fs: convert core infrastructure to new timestamp accessors

Convert the core vfs code to use the new timestamp accessor functions.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20231004185239.80830-2-jlayton@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs: 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.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230705190309.579783-23-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

sched/rt, fs: Use CONFIG_PREEMPTION

CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT.
Both PREEMPT and PREEMPT_RT require the same functionality which today
depends on CONFIG_PREEMPT.

Switch the i_size() and part_nr_sects_…() code over to use
CONFIG_PREEMPTION. Update the comment for fsstack_copy_inode_size() also
to refer to CONFIG_PREEMPTION.

[bigeasy: +PREEMPT comments]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20191015191821.11479-24-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

treewide: Add SPDX license identifier for missed files

Add SPDX license identifiers to all files which:

- Have no license information of any form

- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

block: remove CONFIG_LBDAF

Currently support for 64-bit sector_t and blkcnt_t is optional on 32-bit
architectures. These types are required to support block device and/or
file sizes larger than 2 TiB, and have generally defaulted to on for
a long time. Enabling the option only increases the i386 tinyconfig
size by 145 bytes, and many data structures already always use
64-bit values for their in-core and on-disk data structures anyway,
so there should not be a large change in dynamic memory usage either.

Dropping this option removes a somewhat weird non-default config that
has cause various bugs or compiler warnings when actually used.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs: fix comment for 'CONFIG_LBADF'

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

fs: reduce the use of module.h wherever possible

For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include. Fix up any implicit
include dependencies that were being masked by module.h along
the way.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

filesystems: add set_nlink()

Replace remaining direct i_nlink updates with a new set_nlink()
updater function.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

mm: a few small updates for radix-swap

Remove PageSwapBacked (!page_is_file_cache) cases from
add_to_page_cache_locked() and add_to_page_cache_lru(): those pages now
go through shmem_add_to_page_cache().

Remove a comment on maximum tmpfs size from fsstack_copy_inode_size(),
and add a comment on swap entries to invalidate_mapping_pages().

And mincore_page() uses find_get_page() on what might be shmem or a
tmpfs file: allow for a radix_tree_exceptional_entry(), and proceed to
find_get_page() on swapper_space if so (oh, swapper_space needs #ifdef).

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

VFS/fsstack: handle 32-bit smp + preempt + large files in fsstack_copy_inode_size

Copy the inode size and blocks from one inode to another correctly on 32-bit
systems with CONFIG_SMP, CONFIG_PREEMPT, or CONFIG_LBDAF. Use proper inode
spinlocks only when i_size/i_blocks cannot fit in one 32-bit word.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fsstack/ecryptfs: remove unused get_nlinks param to fsstack_copy_attr_all

This get_nlinks parameter was never used by the only mainline user,
ecryptfs; and it has never been used by unionfs or wrapfs either.

Acked-by: Dustin Kirkland <kirkland@canonical.com>
Acked-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[PATCH] fs/stack.c: Copy i_nlink after all other attributes are copied

A user-specified get_nlinks may depend on other inode attributes.

Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Josef 'Jeff' Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PATCH] fsstack: Remove inode copy

Trevor found a file size problem in eCryptfs in recent kernels, and he
tracked it down to an fsstack change.

This was the eCryptfs copy_attr_all:

> -void ecryptfs_copy_attr_all(struct inode *dest, const struct inode *src)
> -{
> - dest->i_mode = src->i_mode;
> - dest->i_nlink = src->i_nlink;
> - dest->i_uid = src->i_uid;
> - dest->i_gid = src->i_gid;
> - dest->i_rdev = src->i_rdev;
> - dest->i_atime = src->i_atime;
> - dest->i_mtime = src->i_mtime;
> - dest->i_ctime = src->i_ctime;
> - dest->i_blkbits = src->i_blkbits;
> - dest->i_flags = src->i_flags;
> -}

This is the fsstack copy_attr_all:

> +void fsstack_copy_attr_all(struct inode *dest, const struct inode *src,
> + int (*get_nlinks)(struct inode *))
> +{
> + if (!get_nlinks)
> + dest->i_nlink = src->i_nlink;
> + else
> + dest->i_nlink = (*get_nlinks)(dest);
> +
> + dest->i_mode = src->i_mode;
> + dest->i_uid = src->i_uid;
> + dest->i_gid = src->i_gid;
> + dest->i_rdev = src->i_rdev;
> + dest->i_atime = src->i_atime;
> + dest->i_mtime = src->i_mtime;
> + dest->i_ctime = src->i_ctime;
> + dest->i_blkbits = src->i_blkbits;
> + dest->i_flags = src->i_flags;
> +
> + fsstack_copy_inode_size(dest, src);
> +}

The addition of copy_inode_size breaks eCryptfs, since eCryptfs needs to
interpolate the file sizes (eCryptfs has extra space in the lower file for
the header). The setting of the upper inode size occurs elsewhere in
eCryptfs, and the new copy_attr_all now undoes what eCryptfs was doing
right beforehand.

I see three ways of going forward from here. (1) Something like this patch
needs to go in (assuming it jives with Unionfs), (2) we need to make a
change to the fsstack API for more fine-grained control over copying
attributes (e.g., by also including a callback function for calculating the
right file size, which will require some more work on both eCryptfs and
Unionfs), or (3) the fsstack patch on eCryptfs (commit
0cc72dc7f050188d8d7344b1dd688cbc68d3cd30 made on Fri Dec 8 02:36:31 2006
-0800) needs to be yanked in 2.6.20.

I think the simplest solution, from eCryptfs' perspective, is to just
remove the inode size copy.

Remove inode size copy in general fsstack attr copy code. Stacked
filesystems may need to interpolate the inode size, since the file
size in the lower file may be different than the file size in the
stacked layer.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Acked-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] fsstack: Introduce fsstack_copy_{attr,inode}_*

Introduce several fsstack_copy_* functions which allow stackable filesystems
(such as eCryptfs and Unionfs) to easily copy over (currently only) inode
attributes. This prevents code duplication and allows for code reuse.

[akpm@osdl.org: Remove unneeded wrapper]
[bunk@stusta.de: fs/stack.c should #include <linux/fs_stack.h>]
Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>