Add prefix "erofs_" to these functions and print
sb->s_id as a prefix to erofs_{err, info} so that
the user knows which file system is affected.
Reported-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-23-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As Christoph suggested [1], "Please just use plain kmalloc
everywhere and let the normal kernel error injection code
take care of injeting any errors."

[1] https://lore.kernel.org/r/20190829102426.GE20598@infradead.org/Reported-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-20-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add erofs_ prefix to free_inode, alloc_inode, ...
Reported-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-19-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As Christoph said [1], "That is some very verbose
debug info.  We usually don't add that and let
people trace the function instead. "

[1] https://lore.kernel.org/r/20190829101545.GC20598@infradead.org/Reported-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-15-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As Christoph pointed out [1], "Why is the variable name
for the on-disk subperblock layout? We usually still
calls this something with sb in the name, e.g. dsb.
for disksuper block. " Let's fix it.

[1] https://lore.kernel.org/r/20190829101545.GC20598@infradead.org/Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-14-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix as Christoph suggested [1] [2], "remove is_inode_fast_symlink
and just opencode it in the few places using it"

and
"Please just set the ops directly instead of obsfucating that in
a single caller, single line inline function.  And please set it
instead of the normal symlink iops in the same place where you
also set those."

[1] https://lore.kernel.org/r/20190830163910.GB29603@infradead.org/
[2] https://lore.kernel.org/r/20190829102426.GE20598@infradead.org/Reported-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-13-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As Christoph suggested [1], "Why is this called vnode instead
of inode?  That seems like a rather odd naming for a Linux
file system."

[1] https://lore.kernel.org/r/20190829101545.GC20598@infradead.org/Reported-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-10-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As Christoph said [1] "having this function seems
entirely pointless", let's kill those.

filesystem                              function name
ext2,f2fs,ext4,isofs,squashfs,cifs,...  init_inodecache

In addition, add a necessary "rcu_barrier()" on exit_fs();

[1] https://lore.kernel.org/r/20190829101545.GC20598@infradead.org/Reported-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-9-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

updates inode naming
 - kill is_inode_layout_compression [1]
 - kill magic underscores [2] [3]
 - better naming for datamode & data_mapping_mode [3]
 - better naming erofs_inode_{compact, extended} [4]

[1] https://lore.kernel.org/r/20190829102426.GE20598@infradead.org/
[2] https://lore.kernel.org/r/20190829102426.GE20598@infradead.org/
[3] https://lore.kernel.org/r/20190902122627.GN15931@infradead.org/
[4] https://lore.kernel.org/r/20190902125438.GA17750@infradead.org/Reported-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-8-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As Christoph said [1], "This is only cosmetic, why
not stick to feature_compat and feature_incompat?"

In my thought, requirements means "incompatible"
instead of "feature" though.

[1] https://lore.kernel.org/r/20190902125109.GA9826@infradead.org/Reported-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-7-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As Dan Carpenter suggested [1], I have to remove
all erofs likely/unlikely annotations.

[1] https://lore.kernel.org/linux-fsdevel/20190829154346.GK23584@kadam/Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190829163827.203274-1-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

EROFS filesystem has been merged into linux-staging for a year.

EROFS is designed to be a better solution of saving extra storage
space with guaranteed end-to-end performance for read-only files
with the help of reduced metadata, fixed-sized output compression
and decompression inplace technologies.

In the past year, EROFS was greatly improved by many people as
a staging driver, self-tested, betaed by a large number of our
internal users, successfully applied to almost all in-service
HUAWEI smartphones as the part of EMUI 9.1 and proven to be stable
enough to be moved out of staging.

EROFS is a self-contained filesystem driver. Although there are
still some TODOs to be more generic, we have a dedicated team
actively keeping on working on EROFS in order to make it better
with the evolution of Linux kernel as the other in-kernel filesystems.

As Pavel suggested, it's better to do as one commit since git
can do moves and all histories will be saved in this way.

Let's promote it from staging and enhance it more actively as
a "real" part of kernel for more wider scenarios!

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Pavel Machek <pavel@denx.de>
Cc: David Sterba <dsterba@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Darrick J . Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Richard Weinberger <richard@nod.at>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: Li Guifu <bluce.liguifu@huawei.com>
Cc: Fang Wei <fangwei1@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190822213659.5501-1-hsiangkao@aol.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As Richard reminder [1], A valid volume name should be
ended in NIL terminator within the length of volume_name.

Since this field currently isn't really used, let's fix
it to avoid potential bugs in the future.

[1] https://lore.kernel.org/r/1133002215.69049.1566119033047.JavaMail.zimbra@nod.at/Reported-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20190818102824.22330-1-hsiangkao@aol.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Keep in line with erofs-outofstaging patchset:
- "Chao Yu" is most commonly used in Linux community;
- quoted string split across lines.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190731155752.210602-22-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Kill all kconfig cache strategies and turn them into mount options
"cache_strategy={disable|readahead|readaround}".

As the first step, cached pages can still be usable after cache
is disabled by remounting, and these pages will be fallen out
over time, which can be refined in the later version if some
requirement is needed. Update related document as well.
Suggested-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190731155752.210602-20-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

clustersize can now be set on per-file basis
rather than per-filesystem basis.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190731155752.210602-19-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For historical reasons, __GFP_NOFAIL was set for managed inode.
It's no need using that since EROFS can handle it properly.
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20190731155752.210602-13-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

.kill_sb() will do that instead in order to remove duplicated code.

Note that the initialzation of managed_cache is now moved
after s_root is assigned since it's more preferred to iput()
in .put_super() and all inodes should be evicted before
the end of generic_shutdown_super(sb).
Suggested-by: NAl Viro <viro@zeniv.linux.org.uk>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190731155752.210602-12-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As Al said, "the only use of sbi->dev_name is debugging
printks and all of those have sb->s_id available, with
device name stored in there.  Which makes the whole
thing bloody weird".

sbi->dev_name was used for our debugging use and it's
better to just use s_id in community and delete
the whole erofs_mount_private stuff.
Suggested-by: NAl Viro <viro@zeniv.linux.org.uk>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190731155752.210602-11-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

- rename erofs_register_super / erofs_unregister_super
  to erofs_shrinker_register / erofs_shrinker_unregister;
- fold the only erofs_shrink_workstation external call
  to erofs_shrinker_unregister;
- localize erofs_shrink_workstation;
- localize erofs_shrinker_info by introducing
  erofs_init_shrinker and erofs_exit_shrinker.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190731155752.210602-10-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Because #include "internal.h" is included in xattr.h
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20190731155752.210602-8-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Tidy up relative order of variables / declarations in internal.h,
move some local static functions out into other files and
add tags at the end of #endif acrossing several lines.

No logic change.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190731155752.210602-7-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

- Use the correct style for all SPDX License Identifiers;
- Get rid of the unnecessary license boilerplate;
- Use "GPL-2.0-only" instead of "GPL-2.0" suggested-by Stephen.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190731155752.210602-2-gaoxiang25@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove function erofs_kill_sb as all it does is call kill_block_super.
Modify references to the former to point to the latter.
Issue found with Coccinelle.
Signed-off-by: NNishka Dasgupta <nishkadg.linux@gmail.com>
Reviewed-by: NGao Xiang <gaoxiang25@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20190712071247.2357-1-nishkadg.linux@gmail.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Resolve checkpatch warning:
Prefer kzalloc(sizeof(*ptr)...) over kzalloc(sizeof(struct ..)
Signed-off-by: NShobhit Kukreti <shobhitkukreti@gmail.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Reviewed-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There are some backward incompatible features pending
for months, mainly due to on-disk format expensions.

However, we should ensure that it cannot be mounted with
old kernels. Otherwise, it will causes unexpected behaviors.

Fixes: ba2b77a8 ("staging: erofs: add super block operations")
Cc: <stable@vger.kernel.org> # 4.19+
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Set sb->s_root to NULL when failing from __getname(),
so that we can avoid double dput and unnecessary operations
in generic_shutdown_super().
Signed-off-by: NChengguang Xu <cgxu519@gmail.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Reviewed-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Acked-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Used to simulate disk IO read error for testing fatal
error tolerance.

Here are the details,
1) use bio->bi_private to indicate super_block
   for non-compressed bios since some (mainly meta)
   pages can be of the corresponding bdev inode;
2) get super_block dynamically for compressed bios,
   therefore it could not inject bios full of staging
   pages, yet it doesn't affect the normal usage.
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Test for NULL as !x instead of NULL comparisions.
Issue found using coccinelle
Semantic patch used to solve the problem is as follows

// <smpl>
@@
expression x;
statement S;
@@

x = (\(kmalloc\|devm_kzalloc\|kmalloc_array\|devm_ioremap\|
usb_alloc_urb\|alloc_netdev\|dev_alloc_skb\)(...));

-if(x==NULL)
+if(!x)
S

@@
expression e;
@@

-e == NULL
+!e
// </smpl>
Signed-off-by: NBhanusree Pola <bhanusreemahesh@gmail.com>
[ Gao Xiang: fix x != NULL comparision to x as well. ]
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace all NULL comparisons in the file to get rid of checkpatch
warnings
Signed-off-by: NVatsala Narang <vatsalanarang@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix all checkpatch issues: "CHECK: Alignment should match open parenthesis"
Signed-off-by: NJulian Merida <julianmr97@gmail.com>
Reviewed-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Let's add .get_acl() to read the file's acl from its xattrs
to make POSIX ACL usable.

Here is the on-disk detail,
fullname: system.posix_acl_access
struct erofs_xattr_entry:
        .e_name_len = 0
        .e_name_index = EROFS_XATTR_INDEX_POSIX_ACL_ACCESS (2)

fullname: system.posix_acl_default
struct erofs_xattr_entry:
	.e_name_len = 0
	.e_name_index = EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT (3)
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some error cases like failing from d_make_root() will
cause double iput because d_make_root() also does iput
in its error path.
Signed-off-by: NChengguang Xu <cgxu519@gmx.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Reviewed-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Move erofs_shrinker_info to utils.c and therefore
no need to globalize erofs_shrink_count and erofs_shrink_scan.
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is only one user calling erofs_workstation_cleanup_all,
and it is no likely that more users will use in that way
in the future.
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Let's move independent xattr-related stuffs to xattr.h.
No logic changes.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

remove all redundant BUG_ONs, and turn the rest
useful usages to DBG_BUGONs.
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is actually no need at all to d_rehash() for the root dentry
as Al pointed out, fix it.
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Append __init to `erofs_init_inode_cache',
`z_erofs_init_zip_subsystem' and move these
declarations to internal.h.
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>