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author | Alexey Dobriyan <adobriyan@gmail.com> | 2008-10-27 19:48:36 (GMT) |
---|---|---|
committer | Alexey Dobriyan <adobriyan@gmail.com> | 2009-01-05 09:27:44 (GMT) |
commit | b4df2b92d8461444fac429c75ba6e125c63056bc (patch) | |
tree | 15149c192776b817eeb6124978f74411490aa1ce /fs/proc/proc_net.c | |
parent | fe0bdec68b77020281dc814805edfe594ae89e0f (diff) | |
download | linux-b4df2b92d8461444fac429c75ba6e125c63056bc.tar.xz |
proc: stop using BKL
There are four BKL users in proc: de_put(), proc_lookup_de(),
proc_readdir_de(), proc_root_readdir(),
1) de_put()
-----------
de_put() is classic atomic_dec_and_test() refcount wrapper -- no BKL
needed. BKL doesn't matter to possible refcount leak as well.
2) proc_lookup_de()
-------------------
Walking PDE list is protected by proc_subdir_lock(), proc_get_inode() is
potentially blocking, all callers of proc_lookup_de() eventually end up
from ->lookup hooks which is protected by directory's ->i_mutex -- BKL
doesn't protect anything.
3) proc_readdir_de()
--------------------
"." and ".." part doesn't need BKL, walking PDE list is under
proc_subdir_lock, calling filldir callback is potentially blocking
because it writes to luserspace. All proc_readdir_de() callers
eventually come from ->readdir hook which is under directory's
->i_mutex -- BKL doesn't protect anything.
4) proc_root_readdir_de()
-------------------------
proc_root_readdir_de is ->readdir hook, see (3).
Since readdir hooks doesn't use BKL anymore, switch to
generic_file_llseek, since it also takes directory's i_mutex.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Diffstat (limited to 'fs/proc/proc_net.c')
-rw-r--r-- | fs/proc/proc_net.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c index 7bc296f..04d1270 100644 --- a/fs/proc/proc_net.c +++ b/fs/proc/proc_net.c @@ -18,7 +18,6 @@ #include <linux/sched.h> #include <linux/module.h> #include <linux/bitops.h> -#include <linux/smp_lock.h> #include <linux/mount.h> #include <linux/nsproxy.h> #include <net/net_namespace.h> @@ -172,6 +171,7 @@ static int proc_tgid_net_readdir(struct file *filp, void *dirent, } const struct file_operations proc_net_operations = { + .llseek = generic_file_llseek, .read = generic_read_dir, .readdir = proc_tgid_net_readdir, }; |