077130c0cf
The problem: proc_net files remember which network namespace the are against but do not remember hold a reference count (as that would pin the network namespace). So we currently have a small window where the reference count on a network namespace may be incremented when opening a /proc file when it has already gone to zero. To fix this introduce maybe_get_net and get_proc_net. maybe_get_net increments the network namespace reference count only if it is greater then zero, ensuring we don't increment a reference count after it has gone to zero. get_proc_net handles all of the magic to go from a proc inode to the network namespace instance and call maybe_get_net on it. PROC_NET the old accessor is removed so that we don't get confused and use the wrong helper function. Then I fix up the callers to use get_proc_net and handle the case case where get_proc_net returns NULL. In that case I return -ENXIO because effectively the network namespace has already gone away so the files we are trying to access don't exist anymore. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Paul E. McKenney <paulmck@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| .. | ||
| array.c | ||
| base.c | ||
| generic.c | ||
| inode-alloc.txt | ||
| inode.c | ||
| internal.h | ||
| kcore.c | ||
| kmsg.c | ||
| Makefile | ||
| mmu.c | ||
| nommu.c | ||
| proc_devtree.c | ||
| proc_misc.c | ||
| proc_net.c | ||
| proc_sysctl.c | ||
| proc_tty.c | ||
| root.c | ||
| task_mmu.c | ||
| task_nommu.c | ||
| vmcore.c | ||