From patchwork Tue Mar 8 04:47:07 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shirish Pargaonkar X-Patchwork-Id: 617251 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p284iwv4023252 for ; Tue, 8 Mar 2011 04:44:58 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756258Ab1CHEo5 (ORCPT ); Mon, 7 Mar 2011 23:44:57 -0500 Received: from mail-qy0-f181.google.com ([209.85.216.181]:64284 "EHLO mail-qy0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754050Ab1CHEo5 (ORCPT ); Mon, 7 Mar 2011 23:44:57 -0500 Received: by qyg14 with SMTP id 14so4362916qyg.19 for ; Mon, 07 Mar 2011 20:44:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:from:to:cc:subject:date:message-id:x-mailer; bh=Y5OsTgwbOxGHHxDgSWNeJdD/5TNm9Imac2AfA+jQxDQ=; b=PcAPYWQBn8PfL99vlvDfQqqGcf26z9+eUOhIDktgfd/7pZ77CweOxgvSHCwNNYyqEl Z9fXZiN4rO/ojcTm5BV2CwWz5BAjPFVoWtyEZ9HHuXOlWhVN38lVJaMonONaVeVJeA9a EDTnL3HEv3x4TtPSD39vhyod3B50e1DTLmbgg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=gbE6Oi9EkxHgGPnEsk9kDOk9L+Zew/IPI7NADBW3nH7Bcrg2YinsbC6hO9S5QVV3Ux ZldGlYcFLmfktqZErP++xJ89QLXsjhEXdHRQdAC1bcZ9ApoOrR8730Cmna1K1bURPWNd chanWM/zfNPDrzwa0Lk9fgvTYM0FhDlp6DPpo= Received: by 10.229.111.223 with SMTP id t31mr3517448qcp.122.1299559496462; Mon, 07 Mar 2011 20:44:56 -0800 (PST) Received: from localhost ([32.97.110.58]) by mx.google.com with ESMTPS id y17sm290477qci.45.2011.03.07.20.44.55 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 07 Mar 2011 20:44:56 -0800 (PST) From: shirishpargaonkar@gmail.com To: smfrench@gmail.com Cc: linux-cifs@vger.kernel.org, Shirish Pargaonkar Subject: [PATCH 2/2] cifs: Invoke id mapping functions (try #8) Date: Mon, 7 Mar 2011 22:47:07 -0600 Message-Id: <1299559627-15554-1-git-send-email-shirishpargaonkar@gmail.com> X-Mailer: git-send-email 1.6.0.2 Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Tue, 08 Mar 2011 04:44:58 +0000 (UTC) diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c index fc1ec64..e560b04 100644 --- a/fs/cifs/cifsacl.c +++ b/fs/cifs/cifsacl.c @@ -54,7 +54,31 @@ static const struct cifs_sid sid_authusers = { /* group users */ static const struct cifs_sid sid_user = {1, 2 , {0, 0, 0, 0, 0, 5}, {} }; -static const struct cred *root_cred; +const struct cred *root_cred; + +void +shrink_idmap(struct rb_root *root, int nr_to_scan, int *nr_rem) +{ + int nr_del = 0; + struct rb_node *node; + struct rb_node *tmp; + struct cifs_sid_id *psidid; + + node = rb_first(root); + while (node) { + tmp = node; + node = rb_next(tmp); + psidid = rb_entry(tmp, struct cifs_sid_id, rbnode); + if (time_after(psidid->time + SID_MAP_EXPIRE, jiffies) || + test_bit(SID_ID_PENDING, &psidid->state) || + (nr_to_scan == 0) || (nr_del == nr_to_scan)) + ++(*nr_rem); + else { + rb_erase(tmp, root); + ++nr_del; + } + } +} /* * Run idmap cache shrinker. @@ -62,11 +86,23 @@ static const struct cred *root_cred; static int cifs_idmap_shrinker(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask) { - /* Use a pruning scheme in a subsequent patch instead */ - cifs_destroy_idmaptrees(); - return 0; + int nr_rem = 0; + struct rb_root *root; + + root = &uidtree; + spin_lock(&siduidlock); + shrink_idmap(root, nr_to_scan, &nr_rem); + spin_unlock(&siduidlock); + + root = &gidtree; + spin_lock(&sidgidlock); + shrink_idmap(root, nr_to_scan, &nr_rem); + spin_unlock(&sidgidlock); + + return nr_rem; } + static struct shrinker cifs_shrinker = { .shrink = cifs_idmap_shrinker, .seeks = DEFAULT_SEEKS, @@ -92,7 +128,6 @@ cifs_idmap_key_destroy(struct key *key) kfree(key->payload.data); } -static struct key_type cifs_idmap_key_type = { .name = "cifs.cifs_idmap", .instantiate = cifs_idmap_key_instantiate, @@ -101,6 +136,192 @@ struct key_type cifs_idmap_key_type = { .match = user_match, }; +static int +id_rb_search_insert(struct rb_root *root, struct cifs_sid *sidptr, + struct cifs_sid_id **psidid, struct cifs_sid_id **epsidid) +{ + int rc = 1; + struct rb_node *node = root->rb_node; + struct rb_node *parent = NULL; + struct rb_node **linkto = &(root->rb_node); + + while (node) { + *epsidid = rb_entry(node, struct cifs_sid_id, rbnode); + parent = node; + rc = compare_sids(sidptr, &((*epsidid)->sid)); + if (rc > 0) { + linkto = &(node->rb_left); + node = node->rb_left; + } else if (rc < 0) { + linkto = &(node->rb_right); + node = node->rb_right; + } else { /* node found */ + if (test_bit(SID_ID_UNMAPPED, &(*epsidid)->state) && + !time_after((*epsidid)->retry + SID_MAP_RETRY, + jiffies)) { + /* retry mapping this unmapped SID */ + if (!test_and_set_bit(SID_ID_PENDING, + &(*epsidid)->state)) + return 1; + } + /* + * Found a node with either SID mapped to an id + * or a node with unmapped SID but somebody else + * get to map it. + */ + return 0; + } + } + *epsidid = NULL; + + if (rc) { /* node not found, rc is not 0 */ + memcpy(&(*psidid)->sid, sidptr, sizeof(struct cifs_sid)); + set_bit(SID_ID_PENDING, &(*psidid)->state); + set_bit(SID_ID_UNMAPPED, &(*psidid)->state); + + rb_link_node(&(*psidid)->rbnode, parent, linkto); + rb_insert_color(&(*psidid)->rbnode, root); + } + + return rc; +} + +static void +sid_to_str(struct cifs_sid *sidptr, char *sidstr) +{ + int i; + unsigned long saval; + char *strptr; + + strptr = sidstr; + + sprintf(strptr, "%s", "S"); + strptr = sidstr + strlen(sidstr); + + sprintf(strptr, "-%d", sidptr->revision); + strptr = sidstr + strlen(sidstr); + + for (i = 0; i < 6; ++i) { + if (sidptr->authority[i]) { + sprintf(strptr, "-%d", sidptr->authority[i]); + strptr = sidstr + strlen(sidstr); + } + } + + for (i = 0; i < sidptr->num_subauth; ++i) { + saval = le32_to_cpu(sidptr->sub_auth[i]); + sprintf(strptr, "-%ld", saval); + strptr = sidstr + strlen(sidstr); + } +} + +static int +cifs_sid_pending_wait(void *unused) +{ + schedule(); + return signal_pending(current) ? -ERESTARTSYS : 0; +} + +static int +sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid, + struct cifs_fattr *fattr, uint sidtype) +{ + int rc; + unsigned long id; + char *strptr; + char *sidstr; + struct key *idkey; + const struct cred *saved_cred; + struct cifs_sid_id *psidid; + struct cifs_sid_id *epsidid = NULL; + + if (sidtype != SIDOWNER && sidtype != SIDGROUP) + return -ENOENT; + + psidid = kzalloc(sizeof(struct cifs_sid_id), GFP_KERNEL); + if (!psidid) + return -ENOMEM; + + if (sidtype == SIDOWNER) { + id = cifs_sb->mnt_uid; + spin_lock(&siduidlock); + rc = id_rb_search_insert(&uidtree, psid, &psidid, &epsidid); + spin_unlock(&siduidlock); + } else { + id = cifs_sb->mnt_gid; + spin_lock(&sidgidlock); + rc = id_rb_search_insert(&gidtree, psid, &psidid, &epsidid); + spin_unlock(&sidgidlock); + } + + if (!epsidid) + epsidid = psidid; + else + kfree(psidid); + + if (rc) { + sidstr = kzalloc(SIDLEN, GFP_KERNEL); + if (!sidstr) + rc = -ENOMEM; + + /* + * either a new node was created or an existing node + * does not have a SID mapped to an id, so make an upcall. + */ + if (sidtype == SIDOWNER) + sprintf(sidstr, "%s", "os:"); + else if (sidtype == SIDGROUP) + sprintf(sidstr, "%s", "gs:"); + + strptr = sidstr + strlen(sidstr); + sid_to_str(psid, strptr); + + saved_cred = override_creds(root_cred); + idkey = request_key(&cifs_idmap_key_type, sidstr, ""); + if (IS_ERR(idkey)) + cFYI(1, "%s: Can't map SID to an id", __func__); + else { + id = *(unsigned long *)idkey->payload.value; + key_put(idkey); + clear_bit(SID_ID_UNMAPPED, &psidid->state); + } + epsidid->time = jiffies; + epsidid->retry = jiffies; + epsidid->id = id; + clear_bit(SID_ID_PENDING, &epsidid->state); + revert_creds(saved_cred); + kfree(sidstr); + rc = 0; + } else { + /* + * eitehr an existing node with SID mapped or a node for + * whom its SID is being mapped (in which case, wait). + */ + rc = wait_on_bit(&epsidid->state, SID_ID_PENDING, + cifs_sid_pending_wait, TASK_INTERRUPTIBLE); + if (rc) { + cERROR(1, "%s: cifs_sid_pending_wait interrupted %d", + __func__, rc); + return rc; + } + + /* + * No point in checking whether state has bit SID_ID_UNMAPPED + * set. If SID_ID_UNMAPPED state bit is not set, upcall must + * have returned an error. No point in making an upcall here + * again right away, it is likely to fail. + */ + id = epsidid->id; + } + + if (sidtype == SIDOWNER) + fattr->cf_uid = id; + else + fattr->cf_gid = id; + + return 0; +} + int init_cifs_idmap(void) { @@ -242,16 +463,24 @@ int compare_sids(const struct cifs_sid *ctsid, const struct cifs_sid *cwsid) int num_subauth, num_sat, num_saw; if ((!ctsid) || (!cwsid)) - return 0; + return 1; /* compare the revision */ - if (ctsid->revision != cwsid->revision) - return 0; + if (ctsid->revision != cwsid->revision) { + if (ctsid->revision > cwsid->revision) + return 1; + else + return -1; + } /* compare all of the six auth values */ for (i = 0; i < 6; ++i) { - if (ctsid->authority[i] != cwsid->authority[i]) - return 0; + if (ctsid->authority[i] != cwsid->authority[i]) { + if (ctsid->authority[i] > cwsid->authority[i]) + return 1; + else + return -1; + } } /* compare all of the subauth values if any */ @@ -260,12 +489,16 @@ int compare_sids(const struct cifs_sid *ctsid, const struct cifs_sid *cwsid) num_subauth = num_sat < num_saw ? num_sat : num_saw; if (num_subauth) { for (i = 0; i < num_subauth; ++i) { - if (ctsid->sub_auth[i] != cwsid->sub_auth[i]) - return 0; + if (ctsid->sub_auth[i] != cwsid->sub_auth[i]) { + if (ctsid->sub_auth[i] > cwsid->sub_auth[i]) + return 1; + else + return -1; + } } } - return 1; /* sids compare/match */ + return 0; /* sids compare/match */ } @@ -520,22 +753,22 @@ static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl, #ifdef CONFIG_CIFS_DEBUG2 dump_ace(ppace[i], end_of_acl); #endif - if (compare_sids(&(ppace[i]->sid), pownersid)) + if (compare_sids(&(ppace[i]->sid), pownersid) == 0) access_flags_to_mode(ppace[i]->access_req, ppace[i]->type, &fattr->cf_mode, &user_mask); - if (compare_sids(&(ppace[i]->sid), pgrpsid)) + if (compare_sids(&(ppace[i]->sid), pgrpsid) == 0) access_flags_to_mode(ppace[i]->access_req, ppace[i]->type, &fattr->cf_mode, &group_mask); - if (compare_sids(&(ppace[i]->sid), &sid_everyone)) + if (compare_sids(&(ppace[i]->sid), &sid_everyone) == 0) access_flags_to_mode(ppace[i]->access_req, ppace[i]->type, &fattr->cf_mode, &other_mask); - if (compare_sids(&(ppace[i]->sid), &sid_authusers)) + if (compare_sids(&(ppace[i]->sid), &sid_authusers) == 0) access_flags_to_mode(ppace[i]->access_req, ppace[i]->type, &fattr->cf_mode, @@ -613,10 +846,10 @@ static int parse_sid(struct cifs_sid *psid, char *end_of_acl) /* Convert CIFS ACL to POSIX form */ -static int parse_sec_desc(struct cifs_ntsd *pntsd, int acl_len, - struct cifs_fattr *fattr) +static int parse_sec_desc(struct cifs_sb_info *cifs_sb, + struct cifs_ntsd *pntsd, int acl_len, struct cifs_fattr *fattr) { - int rc; + int rc = 0; struct cifs_sid *owner_sid_ptr, *group_sid_ptr; struct cifs_acl *dacl_ptr; /* no need for SACL ptr */ char *end_of_acl = ((char *)pntsd) + acl_len; @@ -638,12 +871,26 @@ static int parse_sec_desc(struct cifs_ntsd *pntsd, int acl_len, le32_to_cpu(pntsd->sacloffset), dacloffset); /* cifs_dump_mem("owner_sid: ", owner_sid_ptr, 64); */ rc = parse_sid(owner_sid_ptr, end_of_acl); - if (rc) + if (rc) { + cFYI(1, "%s: Error %d parsing Owner SID", __func__, rc); + return rc; + } + rc = sid_to_id(cifs_sb, owner_sid_ptr, fattr, SIDOWNER); + if (rc) { + cFYI(1, "%s: Error %d mapping Owner SID to uid", __func__, rc); return rc; + } rc = parse_sid(group_sid_ptr, end_of_acl); - if (rc) + if (rc) { + cFYI(1, "%s: Error %d mapping Owner SID to gid", __func__, rc); return rc; + } + rc = sid_to_id(cifs_sb, group_sid_ptr, fattr, SIDGROUP); + if (rc) { + cFYI(1, "%s: Error %d mapping Group SID to gid", __func__, rc); + return rc; + } if (dacloffset) parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr, @@ -658,7 +905,7 @@ static int parse_sec_desc(struct cifs_ntsd *pntsd, int acl_len, memcpy((void *)(&(cifscred->gsid)), (void *)group_sid_ptr, sizeof(struct cifs_sid)); */ - return 0; + return rc; } @@ -865,7 +1112,7 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr, rc = PTR_ERR(pntsd); cERROR(1, "%s: error %d getting sec desc", __func__, rc); } else { - rc = parse_sec_desc(pntsd, acllen, fattr); + rc = parse_sec_desc(cifs_sb, pntsd, acllen, fattr); kfree(pntsd); if (rc) cERROR(1, "parse sec desc failed rc = %d", rc); diff --git a/fs/cifs/cifsacl.h b/fs/cifs/cifsacl.h index 025e943..5f075c0 100644 --- a/fs/cifs/cifsacl.h +++ b/fs/cifs/cifsacl.h @@ -39,6 +39,15 @@ #define ACCESS_ALLOWED 0 #define ACCESS_DENIED 1 +#define SIDOWNER 1 +#define SIDGROUP 2 +#define SIDLEN 150 /* S- 1 revision- 6 authorities- max 5 sub authorities */ + +#define SID_ID_PENDING 0 +#define SID_ID_UNMAPPED 1 +#define SID_MAP_EXPIRE 1000 /* enough for an upcall to return? */ +#define SID_MAP_RETRY 100 /* retry mapping in case prior attempt failed */ + struct cifs_ntsd { __le16 revision; /* revision level */ __le16 type; @@ -74,6 +83,20 @@ struct cifs_wksid { char sidname[SIDNAMELENGTH]; } __attribute__((packed)); +struct cifs_sid_id { + struct rb_node rbnode; + struct cifs_sid sid; + unsigned long state; + unsigned long id; + unsigned long time; + unsigned long retry; +}; + +#ifdef __KERNEL__ +extern struct key_type cifs_idmap_key_type; +extern const struct cred *root_cred; +#endif /* KERNEL */ + extern int match_sid(struct cifs_sid *); extern int compare_sids(const struct cifs_sid *, const struct cifs_sid *);