@@ -54,7 +54,33 @@ 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;
+
+static void
+shrink_idmap_tree(struct rb_root *root, int nr_to_scan, int *nr_rem,
+ int *nr_del)
+{
+ 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 (nr_to_scan == 0 || *nr_del == nr_to_scan)
+ ++(*nr_rem);
+ else {
+ if (time_after(jiffies, psidid->time + SID_MAP_EXPIRE)
+ && psidid->refcount == 0) {
+ rb_erase(tmp, root);
+ ++(*nr_del);
+ } else
+ ++(*nr_rem);
+ }
+ }
+}
/*
* Run idmap cache shrinker.
@@ -62,9 +88,21 @@ 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_del = 0;
+ int nr_rem = 0;
+ struct rb_root *root;
+
+ root = &uidtree;
+ spin_lock(&siduidlock);
+ shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del);
+ spin_unlock(&siduidlock);
+
+ root = &gidtree;
+ spin_lock(&sidgidlock);
+ shrink_idmap_tree(root, nr_to_scan, &nr_rem, &nr_del);
+ spin_unlock(&sidgidlock);
+
+ return nr_rem;
}
static struct shrinker cifs_shrinker = {
@@ -92,7 +130,6 @@ 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 +138,227 @@ struct key_type cifs_idmap_key_type = {
.match = user_match,
};
+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 void
+id_rb_insert(struct rb_root *root, struct cifs_sid *sidptr,
+ struct cifs_sid_id **psidid, char *typestr)
+{
+ int rc;
+ char *strptr;
+ struct rb_node *node = root->rb_node;
+ struct rb_node *parent = NULL;
+ struct rb_node **linkto = &(root->rb_node);
+ struct cifs_sid_id *lsidid;
+
+ while (node) {
+ lsidid = rb_entry(node, struct cifs_sid_id, rbnode);
+ parent = node;
+ rc = compare_sids(sidptr, &((lsidid)->sid));
+ if (rc > 0) {
+ linkto = &(node->rb_left);
+ node = node->rb_left;
+ } else if (rc < 0) {
+ linkto = &(node->rb_right);
+ node = node->rb_right;
+ }
+ }
+
+ memcpy(&(*psidid)->sid, sidptr, sizeof(struct cifs_sid));
+ (*psidid)->time = jiffies;
+ (*psidid)->retry = jiffies - (SID_MAP_RETRY + 1);
+ (*psidid)->refcount = 0;
+
+ sprintf((*psidid)->sidstr, "%s", typestr);
+ strptr = (*psidid)->sidstr + strlen((*psidid)->sidstr);
+ sid_to_str(&(*psidid)->sid, strptr);
+
+ clear_bit(SID_ID_PENDING, &(*psidid)->state);
+ clear_bit(SID_ID_MAPPED, &(*psidid)->state);
+
+ rb_link_node(&(*psidid)->rbnode, parent, linkto);
+ rb_insert_color(&(*psidid)->rbnode, root);
+}
+
+static struct cifs_sid_id *
+id_rb_search(struct rb_root *root, struct cifs_sid *sidptr)
+{
+ int rc;
+ struct rb_node *node = root->rb_node;
+ struct rb_node *parent = NULL;
+ struct rb_node **linkto = &(root->rb_node);
+ struct cifs_sid_id *lsidid;
+
+ while (node) {
+ lsidid = rb_entry(node, struct cifs_sid_id, rbnode);
+ parent = node;
+ rc = compare_sids(sidptr, &((lsidid)->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 */
+ return lsidid;
+ }
+
+ return NULL;
+}
+
+static int
+sidid_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 cid;
+ struct key *idkey;
+ const struct cred *saved_cred;
+ struct cifs_sid_id *psidid, *npsidid;
+ struct rb_root *cidtree;
+ spinlock_t *cidlock;
+
+ if (sidtype == SIDOWNER) {
+ cid = cifs_sb->mnt_uid; /* default uid, in case upcall fails */
+ cidlock = &siduidlock;
+ cidtree = &uidtree;
+ } else if (sidtype == SIDGROUP) {
+ cid = cifs_sb->mnt_gid; /* default gid, in case upcall fails */
+ cidlock = &sidgidlock;
+ cidtree = &gidtree;
+ } else
+ return -ENOENT;
+
+ spin_lock(cidlock);
+ psidid = id_rb_search(cidtree, psid);
+
+ if (!psidid) { /* node does not exist, allocate one & attempt adding */
+ spin_unlock(cidlock);
+ npsidid = kzalloc(sizeof(struct cifs_sid_id), GFP_KERNEL);
+ if (!npsidid)
+ return -ENOMEM;
+
+ npsidid->sidstr = kmalloc(SIDLEN, GFP_KERNEL);
+ if (!npsidid->sidstr) {
+ kfree(npsidid);
+ return -ENOMEM;
+ }
+
+ spin_lock(cidlock);
+ psidid = id_rb_search(cidtree, psid);
+ if (psidid) { /* node happened to get inserted meanwhile */
+ psidid->time = jiffies; /* update ts for accessing */
+ spin_unlock(cidlock);
+ kfree(npsidid->sidstr);
+ kfree(npsidid);
+ } else {
+ psidid = npsidid;
+ id_rb_insert(cidtree, psid, &psidid,
+ sidtype == SIDOWNER ? "os:" : "gs:");
+ spin_unlock(cidlock);
+ }
+ } else {
+ psidid->time = jiffies; /* update ts for accessing */
+ spin_unlock(cidlock);
+ }
+
+ /*
+ * At this point, psidid is a valid pointer, we just updated
+ * its timestamp inside a spinlock, shrinker will not erase this node.
+ */
+ if (test_bit(SID_ID_MAPPED, &psidid->state)) {
+ cid = psidid->id;
+ goto sid_to_id_out; /* SID mapped */
+ }
+
+ if (time_after(psidid->retry + SID_MAP_RETRY, jiffies))
+ goto sid_to_id_out; /* wait before re-attempting SID mapping */
+
+ /*
+ * Shrinker could be accessing this entry but it will not
+ * get erased at this point in time and to make it stay further,
+ * pretty soon we will take a reference on it only to
+ * release the reference only after upcall returns (or we are
+ * woken up), however longer that upcall may take to return.
+ */
+ if (!test_and_set_bit(SID_ID_PENDING, &psidid->state)) {
+ /* paidid and its fields are being accessed sans spinlock */
+ ++psidid->refcount;
+ saved_cred = override_creds(root_cred);
+ idkey = request_key(&cifs_idmap_key_type, psidid->sidstr, "");
+ if (IS_ERR(idkey)) {
+ psidid->retry = jiffies;
+ cFYI(1, "%s: Can't map SID to an id", __func__);
+ } else {
+ cid = *(unsigned long *)idkey->payload.value;
+ psidid->id = cid;
+ set_bit(SID_ID_MAPPED, &psidid->state);
+ key_put(idkey);
+ kfree(psidid->sidstr);
+ }
+ revert_creds(saved_cred);
+ clear_bit(SID_ID_PENDING, &psidid->state);
+ wake_up_bit(&psidid->state, SID_ID_PENDING);
+ --psidid->refcount;
+ } else {
+ /* paidid and its fields are being accessed sans spinlock */
+ ++psidid->refcount;
+ rc = wait_on_bit(&psidid->state, SID_ID_PENDING,
+ sidid_pending_wait, TASK_INTERRUPTIBLE);
+ if (rc) {
+ cFYI(1, "%s: sidid_pending_wait interrupted %d",
+ __func__, rc);
+ --psidid->refcount;
+ return rc;
+ }
+ if (test_bit(SID_ID_MAPPED, &psidid->state))
+ cid = psidid->id;
+ --psidid->refcount;
+ }
+
+sid_to_id_out:
+ if (sidtype == SIDOWNER)
+ fattr->cf_uid = cid;
+ else
+ fattr->cf_gid = cid;
+
+ return 0;
+}
+
int
init_cifs_idmap(void)
{
@@ -242,16 +500,24 @@ 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 +526,16 @@ 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 +790,22 @@ 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 +883,10 @@ 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 +908,26 @@ 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 +942,7 @@ 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 +1149,7 @@ 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);
@@ -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_MAPPED 0
+#define SID_ID_PENDING 1
+#define SID_MAP_EXPIRE (3600 * HZ) /* map entry expires after one hour */
+#define SID_MAP_RETRY (300 * HZ) /* wait 5 minutes for next attempt to map */
+
struct cifs_ntsd {
__le16 revision; /* revision level */
__le16 type;
@@ -74,6 +83,22 @@ struct cifs_wksid {
char sidname[SIDNAMELENGTH];
} __attribute__((packed));
+struct cifs_sid_id {
+ unsigned int refcount;
+ unsigned long id;
+ unsigned long time;
+ unsigned long retry;
+ unsigned long state;
+ char *sidstr;
+ struct rb_node rbnode;
+ struct cifs_sid sid;
+};
+
+#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 *);