linux.git/fs/jffs2/os-linux.h, branch v5.2

jffs2: use unsigned 32-bit timstamps consistently

2018-07-18T14:44:01+00:00

Most users of jffs2 are 32-bit systems that traditionally only support
timestamps using a 32-bit signed time_t, in the range from years 1902 to
2038. On 64-bit systems, jffs2 however interpreted the same timestamps
as unsigned values, reading back negative times (before 1970) as times
between 2038 and 2106.

Now that Linux supports 64-bit inode timestamps even on 32-bit systems,
let's use the second interpretation everywhere to allow jffs2 to be
used on 32-bit systems beyond 2038 without a fundamental change to the
inode format.

This has a slight risk of regressions, when existing files with timestamps
before 1970 are present in file system images and are now interpreted
as future time stamps. I considered moving the wraparound point a bit,
e.g. to 1960, in order to deal with timestamps that ended up on Dec 31,
1969 due to incorrect timezone handling. However, this would complicate
the implementation unnecessarily, so I went with the simplest possible
method of extending the timestamps.

Writing files with timestamps before 1970 or after 2106 now results
in those times being clamped in the file system.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Boris Brezillon

jffs2: use 64-bit intermediate timestamps

2018-07-18T14:43:58+00:00

The VFS now uses timespec64 timestamps consistently, but jffs2 still
converts them to 32-bit numbers on the storage medium. As the helper
functions for the conversion (get_seconds() and timespec_to_timespec64())
are now deprecated, let's change them over to the more modern
replacements.

This keeps the traditional interpretation of those values, where
the on-disk 32-bit numbers are taken to be negative numbers, i.e.
dates before 1970, on 32-bit machines, but future numbers past 2038
on 64-bit machines.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Boris Brezillon

Rename superblock flags (MS_xyz -> SB_xyz)

2017-11-27T21:05:09+00:00

This is a pure automated search-and-replace of the internal kernel
superblock flags.

The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.

Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.

The script to do this was:

    # places to look in; re security/*: it generally should *not* be
    # touched (that stuff parses mount(2) arguments directly), but
    # there are two places where we really deal with superblock flags.
    FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
            include/linux/fs.h include/uapi/linux/bfs_fs.h \
            security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
    # the list of MS_... constants
    SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
          DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
          POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
          I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
          ACTIVE NOUSER"

    SED_PROG=
    for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done

    # we want files that contain at least one of MS_...,
    # with fs/namespace.c and fs/pnode.c excluded.
    L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')

    for f in $L; do sed -i $f $SED_PROG; done

Requested-by: Al Viro 
Signed-off-by: Linus Torvalds

fs: cleanup slight list_entry abuse

2015-06-23T22:01:59+00:00

list_entry is just a wrapper for container_of, but it is arguably
wrong (and slightly confusing) to use it when the pointed-to struct
member is not a struct list_head. Use container_of directly instead.

Signed-off-by: Rasmus Villemoes 
Signed-off-by: Al Viro

userns: Convert jffs2 to use kuid and kgid where appropriate

2012-09-21T10:13:33+00:00

- General routine uid/gid conversion work
- When storing posix acls treat ACL_USER and ACL_GROUP separately
  so I can call from_kuid or from_kgid as appropriate.
- When reading posix acls treat ACL_USER and ACL_GROUP separately
  so I can call make_kuid or make_kgid as appropriate.

Cc: David Woodhouse 
Signed-off-by: Eric W. Biederman

jffs2: get rid of jffs2_sync_super

2012-05-31T01:04:52+00:00

Currently JFFS2 file-system maps the VFS "superblock" abstraction to the
write-buffer. Namely, it uses VFS services to synchronize the write-buffer
periodically.

The whole "superblock write-out" VFS infrastructure is served by the
'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and
writes out all dirty superblock using the '->write_super()' call-back. But the
problem with this thread is that it wastes power by waking up the system every
5 seconds no matter what. So we want to kill it completely and thus, we need to
make file-systems to stop using the '->write_super' VFS service, and then
remove it together with the kernel thread.

This patch switches the JFFS2 write-buffer management from
'->write_super()'/'->s_dirt' to a delayed work. Instead of setting the 's_dirt'
flag we just schedule a delayed work for synchronizing the write-buffer.

Signed-off-by: Artem Bityutskiy 
Signed-off-by: Al Viro

jffs2: update to new MTD interface

2012-03-26T23:19:38+00:00

There were a few instances of the old MTD interface remaining for JFFS2. We
fix one error that shows up (only when CONFIG_JFFS2_FS_WRITEBUFFER is not
defined) like this:

  fs/jffs2/read.c: In function 'jffs2_read_dnode':
  fs/jffs2/read.c:36:8: error: 'struct mtd_info' has no member named 'read'
  fs/jffs2/read.c:112:8: error: 'struct mtd_info' has no member named 'read'
  ...

We also simply remove two macros that are not in use, were not updated to
the new MTD interface, and don't even utilize the old interface properly.
(That means they weren't used since commit 8593fbc6, year 2006; almost 6
years ago, for those who don't want to do the math)

Reported-by: Randy Dunlap 
Signed-off-by: Brian Norris 
Acked-by: Randy Dunlap 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

jffs2: implement mount option parsing and compression overriding

2011-10-19T14:22:20+00:00

Currently jffs2 has compile-time constants (and .config options)
controlling whether or not the various compression/decompression
drivers are built in and enabled.  This is fine for embedded
systems, but it clashes with distribution kernels.  Distro kernels
tend to turn on everything; this causes OpenFirmware to fall
over, as it understands ZLIB-compressed inodes.  Booting a kernel
that has LZO compression enabled, writing to the boot partition,
and then rebooting causes OFW to fail to read the kernel from
the filesystem.  This is because LZO compression has priority
when writing new data to jffs2, if LZO is enabled.

This patch adds mount option parsing, and a single supported
option ("compr=none").  This adds the flexibility of being
able to specify which compressor overrides on a per-superblock
basis.  For now, we can simply disable compression;
additional flexibility coming soon.

v2: kill some printks, and implement show_options as suggested
by Artem Bityutskiy.

Signed-off-by: Andres Salomon 
Signed-off-by: Artem Bityutskiy

switch posix_acl_create() to umode_t *

2011-08-01T06:09:42+00:00

so we can pass &inode->i_mode to it

Signed-off-by: Al Viro

fix jffs2 ACLs on big-endian with 16bit mode_t

2011-07-24T14:12:01+00:00

casting int * to mode_t * is not a good thing - on a *lot* of big-endian
architectures mode_t happens to be smaller than int and there it breaks
quite spectaculary...

Fucked-up-by: commit cfc8dc6f6f69ede939e09c2af06a01adee577285
Signed-off-by: Al Viro