Author: mav Date: Wed Jul 26 15:29:56 2017 New Revision: 321525 URL: https://svnweb.freebsd.org/changeset/base/321525
Log: MFC r314112 (by tsoome): loader: update symlink support in zfs reader As the current zfs file system is providing symlink via system attributes, need to update the code accordingly. Note, as the zfsboot code does not free the memory at this time, the object list will put some stress on the boot2 heap, eventually we should address the issue. Differential Revision: https://reviews.freebsd.org/D9706 Modified: stable/11/sys/boot/zfs/zfsimpl.c stable/11/sys/cddl/boot/zfs/zfsimpl.h Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/boot/zfs/zfsimpl.c ============================================================================== --- stable/11/sys/boot/zfs/zfsimpl.c Wed Jul 26 15:24:17 2017 (r321524) +++ stable/11/sys/boot/zfs/zfsimpl.c Wed Jul 26 15:29:56 2017 (r321525) @@ -2142,6 +2142,61 @@ zfs_dnode_stat(const spa_t *spa, dnode_phys_t *dn, str return (0); } +static int +zfs_dnode_readlink(const spa_t *spa, dnode_phys_t *dn, char *path, size_t psize) +{ + int rc = 0; + + if (dn->dn_bonustype == DMU_OT_SA) { + sa_hdr_phys_t *sahdrp = NULL; + size_t size = 0; + void *buf = NULL; + int hdrsize; + char *p; + + if (dn->dn_bonuslen != 0) + sahdrp = (sa_hdr_phys_t *)DN_BONUS(dn); + else { + blkptr_t *bp; + + if ((dn->dn_flags & DNODE_FLAG_SPILL_BLKPTR) == 0) + return (EIO); + bp = &dn->dn_spill; + + size = BP_GET_LSIZE(bp); + buf = zfs_alloc(size); + rc = zio_read(spa, bp, buf); + if (rc != 0) { + zfs_free(buf, size); + return (rc); + } + sahdrp = buf; + } + hdrsize = SA_HDR_SIZE(sahdrp); + p = (char *)((uintptr_t)sahdrp + hdrsize + SA_SYMLINK_OFFSET); + memcpy(path, p, psize); + if (buf != NULL) + zfs_free(buf, size); + return (0); + } + /* + * Second test is purely to silence bogus compiler + * warning about accessing past the end of dn_bonus. + */ + if (psize + sizeof(znode_phys_t) <= dn->dn_bonuslen && + sizeof(znode_phys_t) <= sizeof(dn->dn_bonus)) { + memcpy(path, &dn->dn_bonus[sizeof(znode_phys_t)], psize); + } else { + rc = dnode_read(spa, dn, 0, path, psize); + } + return (rc); +} + +struct obj_list { + uint64_t objnum; + STAILQ_ENTRY(obj_list) entry; +}; + /* * Lookup a file and return its dnode. */ @@ -2149,7 +2204,7 @@ static int zfs_lookup(const struct zfsmount *mount, const char *upath, dnode_phys_t *dnode) { int rc; - uint64_t objnum, rootnum, parentnum; + uint64_t objnum; const spa_t *spa; dnode_phys_t dn; const char *p, *q; @@ -2157,6 +2212,8 @@ zfs_lookup(const struct zfsmount *mount, const char *u char path[1024]; int symlinks_followed = 0; struct stat sb; + struct obj_list *entry; + STAILQ_HEAD(, obj_list) on_cache = STAILQ_HEAD_INITIALIZER(on_cache); spa = mount->spa; if (mount->objset.os_type != DMU_OST_ZFS) { @@ -2165,102 +2222,145 @@ zfs_lookup(const struct zfsmount *mount, const char *u return (EIO); } + if ((entry = malloc(sizeof(struct obj_list))) == NULL) + return (ENOMEM); + /* * Get the root directory dnode. */ rc = objset_get_dnode(spa, &mount->objset, MASTER_NODE_OBJ, &dn); - if (rc) + if (rc) { + free(entry); return (rc); + } rc = zap_lookup(spa, &dn, ZFS_ROOT_OBJ, &rootnum); - if (rc) + if (rc) { + free(entry); return (rc); + } + entry->objnum = objnum; + STAILQ_INSERT_HEAD(&on_cache, entry, entry); - rc = objset_get_dnode(spa, &mount->objset, rootnum, &dn); - if (rc) - return (rc); + rc = objset_get_dnode(spa, &mount->objset, objnum, &dn); + if (rc != 0) + goto done; - objnum = rootnum; p = upath; while (p && *p) { + rc = objset_get_dnode(spa, &mount->objset, objnum, &dn); + if (rc != 0) + goto done; + while (*p == '/') p++; - if (!*p) + if (*p == '\0') break; - q = strchr(p, '/'); - if (q) { - memcpy(element, p, q - p); - element[q - p] = 0; - p = q; - } else { - strcpy(element, p); - p = NULL; + q = p; + while (*q != '\0' && *q != '/') + q++; + + /* skip dot */ + if (p + 1 == q && p[0] == '.') { + p++; + continue; } + /* double dot */ + if (p + 2 == q && p[0] == '.' && p[1] == '.') { + p += 2; + if (STAILQ_FIRST(&on_cache) == + STAILQ_LAST(&on_cache, obj_list, entry)) { + rc = ENOENT; + goto done; + } + entry = STAILQ_FIRST(&on_cache); + STAILQ_REMOVE_HEAD(&on_cache, entry); + free(entry); + objnum = (STAILQ_FIRST(&on_cache))->objnum; + continue; + } + if (q - p + 1 > sizeof(element)) { + rc = ENAMETOOLONG; + goto done; + } + memcpy(element, p, q - p); + element[q - p] = 0; + p = q; - rc = zfs_dnode_stat(spa, &dn, &sb); - if (rc) - return (rc); - if (!S_ISDIR(sb.st_mode)) - return (ENOTDIR); + if ((rc = zfs_dnode_stat(spa, &dn, &sb)) != 0) + goto done; + if (!S_ISDIR(sb.st_mode)) { + rc = ENOTDIR; + goto done; + } - parentnum = objnum; rc = zap_lookup(spa, &dn, element, &objnum); if (rc) - return (rc); + goto done; objnum = ZFS_DIRENT_OBJ(objnum); + if ((entry = malloc(sizeof(struct obj_list))) == NULL) { + rc = ENOMEM; + goto done; + } + entry->objnum = objnum; + STAILQ_INSERT_HEAD(&on_cache, entry, entry); rc = objset_get_dnode(spa, &mount->objset, objnum, &dn); if (rc) - return (rc); + goto done; /* * Check for symlink. */ rc = zfs_dnode_stat(spa, &dn, &sb); if (rc) - return (rc); + goto done; if (S_ISLNK(sb.st_mode)) { - if (symlinks_followed > 10) - return (EMLINK); + if (symlinks_followed > 10) { + rc = EMLINK; + goto done; + } symlinks_followed++; /* * Read the link value and copy the tail of our * current path onto the end. */ - if (p) - strcpy(&path[sb.st_size], p); - else - path[sb.st_size] = 0; - /* - * Second test is purely to silence bogus compiler - * warning about accessing past the end of dn_bonus. - */ - if (sb.st_size + sizeof(znode_phys_t) <= - dn.dn_bonuslen && sizeof(znode_phys_t) <= - sizeof(dn.dn_bonus)) { - memcpy(path, &dn.dn_bonus[sizeof(znode_phys_t)], - sb.st_size); - } else { - rc = dnode_read(spa, &dn, 0, path, sb.st_size); - if (rc) - return (rc); + if (sb.st_size + strlen(p) + 1 > sizeof(path)) { + rc = ENAMETOOLONG; + goto done; } + strcpy(&path[sb.st_size], p); + rc = zfs_dnode_readlink(spa, &dn, path, sb.st_size); + if (rc != 0) + goto done; + /* * Restart with the new path, starting either at * the root or at the parent depending whether or * not the link is relative. */ p = path; - if (*p == '/') - objnum = rootnum; - else - objnum = parentnum; - objset_get_dnode(spa, &mount->objset, objnum, &dn); + if (*p == '/') { + while (STAILQ_FIRST(&on_cache) != + STAILQ_LAST(&on_cache, obj_list, entry)) { + entry = STAILQ_FIRST(&on_cache); + STAILQ_REMOVE_HEAD(&on_cache, entry); + free(entry); + } + } else { + entry = STAILQ_FIRST(&on_cache); + STAILQ_REMOVE_HEAD(&on_cache, entry); + free(entry); + } + objnum = (STAILQ_FIRST(&on_cache))->objnum; } } *dnode = dn; - return (0); +done: + STAILQ_FOREACH(entry, &on_cache, entry) + free(entry); + return (rc); } Modified: stable/11/sys/cddl/boot/zfs/zfsimpl.h ============================================================================== --- stable/11/sys/cddl/boot/zfs/zfsimpl.h Wed Jul 26 15:24:17 2017 (r321524) +++ stable/11/sys/cddl/boot/zfs/zfsimpl.h Wed Jul 26 15:29:56 2017 (r321525) @@ -1070,6 +1070,7 @@ typedef struct sa_hdr_phys { #define SA_UID_OFFSET 24 #define SA_GID_OFFSET 32 #define SA_PARENT_OFFSET 40 +#define SA_SYMLINK_OFFSET 160 /* * Intent log header - this on disk structure holds fields to manage _______________________________________________ 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"
