Re: [PATCH 4/6] sysfs: use sysfs_lock to protect the sysfs_dirent tree

On Tue, 29 May 2007 01:36:27 +0900,
Tejun Heo <[email protected]> wrote:

> @@ -795,6 +822,8 @@ static int sysfs_readdir(struct file * f
>  			i++;
>  			/* fallthrough */
>  		default:
> +			spin_lock(&sysfs_lock);
> +
>  			pos = &parent_sd->s_children;
>  			while (*pos != cursor)
>  				pos = &(*pos)->s_sibling;
> @@ -827,6 +856,8 @@ static int sysfs_readdir(struct file * f
>  			/* put cursor back in */
>  			cursor->s_sibling = *pos;
>  			*pos = cursor;
> +
> +			spin_unlock(&sysfs_lock);
>  	}
>  	return 0;
>  }

Here's the cause of the "sleeping function called" I saw. filldir() is
called under sysfs_lock, but calls copy_to_user()... This means you
can't use sysfs_lock for protection here.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

---

• Follow-Ups:
  • Re: [PATCH 4/6] sysfs: use sysfs_lock to protect the sysfs_dirent tree
    • From: Tejun Heo <[email protected]>

• References:
  • [PATCHSET 2.6.22-rc2-mm1 REVIEW] sysfs: make directory dentries/inodes reclaimable
    • From: Tejun Heo <[email protected]>
  • [PATCH 4/6] sysfs: use sysfs_lock to protect the sysfs_dirent tree
    • From: Tejun Heo <[email protected]>

• Prev by Date: Re: [PATCH] FILESYSTEMS: Delete unused "int dummy[5]" from inodes_stat_t.
• Next by Date: Re: [PATCH 02/22] 2.6.22-rc3 perfmon2 : generic kernel modifications
• Previous by thread: [PATCH 4/6] sysfs: use sysfs_lock to protect the sysfs_dirent tree
• Next by thread: Re: [PATCH 4/6] sysfs: use sysfs_lock to protect the sysfs_dirent tree
• Index(es):
  • Date
  • Thread

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]