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net/smc: use mutex instead of rwlock_t to protect buffers

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The locks for sndbufs and rmbs are never used from atomic context. Using
a mutex for these locks will allow to nest locks with other mutexes.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Karsten Graul 2020-04-29 17:10:48 +02:00 committed by David S. Miller
parent ef79d439cd
commit faca536008
2 changed files with 13 additions and 13 deletions
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22
net/smc/smc_core.c
View file

@ -385,8 +385,8 @@ static int smc_lgr_create(struct smc_sock *smc, struct smc_init_info *ini)
lgr->freefast = 0;
lgr->freeing = 0;
lgr->vlan_id = ini->vlan_id;
rwlock_init(&lgr->sndbufs_lock);
rwlock_init(&lgr->rmbs_lock);
mutex_init(&lgr->sndbufs_lock);
mutex_init(&lgr->rmbs_lock);
rwlock_init(&lgr->conns_lock);
for (i = 0; i < SMC_RMBE_SIZES; i++) {
INIT_LIST_HEAD(&lgr->sndbufs[i]);
@ -456,9 +456,9 @@ static void smcr_buf_unuse(struct smc_buf_desc *rmb_desc,
}
if (rmb_desc->is_reg_err) {
/* buf registration failed, reuse not possible */
write_lock_bh(&lgr->rmbs_lock);
mutex_lock(&lgr->rmbs_lock);
list_del(&rmb_desc->list);
write_unlock_bh(&lgr->rmbs_lock);
mutex_unlock(&lgr->rmbs_lock);
smc_buf_free(lgr, true, rmb_desc);
} else {
@ -1059,19 +1059,19 @@ int smc_uncompress_bufsize(u8 compressed)
* buffer size; if not available, return NULL
*/
static struct smc_buf_desc *smc_buf_get_slot(int compressed_bufsize,
rwlock_t *lock,
struct mutex *lock,
struct list_head *buf_list)
{
struct smc_buf_desc *buf_slot;
read_lock_bh(lock);
mutex_lock(lock);
list_for_each_entry(buf_slot, buf_list, list) {
if (cmpxchg(&buf_slot->used, 0, 1) == 0) {
read_unlock_bh(lock);
mutex_unlock(lock);
return buf_slot;
}
}
read_unlock_bh(lock);
mutex_unlock(lock);
return NULL;
}
@ -1220,8 +1220,8 @@ static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
struct smc_link_group *lgr = conn->lgr;
struct list_head *buf_list;
int bufsize, bufsize_short;
struct mutex *lock; /* lock buffer list */
int sk_buf_size;
rwlock_t *lock;
if (is_rmb)
/* use socket recv buffer size (w/o overhead) as start value */
@ -1262,9 +1262,9 @@ static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
continue;
buf_desc->used = 1;
write_lock_bh(lock);
mutex_lock(lock);
list_add(&buf_desc->list, buf_list);
write_unlock_bh(lock);
mutex_unlock(lock);
break; /* found */
}

4
net/smc/smc_core.h
View file

@ -205,9 +205,9 @@ struct smc_link_group {
unsigned short vlan_id; /* vlan id of link group */
struct list_head sndbufs[SMC_RMBE_SIZES];/* tx buffers */
rwlock_t sndbufs_lock; /* protects tx buffers */
struct mutex sndbufs_lock; /* protects tx buffers */
struct list_head rmbs[SMC_RMBE_SIZES]; /* rx buffers */
rwlock_t rmbs_lock; /* protects rx buffers */
struct mutex rmbs_lock; /* protects rx buffers */
u8 id[SMC_LGR_ID_SIZE]; /* unique lgr id */
struct delayed_work free_work; /* delayed freeing of an lgr */