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    SubjectRe: [PATCH] sysfs: kill an extra put in sysfs_create_link() failure path
    Hi Tejun,

    Thanks for tracking this down and fixing it.

    On 7/18/07, Tejun Heo <> 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,
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      Last update: 2007-07-18 16:51    [W:0.025 / U:0.428 seconds]
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