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| author | John Stultz <john.stultz@linaro.org> | 2013-10-07 15:51:59 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-11-06 12:40:26 +0100 |
| commit | 1ca7d67cf5d5a2aef26a8d9afd789006fa098347 (patch) | |
| tree | 8f4f7d1f189d7a08983ab5ef522330f08f337459 /fs | |
| parent | 827da44c61419f29ae3be198c342e2147f1a10cb (diff) | |
| download | op-kernel-dev-1ca7d67cf5d5a2aef26a8d9afd789006fa098347.zip op-kernel-dev-1ca7d67cf5d5a2aef26a8d9afd789006fa098347.tar.gz | |
seqcount: Add lockdep functionality to seqcount/seqlock structures
Currently seqlocks and seqcounts don't support lockdep.
After running across a seqcount related deadlock in the timekeeping
code, I used a less-refined and more focused variant of this patch
to narrow down the cause of the issue.
This is a first-pass attempt to properly enable lockdep functionality
on seqlocks and seqcounts.
Since seqcounts are used in the vdso gettimeofday code, I've provided
non-lockdep accessors for those needs.
I've also handled one case where there were nested seqlock writers
and there may be more edge cases.
Comments and feedback would be appreciated!
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1381186321-4906-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/dcache.c | 4 | ||||
| -rw-r--r-- | fs/fs_struct.c | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index ae6ebb8..f750be2 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2574,7 +2574,7 @@ static void __d_move(struct dentry * dentry, struct dentry * target) dentry_lock_for_move(dentry, target); write_seqcount_begin(&dentry->d_seq); - write_seqcount_begin(&target->d_seq); + write_seqcount_begin_nested(&target->d_seq, DENTRY_D_LOCK_NESTED); /* __d_drop does write_seqcount_barrier, but they're OK to nest. */ @@ -2706,7 +2706,7 @@ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon) dentry_lock_for_move(anon, dentry); write_seqcount_begin(&dentry->d_seq); - write_seqcount_begin(&anon->d_seq); + write_seqcount_begin_nested(&anon->d_seq, DENTRY_D_LOCK_NESTED); dparent = dentry->d_parent; diff --git a/fs/fs_struct.c b/fs/fs_struct.c index d8ac61d..7dca743 100644 --- a/fs/fs_struct.c +++ b/fs/fs_struct.c @@ -161,6 +161,6 @@ EXPORT_SYMBOL(current_umask); struct fs_struct init_fs = { .users = 1, .lock = __SPIN_LOCK_UNLOCKED(init_fs.lock), - .seq = SEQCNT_ZERO, + .seq = SEQCNT_ZERO(init_fs.seq), .umask = 0022, }; |
