We can't have references held on pages in the s_buddy_cache while we are
trying to truncate its pages and put the inode.  All the pages must be
gone before we reach clear_inode.  This can only be gauranteed if we
can prevent new users from grabbing references to s_buddy_cache's pages.

The original bug can be reproduced and the bug fix can be verified by:

while true; do mount -t ext4 /dev/ram0 /export/hda3/ram0; \
	umount /export/hda3/ram0; done &

while true; do cat /proc/fs/ext4/ram0/mb_groups; done
Signed-off-by: NSalman Qazi <sqazi@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

ext4_free_blocks fails to pair an ext4_mb_load_buddy with a matching
ext4_mb_unload_buddy when it fails a memory allocation.
Signed-off-by: NSalman Qazi <sqazi@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

remove 'len' variable in ext4_discard_allocated_blocks() because it is
useless.
Signed-off-by: NZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

needs_recovery in ext4_mb_init() is not used, remove it.
Signed-off-by: NAkira Fujita <a-fujita@rs.jp.ne.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

metadata_csum supersedes uninit_bg.  Convert the ROCOMPAT uninit_bg
flag check to a helper function that covers both, and make the
checksum calculation algorithm use either crc16 or the metadata_csum
chosen algorithm depending on which flag is set.  Print a warning if
we try to mount a filesystem with both feature flags set.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Compute and verify the checksum of the block bitmap; this checksum is
stored in the block group descriptor.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Currently if the range to trim is too small, for example on 1K fs
the request to trim the first block, then the 'range->len' is not set
reporting wrong number of discarded block to the caller.

Fix this by always setting the 'range->len' before we return. Note that
when there is a failure (-EINVAL) caller can not depend on 'range->len'
being set properly.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Currently when there is not enough free blocks in the block group to
discard (grp->bb_free < minlen) the 'trimmed' is bumped up anyway with
the number of discarded blocks from the previous iteration. Fix this
by bumping up 'trimmed' only if the ext4_trim_all_free() was actually
run.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The overflow can happen when we are calling get_group_no_and_offset()
which stores the group number in the ext4_grpblk_t type which is
actually int. However when the blocknr is big enough the group number
might be bigger than ext4_grpblk_t resulting in overflow. This will
most likely happen with FITRIM default argument len = ULLONG_MAX.

Fix this by using "end" variable instead of "start+len" as it is easier
to get right and specifically check that the end is not beyond the end
of the file system, so we are sure that the result of
get_group_no_and_offset() will not overflow. Otherwise truncate it to
the size of the file system.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The functions ext4_msg() and ext4_error() already tack on a trailing
newline, so remove the unnecessary extra newline.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

ext4_msg adds "EXT4-fs: " to the messsage output.
Remove the redundant bits from uses.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The EXT4_MB_BITMAP and EXT4_MB_BUDDY macros obfuscate more than they
provide any abstraction.   So remove them.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The 'orig_size' local variable is only used in a call to
mb_debug().  Mark it with '__maybe_unused'.
Signed-off-by: NCurt Wohlgemuth <curtw@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The per-commit callback was used by mballoc code to manage free space
bitmaps after deleted blocks have been released.  This patch expands
it to support multiple different callbacks, to allow other things to
be done after the commit has been completed.
Signed-off-by: NBobi Jam <bobijam@whamcloud.com>
Signed-off-by: NAndreas Dilger <adilger@whamcloud.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

In ext4_read_{inode,block}_bitmap() we were setting bitmap_uptodate()
before submitting the buffer for read.  The is bad, since we check
bitmap_uptodate() without locking the buffer, and so if another
process is racing with us, it's possible that they will think the
bitmap is uptodate even though the read has not completed yet,
resulting in inodes and blocks potentially getting allocated more than
once if we get really unlucky.

Addresses-Google-Bug: 2828254
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

pa_inode in group_pa is set NULL in ext4_mb_new_group_pa, so
pa_inode should be not referenced.
Reported-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The comment says the bit should be 0, but the after code assert the
bit to be 1.  This makes people confused, so fix it.
Signed-off-by: NRobin Dong <sanbai@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The variable 'ord' in function mb_find_extent() is redundant, so
remove it.
Signed-off-by: NRobin Dong <sanbai@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The variable 'count' in function ext4_mb_generate_from_pa() looks
useless, so remove it.
Signed-off-by: NRobin Dong <sanbai@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The kernel will crash on 

ext4_mb_mark_diskspace_used:
	BUG_ON(ac->ac_b_ex.fe_len <= 0);

after we set /sys/fs/ext4/sda/mb_group_prealloc to zero and create new files in an ext4 filesystem.

The reason is: ac_b_ex.fe_len also set to zero(mb_group_prealloc) in ext4_mb_normalize_group_request
because the ac_flags contains EXT4_MB_HINT_GROUP_ALLOC.

I think when someone set mb_group_prealloc to zero, it means DO NOT USE GROUP PREALLOCATION,
so we should set alloc-strategy to STREAM in this case.
Signed-off-by: NRobin Dong <sanbai@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Quota file is fs's metadata, so it is reasonable  to permit use
root resevation if necessary. This patch fix 265'th xfstest failure
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

In commit 79a77c5a, we move ext4_mb_init_backend after the allocation
of s_locality_group to avoid memory leak in error path, but there are
still some other error paths in ext4_mb_init that need to do the same
work. So this patch adds all the error patch for ext4_mb_init. And all
the pointers are reset to NULL in case the caller may double free them.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This function really claims a number of free clusters, not blocks, so
rename it so it's clearer what's going on.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This function really returns the number of clusters after initializing
an uninitalized block bitmap has been initialized.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The field bg_free_blocks_count_{lo,high} in the block group
descriptor has been repurposed to hold the number of free clusters for
bigalloc functions.  So rename the functions so it makes it easier to
read and audit the block allocation and block freeing code.

Note: at this point in bigalloc development we doesn't support
online resize, so this also makes it really obvious all of the places
we need to fix up to add support for online resize.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

With bigalloc changes, the i_blocks value was not correctly set (it was still
set to number of blocks being used, but in case of bigalloc, we want i_blocks
to represent the number of clusters being used). Since the quota subsystem sets
the i_blocks value, this patch fixes the quota accounting and makes sure that
the i_blocks value is set correctly.
Signed-off-by: NAditya Kali <adityakali@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The default group preallocation size had been previously set to 512
blocks/clusters, regardless of the block/cluster size.  This is
probably too big for large cluster sizes.  So adjust the default so
that it is 2 megabytes or 32 clusters, whichever is larger.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Convert the free_blocks to be free_clusters to make the final revised
bigalloc changes easier to read/understand.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Convert the percpu counters s_dirtyblocks_counter and
s_freeblocks_counter in struct ext4_super_info to be
s_dirtyclusters_counter and s_freeclusters_counter.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The ext4_free_blocks() function now has two new flags that indicate
whether a partial cluster at the beginning or the end of the block
extents should be freed or not.  That will be up the caller (i.e.,
truncate), who can figure out whether partial clusters at the
beginning or the end of a block range can be freed.

We also have to update the ext4_mb_free_metadata() and
release_blocks_on_commit() machinery to be cluster-based, since it is
used by ext4_free_blocks().
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

In most of mballoc.c, we do everything in units of clusters, since the
block allocation bitmaps and buddy bitmaps are all denominated in
clusters.  The one place where we do deal with absolute block numbers
is in the code that handles the preallocation regions, since in the
case of inode-based preallocation regions, the start of the
preallocation region can't be relative to the beginning of the group.

So this adds a bit of complexity, where pa_pstart and pa_lstart are
block numbers, while pa_free, pa_len, and fe_len are denominated in
units of clusters.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Change the places in fs/ext4/mballoc.c where EXT4_BLOCKS_PER_GROUP are
used to indicate the number of bits in a block bitmap (which is really
a cluster allocation bitmap in bigalloc file systems).  There are
still some places in the ext4 codebase where usage of
EXT4_BLOCKS_PER_GROUP needs to be audited/fixed, in code paths that
aren't used given the initial restricted assumptions for bigalloc.
These will need to be fixed before we can relax those restrictions.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

In ext4_mb_init(), if the s_locality_group allocation fails it will
currently cause the allocations made in ext4_mb_init_backend() to
be leaked.  Moving the ext4_mb_init_backend() allocation after the
s_locality_group allocation avoids that problem.
Signed-off-by: NYu Jian <yujian@whamcloud.com>
Signed-off-by: NAndreas Dilger <adilger@whamcloud.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: NYu Jian <yujian@whamcloud.com>
Signed-off-by: NAndreas Dilger <adilger@whamcloud.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Rename mb_set_bits() to ext4_set_bits() and make it a global function
so that setup_new_group_blocks() can use it.
Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

If ext4_group_add_blocks() is called with 0 block, make it return 0
without doing any extra work.
Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This patch lets ext4_group_add_blocks() return an error code if it
fails, so that upper functions can handle error correctly.
Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>