Messages in this thread | | | Date | Wed, 18 Jul 2007 20:18:40 +0530 | From | "Satyam Sharma" <> | Subject | Re: [PATCH] sysfs: kill an extra put in sysfs_create_link() failure path |
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Hi Tejun,
Thanks for tracking this down and fixing it.
On 7/18/07, Tejun Heo <htejun@gmail.com> wrote: > There is a subtle bug in sysfs_create_link() failure path. When > symlink creation fails because there's already a node with the same > name, the target sysfs_dirent is put twice - once by failure path of > sysfs_create_link() and once more when the symlink is released.
The "symlink" is released? But the creation of the symlink is precisely what failed here ... did it not?
> Fix it by making only the symlink node responsible for putting > target_sd.
And again ... the changelog sounds confusing indeed, perhaps I'm not familiar enough with sysfs symlink-related terminology/semantics. Care to elaborate?
> sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK); > if (!sd) > goto out_put; > + > sd->s_elem.symlink.target_sd = target_sd; > + target_sd = NULL; /* reference is now owned by the symlink */
Wow. This looks like a very mysterious way to fix a mysterious bug :-) BTW I just looked over at sysfs_create_link() and ... it looks quite ... unnecessarily complicated/obfuscated ...
Thanks again, Satyam - 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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