ext4: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

ext4: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-40-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

show more ...

fs: port acl to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversi

fs: port acl to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

show more ...

fs: port ->set_acl() to pass mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just

fs: port ->set_acl() to pass mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

show more ...

fs: pass dentry to set acl method

The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acl

fs: pass dentry to set acl method

The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acls before storing or reporting it to
userspace. Various hacks exist to make this work. The code is hard to
understand and difficult to maintain in it's current form. Instead of
making this work by hacking posix acls through xattr handlers we are
building a dedicated posix acl api around the get and set inode
operations. This removes a lot of hackiness and makes the codepaths
easier to maintain. A lot of background can be found in [1].

Since some filesystem rely on the dentry being available to them when
setting posix acls (e.g., 9p and cifs) they cannot rely on set acl inode
operation. But since ->set_acl() is required in order to use the generic
posix acl xattr handlers filesystems that do not implement this inode
operation cannot use the handler and need to implement their own
dedicated posix acl handlers.

Update the ->set_acl() inode method to take a dentry argument. This
allows all filesystems to rely on ->set_acl().

As far as I can tell all codepaths can be switched to rely on the dentry
instead of just the inode. Note that the original motivation for passing
the dentry separate from the inode instead of just the dentry in the
xattr handlers was because of security modules that call
security_d_instantiate(). This hook is called during
d_instantiate_new(), d_add(), __d_instantiate_anon(), and
d_splice_alias() to initialize the inode's security context and possibly
to set security.* xattrs. Since this only affects security.* xattrs this
is completely irrelevant for posix acls.

Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1]
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

show more ...

fs/ext4: fix comments mentioning i_mutex

inode->i_mutex has been replaced with inode->i_rwsem long ago. Fix
comments still mentioning i_mutex.

Signed-off-by: hongnanli <hongnan.li@linux.alibaba.com

fs/ext4: fix comments mentioning i_mutex

inode->i_mutex has been replaced with inode->i_rwsem long ago. Fix
comments still mentioning i_mutex.

Signed-off-by: hongnanli <hongnan.li@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220121070611.21618-1-hongnan.li@linux.alibaba.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

ext4: use ext4_journal_start/stop for fast commit transactions

This patch drops all calls to ext4_fc_start_update() and
ext4_fc_stop_update(). To ensure that there are no ongoing journal
updates dur

ext4: use ext4_journal_start/stop for fast commit transactions

This patch drops all calls to ext4_fc_start_update() and
ext4_fc_stop_update(). To ensure that there are no ongoing journal
updates during fast commit, we also make jbd2_fc_begin_commit() lock
journal for updates. This way we don't have to maintain two different
transaction start stop APIs for fast commit and full commit. This
patch doesn't remove the functions altogether since in future we want
to have inode level locking for fast commits.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20211223202140.2061101-2-harshads@google.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

vfs: add rcu argument to ->get_acl() callback

Add a rcu argument to the ->get_acl() callback to allow
get_cached_acl_rcu() to call the ->get_acl() method in the next patch.

Signed-off-by: Miklos Sz

vfs: add rcu argument to ->get_acl() callback

Add a rcu argument to the ->get_acl() callback to allow
get_cached_acl_rcu() to call the ->get_acl() method in the next patch.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

show more ...

ext4: support idmapped mounts

Enable idmapped mounts for ext4. All dedicated helpers we need for this
exist. So this basically just means we're passing down the
user_namespace argument from the VFS

ext4: support idmapped mounts

Enable idmapped mounts for ext4. All dedicated helpers we need for this
exist. So this basically just means we're passing down the
user_namespace argument from the VFS methods to the relevant helpers.

Let's create simple example where we idmap an ext4 filesystem:

root@f2-vm:~# truncate -s 5G ext4.img

root@f2-vm:~# mkfs.ext4 ./ext4.img
mke2fs 1.45.5 (07-Jan-2020)
Discarding device blocks: done
Creating filesystem with 1310720 4k blocks and 327680 inodes
Filesystem UUID: 3fd91794-c6ca-4b0f-9964-289a000919cf
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736

Allocating group tables: done
Writing inode tables: done
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done

root@f2-vm:~# losetup -f --show ./ext4.img
/dev/loop0

root@f2-vm:~# mount /dev/loop0 /mnt

root@f2-vm:~# ls -al /mnt/
total 24
drwxr-xr-x 3 root root 4096 Oct 28 13:34 .
drwxr-xr-x 30 root root 4096 Oct 28 13:22 ..
drwx------ 2 root root 16384 Oct 28 13:34 lost+found

# Let's create an idmapped mount at /idmapped1 where we map uid and gid
# 0 to uid and gid 1000
root@f2-vm:/# ./mount-idmapped --map-mount b:0:1000:1 /mnt/ /idmapped1/

root@f2-vm:/# ls -al /idmapped1/
total 24
drwxr-xr-x 3 ubuntu ubuntu 4096 Oct 28 13:34 .
drwxr-xr-x 30 root root 4096 Oct 28 13:22 ..
drwx------ 2 ubuntu ubuntu 16384 Oct 28 13:34 lost+found

# Let's create an idmapped mount at /idmapped2 where we map uid and gid
# 0 to uid and gid 2000
root@f2-vm:/# ./mount-idmapped --map-mount b:0:2000:1 /mnt/ /idmapped2/

root@f2-vm:/# ls -al /idmapped2/
total 24
drwxr-xr-x 3 2000 2000 4096 Oct 28 13:34 .
drwxr-xr-x 31 root root 4096 Oct 28 13:39 ..
drwx------ 2 2000 2000 16384 Oct 28 13:34 lost+found

Let's create another example where we idmap the rootfs filesystem
without a mapping for uid 0 and gid 0:

# Create an idmapped mount of for a full POSIX range of rootfs under
# /mnt but without a mapping for uid 0 to reduce attack surface

root@f2-vm:/# ./mount-idmapped --map-mount b:1:1:65536 / /mnt/

# Since we don't have a mapping for uid and gid 0 all files owned by
# uid and gid 0 should show up as uid and gid 65534:
root@f2-vm:/# ls -al /mnt/
total 664
drwxr-xr-x 31 nobody nogroup 4096 Oct 28 13:39 .
drwxr-xr-x 31 root root 4096 Oct 28 13:39 ..
lrwxrwxrwx 1 nobody nogroup 7 Aug 25 07:44 bin -> usr/bin
drwxr-xr-x 4 nobody nogroup 4096 Oct 28 13:17 boot
drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:48 dev
drwxr-xr-x 81 nobody nogroup 4096 Oct 28 04:00 etc
drwxr-xr-x 4 nobody nogroup 4096 Oct 28 04:00 home
lrwxrwxrwx 1 nobody nogroup 7 Aug 25 07:44 lib -> usr/lib
lrwxrwxrwx 1 nobody nogroup 9 Aug 25 07:44 lib32 -> usr/lib32
lrwxrwxrwx 1 nobody nogroup 9 Aug 25 07:44 lib64 -> usr/lib64
lrwxrwxrwx 1 nobody nogroup 10 Aug 25 07:44 libx32 -> usr/libx32
drwx------ 2 nobody nogroup 16384 Aug 25 07:47 lost+found
drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:44 media
drwxr-xr-x 31 nobody nogroup 4096 Oct 28 13:39 mnt
drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:44 opt
drwxr-xr-x 2 nobody nogroup 4096 Apr 15 2020 proc
drwx--x--x 6 nobody nogroup 4096 Oct 28 13:34 root
drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:46 run
lrwxrwxrwx 1 nobody nogroup 8 Aug 25 07:44 sbin -> usr/sbin
drwxr-xr-x 2 nobody nogroup 4096 Aug 25 07:44 srv
drwxr-xr-x 2 nobody nogroup 4096 Apr 15 2020 sys
drwxrwxrwt 10 nobody nogroup 4096 Oct 28 13:19 tmp
drwxr-xr-x 14 nobody nogroup 4096 Oct 20 13:00 usr
drwxr-xr-x 12 nobody nogroup 4096 Aug 25 07:45 var

# Since we do have a mapping for uid and gid 1000 all files owned by
# uid and gid 1000 should simply show up as uid and gid 1000:
root@f2-vm:/# ls -al /mnt/home/ubuntu/
total 40
drwxr-xr-x 3 ubuntu ubuntu 4096 Oct 28 00:43 .
drwxr-xr-x 4 nobody nogroup 4096 Oct 28 04:00 ..
-rw------- 1 ubuntu ubuntu 2936 Oct 28 12:26 .bash_history
-rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile
-rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo

Link: https://lore.kernel.org/r/20210121131959.646623-39-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-ext4@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

show more ...

fs: make helpers idmap mount aware

Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has b

fs: make helpers idmap mount aware

Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

show more ...

acl: handle idmapped mounts

The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it

acl: handle idmapped mounts

The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it possible to handle acls on idmapped
mounts.

The vfs and the filesystems targeted by this first iteration make use of
posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to
translate basic posix access and default permissions such as the
ACL_USER and ACL_GROUP type according to the initial user namespace (or
the superblock's user namespace) to and from the caller's current user
namespace. Adapt these two helpers to handle idmapped mounts whereby we
either map from or into the mount's user namespace depending on in which
direction we're translating.
Similarly, cap_convert_nscap() is used by the vfs to translate user
namespace and non-user namespace aware filesystem capabilities from the
superblock's user namespace to the caller's user namespace. Enable it to
handle idmapped mounts by accounting for the mount's user namespace.

In addition the fileystems targeted in the first iteration of this patch
series make use of the posix_acl_chmod() and, posix_acl_update_mode()
helpers. Both helpers perform permission checks on the target inode. Let
them handle idmapped mounts. These two helpers are called when posix
acls are set by the respective filesystems to handle this case we extend
the ->set() method to take an additional user namespace argument to pass
the mount's user namespace down.

Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

show more ...

ext4: main fast-commit commit path

This patch adds main fast commit commit path handlers. The overall
patch can be divided into two inter-related parts:

(A) Metadata updates tracking

This part

ext4: main fast-commit commit path

This patch adds main fast commit commit path handlers. The overall
patch can be divided into two inter-related parts:

(A) Metadata updates tracking

This part consists of helper functions to track changes that need
to be committed during a commit operation. These updates are
maintained by Ext4 in different in-memory queues. Following are
the APIs and their short description that are implemented in this
patch:

- ext4_fc_track_link/unlink/creat() - Track unlink. link and creat
operations
- ext4_fc_track_range() - Track changed logical block offsets
inodes
- ext4_fc_track_inode() - Track inodes
- ext4_fc_mark_ineligible() - Mark file system fast commit
ineligible()
- ext4_fc_start_update() / ext4_fc_stop_update() /
ext4_fc_start_ineligible() / ext4_fc_stop_ineligible() These
functions are useful for co-ordinating inode updates with
commits.

(B) Main commit Path

This part consists of functions to convert updates tracked in
in-memory data structures into on-disk commits. Function
ext4_fc_commit() is the main entry point to commit path.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201015203802.3597742-6-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

ext4: handle ext4_mark_inode_dirty errors

ext4_mark_inode_dirty() can fail for real reasons. Ignoring its return
value may lead ext4 to ignore real failures that would result in
corruption / crashes

ext4: handle ext4_mark_inode_dirty errors

ext4_mark_inode_dirty() can fail for real reasons. Ignoring its return
value may lead ext4 to ignore real failures that would result in
corruption / crashes. Harden ext4_mark_inode_dirty error paths to fail
as soon as possible and return errors to the caller whenever
appropriate.

One of the possible scnearios when this bug could affected is that
while creating a new inode, its directory entry gets added
successfully but while writing the inode itself mark_inode_dirty
returns error which is ignored. This would result in inconsistency
that the directory entry points to a non-existent inode.

Ran gce-xfstests smoke tests and verified that there were no
regressions.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20200427013438.219117-1-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

ext4: fix a style issue in fs/ext4/acl.c

Fixed an if statement where braces were not needed.

Link: https://lore.kernel.org/r/20200416141456.1089-1-carlosteniswarrior@gmail.com
Signed-off-by: Carlos

ext4: fix a style issue in fs/ext4/acl.c

Fixed an if statement where braces were not needed.

Link: https://lore.kernel.org/r/20200416141456.1089-1-carlosteniswarrior@gmail.com
Signed-off-by: Carlos Guerrero Álvarez <carlosteniswarrior@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>

show more ...

ext4: compare old and new mode before setting update_mode flag

If new mode is the same as old mode we don't have to reset
inode mode in the rest of the code, so compare old and new
mode before setti

ext4: compare old and new mode before setting update_mode flag

If new mode is the same as old mode we don't have to reset
inode mode in the rest of the code, so compare old and new
mode before setting update_mode flag.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

ext4: cache NULL when both default_acl and acl are NULL

default_acl and acl of newly created inode will be initiated as
ACL_NOT_CACHED in vfs function inode_init_always() and later will be
updated b

ext4: cache NULL when both default_acl and acl are NULL

default_acl and acl of newly created inode will be initiated as
ACL_NOT_CACHED in vfs function inode_init_always() and later will be
updated by calling xxx_init_acl() in specific filesystems. However,
when default_acl and acl are NULL then they keep the value of
ACL_NOT_CACHED. This patch changes the code to cache NULL for acl /
default_acl in this case to save unnecessary ACL lookup attempt.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

show more ...

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

ext4: Don't clear SGID when inheriting ACLs

When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning

ext4: Don't clear SGID when inheriting ACLs

When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0'). However when 'DIR0' also has some default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.

Fix the problem by moving posix_acl_update_mode() out of
__ext4_set_acl() into ext4_set_acl(). That way the function will not be
called when inheriting ACLs which is what we want as it prevents SGID
bit clearing and the mode has been properly set by posix_acl_create()
anyway.

Fixes: 073931017b49d9458aa351605b43a7e34598caef
CC: stable@vger.kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>

show more ...

ext4: preserve i_mode if __ext4_set_acl() fails

When changing a file's acl mask, __ext4_set_acl() will first set the group
bits of i_mode to the value of the mask, and only then set the actual
exten

ext4: preserve i_mode if __ext4_set_acl() fails

When changing a file's acl mask, __ext4_set_acl() will first set the group
bits of i_mode to the value of the mask, and only then set the actual
extended attribute representing the new acl.

If the second part fails (due to lack of space, for example) and the file
had no acl attribute to begin with, the system will from now on assume
that the mask permission bits are actual group permission bits, potentially
granting access to the wrong users.

Prevent this by only changing the inode mode after the acl has been set.

Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

show more ...

ext4: fix __ext4_new_inode() journal credits calculation

ea_inode feature allows creating extended attributes that are up to
64k in size. Update __ext4_new_inode() to pick increased credit limits.

ext4: fix __ext4_new_inode() journal credits calculation

ea_inode feature allows creating extended attributes that are up to
64k in size. Update __ext4_new_inode() to pick increased credit limits.

To avoid overallocating too many journal credits, update
__ext4_xattr_set_credits() to make a distinction between xattr create
vs update. This helps __ext4_new_inode() because all attributes are
known to be new, so we can save credits that are normally needed to
delete old values.

Also, have fscrypt specify its maximum context size so that we don't
end up allocating credits for 64k size.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

ext4: xattr inode deduplication

Ext4 now supports xattr values that are up to 64k in size (vfs limit).
Large xattr values are stored in external inodes each one holding a
single value. Once written

ext4: xattr inode deduplication

Ext4 now supports xattr values that are up to 64k in size (vfs limit).
Large xattr values are stored in external inodes each one holding a
single value. Once written the data blocks of these inodes are immutable.

The real world use cases are expected to have a lot of value duplication
such as inherited acls etc. To reduce data duplication on disk, this patch
implements a deduplicator that allows sharing of xattr inodes.

The deduplication is based on an in-memory hash lookup that is a best
effort sharing scheme. When a xattr inode is read from disk (i.e.
getxattr() call), its crc32c hash is added to a hash table. Before
creating a new xattr inode for a value being set, the hash table is
checked to see if an existing inode holds an identical value. If such an
inode is found, the ref count on that inode is incremented. On value
removal the ref count is decremented and if it reaches zero the inode is
deleted.

The quota charging for such inodes is manually managed. Every reference
holder is charged the full size as if there was no sharing happening.
This is consistent with how xattr blocks are also charged.

[ Fixed up journal credits calculation to handle inline data and the
rare case where an shared xattr block can get freed when two thread
race on breaking the xattr block sharing. --tytso ]

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

ext4: improve journal credit handling in set xattr paths

Both ext4_set_acl() and ext4_set_context() need to be made aware of
ea_inode feature when it comes to credits calculation.

Also add a suffic

ext4: improve journal credit handling in set xattr paths

Both ext4_set_acl() and ext4_set_context() need to be made aware of
ea_inode feature when it comes to credits calculation.

Also add a sufficient credits check in ext4_xattr_set_handle() right
after xattr write lock is grabbed. Original credits calculation is done
outside the lock so there is a possiblity that the initially calculated
credits are not sufficient anymore.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

show more ...

ext4: fix quota charging for shared xattr blocks

ext4_xattr_block_set() calls dquot_alloc_block() to charge for an xattr
block when new references are made. However if dquot_initialize() hasn't
been

ext4: fix quota charging for shared xattr blocks

ext4_xattr_block_set() calls dquot_alloc_block() to charge for an xattr
block when new references are made. However if dquot_initialize() hasn't
been called on an inode, request for charging is effectively ignored
because ext4_inode_info->i_dquot is not initialized yet.

Add dquot_initialize() to call paths that lead to ext4_xattr_block_set().

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

show more ...

ext4: use current_time() for inode timestamps

CURRENT_TIME_SEC and CURRENT_TIME are not y2038 safe.
current_time() will be transitioned to be y2038 safe
along with vfs.

current_time() returns times

ext4: use current_time() for inode timestamps

CURRENT_TIME_SEC and CURRENT_TIME are not y2038 safe.
current_time() will be transitioned to be y2038 safe
along with vfs.

current_time() returns timestamps according to the
granularities set in the super_block.
The granularity check in ext4_current_time() to call
current_time() or CURRENT_TIME_SEC is not required.
Use current_time() directly to obtain timestamps
unconditionally, and remove ext4_current_time().

Quota files are assumed to be on the same filesystem.
Hence, use current_time() for these files as well.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

show more ...

posix_acl: Clear SGID bit when setting file permissions

When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in

posix_acl: Clear SGID bit when setting file permissions

When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2). Fix that.

References: CVE-2016-7097
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

show more ...

posix_acl: Inode acl caching fixes

When get_acl() is called for an inode whose ACL is not cached yet, the
get_acl inode operation is called to fetch the ACL from the filesystem.
The inode operation

posix_acl: Inode acl caching fixes

When get_acl() is called for an inode whose ACL is not cached yet, the
get_acl inode operation is called to fetch the ACL from the filesystem.
The inode operation is responsible for updating the cached acl with
set_cached_acl(). This is done without locking at the VFS level, so
another task can call set_cached_acl() or forget_cached_acl() before the
get_acl inode operation gets to calling set_cached_acl(), and then
get_acl's call to set_cached_acl() results in caching an outdate ACL.

Prevent this from happening by setting the cached ACL pointer to a
task-specific sentinel value before calling the get_acl inode operation.
Move the responsibility for updating the cached ACL from the get_acl
inode operations to get_acl(). There, only set the cached ACL if the
sentinel value hasn't changed.

The sentinel values are chosen to have odd values. Likewise, the value
of ACL_NOT_CACHED is odd. In contrast, ACL object pointers always have
an even value (ACLs are aligned in memory). This allows to distinguish
uncached ACLs values from ACL objects.

In addition, switch from guarding inode->i_acl and inode->i_default_acl
upates by the inode->i_lock spinlock to using xchg() and cmpxchg().

Filesystems that do not want ACLs returned from their get_acl inode
operations to be cached must call forget_cached_acl() to prevent the VFS
from doing so.

(Patch written by Al Viro and Andreas Gruenbacher.)

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

show more ...