Author: trasz Date: Sat Mar 12 07:54:42 2016 New Revision: 296715 URL: https://svnweb.freebsd.org/changeset/base/296715
Log: Fix autofs triggering problem. Assume you have an NFS server, 192.168.1.1, with share "share". This commit fixes a problem where "mkdir /net/192.168.1.1/share/meh" would return spurious error instead of creating the directory if the target filesystem wasn't mounted yet; subsequent attempts would work correctly. The failure scenario is kind of complicated to explain, but it all boils down to calling VOP_MKDIR() for the target filesystem (NFS) with wrong dvp - the autofs vnode instead of the filesystem root mounted over it. Reviewed by: kib@ MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D5442 Modified: head/sys/fs/autofs/autofs_vnops.c head/sys/kern/vfs_lookup.c head/sys/sys/errno.h Modified: head/sys/fs/autofs/autofs_vnops.c ============================================================================== --- head/sys/fs/autofs/autofs_vnops.c Sat Mar 12 07:13:20 2016 (r296714) +++ head/sys/fs/autofs/autofs_vnops.c Sat Mar 12 07:54:42 2016 (r296715) @@ -214,7 +214,7 @@ autofs_lookup(struct vop_lookup_args *ap struct autofs_mount *amp; struct autofs_node *anp, *child; struct componentname *cnp; - int error, lock_flags; + int error; dvp = ap->a_dvp; vpp = ap->a_vpp; @@ -257,23 +257,13 @@ autofs_lookup(struct vop_lookup_args *ap return (error); if (newvp != NULL) { - error = VOP_LOOKUP(newvp, ap->a_vpp, ap->a_cnp); - /* - * Instead of figuring out whether our vnode should - * be locked or not given the error and cnp flags, - * just "copy" the lock status from vnode returned - * by mounted filesystem's VOP_LOOKUP(). Get rid - * of that new vnode afterwards. + * The target filesystem got automounted. + * Let the lookup(9) go around with the same + * path component. */ - lock_flags = VOP_ISLOCKED(newvp); - if (lock_flags == 0) { - VOP_UNLOCK(dvp, 0); - vrele(newvp); - } else { - vput(newvp); - } - return (error); + vput(newvp); + return (ERELOOKUP); } } Modified: head/sys/kern/vfs_lookup.c ============================================================================== --- head/sys/kern/vfs_lookup.c Sat Mar 12 07:13:20 2016 (r296714) +++ head/sys/kern/vfs_lookup.c Sat Mar 12 07:54:42 2016 (r296715) @@ -495,6 +495,7 @@ lookup(struct nameidata *ndp) int rdonly; /* lookup read-only flag bit */ int error = 0; int dpunlocked = 0; /* dp has already been unlocked */ + int relookup = 0; /* do not consume the path component */ struct componentname *cnp = &ndp->ni_cnd; int lkflags_save; int ni_dvp_unlocked; @@ -745,6 +746,14 @@ unionlookup: goto unionlookup; } + if (error == ERELOOKUP) { + vref(dp); + ndp->ni_vp = dp; + error = 0; + relookup = 1; + goto good; + } + if (error != EJUSTRETURN) goto bad; /* @@ -777,6 +786,8 @@ unionlookup: goto success; } else cnp->cn_lkflags = lkflags_save; + +good: #ifdef NAMEI_DIAGNOSTIC printf("found\n"); #endif @@ -856,6 +867,14 @@ nextname: */ KASSERT((cnp->cn_flags & ISLASTCN) || *ndp->ni_next == '/', ("lookup: invalid path state.")); + if (relookup) { + relookup = 0; + if (ndp->ni_dvp != dp) + vput(ndp->ni_dvp); + else + vrele(ndp->ni_dvp); + goto dirloop; + } if (*ndp->ni_next == '/') { cnp->cn_nameptr = ndp->ni_next; while (*cnp->cn_nameptr == '/') { Modified: head/sys/sys/errno.h ============================================================================== --- head/sys/sys/errno.h Sat Mar 12 07:13:20 2016 (r296714) +++ head/sys/sys/errno.h Sat Mar 12 07:54:42 2016 (r296715) @@ -190,6 +190,7 @@ __END_DECLS #define EJUSTRETURN (-2) /* don't modify regs, just return */ #define ENOIOCTL (-3) /* ioctl not handled by this layer */ #define EDIRIOCTL (-4) /* do direct ioctl in GEOM */ +#define ERELOOKUP (-5) /* retry the directory lookup */ #endif #endif _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
