Move the page_done callback into a separate iomap_page_ops structure and
add a page_prepare calback to be called before the next page is written
to.  In gfs2, we'll want to start a transaction in page_prepare and end
it in page_done.  Other filesystems that implement data journaling will
require the same kind of mechanism.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Before this patch, function do_grow would not reserve enough journal
blocks in the transaction to unstuff jdata files while growing them.
This patch adds the logic to add one more block if the file to grow
is jdata.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Reviewed-by: NAndreas Gruenbacher <agruenba@redhat.com>

Tells you how many milliseconds map_journal_extents and find_jhead
take.
Signed-off-by: NAbhi Das <adas@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

GFS2 passes the inode buffer head (dibh) from gfs2_iomap_begin to
gfs2_iomap_end in iomap->private.  It sets that private pointer in
gfs2_iomap_get.  Users of gfs2_iomap_get other than gfs2_iomap_begin
would have to release iomap->private, but this isn't done correctly,
leading to a leak of buffer head references.

To fix this, move the code for setting iomap->private from
gfs2_iomap_get to gfs2_iomap_begin.

Fixes: 64bc06bb ("gfs2: iomap buffered write support")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The previous attempt to fix for metadata read-ahead during truncate was
incorrect: for files with a height > 2 (1006989312 bytes with a block
size of 4096 bytes), read-ahead requests were not being issued for some
of the indirect blocks discovered while walking the metadata tree,
leading to significant slow-downs when deleting large files.  Fix that.

In addition, only issue read-ahead requests in the first pass through
the meta-data tree, while deallocating data blocks.

Fixes: c3ce5aa9 ("gfs2: Fix metadata read-ahead during truncate")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

It turns out that the fix in commit 6636c3cc56 is bad; the assertion
that the iomap code no longer creates buffer heads is incorrect for
filesystems that set the IOMAP_F_BUFFER_HEAD flag.

Instead, what's happening is that gfs2_iomap_begin_write treats all
files that have the jdata flag set as journaled files, which is
incorrect as long as those files are inline ("stuffed").  We're handling
stuffed files directly via the page cache, which is why we ended up with
pages without buffer heads in gfs2_page_add_databufs.

Fix this by handling stuffed journaled files correctly in
gfs2_iomap_begin_write.

This reverts commit 6636c3cc5690c11631e6366cf9a28fb99c8b25bb.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

Function rgblk_free can only deal with one resource group at a time, so
pass that resource group is as a parameter.  Several of the callers
already have the resource group at hand, so we only need additional
lookup code in a few places.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Reviewed-by: NSteven Whitehouse <swhiteho@redhat.com>

Commit 64bc06bb broke buffered writes to journaled files (chattr
+j): we'll try to journal the buffer heads of the page being written to
in gfs2_iomap_journaled_page_done.  However, the iomap code no longer
creates buffer heads, so we'll BUG() in gfs2_page_add_databufs.  Fix
that by creating buffer heads ourself when needed.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

To speed up the common case of appending to a file,
gfs2_write_alloc_required presumes that writing beyond the end of a file
will always require additional blocks to be allocated.  This assumption
is incorrect for preallocates files, but there are no negative
consequences as long as *some* space is still left on the filesystem.

One special file that always has some space preallocated beyond the end
of the file is the rindex: when growing a filesystem, gfs2_grow adds one
or more new resource groups and appends records describing those
resource groups to the rindex; the preallocated space ensures that this
is always possible.

However, when a filesystem is completely full, gfs2_write_alloc_required
will indicate that an additional allocation is required, and appending
the next record to the rindex will fail even though space for that
record has already been preallocated.  To fix that, skip the incorrect
optimization in gfs2_write_alloc_required, but for the rindex only.
Other writes to preallocated space beyond the end of the file are still
allowed to fail on completely full filesystems.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NBob Peterson <rpeterso@redhat.com>

The page unmapping previously done in gfs2_direct_IO is now done
generically in iomap_dio_rw.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NBob Peterson <rpeterso@redhat.com>

Now that gfs2_extent_length is no longer used for determining the size
of a hole and always with an upper size limit, the function can be
simplified.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NBob Peterson <rpeterso@redhat.com>

With the traditional page-based writes, blocks are allocated separately
for each page written to.  With iomap writes, we can allocate a lot more
blocks at once, with a fraction of the allocation overhead for each
page.

Split calculating the number of blocks that can be allocated at a given
position (gfs2_alloc_size) off from gfs2_iomap_alloc: that size
determines the number of blocks to allocate and reserve in the journal.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NBob Peterson <rpeterso@redhat.com>

In gfs2_iomap_alloc, set the type of newly allocated extents to
IOMAP_MAPPED so that iomap_to_bh will set the bh states correctly:
otherwise, the bhs would not be marked as mapped, confusing
__mpage_writepage.  This means that we need to check for the IOMAP_F_NEW
flag in fallocate_chunk now.

Further clean up gfs2_iomap_get and implement gfs2_stuffed_iomap here
directly.  For reads beyond the end of the file, return holes instead of
failing with -ENOENT so that we can get rid of that special case in
gfs2_block_map.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NBob Peterson <rpeterso@redhat.com>

Rename end_off to end_len to make the code less confusing.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Clean up gfs2_iomap_alloc and gfs2_iomap_get.  Document how
gfs2_iomap_alloc works: it now needs to be called separately after
gfs2_iomap_get where necessary; this will be used later by iomap write.
Move gfs2_iomap_ops into bmap.c.

Introduce a new gfs2_iomap_get_alloc helper and use it in
fallocate_chunk: gfs2_iomap_begin will become unsuitable for fallocate
with proper iomap write support.

In gfs2_block_map and fallocate_chunk, zero-initialize struct iomap.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

In journaled data mode, we need to add each buffer head to the current
transaction.  In ordered write mode, we only need to add the inode to
the ordered inode list.  So far, both cases are handled in
gfs2_trans_add_data.  This makes the code look misleading and is
inefficient for small block sizes as well.  Handle both cases separately
instead.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Reimplement function hole_size based on a generic function for walking
the metadata tree and rename hole_size to gfs2_hole_size.  While
previously, multiple invocations of hole_size were sometimes needed to
walk across the entire hole, the new implementation always returns the
entire hole at once (provided that the caller is interested in the total
size).
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Just define a range of fs specific flags and use that in gfs2 instead of
exposing this internal flag globally.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Inline data is fundamentally different from our normal mapped case in that
it doesn't even have a block address.  So instead of having a flag for it
it should be an entirely separate iomap range type.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

GFS2 keeps two arrarys in the superblock that define the maximum size of
an inode depending on the inode's height: sdp->sd_heightsize defines the
heights in units of sb->s_blocksize; sdp->sd_jheightsize defines them in
units of sb->s_blocksize - sizeof(struct gfs2_meta_header).  These
arrays are used to determine when additional layers of indirect blocks
are needed.  The second array is used for directories which have an
additional gfs2_meta_header at the beginning of each block.

Distinguishing between these two cases makes no sense: the height
required for representing N blocks will come out the same no matter if
the calculation is done in gross (sb->s_blocksize) or net
(sb->s_blocksize - sizeof(struct gfs2_meta_header)) units.

Stuffed directories don't have an additional gfs2_meta_header, but the
stuffed case is handled separately for both files and directories,
anyway.

Remove the unncessary sdp->sd_jheightsize array.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

This patch simply fixes some comments and the gfs2-glocks.txt file:
Places where i_rwsem was called i_mutex, and adding i_rw_mutex.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Instead of zeroing out fallocated blocks in gfs2_iomap_alloc, zero them
out in fallocate_chunk, much higher up the call stack.  This gets rid of
gfs2's abuse of the IOMAP_ZERO flag as well as the gfs2 specific zeronew
buffer flag.  I can't think of a reason why zeroing out the blocks in
gfs2_iomap_alloc would have any benefits: there is no additional locking
at that level that would add protection to the newly allocated blocks.

While at it, change fallocate over from gs2_block_map to gfs2_iomap_begin.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Acked-by: NChristoph Hellwig <hch@lst.de>

When punching a hole or truncating an inode down to a given size, also
check if the truncate point / start of the hole is within the range we
have metadata for.  Otherwise, we can end up freeing blocks that
shouldn't be freed, corrupting the inode, or crashing the machine when
trying to punch a hole into the void.

When growing an inode via truncate, we set the new size but we don't
allocate additional levels of indirect blocks and grow the inode height.
When shrinking that inode again, the new size may still point beyond the
end of the inode's metadata.

Fixes xfstest generic/476.
Debugged-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

It turns out that commit 3229c18c0d6b2 'Fixes to "Implement iomap for
block_map"' introduced another bug in gfs2_iomap_begin that can cause
gfs2_block_map to set bh->b_size of an actual buffer to 0.  This can
lead to arbitrary incorrect behavior including crashes or disk
corruption.  Revert the incorrect part of that commit.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

It turns out that commit 3974320c "Implement iomap for block_map"
introduced a few bugs that trigger occasional failures with xfstest
generic/476:

In gfs2_iomap_begin, we jump to do_alloc when we determine that we are
beyond the end of the allocated metadata (height > ip->i_height).
There, we can end up calling hole_size with a metapath that doesn't
match the current metadata tree, which doesn't make sense.  After
untangling the code at do_alloc, fix this by checking if the block we
are looking for is within the range of allocated metadata.

In addition, add a BUG() in case gfs2_iomap_begin is accidentally called
for reading stuffed files: this is handled separately.  Make sure we
don't truncate iomap->length for reads beyond the end of the file; in
that case, the entire range counts as a hole.

Finally, revert to taking a bitmap write lock when doing allocations.
It's unclear why that change didn't lead to any failures during testing.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Add a small inline function for computing the maximum size of a stuffed
inode instead of open coding that in several places throughout the code.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Implement the top-level bits of punching a hole into a file.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Add an upper bound to the range of blocks to deallocate blocks to
function trunc_dealloc so that this function can be used for truncating
a file as well as for punching a hole into a file.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Pull the code for computing the range of metapointers to iterate out of
gfs2_metapath_ra (for readahead), sweep_bh_for_rgrps (for deallocating
metapointers within a block), and trunc_dealloc (for walking the
metadata tree).

In sweep_bh_for_rgrps, move the code for looking up the resource group
descriptor of the current resource group out of the inner loop.  The
metatype check moves to trunc_dealloc.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Turn gfs2_block_truncate_page into a function that zeroes a range within
a block rather than only the end of a block.  This will be used for
cleaning the end of the first partial block and the start of the last
partial block when punching a hole in a file.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

In rare cases, the current non-recursive delete algorithm doesn't
deallocate empty intermediary indirect blocks.  This should have very
little practical effect, but deallocating all blocks correctly should
still be preferable as it is cleaner and easier to validate.

The fix consists of using the first block to deallocate to compute the
start marker of the truncate point instead of the last block that needs
to be kept.  With that change, computing which indirect blocks are still
needed becomes relatively easy.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

The metadata read-ahead algorithm broke when switching from recursive to
non-recursive delete: the current algorithm reads ahead blocks at height
N - 1 while deallocating the blocks at hight N.  However, deallocating
the blocks at height N requires a complete walk of the metadata tree,
not only down to height N - 1.  Consequently, all blocks below height
N - 1 will be accessed without read-ahead.

Fix this by issuing read-aheads as early as possible, after each
metapath lookup.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Split out the entire lookup loop from lookup_metapath and
fillup_metapath.  Make both functions return the actual height in
mp->mp_aheight, and return 0 on success.  Handle lookup errors properly
in trunc_dealloc.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

First, this function truncates the file in chunks.  When the original
file size isn't block aligned, each chunk that is truncated will remain
be misaligned.  This is inefficient.

Second, this function doesn't recognize where holes are, so it loops
through them.  For each chunk of a hole, it creates a new transaction.
At least avoid creating another transactions whe the current one is
still empty.  (An better fix would be to skip large holes, of course.)
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

Document when to use gfs2_blk2rgrpd for "inexact" resource group
matching.  Based on that, fix an incorrect use of gfs2_blk2rgrpd in
sweep_bh_for_rgrps.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>

This patch implements iomap for block mapping, and switches the
block_map function to use it under the covers.

The additional IOMAP_F_BOUNDARY iomap flag indicates when iomap has
reached a "metadata boundary" and fetching the next mapping is likely to
incur an additional I/O.  This flag is used for setting the bh buffer
boundary flag.
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>