From: Dave Chinner <david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org>
To: Ryan Mallon <ryan-7Wk5F4Od5/oYd5yxfr4S2w@public.gmane.org>
Cc: viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org,
dchinner-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org,
Trond.Myklebust-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [RFC PATCH 0/2] Introduce unlocked version of igrab
Date: Mon, 28 Mar 2011 15:43:34 +1100 [thread overview]
Message-ID: <20110328044334.GA1022@dastard> (raw)
In-Reply-To: <1301277361-9453-1-git-send-email-ryan-7Wk5F4Od5/oYd5yxfr4S2w@public.gmane.org>
On Mon, Mar 28, 2011 at 02:55:59PM +1300, Ryan Mallon wrote:
> Commit 250df6ed274d767da844a5d9f05720b804240197 "fs: protect
> inode->i_state with inode->i_lock" introduces a change to igrab to acquire
> inode->i_lock.
>
> This change causes a panic on boot on my ARM EP93xx board when the rootfs
> uses NFS. The problem occurs because nfs_inode_add_request acquires
> inode->i_lock and then calls igrab, resulting in the following panic:
>
> BUG: spinlock recursion on CPU#0, getty/262
> lock: cc421cb4, .magic: dead4ead, .owner: getty/262, .owner_cpu: 0
> [<c0031b0c>] (unwind_backtrace+0x0/0xe4) from [<c015f16c>] (do_raw_spin_lock+0x40/0x13c)
> [<c015f16c>] (do_raw_spin_lock+0x40/0x13c) from [<c00a938c>] (igrab+0x14/0x48)
> [<c00a938c>] (igrab+0x14/0x48) from [<c01186bc>] (nfs_updatepage+0x2e0/0x524)
> [<c01186bc>] (nfs_updatepage+0x2e0/0x524) from [<c010b19c>] (nfs_write_end+0x23c/0x270)
> [<c010b19c>] (nfs_write_end+0x23c/0x270) from [<c006b484>] (generic_file_buffered_write+0x180/0x248)
> [<c006b484>] (generic_file_buffered_write+0x180/0x248) from [<c006d060>] (__generic_file_aio_write+0x3b8/0x3f4)
> [<c006d060>] (__generic_file_aio_write+0x3b8/0x3f4) from [<c006d108>] (generic_file_aio_write+0x6c/0xdc)
> [<c006d108>] (generic_file_aio_write+0x6c/0xdc) from [<c010bce0>] (nfs_file_write+0xec/0x178)
> [<c010bce0>] (nfs_file_write+0xec/0x178) from [<c00956ac>] (do_sync_write+0xa4/0xe4)
> [<c00956ac>] (do_sync_write+0xa4/0xe4) from [<c00960c8>] (vfs_write+0xb4/0x12c)
> [<c00960c8>] (vfs_write+0xb4/0x12c) from [<c00961f0>] (sys_write+0x3c/0x68)
> [<c00961f0>] (sys_write+0x3c/0x68) from [<c002c8e0>] (ret_fast_syscall+0x0/0x2c)
>
> This series introduces a new function called __igrab, which is an unlocked
> version of igrab and modifies nfs_inode_add_request to use the unlocked
> version.
It's called ihold() and already exists.
As it is, I thought I posted a igrab->ihold fix to lkml a couple of
days ago when this first came up. Trond then posted a better fix by
removingthe igrab() altoegther in the same thread.
Turns out, someone removed LKML from the cc list on the thread half
way through so neither of those patches made it to lkml.
Trond, can you push your fix for this (NFS: Fix a hang in the
writeback path) to Linus?
Cheers,
Dave.
--
Dave Chinner
david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2011-03-28 4:43 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-28 1:55 [RFC PATCH 0/2] Introduce unlocked version of igrab Ryan Mallon
2011-03-28 1:56 ` [RFC PATCH 1/2] Add " Ryan Mallon
[not found] ` <1301277361-9453-2-git-send-email-ryan-7Wk5F4Od5/oYd5yxfr4S2w@public.gmane.org>
2011-03-28 2:54 ` Matthew Wilcox
[not found] ` <20110328025423.GN13806-6jwH94ZQLHl74goWV3ctuw@public.gmane.org>
2011-03-28 4:39 ` Ryan Mallon
[not found] ` <4D9010F1.1040909-7Wk5F4Od5/oYd5yxfr4S2w@public.gmane.org>
2011-03-28 5:19 ` [PATCH] fs: don't use igrab() while holding i_lock (was Re: [RFC PATCH 1/2] Add unlocked version of igrab.) Dave Chinner
2011-03-28 1:56 ` [RFC PATCH 2/2] Use __igrab instead of igrab in nfs_inode_add_request Ryan Mallon
[not found] ` <1301277361-9453-1-git-send-email-ryan-7Wk5F4Od5/oYd5yxfr4S2w@public.gmane.org>
2011-03-28 4:43 ` Dave Chinner [this message]
2011-03-28 4:47 ` [RFC PATCH 0/2] Introduce unlocked version of igrab Ryan Mallon
2011-03-28 5:03 ` Ryan Mallon
[not found] ` <4D9016B7.1080505-7Wk5F4Od5/oYd5yxfr4S2w@public.gmane.org>
2011-03-28 6:01 ` Dave Chinner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110328044334.GA1022@dastard \
--to=david-fqsqvqoi3ljby3ivrkzq2a@public.gmane.org \
--cc=Trond.Myklebust-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org \
--cc=dchinner-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org \
--cc=linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=ryan-7Wk5F4Od5/oYd5yxfr4S2w@public.gmane.org \
--cc=viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).