Messages in this thread Patch in this message | | | Date | Mon, 24 Feb 2003 17:44:42 +0530 | From | Maneesh Soni <> | Subject | Re: Oops in rpc_depopulate with 2.5.62 |
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On Sat, Feb 22, 2003 at 12:49:30AM -0800, Andrew Morton wrote: > > Maneesh and Dipankar may be able to plug this one. I've looked, > and apart from a seemingly-unneeded test for !d_unhashed I can't > see the problem. > > Perhaps the problem lies with a different part of the code. > > I cannot reproduce the crash.
Same with me also. Surprisingly I am getting same oops on 2.5.61. Can send .config and ksymoops output if required.
rpc_rmdir does lookup_hash(), which may return a negative dentry. If a negative dentry is possible at this point then testing for d_inode in rpc_rmdir() fixes this problem. Like we have in rpc_unlink(). Probably Trond knows better.
Following patch fixes the oops I am seeing in 2.5.61 and should fix the oops seen on 2.5.62 also.
diff -urN linux-2.5.62-bk6/net/sunrpc/rpc_pipe.c linux-2.5.62-bk6-rpc_depopulate/net/sunrpc/rpc_pipe.c --- linux-2.5.62-bk6/net/sunrpc/rpc_pipe.c 2003-02-24 16:06:46.000000000 +0530 +++ linux-2.5.62-bk6-rpc_depopulate/net/sunrpc/rpc_pipe.c 2003-02-24 16:57:14.000000000 +0530 @@ -665,8 +665,10 @@ error = PTR_ERR(dentry); goto out_release; } - rpc_depopulate(dentry); - error = __rpc_rmdir(dir, dentry); + if (dentry->d_inode) { + rpc_depopulate(dentry); + error = __rpc_rmdir(dir, dentry); + } dput(dentry); out_release: up(&dir->i_sem);
Regards Maneesh
> "Martin J. Bligh" <mbligh@aracnet.com> wrote: > > > > Getting rpc/nfs bugs on at least two different machines I've seen > > and reports of a third from Zwane - all look similar. Anyone got > > any bright ideas? > > > > M. > > > > Unable to handle kernel NULL pointer dereference at virtual address 0000006c > > printing eip: > > c03415e2 > > *pde = 358d2001 > > *pte = 00000000 > > Oops: 0002 > > CPU: 1 > > EIP: 0060:[<c03415e2>] Not tainted > > EFLAGS: 00010206 > > EIP is at rpc_depopulate+0x22/0xf0 > > eax: 00000000 ebx: f5133680 ecx: 0000006c edx: f50afc1c > > esi: f50afbf4 edi: f50afbf4 ebp: f50afc08 esp: f50afbec > > ds: 007b es: 007b ss: 0068 > > Process mount (pid: 1166, threadinfo=f50ae000 task=f5766d80) > > Stack: c01562f0 00000000 f50afbf4 f50afbf4 f5133680 f5133680 f51c1e00 f50afc40 > > c0341af5 f5133680 f5117880 f7ff9800 f50afcec 00000000 f50afc34 00000010 > > 00000001 00000000 f5982680 f50afcec 00000000 f50afc50 c0333066 f5982714 > > Call Trace: > > [<c01562f0>] lookup_hash+0x70/0xa0 > > [<c0341af5>] rpc_rmdir+0x55/0x90 > > [<c0333066>] rpc_destroy_client+0x46/0x70 > > [<c03330db>] rpc_release_client+0x4b/0x60 > > [<c0337bc7>] rpc_release_task+0x1a7/0x1d0 > > [<c033754b>] __rpc_execute+0x35b/0x370 > > [<c011a980>] default_wake_function+0x0/0x20 > > [<c0333274>] rpc_call_sync+0x64/0xa0 > > [<c0333287>] rpc_call_sync+0x77/0xa0 > > [<c03366b0>] rpc_run_timer+0x0/0xa0 > > [<c033e5fb>] rpc_register+0xcb/0x100 > > [<c0110000>] mask_and_ack_8259A+0x10/0xf0 > > [<c0339d24>] svc_register+0x94/0x100 > > [<c0339944>] svc_create+0xd4/0xe0 > > [<c01c1fb8>] lockd_up+0x58/0x110 > > [<c01a63f4>] nfs_fill_super+0x374/0x3a0 > > [<c01a7e90>] nfs_get_sb+0x1f0/0x230 > > [<c0150052>] do_kern_mount+0x42/0xa0 > > [<c01631e6>] do_add_mount+0x76/0x150 > > [<c0133596>] __alloc_pages+0x76/0x2c0 > > [<c01634d7>] do_mount+0x147/0x160 > > [<c0163908>] sys_mount+0xa8/0x110 > > [<c010ae7b>] syscall_call+0x7/0xb > > > > Code: f0 ff 48 6c 0f 88 70 09 00 00 f0 fe 0d 00 d2 44 c0 0f 88 6d > > > > Seems to be crashing on the deference of: > > > > down(&dir->i_sem); > > > > in rpc_depopulate. But there's a big comment just above saying: > > > > ----------------------- > > /* > > * FIXME: This probably has races. > > */ > > static void > > rpc_depopulate(struct dentry *parent) > > { > > struct inode *dir = parent->d_inode; > > LIST_HEAD(head); > > struct list_head *pos, *next; > > struct dentry *dentry; > > > > down(&dir->i_sem); > > > > ------------------ > > > > Looks like dir is NULL here ... might be dcache_rcu (a recent dcache_rcu > > patch fixed the same file) or a race brought out by the changes. > > > > > > - > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/
-- Maneesh Soni IBM Linux Technology Center, IBM India Software Lab, Bangalore. Phone: +91-80-5044999 email: maneesh@in.ibm.com http://lse.sourceforge.net/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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