diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c
index e20f8880363fab1c34a6e69c6a802761c148b89f..ac86bd0ebd637bc2d1440c3f2858489ed27b5364 100644
--- a/fs/cifs/dfs_cache.c
+++ b/fs/cifs/dfs_cache.c
@@ -269,7 +269,7 @@ static int dfscache_proc_show(struct seq_file *m, void *v)
list_for_each_entry(t, &ce->tlist, list) {
seq_printf(m, " %s%s\n",
t->name,
- ce->tgthint == t ? " (target hint)" : "");
+ READ_ONCE(ce->tgthint) == t ? " (target hint)" : "");
}
}
}
@@ -321,7 +321,7 @@ static inline void dump_tgts(const struct cache_entry *ce)
cifs_dbg(FYI, "target list:\n");
list_for_each_entry(t, &ce->tlist, list) {
cifs_dbg(FYI, " %s%s\n", t->name,
- ce->tgthint == t ? " (target hint)" : "");
+ READ_ONCE(ce->tgthint) == t ? " (target hint)" : "");
}
}
@@ -427,7 +427,7 @@ static int cache_entry_hash(const void *data, int size, unsigned int *hash)
/* Return target hint of a DFS cache entry */
static inline char *get_tgt_name(const struct cache_entry *ce)
{
- struct cache_dfs_tgt *t = ce->tgthint;
+ struct cache_dfs_tgt *t = READ_ONCE(ce->tgthint);
return t ? t->name : ERR_PTR(-ENOENT);
}
@@ -470,6 +470,7 @@ static struct cache_dfs_tgt *alloc_target(const char *name, int path_consumed)
static int copy_ref_data(const struct dfs_info3_param *refs, int numrefs,
struct cache_entry *ce, const char *tgthint)
{
+ struct cache_dfs_tgt *target;
int i;
ce->ttl = max_t(int, refs[0].ttl, CACHE_MIN_TTL);
@@ -496,8 +497,9 @@ static int copy_ref_data(const struct dfs_info3_param *refs, int numrefs,
ce->numtgts++;
}
- ce->tgthint = list_first_entry_or_null(&ce->tlist,
- struct cache_dfs_tgt, list);
+ target = list_first_entry_or_null(&ce->tlist, struct cache_dfs_tgt,
+ list);
+ WRITE_ONCE(ce->tgthint, target);
return 0;
}
@@ -558,7 +560,8 @@ static void remove_oldest_entry_locked(void)
}
/* Add a new DFS cache entry */
-static int add_cache_entry_locked(struct dfs_info3_param *refs, int numrefs)
+static struct cache_entry *add_cache_entry_locked(struct dfs_info3_param *refs,
+ int numrefs)
{
int rc;
struct cache_entry *ce;
@@ -573,11 +576,11 @@ static int add_cache_entry_locked(struct dfs_info3_param *refs, int numrefs)
rc = cache_entry_hash(refs[0].path_name, strlen(refs[0].path_name), &hash);
if (rc)
- return rc;
+ return ERR_PTR(rc);
ce = alloc_cache_entry(refs, numrefs);
if (IS_ERR(ce))
- return PTR_ERR(ce);
+ return ce;
spin_lock(&cache_ttl_lock);
if (!cache_ttl) {
@@ -594,7 +597,7 @@ static int add_cache_entry_locked(struct dfs_info3_param *refs, int numrefs)
atomic_inc(&cache_count);
- return 0;
+ return ce;
}
/* Check if two DFS paths are equal. @s1 and @s2 are expected to be in @cache_cp's charset */
@@ -641,7 +644,9 @@ static struct cache_entry *__lookup_cache_entry(const char *path, unsigned int h
*
* Use whole path components in the match. Must be called with htable_rw_lock held.
*
+ * Return cached entry if successful.
* Return ERR_PTR(-ENOENT) if the entry is not found.
+ * Return error ptr otherwise.
*/
static struct cache_entry *lookup_cache_entry(const char *path)
{
@@ -711,14 +716,15 @@ void dfs_cache_destroy(void)
static int update_cache_entry_locked(struct cache_entry *ce, const struct dfs_info3_param *refs,
int numrefs)
{
+ struct cache_dfs_tgt *target;
+ char *th = NULL;
int rc;
- char *s, *th = NULL;
WARN_ON(!rwsem_is_locked(&htable_rw_lock));
- if (ce->tgthint) {
- s = ce->tgthint->name;
- th = kstrdup(s, GFP_ATOMIC);
+ target = READ_ONCE(ce->tgthint);
+ if (target) {
+ th = kstrdup(target->name, GFP_ATOMIC);
if (!th)
return -ENOMEM;
}
@@ -767,51 +773,75 @@ static int get_dfs_referral(const unsigned int xid, struct cifs_ses *ses, const
*
* For interlinks, cifs_mount() and expand_dfs_referral() are supposed to
* handle them properly.
+ *
+ * On success, return entry with acquired lock for reading, otherwise error ptr.
*/
-static int cache_refresh_path(const unsigned int xid, struct cifs_ses *ses, const char *path)
+static struct cache_entry *cache_refresh_path(const unsigned int xid,
+ struct cifs_ses *ses,
+ const char *path,
+ bool force_refresh)
{
- int rc;
- struct cache_entry *ce;
struct dfs_info3_param *refs = NULL;
+ struct cache_entry *ce;
int numrefs = 0;
- bool newent = false;
+ int rc;
cifs_dbg(FYI, "%s: search path: %s\n", __func__, path);
- down_write(&htable_rw_lock);
+ down_read(&htable_rw_lock);
ce = lookup_cache_entry(path);
if (!IS_ERR(ce)) {
- if (!cache_entry_expired(ce)) {
- dump_ce(ce);
- up_write(&htable_rw_lock);
- return 0;
- }
- } else {
- newent = true;
+ if (!force_refresh && !cache_entry_expired(ce))
+ return ce;
+ } else if (PTR_ERR(ce) != -ENOENT) {
+ up_read(&htable_rw_lock);
+ return ce;
}
/*
- * Either the entry was not found, or it is expired.
+ * Unlock shared access as we don't want to hold any locks while getting
+ * a new referral. The @ses used for performing the I/O could be
+ * reconnecting and it acquires @htable_rw_lock to look up the dfs cache
+ * in order to failover -- if necessary.
+ */
+ up_read(&htable_rw_lock);
+
+ /*
+ * Either the entry was not found, or it is expired, or it is a forced
+ * refresh.
* Request a new DFS referral in order to create or update a cache entry.
*/
rc = get_dfs_referral(xid, ses, path, &refs, &numrefs);
- if (rc)
- goto out_unlock;
+ if (rc) {
+ ce = ERR_PTR(rc);
+ goto out;
+ }
dump_refs(refs, numrefs);
- if (!newent) {
- rc = update_cache_entry_locked(ce, refs, numrefs);
- goto out_unlock;
+ down_write(&htable_rw_lock);
+ /* Re-check as another task might have it added or refreshed already */
+ ce = lookup_cache_entry(path);
+ if (!IS_ERR(ce)) {
+ if (force_refresh || cache_entry_expired(ce)) {
+ rc = update_cache_entry_locked(ce, refs, numrefs);
+ if (rc)
+ ce = ERR_PTR(rc);
+ }
+ } else if (PTR_ERR(ce) == -ENOENT) {
+ ce = add_cache_entry_locked(refs, numrefs);
}
- rc = add_cache_entry_locked(refs, numrefs);
+ if (IS_ERR(ce)) {
+ up_write(&htable_rw_lock);
+ goto out;
+ }
-out_unlock:
- up_write(&htable_rw_lock);
+ downgrade_write(&htable_rw_lock);
+out:
free_dfs_info_array(refs, numrefs);
- return rc;
+ return ce;
}
/*
@@ -878,7 +908,7 @@ static int get_targets(struct cache_entry *ce, struct dfs_cache_tgt_list *tl)
}
it->it_path_consumed = t->path_consumed;
- if (ce->tgthint == t)
+ if (READ_ONCE(ce->tgthint) == t)
list_add(&it->it_list, head);
else
list_add_tail(&it->it_list, head);
@@ -931,15 +961,8 @@ int dfs_cache_find(const unsigned int xid, struct cifs_ses *ses, const struct nl
if (IS_ERR(npath))
return PTR_ERR(npath);
- rc = cache_refresh_path(xid, ses, npath);
- if (rc)
- goto out_free_path;
-
- down_read(&htable_rw_lock);
-
- ce = lookup_cache_entry(npath);
+ ce = cache_refresh_path(xid, ses, npath, false);
if (IS_ERR(ce)) {
- up_read(&htable_rw_lock);
rc = PTR_ERR(ce);
goto out_free_path;
}
@@ -1002,72 +1025,6 @@ int dfs_cache_noreq_find(const char *path, struct dfs_info3_param *ref,
return rc;
}
-/**
- * dfs_cache_update_tgthint - update target hint of a DFS cache entry
- *
- * If it doesn't find the cache entry, then it will get a DFS referral for @path
- * and create a new entry.
- *
- * In case the cache entry exists but expired, it will get a DFS referral
- * for @path and then update the respective cache entry.
- *
- * @xid: syscall id
- * @ses: smb session
- * @cp: codepage
- * @remap: type of character remapping for paths
- * @path: path to lookup in DFS referral cache
- * @it: DFS target iterator
- *
- * Return zero if the target hint was updated successfully, otherwise non-zero.
- */
-int dfs_cache_update_tgthint(const unsigned int xid, struct cifs_ses *ses,
- const struct nls_table *cp, int remap, const char *path,
- const struct dfs_cache_tgt_iterator *it)
-{
- int rc;
- const char *npath;
- struct cache_entry *ce;
- struct cache_dfs_tgt *t;
-
- npath = dfs_cache_canonical_path(path, cp, remap);
- if (IS_ERR(npath))
- return PTR_ERR(npath);
-
- cifs_dbg(FYI, "%s: update target hint - path: %s\n", __func__, npath);
-
- rc = cache_refresh_path(xid, ses, npath);
- if (rc)
- goto out_free_path;
-
- down_write(&htable_rw_lock);
-
- ce = lookup_cache_entry(npath);
- if (IS_ERR(ce)) {
- rc = PTR_ERR(ce);
- goto out_unlock;
- }
-
- t = ce->tgthint;
-
- if (likely(!strcasecmp(it->it_name, t->name)))
- goto out_unlock;
-
- list_for_each_entry(t, &ce->tlist, list) {
- if (!strcasecmp(t->name, it->it_name)) {
- ce->tgthint = t;
- cifs_dbg(FYI, "%s: new target hint: %s\n", __func__,
- it->it_name);
- break;
- }
- }
-
-out_unlock:
- up_write(&htable_rw_lock);
-out_free_path:
- kfree(npath);
- return rc;
-}
-
/**
* dfs_cache_noreq_update_tgthint - update target hint of a DFS cache entry
* without sending any requests to the currently connected server.
@@ -1092,21 +1049,20 @@ void dfs_cache_noreq_update_tgthint(const char *path, const struct dfs_cache_tgt
cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
- if (!down_write_trylock(&htable_rw_lock))
- return;
+ down_read(&htable_rw_lock);
ce = lookup_cache_entry(path);
if (IS_ERR(ce))
goto out_unlock;
- t = ce->tgthint;
+ t = READ_ONCE(ce->tgthint);
if (unlikely(!strcasecmp(it->it_name, t->name)))
goto out_unlock;
list_for_each_entry(t, &ce->tlist, list) {
if (!strcasecmp(t->name, it->it_name)) {
- ce->tgthint = t;
+ WRITE_ONCE(ce->tgthint, t);
cifs_dbg(FYI, "%s: new target hint: %s\n", __func__,
it->it_name);
break;
@@ -1114,7 +1070,7 @@ void dfs_cache_noreq_update_tgthint(const char *path, const struct dfs_cache_tgt
}
out_unlock:
- up_write(&htable_rw_lock);
+ up_read(&htable_rw_lock);
}
/**
@@ -1320,35 +1276,37 @@ static bool target_share_equal(struct TCP_Server_Info *server, const char *s1, c
* Mark dfs tcon for reconnecting when the currently connected tcon does not match any of the new
* target shares in @refs.
*/
-static void mark_for_reconnect_if_needed(struct cifs_tcon *tcon, struct dfs_cache_tgt_list *tl,
- const struct dfs_info3_param *refs, int numrefs)
+static void mark_for_reconnect_if_needed(struct TCP_Server_Info *server,
+ struct dfs_cache_tgt_list *old_tl,
+ struct dfs_cache_tgt_list *new_tl)
{
- struct dfs_cache_tgt_iterator *it;
- int i;
-
- for (it = dfs_cache_get_tgt_iterator(tl); it; it = dfs_cache_get_next_tgt(tl, it)) {
- for (i = 0; i < numrefs; i++) {
- if (target_share_equal(tcon->ses->server, dfs_cache_get_tgt_name(it),
- refs[i].node_name))
+ struct dfs_cache_tgt_iterator *oit, *nit;
+
+ for (oit = dfs_cache_get_tgt_iterator(old_tl); oit;
+ oit = dfs_cache_get_next_tgt(old_tl, oit)) {
+ for (nit = dfs_cache_get_tgt_iterator(new_tl); nit;
+ nit = dfs_cache_get_next_tgt(new_tl, nit)) {
+ if (target_share_equal(server,
+ dfs_cache_get_tgt_name(oit),
+ dfs_cache_get_tgt_name(nit)))
return;
}
}
cifs_dbg(FYI, "%s: no cached or matched targets. mark dfs share for reconnect.\n", __func__);
- cifs_signal_cifsd_for_reconnect(tcon->ses->server, true);
+ cifs_signal_cifsd_for_reconnect(server, true);
}
/* Refresh dfs referral of tcon and mark it for reconnect if needed */
static int __refresh_tcon(const char *path, struct cifs_tcon *tcon, bool force_refresh)
{
- struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
+ struct dfs_cache_tgt_list old_tl = DFS_CACHE_TGT_LIST_INIT(old_tl);
+ struct dfs_cache_tgt_list new_tl = DFS_CACHE_TGT_LIST_INIT(new_tl);
struct cifs_ses *ses = CIFS_DFS_ROOT_SES(tcon->ses);
struct cifs_tcon *ipc = ses->tcon_ipc;
- struct dfs_info3_param *refs = NULL;
bool needs_refresh = false;
struct cache_entry *ce;
unsigned int xid;
- int numrefs = 0;
int rc = 0;
xid = get_xid();
@@ -1357,9 +1315,8 @@ static int __refresh_tcon(const char *path, struct cifs_tcon *tcon, bool force_r
ce = lookup_cache_entry(path);
needs_refresh = force_refresh || IS_ERR(ce) || cache_entry_expired(ce);
if (!IS_ERR(ce)) {
- rc = get_targets(ce, &tl);
- if (rc)
- cifs_dbg(FYI, "%s: could not get dfs targets: %d\n", __func__, rc);
+ rc = get_targets(ce, &old_tl);
+ cifs_dbg(FYI, "%s: get_targets: %d\n", __func__, rc);
}
up_read(&htable_rw_lock);
@@ -1376,26 +1333,18 @@ static int __refresh_tcon(const char *path, struct cifs_tcon *tcon, bool force_r
}
spin_unlock(&ipc->tc_lock);
- rc = get_dfs_referral(xid, ses, path, &refs, &numrefs);
- if (!rc) {
- /* Create or update a cache entry with the new referral */
- dump_refs(refs, numrefs);
-
- down_write(&htable_rw_lock);
- ce = lookup_cache_entry(path);
- if (IS_ERR(ce))
- add_cache_entry_locked(refs, numrefs);
- else if (force_refresh || cache_entry_expired(ce))
- update_cache_entry_locked(ce, refs, numrefs);
- up_write(&htable_rw_lock);
-
- mark_for_reconnect_if_needed(tcon, &tl, refs, numrefs);
+ ce = cache_refresh_path(xid, ses, path, true);
+ if (!IS_ERR(ce)) {
+ rc = get_targets(ce, &new_tl);
+ up_read(&htable_rw_lock);
+ cifs_dbg(FYI, "%s: get_targets: %d\n", __func__, rc);
+ mark_for_reconnect_if_needed(tcon->ses->server, &old_tl, &new_tl);
}
out:
free_xid(xid);
- dfs_cache_free_tgts(&tl);
- free_dfs_info_array(refs, numrefs);
+ dfs_cache_free_tgts(&old_tl);
+ dfs_cache_free_tgts(&new_tl);
return rc;
}
diff --git a/fs/cifs/dfs_cache.h b/fs/cifs/dfs_cache.h
index f7cff0be932747af2d4261272bae880d60ba6f00..be3b5a44cf82711a575e8efe70934f7e07109131 100644
--- a/fs/cifs/dfs_cache.h
+++ b/fs/cifs/dfs_cache.h
@@ -35,9 +35,6 @@ int dfs_cache_find(const unsigned int xid, struct cifs_ses *ses, const struct nl
struct dfs_cache_tgt_list *tgt_list);
int dfs_cache_noreq_find(const char *path, struct dfs_info3_param *ref,
struct dfs_cache_tgt_list *tgt_list);
-int dfs_cache_update_tgthint(const unsigned int xid, struct cifs_ses *ses,
- const struct nls_table *cp, int remap, const char *path,
- const struct dfs_cache_tgt_iterator *it);
void dfs_cache_noreq_update_tgthint(const char *path, const struct dfs_cache_tgt_iterator *it);
int dfs_cache_get_tgt_referral(const char *path, const struct dfs_cache_tgt_iterator *it,
struct dfs_info3_param *ref);
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 4b71f4a92f76cf42af8de2adb868b8507c576591..2c9ffa921e6f68db581c9ee8d4dc316d5e15ba45 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -4163,12 +4163,15 @@ smb2_readv_callback(struct mid_q_entry *mid)
(struct smb2_hdr *)rdata->iov[0].iov_base;
struct cifs_credits credits = { .value = 0, .instance = 0 };
struct smb_rqst rqst = { .rq_iov = &rdata->iov[1],
- .rq_nvec = 1,
- .rq_pages = rdata->pages,
- .rq_offset = rdata->page_offset,
- .rq_npages = rdata->nr_pages,
- .rq_pagesz = rdata->pagesz,
- .rq_tailsz = rdata->tailsz };
+ .rq_nvec = 1, };
+
+ if (rdata->got_bytes) {
+ rqst.rq_pages = rdata->pages;
+ rqst.rq_offset = rdata->page_offset;
+ rqst.rq_npages = rdata->nr_pages;
+ rqst.rq_pagesz = rdata->pagesz;
+ rqst.rq_tailsz = rdata->tailsz;
+ }
WARN_ONCE(rdata->server != mid->server,
"rdata server %p != mid server %p",