Date: Tue, 16 Aug 2011 04:35:42 +0000 (UTC) From: "Justin T. Gibbs" <gibbs@FreeBSD.org> To: src-committers@freebsd.org, svn-src-projects@freebsd.org Subject: svn commit: r224901 - projects/zfsd/head/sys/fs/devfs Message-ID: <201108160435.p7G4ZgNO041036@svn.freebsd.org>
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Author: gibbs Date: Tue Aug 16 04:35:42 2011 New Revision: 224901 URL: http://svn.freebsd.org/changeset/base/224901 Log: Correct the rendering of device aliases that reside in subdirectories of a devfs. devfs/devfs_vnops.c: In devfs_readlink(), convert the devfs root relative path of an alias's parent, that is recorded in the alias, into a fully qualified path that includes the root of the containing devfs. This avoids the ugliness of generating a relative path by prepending "../"'s. For a non-jailed process, the "symlink root" is the devfs's mount point. For a jailed process, we must remove any jail prefix in the mount point so that our response matches the user process's world view. Sponsored by: Spectra Logic Corporation Modified: projects/zfsd/head/sys/fs/devfs/devfs_vnops.c Modified: projects/zfsd/head/sys/fs/devfs/devfs_vnops.c ============================================================================== --- projects/zfsd/head/sys/fs/devfs/devfs_vnops.c Tue Aug 16 00:43:25 2011 (r224900) +++ projects/zfsd/head/sys/fs/devfs/devfs_vnops.c Tue Aug 16 04:35:42 2011 (r224901) @@ -1248,8 +1248,53 @@ static int devfs_readlink(struct vop_readlink_args *ap) { struct devfs_dirent *de; + struct cdev_priv *cdp; de = ap->a_vp->v_data; + cdp = de->de_cdp; + + if (cdp != NULL && (cdp->cdp_c.si_flags & SI_ALIAS) != 0) { + struct devfs_mount *dmp; + struct prison *pr; + char *mp; + int mp_len; + int pr_path_len; + int err; + + /* + * For device aliases, construct an absolute symlink (to + * shorten its length and avoid the ugliness of a relative + * link) by prepending the fully qualified path to the root + * of this devfs. For a non-jailed process, the devfs root + * is our mount point. For a jailed process, we must remove + * any jail prefix in our mount point so that our response + * matches the user process's world view. + */ + dmp = VFSTODEVFS(ap->a_vp->v_mount); + mp = dmp->dm_mount->mnt_stat.f_mntonname; + mp_len = strlen(mp); + + pr = ap->a_cred->cr_prison; + pr_path_len = strlen(pr->pr_path); + + if (strncmp(pr->pr_path, mp, pr_path_len) == 0 + && mp[pr_path_len] == '/') { + mp += pr_path_len; + mp_len -= pr_path_len; + } + + err = uiomove(mp, mp_len, ap->a_uio); + if (err != 0) + return (err); + + /* + * Devfs cannot be the root file system, so its + * mount point must always be terminated by a '/'. + */ + err = uiomove("/", 1, ap->a_uio); + if (err != 0) + return (err); + } return (uiomove(de->de_symlink, strlen(de->de_symlink), ap->a_uio)); }
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