Store the frozen superblock in struct block_device to avoid the awkward
interface that can return a sb only used a cookie, an ERR_PTR or NULL.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Chao Yu <yuchao0@huawei.com> [f2fs]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
bd_part is never NULL for a block device in use by a file system, so
remove the checks.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Let's allow mounting readonly partition. We're able to recovery later once we
have it as read-write back.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Added "ckpt_thread_ioprio" sysfs node to give a way to change checkpoint
merge daemon's io priority. Its default value is "be,3", which means
"BE" I/O class and I/O priority "3". We can select the class between "rt"
and "be", and set the I/O priority within valid range of it.
"," delimiter is necessary in between I/O class and priority number.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We've added a new mount options, "checkpoint_merge" and "nocheckpoint_merge",
which creates a kernel daemon and makes it to merge concurrent checkpoint
requests as much as possible to eliminate redundant checkpoint issues. Plus,
we can eliminate the sluggish issue caused by slow checkpoint operation
when the checkpoint is done in a process context in a cgroup having
low i/o budget and cpu shares. To make this do better, we set the
default i/o priority of the kernel daemon to "3", to give one higher
priority than other kernel threads. The below verification result
explains this.
The basic idea has come from https://opensource.samsung.com.
[Verification]
Android Pixel Device(ARM64, 7GB RAM, 256GB UFS)
Create two I/O cgroups (fg w/ weight 100, bg w/ wight 20)
Set "strict_guarantees" to "1" in BFQ tunables
In "fg" cgroup,
- thread A => trigger 1000 checkpoint operations
"for i in `seq 1 1000`; do touch test_dir1/file; fsync test_dir1;
done"
- thread B => gererating async. I/O
"fio --rw=write --numjobs=1 --bs=128k --runtime=3600 --time_based=1
--filename=test_img --name=test"
In "bg" cgroup,
- thread C => trigger repeated checkpoint operations
"echo $$ > /dev/blkio/bg/tasks; while true; do touch test_dir2/file;
fsync test_dir2; done"
We've measured thread A's execution time.
[ w/o patch ]
Elapsed Time: Avg. 68 seconds
[ w/ patch ]
Elapsed Time: Avg. 48 seconds
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
[Jaegeuk Kim: fix the return value in f2fs_start_ckpt_thread, reported by Dan]
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If there is page fault only for read case on inline inode, we don't need
to convert inline inode, instead, let's do conversion for write case.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
These variables will be explicitly assigned before use,
so there is no need to initialize.
Signed-off-by: Liu Song <liu.song11@zte.com.cn>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Occasionally, quota data may be corrupted detected by fsck:
Info: checkpoint state = 45 : crc compacted_summary unmount
[QUOTA WARNING] Usage inconsistent for ID 0:actual (1543036928, 762) != expected (1543032832, 762)
[ASSERT] (fsck_chk_quota_files:1986) --> Quota file is missing or invalid quota file content found.
[QUOTA WARNING] Usage inconsistent for ID 0:actual (1352478720, 344) != expected (1352474624, 344)
[ASSERT] (fsck_chk_quota_files:1986) --> Quota file is missing or invalid quota file content found.
[FSCK] Unreachable nat entries [Ok..] [0x0]
[FSCK] SIT valid block bitmap checking [Ok..]
[FSCK] Hard link checking for regular file [Ok..] [0x0]
[FSCK] valid_block_count matching with CP [Ok..] [0xdf299]
[FSCK] valid_node_count matcing with CP (de lookup) [Ok..] [0x2b01]
[FSCK] valid_node_count matcing with CP (nat lookup) [Ok..] [0x2b01]
[FSCK] valid_inode_count matched with CP [Ok..] [0x2665]
[FSCK] free segment_count matched with CP [Ok..] [0xcb04]
[FSCK] next block offset is free [Ok..]
[FSCK] fixing SIT types
[FSCK] other corrupted bugs [Fail]
The root cause is:
If we open file w/ readonly flag, disk quota info won't be initialized
for this file, however, following mmap() will force to convert inline
inode via f2fs_convert_inline_inode(), which may increase block usage
for this inode w/o updating quota data, it causes inconsistent disk quota
info.
The issue will happen in following stack:
open(file, O_RDONLY)
mmap(file)
- f2fs_convert_inline_inode
- f2fs_convert_inline_page
- f2fs_reserve_block
- f2fs_reserve_new_block
- f2fs_reserve_new_blocks
- f2fs_i_blocks_write
- dquot_claim_block
inode->i_blocks increase, but the dqb_curspace keep the size for the dquots
is NULL.
To fix this issue, let's call dquot_initialize() anyway in both
f2fs_truncate() and f2fs_convert_inline_inode() functions to avoid potential
inconsistent quota data issue.
Fixes: 0abd675e97 ("f2fs: support plain user/group quota")
Signed-off-by: Daiyue Zhang <zhangdaiyue1@huawei.com>
Signed-off-by: Dehe Gu <gudehe@huawei.com>
Signed-off-by: Junchao Jiang <jiangjunchao1@huawei.com>
Signed-off-by: Ge Qiu <qiuge@huawei.com>
Signed-off-by: Yi Chen <chenyi77@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
During checkpoint=disable period, f2fs bypasses all the synchronous IOs such as
sync and fsync. So, when enabling it back, we must flush all of them in order
to keep the data persistent. Otherwise, suddern power-cut right after enabling
checkpoint will cause data loss.
Fixes: 4354994f09 ("f2fs: checkpoint disabling")
Cc: stable@vger.kernel.org
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch deprecates f2fs_trace_io, since f2fs uses page->private more broadly,
resulting in more buggy cases.
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
With the new ->readahead operation, locked pages are added to the page
cache, preventing two threads from racing with each other to read the
same chunk of file, so this is dead code.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Introduce /sys/fs/f2fs/<devname>/stat/sb_status to show superblock
status in real time as a hexadecimal value.
value sb status macro description
0x1 SBI_IS_DIRTY, /* dirty flag for checkpoint */
0x2 SBI_IS_CLOSE, /* specify unmounting */
0x4 SBI_NEED_FSCK, /* need fsck.f2fs to fix */
0x8 SBI_POR_DOING, /* recovery is doing or not */
0x10 SBI_NEED_SB_WRITE, /* need to recover superblock */
0x20 SBI_NEED_CP, /* need to checkpoint */
0x40 SBI_IS_SHUTDOWN, /* shutdown by ioctl */
0x80 SBI_IS_RECOVERED, /* recovered orphan/data */
0x100 SBI_CP_DISABLED, /* CP was disabled last mount */
0x200 SBI_CP_DISABLED_QUICK, /* CP was disabled quickly */
0x400 SBI_QUOTA_NEED_FLUSH, /* need to flush quota info in CP */
0x800 SBI_QUOTA_SKIP_FLUSH, /* skip flushing quota in current CP */
0x1000 SBI_QUOTA_NEED_REPAIR, /* quota file may be corrupted */
0x2000 SBI_IS_RESIZEFS, /* resizefs is in process */
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
F2FS inode may have different max size, e.g. compressed file have
less blkaddr entries in all its direct-node blocks, result in being
with less max filesize. So change to use per-inode maxbytes.
Suggested-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
generic/269 reports a hangtask issue, the root cause is ABBA deadlock
described as below:
Thread A Thread B
- down_write(&sbi->gc_lock) -- A
- f2fs_write_data_pages
- lock all pages in cluster -- B
- f2fs_write_multi_pages
- f2fs_write_raw_pages
- f2fs_write_single_data_page
- f2fs_balance_fs
- down_write(&sbi->gc_lock) -- A
- f2fs_gc
- do_garbage_collect
- ra_data_block
- pagecache_get_page -- B
To fix this, it needs to avoid calling f2fs_balance_fs() if there is
still cluster pages been locked in context of cluster writeback, so
instead, let's call f2fs_balance_fs() in the end of
f2fs_write_raw_pages() when all cluster pages were unlocked.
Fixes: 4c8ff7095b ("f2fs: support data compression")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Now that generic_set_encrypted_ci_d_ops() has been added and ext4 and
f2fs are using it, it's no longer necessary to export
generic_ci_d_compare() and generic_ci_d_hash() to filesystems.
Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
By Colin's static analysis, we found out there is a null page reference
under low memory situation in redirty_blocks. I've made the page finding
loop stop immediately and return an error not to cause further memory
pressure when we run into a failure to find a page under low memory
condition.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reported-by: Colin Ian King <colin.king@canonical.com>
Fixes: 5fdb322ff2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE")
Reviewed-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Rework the post-read processing logic to be much easier to understand.
At least one bug is fixed by this: if an I/O error occurred when reading
from disk, decryption and verity would be performed on the uninitialized
data, causing misleading messages in the kernel log.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Trival cleanups:
- relocate set_summary() before its use
- relocate "allocate block address" to correct place
- remove unneeded f2fs_wait_on_page_writeback()
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
__setattr_copy() was copied from setattr_copy() in fs/attr.c, there is
two missing patches doesn't cover this inner function, fix it.
Commit 7fa294c899 ("userns: Allow chown and setgid preservation")
Commit 23adbe12ef ("fs,userns: Change inode_capable to capable_wrt_inode_uidgid")
Fixes: fbfa2cc58d ("f2fs: add file operations")
Cc: stable@vger.kernel.org
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs does not natively support extents in metadata, 'extent' in f2fs
is used as a virtual concept, so in f2fs_fiemap() interface, it needs
to tag FIEMAP_EXTENT_MERGED flag to indicated the extent status is a
result of merging.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Add a new directory 'stat' in path of /sys/fs/f2fs/<devname>/, later
we can add new readonly stat sysfs file into this directory, it will
make <devname> directory less mess.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Expand 'compress_algorithm' mount option to accept parameter as format of
<algorithm>:<level>, by this way, it gives a way to allow user to do more
specified config on lz4 and zstd compression level, then f2fs compression
can provide higher compress ratio.
In order to set compress level for lz4 algorithm, it needs to set
CONFIG_LZ4HC_COMPRESS and CONFIG_F2FS_FS_LZ4HC config to enable lz4hc
compress algorithm.
CR and performance number on lz4/lz4hc algorithm:
dd if=enwik9 of=compressed_file conv=fsync
Original blocks: 244382
lz4 lz4hc-9
compressed blocks 170647 163270
compress ratio 69.8% 66.8%
speed 16.4207 s, 60.9 MB/s 26.7299 s, 37.4 MB/s
compress ratio = after / before
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If kernel doesn't support certain kinds of compress algorithm, deny to set
them as compress algorithm of f2fs via 'compress_algorithm=%s' mount option.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Relocate f2fs_precache_extents() in prior to check_swap_activate(),
then extent cache can be enabled before its use.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch ports commit 02b016ca7f ("ext4: enforce the immutable
flag on open files") to f2fs.
According to the chattr man page, "a file with the 'i' attribute
cannot be modified..." Historically, this was only enforced when the
file was opened, per the rest of the description, "... and the file
can not be opened in write mode".
There is general agreement that we should standardize all file systems
to prevent modifications even for files that were opened at the time
the immutable flag is set. Eventually, a change to enforce this at
the VFS layer should be landing in mainline.
Cc: stable@kernel.org
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Previously, in f2fs_setattr(), we don't update S_ISUID|S_ISGID|S_ISVTX
bits with S_IRWXUGO bits and acl entries atomically, so in error path,
chmod() may partially success, this patch enhances to make chmod() flow
being atomical.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We should update the ~S_IRWXUGO part of inode->i_mode in __setattr_copy,
because posix_acl_update_mode updates mode based on inode->i_mode,
which finally overwrites the ~S_IRWXUGO part of i_acl_mode with old i_mode.
Testcase to reproduce this bug:
0. adduser abc
1. mkfs.f2fs /dev/sdd
2. mount -t f2fs /dev/sdd /mnt/f2fs
3. mkdir /mnt/f2fs/test
4. setfacl -m u:abc:r /mnt/f2fs/test
5. chmod +s /mnt/f2fs/test
Signed-off-by: Weichao Guo <guoweichao@oppo.com>
Signed-off-by: Bin Shu <shubin@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If we have large section/zone, unallocated segment makes them corrupted.
E.g.,
- Pinned file: -1 119304647 119304647
- ATGC data: -1 119304647 119304647
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Although it isn't used directly by the ioctls,
"struct fsverity_descriptor" is required by userspace programs that need
to compute fs-verity file digests in a standalone way. Therefore
it's also needed to sign files in a standalone way.
Similarly, "struct fsverity_formatted_digest" (previously called
"struct fsverity_signed_digest" which was misleading) is also needed to
sign files if the built-in signature verification is being used.
Therefore, move these structs to the UAPI header.
While doing this, try to make it clear that the signature-related fields
in fsverity_descriptor aren't used in the file digest computation.
Acked-by: Luca Boccassi <luca.boccassi@microsoft.com>
Link: https://lore.kernel.org/r/20201113211918.71883-5-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
I originally chose the name "file measurement" to refer to the fs-verity
file digest to avoid confusion with traditional full-file digests or
with the bare root hash of the Merkle tree.
But the name "file measurement" hasn't caught on, and usually people are
calling it something else, usually the "file digest". E.g. see
"struct fsverity_digest" and "struct fsverity_formatted_digest", the
libfsverity_compute_digest() and libfsverity_sign_digest() functions in
libfsverity, and the "fsverity digest" command.
Having multiple names for the same thing is always confusing.
So to hopefully avoid confusion in the future, rename
"fs-verity file measurement" to "fs-verity file digest".
This leaves FS_IOC_MEASURE_VERITY as the only reference to "measure" in
the kernel, which makes some amount of sense since the ioctl is actively
"measuring" the file.
I'll be renaming this in fsverity-utils too (though similarly the
'fsverity measure' command, which is a wrapper for
FS_IOC_MEASURE_VERITY, will stay).
Acked-by: Luca Boccassi <luca.boccassi@microsoft.com>
Link: https://lore.kernel.org/r/20201113211918.71883-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
The name "struct fsverity_signed_digest" is causing confusion because it
isn't actually a signed digest, but rather it's the way that the digest
is formatted in order to be signed. Rename it to
"struct fsverity_formatted_digest" to prevent this confusion.
Also update the struct's comment to clarify that it's specific to the
built-in signature verification support and isn't a requirement for all
fs-verity users.
I'll be renaming this struct in fsverity-utils too.
Acked-by: Luca Boccassi <luca.boccassi@microsoft.com>
Link: https://lore.kernel.org/r/20201113211918.71883-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Currently it's impossible to delete files that use an unsupported
encryption policy, as the kernel will just return an error when
performing any operation on the top-level encrypted directory, even just
a path lookup into the directory or opening the directory for readdir.
More specifically, this occurs in any of the following cases:
- The encryption context has an unrecognized version number. Current
kernels know about v1 and v2, but there could be more versions in the
future.
- The encryption context has unrecognized encryption modes
(FSCRYPT_MODE_*) or flags (FSCRYPT_POLICY_FLAG_*), an unrecognized
combination of modes, or reserved bits set.
- The encryption key has been added and the encryption modes are
recognized but aren't available in the crypto API -- for example, a
directory is encrypted with FSCRYPT_MODE_ADIANTUM but the kernel
doesn't have CONFIG_CRYPTO_ADIANTUM enabled.
It's desirable to return errors for most operations on files that use an
unsupported encryption policy, but the current behavior is too strict.
We need to allow enough to delete files, so that people can't be stuck
with undeletable files when downgrading kernel versions. That includes
allowing directories to be listed and allowing dentries to be looked up.
Fix this by modifying the key setup logic to treat an unsupported
encryption policy in the same way as "key unavailable" in the cases that
are required for a recursive delete to work: preparing for a readdir or
a dentry lookup, revalidating a dentry, or checking whether an inode has
the same encryption policy as its parent directory.
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20201203022041.230976-10-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Now that fscrypt_get_encryption_info() is only called from files in
fs/crypto/ (due to all key setup now being handled by higher-level
helper functions instead of directly by filesystems), unexport it and
move its declaration to fscrypt_private.h.
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20201203022041.230976-9-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
The last remaining use of fscrypt_get_encryption_info() from filesystems
is for readdir (->iterate_shared()). Every other call is now in
fs/crypto/ as part of some other higher-level operation.
We need to add a new argument to fscrypt_get_encryption_info() to
indicate whether the encryption policy is allowed to be unrecognized or
not. Doing this is easier if we can work with high-level operations
rather than direct filesystem use of fscrypt_get_encryption_info().
So add a function fscrypt_prepare_readdir() which wraps the call to
fscrypt_get_encryption_info() for the readdir use case.
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20201203022041.230976-6-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
The call to fscrypt_get_encryption_info() in dx_show_leaf() is too low
in the call tree; fscrypt_get_encryption_info() should have already been
called when starting the directory operation. And indeed, it already
is. Moreover, the encryption key is guaranteed to already be available
because dx_show_leaf() is only called when adding a new directory entry.
And even if the key wasn't available, dx_show_leaf() uses
fscrypt_fname_disk_to_usr() which knows how to create a no-key name.
So for the above reasons, and because it would be desirable to stop
exporting fscrypt_get_encryption_info() directly to filesystems, remove
the call to fscrypt_get_encryption_info() from dx_show_leaf().
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20201203022041.230976-5-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Since encrypted directories can be opened and searched without their key
being available, and each readdir and ->lookup() tries to set up the
key, trying to set up the key in ->open() too isn't really useful.
Just remove it so that directories don't need an ->open() method
anymore, and so that we eliminate a use of fscrypt_get_encryption_info()
(which I'd like to stop exporting to filesystems).
Link: https://lore.kernel.org/r/20201203022041.230976-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Since encrypted directories can be opened and searched without their key
being available, and each readdir and ->lookup() tries to set up the
key, trying to set up the key in ->open() too isn't really useful.
Just remove it so that directories don't need an ->open() method
anymore, and so that we eliminate a use of fscrypt_get_encryption_info()
(which I'd like to stop exporting to filesystems).
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20201203022041.230976-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Since encrypted directories can be opened and searched without their key
being available, and each readdir and ->lookup() tries to set up the
key, trying to set up the key in ->open() too isn't really useful.
Just remove it so that directories don't need an ->open() method
anymore, and so that we eliminate a use of fscrypt_get_encryption_info()
(which I'd like to stop exporting to filesystems).
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20201203022041.230976-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
The stated reasons for separating fscrypt_master_key::mk_secret_sem from
the standard semaphore contained in every 'struct key' no longer apply.
First, due to commit a992b20cd4 ("fscrypt: add
fscrypt_prepare_new_inode() and fscrypt_set_context()"),
fscrypt_get_encryption_info() is no longer called from within a
filesystem transaction.
Second, due to commit d3ec10aa95 ("KEYS: Don't write out to userspace
while holding key semaphore"), the semaphore for the "keyring" key type
no longer ranks above page faults.
That leaves performance as the only possible reason to keep the separate
mk_secret_sem. Specifically, having mk_secret_sem reduces the
contention between setup_file_encryption_key() and
FS_IOC_{ADD,REMOVE}_ENCRYPTION_KEY. However, these ioctls aren't
executed often, so this doesn't seem to be worth the extra complexity.
Therefore, simplify the locking design by just using key->sem instead of
mk_secret_sem.
Link: https://lore.kernel.org/r/20201117032626.320275-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
