_resched+0x23/0x2d
 [<ffffffff814006a6>] ? thread_return+0xa2/0xbc
 [<ffffffffa01f6224>] ? jbd2_journal_dirty_metadata+0x116/0x126 [jbd2]
 [<ffffffffa01f6224>] ? jbd2_journal_dirty_metadata+0x116/0x126 [jbd2]
 [<ffffffff81400d31>] __mutex_lock_common+0x14e/0x1a9
 [<ffffffffa021dbfb>] ? brelse+0x13/0x15 [ext4]
 [<ffffffff81400ddb>] __mutex_lock_slowpath+0x19/0x1b
 [<ffffffff81400b2d>] mutex_lock+0x1b/0x32
 [<ffffffffa01f927b>] __jbd2_journal_insert_checkpoint+0xe3/0x20c [jbd2]
 [<ffffffffa01f547b>] start_this_handle+0x438/0x527 [jbd2]
 [<ffffffff8106f491>] ? autoremove_wake_function+0x0/0x3e
 [<ffffffffa01f560b>] jbd2_journal_start+0xa1/0xcc [jbd2]
 [<ffffffffa02353be>] ext4_journal_start_sb+0x57/0x81 [ext4]
 [<ffffffffa024a314>] ext4_xattr_set+0x6c/0xe3 [ext4]
 [<ffffffffa024aaff>] ext4_xattr_user_set+0x42/0x4b [ext4]
 [<ffffffff81145adb>] generic_setxattr+0x6b/0x76
 [<ffffffff81146ac0>] __vfs_setxattr_noperm+0x47/0xc0
 [<ffffffff81146bb8>] vfs_setxattr+0x7f/0x9a
 [<ffffffff81146c88>] setxattr+0xb5/0xe8
 [<ffffffff81137467>] ? do_filp_open+0x571/0xa6e
 [<ffffffff81146d26>] sys_fsetxattr+0x6b/0x91
 [<ffffffff81002d32>] system_call_fastpath+0x16/0x1b

So this patch tries to use WRITE_SYNC in __flush_batch so that the request will
be moved into sync queue and handled by cfq timely. We also use the new plug,
sot that all the WRITE_SYNC requests can be given as a whole when we unplug it.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Reported-by: Robin Dong <sanbai@taobao.com>