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| author | Dipankar Sarma <dipankar@in.ibm.com> | 2004-08-22 22:58:51 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-08-22 22:58:51 -0700 |
| commit | 5dae7a69a46f3a9f6562a4702f8beaa7f77e94f6 (patch) | |
| tree | 40daf62eb530c10372f9cb90f600a0b040c5e725 /fs | |
| parent | 9711268caede0cbd322244d70145a6e914fac52e (diff) | |
| download | history-5dae7a69a46f3a9f6562a4702f8beaa7f77e94f6.tar.gz | |
[PATCH] rcu: abstracted RCU dereferencing
Use abstracted RCU API to dereference RCU protected data. Hides barrier
details. Patch from Paul McKenney.
This patch introduced an rcu_dereference() macro that replaces most uses of
smp_read_barrier_depends(). The new macro has the advantage of explicitly
documenting which pointers are protected by RCU -- in contrast, it is
sometimes difficult to figure out which pointer is being protected by a given
smp_read_barrier_depends() call.
Signed-off-by: Paul McKenney <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/dcache.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 425c2e56894839..092323cf4646d5 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -613,7 +613,7 @@ void shrink_dcache_parent(struct dentry * parent) * * Prune the dentries that are anonymous * - * parsing d_hash list does not read_barrier_depends() as it + * parsing d_hash list does not hlist_for_each_rcu() as it * done under dcache_lock. * */ @@ -970,11 +970,10 @@ struct dentry * __d_lookup(struct dentry * parent, struct qstr * name) rcu_read_lock(); - hlist_for_each (node, head) { + hlist_for_each_rcu(node, head) { struct dentry *dentry; struct qstr *qstr; - smp_read_barrier_depends(); dentry = hlist_entry(node, struct dentry, d_hash); smp_rmb(); @@ -1001,8 +1000,7 @@ struct dentry * __d_lookup(struct dentry * parent, struct qstr * name) if (dentry->d_parent != parent) goto next; - qstr = &dentry->d_name; - smp_read_barrier_depends(); + qstr = rcu_dereference(&dentry->d_name); if (parent->d_op && parent->d_op->d_compare) { if (parent->d_op->d_compare(parent, qstr, name)) goto next; @@ -1055,7 +1053,7 @@ int d_validate(struct dentry *dentry, struct dentry *dparent) spin_lock(&dcache_lock); base = d_hash(dparent, dentry->d_name.hash); hlist_for_each(lhp,base) { - /* read_barrier_depends() not required for d_hash list + /* hlist_for_each_rcu() not required for d_hash list * as it is parsed under dcache_lock */ if (dentry == hlist_entry(lhp, struct dentry, d_hash)) { |