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| author | Ahmed S. Darwish <a.darwish@linutronix.de> | 2020-07-20 17:55:24 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-07-29 16:14:27 +0200 |
| commit | 26475371976c69489d3a8e6c8bbf35afbbc25055 (patch) | |
| tree | 5f7ac08bbe80ab13cd56cd4dcf0cdf4d6829d061 /fs/fs_struct.c | |
| parent | 025e82bcbc34cd071390e72fd0b31593282f9425 (diff) | |
| download | linux-stable-26475371976c69489d3a8e6c8bbf35afbbc25055.tar.gz linux-stable-26475371976c69489d3a8e6c8bbf35afbbc25055.tar.bz2 linux-stable-26475371976c69489d3a8e6c8bbf35afbbc25055.zip | |
vfs: Use sequence counter with associated spinlock
A sequence counter write side critical section must be protected by some
form of locking to serialize writers. A plain seqcount_t does not
contain the information of which lock must be held when entering a write
side critical section.
Use the new seqcount_spinlock_t data type, which allows to associate a
spinlock with the sequence counter. This enables lockdep to verify that
the spinlock used for writer serialization is held when the write side
critical section is entered.
If lockdep is disabled this lock association is compiled out and has
neither storage size nor runtime overhead.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-19-a.darwish@linutronix.de
Diffstat (limited to 'fs/fs_struct.c')
| -rw-r--r-- | fs/fs_struct.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/fs_struct.c b/fs/fs_struct.c index ca639ed967b7..04b3f5b9c629 100644 --- a/fs/fs_struct.c +++ b/fs/fs_struct.c @@ -117,7 +117,7 @@ struct fs_struct *copy_fs_struct(struct fs_struct *old) fs->users = 1; fs->in_exec = 0; spin_lock_init(&fs->lock); - seqcount_init(&fs->seq); + seqcount_spinlock_init(&fs->seq, &fs->lock); fs->umask = old->umask; spin_lock(&old->lock); @@ -163,6 +163,6 @@ EXPORT_SYMBOL(current_umask); struct fs_struct init_fs = { .users = 1, .lock = __SPIN_LOCK_UNLOCKED(init_fs.lock), - .seq = SEQCNT_ZERO(init_fs.seq), + .seq = SEQCNT_SPINLOCK_ZERO(init_fs.seq, &init_fs.lock), .umask = 0022, }; |