linux.git/fs/erofs, branch v5.14

erofs: clean up file headers & footers

2021-06-07T16:41:24+00:00

 - Remove my outdated misleading email address;

 - Get rid of all unnecessary trailing newline by accident.

Link: https://lore.kernel.org/r/20210602160634.10757-1-xiang@kernel.org
Reviewed-by: Chao Yu 
Signed-off-by: Gao Xiang

erofs: remove the occupied parameter from z_erofs_pagevec_enqueue()

2021-06-07T16:40:18+00:00

No any behavior to variable occupied in z_erofs_attach_page() which
is only caller to z_erofs_pagevec_enqueue().

Link: https://lore.kernel.org/r/20210419102623.2015-1-zbestahu@gmail.com
Signed-off-by: Yue Hu 
Reviewed-by: Gao Xiang 
Signed-off-by: Gao Xiang

erofs: fix error return code in erofs_read_superblock()

2021-06-07T16:40:18+00:00

'ret' will be overwritten to 0 if erofs_sb_has_sb_chksum() return true,
thus 0 will return in some error handling cases. Fix to return negative
error code -EINVAL instead of 0.

Link: https://lore.kernel.org/r/20210519141657.3062715-1-weiyongjun1@huawei.com
Fixes: b858a4844cfb ("erofs: support superblock checksum")
Cc: stable  # 5.5+
Reported-by: Hulk Robot 
Signed-off-by: Wei Yongjun 
Reviewed-by: Gao Xiang 
Reviewed-by: Chao Yu 
Signed-off-by: Gao Xiang

erofs: fix 1 lcluster-sized pcluster for big pcluster

2021-05-13T07:58:46+00:00

If the 1st NONHEAD lcluster of a pcluster isn't CBLKCNT lcluster type
rather than a HEAD or PLAIN type instead, which means its pclustersize
_must_ be 1 lcluster (since its uncompressed size < 2 lclusters),
as illustrated below:

       HEAD     HEAD / PLAIN    lcluster type
   ____________ ____________
  |_:__________|_________:__|   file data (uncompressed)
   .                .
  .____________.
  |____________|                pcluster data (compressed)

Such on-disk case was explained before [1] but missed to be handled
properly in the runtime implementation.

It can be observed if manually generating 1 lcluster-sized pcluster
with 2 lclusters (thus CBLKCNT doesn't exist.) Let's fix it now.

[1] https://lore.kernel.org/r/20210407043927.10623-1-xiang@kernel.org

Link: https://lore.kernel.org/r/20210510064715.29123-1-xiang@kernel.org
Fixes: cec6e93beadf ("erofs: support parsing big pcluster compress indexes")
Reviewed-by: Chao Yu 
Signed-off-by: Gao Xiang

erofs: enable big pcluster feature

2021-04-09T19:20:19+00:00

Enable COMPR_CFGS and BIG_PCLUSTER since the implementations are
all settled properly.

Link: https://lore.kernel.org/r/20210407043927.10623-11-xiang@kernel.org
Acked-by: Chao Yu 
Signed-off-by: Gao Xiang

erofs: support decompress big pcluster for lz4 backend

2021-04-09T19:20:19+00:00

Prior to big pcluster, there was only one compressed page so it'd
easy to map this. However, when big pcluster is enabled, more work
needs to be done to handle multiple compressed pages. In detail,

 - (maptype 0) if there is only one compressed page + no need
   to copy inplace I/O, just map it directly what we did before;

 - (maptype 1) if there are more compressed pages + no need to
   copy inplace I/O, vmap such compressed pages instead;

 - (maptype 2) if inplace I/O needs to be copied, use per-CPU
   buffers for decompression then.

Another thing is how to detect inplace decompression is feasable or
not (it's still quite easy for non big pclusters), apart from the
inplace margin calculation, inplace I/O page reusing order is also
needed to be considered for each compressed page. Currently, if the
compressed page is the xth page, it shouldn't be reused as [0 ...
nrpages_out - nrpages_in + x], otherwise a full copy will be triggered.

Although there are some extra optimization ideas for this, I'd like
to make big pcluster work correctly first and obviously it can be
further optimized later since it has nothing with the on-disk format
at all.

Link: https://lore.kernel.org/r/20210407043927.10623-10-xiang@kernel.org
Acked-by: Chao Yu 
Signed-off-by: Gao Xiang

erofs: support parsing big pcluster compact indexes

2021-04-09T19:20:18+00:00

Different from non-compact indexes, several lclusters are packed
as the compact form at once and an unique base blkaddr is stored for
each pack, so each lcluster index would take less space on avarage
(e.g. 2 bytes for COMPACT_2B.) btw, that is also why BIG_PCLUSTER
switch should be consistent for compact head0/1.

Prior to big pcluster, the size of all pclusters was 1 lcluster.
Therefore, when a new HEAD lcluster was scanned, blkaddr would be
bumped by 1 lcluster. However, that way doesn't work anymore for
big pcluster since we actually don't know the compressed size of
pclusters in advance (before reading CBLKCNT lcluster).

So, instead, let blkaddr of each pack be the first pcluster blkaddr
with a valid CBLKCNT, in detail,

 1) if CBLKCNT starts at the pack, this first valid pcluster is
    itself, e.g.
  _____________________________________________________________
 |_CBLKCNT0_|_NONHEAD_| .. |_HEAD_|_CBLKCNT1_| ... |_HEAD_| ...
 ^ = blkaddr base          ^ += CBLKCNT0           ^ += CBLKCNT1

 2) if CBLKCNT doesn't start at the pack, the first valid pcluster
    is the next pcluster, e.g.
  _________________________________________________________
 | NONHEAD_| .. |_HEAD_|_CBLKCNT0_| ... |_HEAD_|_HEAD_| ...
                ^ = blkaddr base        ^ += CBLKCNT0
                                               ^ += 1

When a CBLKCNT is found, blkaddr will be increased by CBLKCNT
lclusters, or a new HEAD is found immediately, bump blkaddr by 1
instead (see the picture above.)

Also noted if CBLKCNT is the end of the pack, instead of storing
delta1 (distance of the next HEAD lcluster) as normal NONHEADs,
it still uses the compressed block count (delta0) since delta1
can be calculated indirectly but the block count can't.

Adjust decoding logic to fit big pcluster compact indexes as well.

Link: https://lore.kernel.org/r/20210407043927.10623-9-xiang@kernel.org
Acked-by: Chao Yu 
Signed-off-by: Gao Xiang

erofs: support parsing big pcluster compress indexes

2021-04-09T19:20:18+00:00

When INCOMPAT_BIG_PCLUSTER sb feature is enabled, legacy compress indexes
will also have the same on-disk header compact indexes to keep per-file
configurations instead of leaving it zeroed.

If ADVISE_BIG_PCLUSTER is set for a file, CBLKCNT will be loaded for each
pcluster in this file by parsing 1st non-head lcluster.

Link: https://lore.kernel.org/r/20210407043927.10623-8-xiang@kernel.org
Acked-by: Chao Yu 
Signed-off-by: Gao Xiang

erofs: adjust per-CPU buffers according to max_pclusterblks

2021-04-09T19:20:17+00:00

Adjust per-CPU buffers on demand since big pcluster definition is
available. Also, bail out unsupported pcluster size according to
Z_EROFS_PCLUSTER_MAX_SIZE.

Link: https://lore.kernel.org/r/20210407043927.10623-7-xiang@kernel.org
Acked-by: Chao Yu 
Signed-off-by: Gao Xiang

erofs: add big physical cluster definition

2021-04-09T19:20:17+00:00

Big pcluster indicates the size of compressed data for each physical
pcluster is no longer fixed as block size, but could be more than 1
block (more accurately, 1 logical pcluster)

When big pcluster feature is enabled for head0/1, delta0 of the 1st
non-head lcluster index will keep block count of this pcluster in
lcluster size instead of 1. Or, the compressed size of pcluster
should be 1 lcluster if pcluster has no non-head lcluster index.

Also note that BIG_PCLUSTER feature reuses COMPR_CFGS feature since
it depends on COMPR_CFGS and will be released together.

Link: https://lore.kernel.org/r/20210407043927.10623-6-xiang@kernel.org
Acked-by: Chao Yu 
Signed-off-by: Gao Xiang