diff options
Diffstat (limited to 'sys/kern/vfs_cache.c')
-rw-r--r-- | sys/kern/vfs_cache.c | 160 |
1 files changed, 75 insertions, 85 deletions
diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c index 01c5e4c..cdfb308 100644 --- a/sys/kern/vfs_cache.c +++ b/sys/kern/vfs_cache.c @@ -206,7 +206,7 @@ SYSCTL_OPAQUE(_vfs_cache, OID_AUTO, nchstats, CTLFLAG_RD | CTLFLAG_MPSAFE, static void cache_zap(struct namecache *ncp); -static int vn_vptocnp(struct vnode **vp, char **bp, char *buf, u_int *buflen); +static int vn_vptocnp_locked(struct vnode **vp, char *buf, u_int *buflen); static int vn_fullpath1(struct thread *td, struct vnode *vp, struct vnode *rdir, char *buf, char **retbuf, u_int buflen); @@ -1036,12 +1036,55 @@ vn_fullpath_global(struct thread *td, struct vnode *vn, return (error); } +int +vn_vptocnp(struct vnode **vp, char *buf, u_int *buflen) +{ + int error; + + CACHE_RLOCK(); + error = vn_vptocnp_locked(vp, buf, buflen); + if (error == 0) { + /* + * vn_vptocnp_locked() dropped hold acquired by + * VOP_VPTOCNP immediately after locking the + * cache. Since we are going to drop the cache rlock, + * re-hold the result. + */ + vhold(*vp); + CACHE_RUNLOCK(); + } + return (error); +} + static int -vn_vptocnp(struct vnode **vp, char **bp, char *buf, u_int *buflen) +vn_vptocnp_locked(struct vnode **vp, char *buf, u_int *buflen) { struct vnode *dvp; + struct namecache *ncp; int error, vfslocked; + TAILQ_FOREACH(ncp, &((*vp)->v_cache_dst), nc_dst) { + if ((ncp->nc_flag & NCF_ISDOTDOT) == 0) + break; + } + if (ncp != NULL) { + if (*buflen < ncp->nc_nlen) { + CACHE_RUNLOCK(); + numfullpathfail4++; + error = ENOMEM; + SDT_PROBE(vfs, namecache, fullpath, return, error, + startvp, NULL, 0, 0); + return (error); + } + *buflen -= ncp->nc_nlen; + memcpy(buf + *buflen, ncp->nc_name, ncp->nc_nlen); + SDT_PROBE(vfs, namecache, fullpath, hit, ncp->nc_dvp, + ncp->nc_name, vp, 0, 0); + *vp = ncp->nc_dvp; + return (0); + } + SDT_PROBE(vfs, namecache, fullpath, miss, vp, 0, 0, 0, 0); + vhold(*vp); CACHE_RUNLOCK(); vfslocked = VFS_LOCK_GIANT((*vp)->v_mount); @@ -1052,16 +1095,21 @@ vn_vptocnp(struct vnode **vp, char **bp, char *buf, u_int *buflen) VFS_UNLOCK_GIANT(vfslocked); if (error) { numfullpathfail2++; + SDT_PROBE(vfs, namecache, fullpath, return, error, startvp, + NULL, 0, 0); return (error); } - *bp = buf + *buflen; + *vp = dvp; CACHE_RLOCK(); if ((*vp)->v_iflag & VI_DOOMED) { /* forced unmount */ CACHE_RUNLOCK(); vdrop(*vp); - return (ENOENT); + error = ENOENT; + SDT_PROBE(vfs, namecache, fullpath, return, error, startvp, + NULL, 0, 0); + return (error); } vdrop(*vp); @@ -1075,59 +1123,26 @@ static int vn_fullpath1(struct thread *td, struct vnode *vp, struct vnode *rdir, char *buf, char **retbuf, u_int buflen) { - char *bp; - int error, i, slash_prefixed; - struct namecache *ncp; + int error, slash_prefixed; #ifdef KDTRACE_HOOKS struct vnode *startvp = vp; #endif buflen--; - bp = buf + buflen; - *bp = '\0'; + buf[buflen] = '\0'; error = 0; slash_prefixed = 0; SDT_PROBE(vfs, namecache, fullpath, entry, vp, 0, 0, 0, 0); - CACHE_RLOCK(); numfullpathcalls++; + CACHE_RLOCK(); if (vp->v_type != VDIR) { - ncp = TAILQ_FIRST(&vp->v_cache_dst); - if (ncp != NULL) { - buflen -= ncp->nc_nlen; - for (i = ncp->nc_nlen - 1; i >= 0 && bp != buf; i--) - *--bp = ncp->nc_name[i]; - if (bp == buf) { - numfullpathfail4++; - CACHE_RUNLOCK(); - error = ENOMEM; - SDT_PROBE(vfs, namecache, fullpath, return, - error, startvp, NULL, 0, 0); - return (error); - } - SDT_PROBE(vfs, namecache, fullpath, hit, ncp->nc_dvp, - ncp->nc_name, vp, 0, 0); - vp = ncp->nc_dvp; - } else { - SDT_PROBE(vfs, namecache, fullpath, miss, vp, 0, 0, - 0, 0); - error = vn_vptocnp(&vp, &bp, buf, &buflen); - if (error) { - SDT_PROBE(vfs, namecache, fullpath, return, - error, startvp, NULL, 0, 0); - return (error); - } - } - if (buflen <= 0) { - numfullpathfail4++; - CACHE_RUNLOCK(); - error = ENOMEM; - SDT_PROBE(vfs, namecache, fullpath, return, error, - startvp, NULL, 0, 0); + error = vn_vptocnp_locked(&vp, buf, &buflen); + if (error) return (error); - } - *--bp = '/'; - buflen--; + if (buflen == 0) + return (ENOMEM); + buf[--buflen] = '/'; slash_prefixed = 1; } while (vp != rdir && vp != rootvnode) { @@ -1141,64 +1156,39 @@ vn_fullpath1(struct thread *td, struct vnode *vp, struct vnode *rdir, continue; } if (vp->v_type != VDIR) { - numfullpathfail1++; CACHE_RUNLOCK(); + numfullpathfail1++; error = ENOTDIR; break; } - TAILQ_FOREACH(ncp, &vp->v_cache_dst, nc_dst) - if ((ncp->nc_flag & NCF_ISDOTDOT) == 0) - break; - if (ncp != NULL) { - buflen -= ncp->nc_nlen; - for (i = ncp->nc_nlen - 1; i >= 0 && bp != buf; i--) - *--bp = ncp->nc_name[i]; - if (bp == buf) { - numfullpathfail4++; - CACHE_RUNLOCK(); - error = ENOMEM; - break; - } - SDT_PROBE(vfs, namecache, fullpath, hit, ncp->nc_dvp, - ncp->nc_name, vp, 0, 0); - vp = ncp->nc_dvp; - } else { - SDT_PROBE(vfs, namecache, fullpath, miss, vp, 0, 0, - 0, 0); - error = vn_vptocnp(&vp, &bp, buf, &buflen); - if (error) - break; - } - if (buflen <= 0) { - numfullpathfail4++; - CACHE_RUNLOCK(); + error = vn_vptocnp_locked(&vp, buf, &buflen); + if (error) + break; + if (buflen == 0) { error = ENOMEM; break; } - *--bp = '/'; - buflen--; + buf[--buflen] = '/'; slash_prefixed = 1; } - if (error) { - SDT_PROBE(vfs, namecache, fullpath, return, error, startvp, - NULL, 0, 0); + if (error) return (error); - } if (!slash_prefixed) { - if (bp == buf) { - numfullpathfail4++; + if (buflen == 0) { CACHE_RUNLOCK(); + numfullpathfail4++; SDT_PROBE(vfs, namecache, fullpath, return, 0, - startvp, bp, 0, 0); + startvp, fullpath, 0, 0); return (ENOMEM); - } else - *--bp = '/'; + } + buf[--buflen] = '/'; } numfullpathfound++; CACHE_RUNLOCK(); - SDT_PROBE(vfs, namecache, fullpath, return, 0, startvp, bp, 0, 0); - *retbuf = bp; + SDT_PROBE(vfs, namecache, fullpath, return, 0, startvp, buf + *buflen, + 0, 0); + *retbuf = buf + buflen; return (0); } |