linux.git/fs/romfs, branch v6.3

mm/nommu: factor out check for NOMMU shared mappings into is_nommu_shared_mapping()

2023-01-19T01:12:56+00:00

Patch series "mm/nommu: don't use VM_MAYSHARE for MAP_PRIVATE mappings".

Trying to reduce the confusion around VM_SHARED and VM_MAYSHARE first
requires !CONFIG_MMU to stop using VM_MAYSHARE for MAP_PRIVATE mappings. 
CONFIG_MMU only sets VM_MAYSHARE for MAP_SHARED mappings.

This paves the way for further VM_MAYSHARE and VM_SHARED cleanups: for
example, renaming VM_MAYSHARED to VM_MAP_SHARED to make it cleaner what is
actually means.

Let's first get the weird case out of the way and not use VM_MAYSHARE in
MAP_PRIVATE mappings, using a new VM_MAYOVERLAY flag instead.


This patch (of 3):

We want to stop using VM_MAYSHARE in private mappings to pave the way for
clarifying the semantics of VM_MAYSHARE vs.  VM_SHARED and reduce the
confusion.  While CONFIG_MMU uses VM_MAYSHARE to represent MAP_SHARED,
!CONFIG_MMU also sets VM_MAYSHARE for selected R/O private file mappings
that are an effective overlay of a file mapping.

Let's factor out all relevant VM_MAYSHARE checks in !CONFIG_MMU code into
is_nommu_shared_mapping() first.

Note that whenever VM_SHARED is set, VM_MAYSHARE must be set as well
(unless there is a serious BUG).  So there is not need to test for
VM_SHARED manually.

No functional change intended.

Link: https://lkml.kernel.org/r/20230102160856.500584-1-david@redhat.com
Link: https://lkml.kernel.org/r/20230102160856.500584-2-david@redhat.com
Signed-off-by: David Hildenbrand 
Cc: Arnd Bergmann 
Cc: David Hildenbrand 
Cc: Greg Kroah-Hartman 
Cc: Jens Axboe 
Cc: Nicolas Pitre 
Cc: Pavel Begunkov 
Signed-off-by: Andrew Morton

romfs: Convert romfs to read_folio

2022-05-09T20:21:46+00:00

This is a "weak" conversion which converts straight back to using pages.
A full conversion should be performed at some point, hopefully by
someone familiar with the filesystem.

Signed-off-by: Matthew Wilcox (Oracle)

fs: allocate inode by using alloc_inode_sb()

2022-03-22T22:57:03+00:00

The inode allocation is supposed to use alloc_inode_sb(), so convert
kmem_cache_alloc() of all filesystems to alloc_inode_sb().

Link: https://lkml.kernel.org/r/20220228122126.37293-5-songmuchun@bytedance.com
Signed-off-by: Muchun Song 
Acked-by: Theodore Ts'o 		[ext4]
Acked-by: Roman Gushchin 
Cc: Alex Shi 
Cc: Anna Schumaker 
Cc: Chao Yu 
Cc: Dave Chinner 
Cc: Fam Zheng 
Cc: Jaegeuk Kim 
Cc: Johannes Weiner 
Cc: Kari Argillander 
Cc: Matthew Wilcox (Oracle) 
Cc: Michal Hocko 
Cc: Qi Zheng 
Cc: Shakeel Butt 
Cc: Trond Myklebust 
Cc: Vladimir Davydov 
Cc: Vlastimil Babka 
Cc: Wei Yang 
Cc: Xiongchun Duan 
Cc: Yang Shi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-10-24T19:26:05+00:00

Pull misc vfs updates from Al Viro:
 "Assorted stuff all over the place (the largest group here is
  Christoph's stat cleanups)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: remove KSTAT_QUERY_FLAGS
  fs: remove vfs_stat_set_lookup_flags
  fs: move vfs_fstatat out of line
  fs: implement vfs_stat and vfs_lstat in terms of vfs_fstatat
  fs: remove vfs_statx_fd
  fs: omfs: use kmemdup() rather than kmalloc+memcpy
  [PATCH] reduce boilerplate in fsid handling
  fs: Remove duplicated flag O_NDELAY occurring twice in VALID_OPEN_FLAGS
  selftests: mount: add nosymfollow tests
  Add a "nosymfollow" mount option.

ROMFS: support inode blocks calculation

2020-10-16T18:11:22+00:00

When use 'stat' tool to display file status, the 'Blocks' field always in
'0', this is not good for tool 'du'(e.g.: busybox 'du'), it always output
'0' size for the files under ROMFS since such tool calculates number of
512B Blocks.

This patch calculates approx.  number of 512B blocks based on inode size.

Signed-off-by: Libing Zhou 
Signed-off-by: Andrew Morton 
Cc: David Howells 
Cc: Al Viro 
Link: http://lkml.kernel.org/r/20200811052606.4243-1-libing.zhou@nokia-sbell.com
Signed-off-by: Linus Torvalds

[PATCH] reduce boilerplate in fsid handling

2020-09-18T20:45:50+00:00

Get rid of boilerplate in most of ->statfs()
instances...

Signed-off-by: Al Viro

romfs: fix uninitialized memory leak in romfs_dev_read()

2020-08-21T16:52:53+00:00

romfs has a superblock field that limits the size of the filesystem; data
beyond that limit is never accessed.

romfs_dev_read() fetches a caller-supplied number of bytes from the
backing device.  It returns 0 on success or an error code on failure;
therefore, its API can't represent short reads, it's all-or-nothing.

However, when romfs_dev_read() detects that the requested operation would
cross the filesystem size limit, it currently silently truncates the
requested number of bytes.  This e.g.  means that when the content of a
file with size 0x1000 starts one byte before the filesystem size limit,
->readpage() will only fill a single byte of the supplied page while
leaving the rest uninitialized, leaking that uninitialized memory to
userspace.

Fix it by returning an error code instead of truncating the read when the
requested read operation would go beyond the end of the filesystem.

Fixes: da4458bda237 ("NOMMU: Make it possible for RomFS to use MTD devices directly")
Signed-off-by: Jann Horn 
Signed-off-by: Andrew Morton 
Reviewed-by: Greg Kroah-Hartman 
Cc: David Howells 
Cc: 
Link: http://lkml.kernel.org/r/20200818013202.2246365-1-jannh@google.com
Signed-off-by: Linus Torvalds

treewide: replace '---help---' in Kconfig files with 'help'

2020-06-13T16:57:21+00:00

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada

docs: filesystems: fix renamed references

2020-04-20T21:45:22+00:00

Some filesystem references got broken by a previous patch
series I submitted. Address those.

Signed-off-by: Mauro Carvalho Chehab 
Acked-by: David Sterba  # fs/affs/Kconfig
Link: https://lore.kernel.org/r/57318c53008dbda7f6f4a5a9e5787f4d37e8565a.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet

Merge branch 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2019-09-19T17:06:57+00:00

Pull misc mount API conversions from Al Viro:
 "Conversions to new API for shmem and friends and for mount_mtd()-using
  filesystems.

  As for the rest of the mount API conversions in -next, some of them
  belong in the individual trees (e.g. binderfs one should definitely go
  through android folks, after getting redone on top of their changes).
  I'm going to drop those and send the rest (trivial ones + stuff ACKed
  by maintainers) in a separate series - by that point they are
  independent from each other.

  Some stuff has already migrated into individual trees (NFS conversion,
  for example, or FUSE stuff, etc.); those presumably will go through
  the regular merges from corresponding trees."

* 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: Make fs_parse() handle fs_param_is_fd-type params better
  vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API
  shmem_parse_one(): switch to use of fs_parse()
  shmem_parse_options(): take handling a single option into a helper
  shmem_parse_options(): don't bother with mpol in separate variable
  shmem_parse_options(): use a separate structure to keep the results
  make shmem_fill_super() static
  make ramfs_fill_super() static
  devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()
  vfs: Convert squashfs to use the new mount API
  mtd: Kill mount_mtd()
  vfs: Convert jffs2 to use the new mount API
  vfs: Convert cramfs to use the new mount API
  vfs: Convert romfs to use the new mount API
  vfs: Add a single-or-reconfig keying to vfs_get_super()