orangefs: hopefully saner op refcounting and locking

* create with refcount 1
* make op_release() decrement and free if zero (i.e. old put_op()
  has become that).
* mark when submitter has given up waiting; from that point nobody
  else can move between the lists, change state, etc.
* have daemon read/write_iter grab a reference when picking op
  and *always* give it up in the end
* don't put into hash until we know it's been successfully passed to
  daemon

* move op->lock _lower_ than htab_in_progress_lock (and make sure
  to take it in purge_inprogress_ops())

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
This commit is contained in:
Al Viro 2016-01-22 19:47:47 -05:00 committed by Mike Marshall
parent fee25ce125
commit ed42fe0593
8 changed files with 107 additions and 143 deletions

View File

@ -43,9 +43,7 @@ static void orangefs_devreq_add_op(struct orangefs_kernel_op_s *op)
{
int index = hash_func(op->tag, hash_table_size);
spin_lock(&htable_ops_in_progress_lock);
list_add_tail(&op->list, &htable_ops_in_progress[index]);
spin_unlock(&htable_ops_in_progress_lock);
}
static struct orangefs_kernel_op_s *orangefs_devreq_remove_op(__u64 tag)
@ -60,8 +58,9 @@ static struct orangefs_kernel_op_s *orangefs_devreq_remove_op(__u64 tag)
next,
&htable_ops_in_progress[index],
list) {
if (op->tag == tag) {
list_del(&op->list);
if (op->tag == tag && !op_state_purged(op)) {
list_del_init(&op->list);
get_op(op); /* increase ref count. */
spin_unlock(&htable_ops_in_progress_lock);
return op;
}
@ -127,12 +126,17 @@ static ssize_t orangefs_devreq_read(struct file *file,
return -EINVAL;
}
restart:
/* Get next op (if any) from top of list. */
spin_lock(&orangefs_request_list_lock);
list_for_each_entry_safe(op, temp, &orangefs_request_list, list) {
__s32 fsid;
/* This lock is held past the end of the loop when we break. */
spin_lock(&op->lock);
if (unlikely(op_state_purged(op))) {
spin_unlock(&op->lock);
continue;
}
fsid = fsid_of_op(op);
if (fsid != ORANGEFS_FS_ID_NULL) {
@ -197,16 +201,10 @@ static ssize_t orangefs_devreq_read(struct file *file,
spin_unlock(&orangefs_request_list_lock);
return -EAGAIN;
}
/*
* Set the operation to be in progress and move it between lists since
* it has been sent to the client.
*/
set_op_state_inprogress(cur_op);
list_del(&cur_op->list);
list_del_init(&cur_op->list);
get_op(op);
spin_unlock(&orangefs_request_list_lock);
orangefs_devreq_add_op(cur_op);
spin_unlock(&cur_op->lock);
/* Push the upcall out. */
@ -224,6 +222,25 @@ static ssize_t orangefs_devreq_read(struct file *file,
if (ret != 0)
goto error;
spin_lock(&htable_ops_in_progress_lock);
spin_lock(&cur_op->lock);
if (unlikely(op_state_given_up(cur_op))) {
spin_unlock(&cur_op->lock);
spin_unlock(&htable_ops_in_progress_lock);
op_release(cur_op);
goto restart;
}
/*
* Set the operation to be in progress and move it between lists since
* it has been sent to the client.
*/
set_op_state_inprogress(cur_op);
orangefs_devreq_add_op(cur_op);
spin_unlock(&cur_op->lock);
spin_unlock(&htable_ops_in_progress_lock);
op_release(cur_op);
/* The client only asks to read one size buffer. */
return MAX_DEV_REQ_UPSIZE;
error:
@ -235,11 +252,13 @@ error:
gossip_err("orangefs: Failed to copy data to user space\n");
spin_lock(&orangefs_request_list_lock);
spin_lock(&cur_op->lock);
set_op_state_waiting(cur_op);
orangefs_devreq_remove_op(cur_op->tag);
list_add(&cur_op->list, &orangefs_request_list);
if (likely(!op_state_given_up(cur_op))) {
set_op_state_waiting(cur_op);
list_add(&cur_op->list, &orangefs_request_list);
}
spin_unlock(&cur_op->lock);
spin_unlock(&orangefs_request_list_lock);
op_release(cur_op);
return -EFAULT;
}
@ -278,15 +297,13 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
__func__,
total,
(unsigned int) MAX_DEV_REQ_DOWNSIZE);
ret = -EFAULT;
goto out;
return -EFAULT;
}
n = copy_from_iter(&head, head_size, iter);
if (n < head_size) {
gossip_err("%s: failed to copy head.\n", __func__);
ret = -EFAULT;
goto out;
return -EFAULT;
}
if (head.version < ORANGEFS_MINIMUM_USERSPACE_VERSION) {
@ -295,31 +312,26 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
__func__,
head.version,
ORANGEFS_MINIMUM_USERSPACE_VERSION);
ret = -EPROTO;
goto out;
return -EPROTO;
}
if (head.magic != ORANGEFS_DEVREQ_MAGIC) {
gossip_err("Error: Device magic number does not match.\n");
ret = -EPROTO;
goto out;
return -EPROTO;
}
op = orangefs_devreq_remove_op(head.tag);
if (!op) {
gossip_err("WARNING: No one's waiting for tag %llu\n",
llu(head.tag));
goto out;
return ret;
}
get_op(op); /* increase ref count. */
n = copy_from_iter(&op->downcall, downcall_size, iter);
if (n != downcall_size) {
gossip_err("%s: failed to copy downcall.\n", __func__);
put_op(op);
ret = -EFAULT;
goto out;
goto Broken;
}
if (op->downcall.status)
@ -339,9 +351,8 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
downcall_size,
op->downcall.trailer_size,
total);
put_op(op);
ret = -EFAULT;
goto out;
goto Broken;
}
/* Only READDIR operations should have trailers. */
@ -350,9 +361,8 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
gossip_err("%s: %x operation with trailer.",
__func__,
op->downcall.type);
put_op(op);
ret = -EFAULT;
goto out;
goto Broken;
}
/* READDIR operations should always have trailers. */
@ -361,9 +371,8 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
gossip_err("%s: %x operation with no trailer.",
__func__,
op->downcall.type);
put_op(op);
ret = -EFAULT;
goto out;
goto Broken;
}
if (op->downcall.type != ORANGEFS_VFS_OP_READDIR)
@ -374,9 +383,8 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
if (op->downcall.trailer_buf == NULL) {
gossip_err("%s: failed trailer vmalloc.\n",
__func__);
put_op(op);
ret = -ENOMEM;
goto out;
goto Broken;
}
memset(op->downcall.trailer_buf, 0, op->downcall.trailer_size);
n = copy_from_iter(op->downcall.trailer_buf,
@ -385,9 +393,8 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb,
if (n != op->downcall.trailer_size) {
gossip_err("%s: failed to copy trailer.\n", __func__);
vfree(op->downcall.trailer_buf);
put_op(op);
ret = -EFAULT;
goto out;
goto Broken;
}
wakeup:
@ -404,7 +411,6 @@ wakeup:
* the buffers are done being used.
*/
if (op->downcall.type == ORANGEFS_VFS_OP_FILE_IO) {
int timed_out = 0;
DEFINE_WAIT(wait_entry);
/*
@ -412,7 +418,8 @@ wakeup:
* that this op is done
*/
spin_lock(&op->lock);
set_op_state_serviced(op);
if (!op_state_given_up(op))
set_op_state_serviced(op);
spin_unlock(&op->lock);
while (1) {
@ -435,7 +442,6 @@ wakeup:
gossip_debug(GOSSIP_DEV_DEBUG,
"%s: timed out.\n",
__func__);
timed_out = 1;
break;
}
continue;
@ -450,15 +456,6 @@ wakeup:
spin_lock(&op->lock);
finish_wait(&op->io_completion_waitq, &wait_entry);
spin_unlock(&op->lock);
/* NOTE: for I/O operations we handle releasing the op
* object except in the case of timeout. the reason we
* can't free the op in timeout cases is that the op
* service logic in the vfs retries operations using
* the same op ptr, thus it can't be freed.
*/
if (!timed_out)
op_release(op);
} else {
/*
* tell the vfs op waiting on a waitqueue that
@ -468,11 +465,22 @@ wakeup:
* notification
*/
spin_lock(&op->lock);
set_op_state_serviced(op);
if (!op_state_given_up(op))
set_op_state_serviced(op);
spin_unlock(&op->lock);
}
out:
op_release(op);
return ret;
Broken:
spin_lock(&op->lock);
if (!op_state_given_up(op)) {
op->downcall.status = ret;
set_op_state_serviced(op);
}
spin_unlock(&op->lock);
goto out;
}
/* Returns whether any FS are still pending remounted */

View File

@ -105,10 +105,9 @@ static ssize_t wait_for_direct_io(enum ORANGEFS_io_type type, struct inode *inod
ssize_t ret;
new_op = op_alloc(ORANGEFS_VFS_OP_FILE_IO);
if (!new_op) {
ret = -ENOMEM;
goto out;
}
if (!new_op)
return -ENOMEM;
/* synchronous I/O */
new_op->upcall.req.io.async_vfs_io = ORANGEFS_VFS_SYNC_IO;
new_op->upcall.req.io.readahead_size = readahead_size;
@ -234,12 +233,9 @@ populate_shared_memory:
/*
* tell the device file owner waiting on I/O that this read has
* completed and it can return now. in this exact case, on
* wakeup the daemon will free the op, so we *cannot* touch it
* after this.
* completed and it can return now.
*/
wake_up_daemon_for_return(new_op);
new_op = NULL;
out:
if (buffer_index >= 0) {
@ -249,10 +245,7 @@ out:
__func__, handle, buffer_index);
buffer_index = -1;
}
if (new_op) {
op_release(new_op);
new_op = NULL;
}
op_release(new_op);
return ret;
}

View File

@ -120,7 +120,7 @@ struct orangefs_kernel_op_s *op_alloc(__s32 type)
init_waitqueue_head(&new_op->waitq);
init_waitqueue_head(&new_op->io_completion_waitq);
atomic_set(&new_op->ref_count, 0);
atomic_set(&new_op->ref_count, 1);
orangefs_op_initialize(new_op);
@ -149,14 +149,13 @@ struct orangefs_kernel_op_s *op_alloc(__s32 type)
return new_op;
}
void op_release(struct orangefs_kernel_op_s *orangefs_op)
void __op_release(struct orangefs_kernel_op_s *orangefs_op)
{
if (orangefs_op) {
gossip_debug(GOSSIP_CACHE_DEBUG,
"Releasing OP (%p: %llu)\n",
orangefs_op,
llu(orangefs_op->tag));
orangefs_op_initialize(orangefs_op);
kmem_cache_free(op_cache, orangefs_op);
} else {
gossip_err("NULL pointer in op_release\n");

View File

@ -94,6 +94,7 @@ sizeof(__u64) + sizeof(struct orangefs_downcall_s))
* serviced - op has matching downcall; ok
* purged - op has to start a timer since client-core
* exited uncleanly before servicing op
* given up - submitter has given up waiting for it
*/
enum orangefs_vfs_op_states {
OP_VFS_STATE_UNKNOWN = 0,
@ -101,30 +102,9 @@ enum orangefs_vfs_op_states {
OP_VFS_STATE_INPROGR = 2,
OP_VFS_STATE_SERVICED = 4,
OP_VFS_STATE_PURGED = 8,
OP_VFS_STATE_GIVEN_UP = 16,
};
#define get_op(op) \
do { \
atomic_inc(&(op)->ref_count); \
gossip_debug(GOSSIP_DEV_DEBUG, \
"(get) Alloced OP (%p:%llu)\n", \
op, \
llu((op)->tag)); \
} while (0)
#define put_op(op) \
do { \
if (atomic_sub_and_test(1, &(op)->ref_count) == 1) { \
gossip_debug(GOSSIP_DEV_DEBUG, \
"(put) Releasing OP (%p:%llu)\n", \
op, \
llu((op)->tag)); \
op_release(op); \
} \
} while (0)
#define op_wait(op) (atomic_read(&(op)->ref_count) <= 2 ? 0 : 1)
/*
* Defines for controlling whether I/O upcalls are for async or sync operations
*/
@ -258,6 +238,25 @@ static inline void set_op_state_purged(struct orangefs_kernel_op_s *op)
#define op_state_in_progress(op) ((op)->op_state & OP_VFS_STATE_INPROGR)
#define op_state_serviced(op) ((op)->op_state & OP_VFS_STATE_SERVICED)
#define op_state_purged(op) ((op)->op_state & OP_VFS_STATE_PURGED)
#define op_state_given_up(op) ((op)->op_state & OP_VFS_STATE_GIVEN_UP)
static inline void get_op(struct orangefs_kernel_op_s *op)
{
atomic_inc(&op->ref_count);
gossip_debug(GOSSIP_DEV_DEBUG,
"(get) Alloced OP (%p:%llu)\n", op, llu(op->tag));
}
void __op_release(struct orangefs_kernel_op_s *op);
static inline void op_release(struct orangefs_kernel_op_s *op)
{
if (atomic_dec_and_test(&op->ref_count)) {
gossip_debug(GOSSIP_DEV_DEBUG,
"(put) Releasing OP (%p:%llu)\n", op, llu((op)->tag));
__op_release(op);
}
}
/* per inode private orangefs info */
struct orangefs_inode_s {
@ -459,7 +458,6 @@ int op_cache_initialize(void);
int op_cache_finalize(void);
struct orangefs_kernel_op_s *op_alloc(__s32 type);
char *get_opname_string(struct orangefs_kernel_op_s *new_op);
void op_release(struct orangefs_kernel_op_s *op);
int dev_req_cache_initialize(void);
int dev_req_cache_finalize(void);
@ -665,11 +663,9 @@ int service_operation(struct orangefs_kernel_op_s *op,
do { \
if (!op_state_serviced(new_op)) { \
orangefs_cancel_op_in_progress(new_op->tag); \
op_release(new_op); \
} else { \
wake_up_daemon_for_return(new_op); \
} \
new_op = NULL; \
orangefs_bufmap_put(bufmap, buffer_index); \
buffer_index = -1; \
} while (0)

View File

@ -271,6 +271,7 @@ void purge_inprogress_ops(void)
struct orangefs_kernel_op_s *op;
struct orangefs_kernel_op_s *next;
spin_lock(&htable_ops_in_progress_lock);
list_for_each_entry_safe(op,
next,
&htable_ops_in_progress[i],
@ -284,6 +285,7 @@ void purge_inprogress_ops(void)
set_op_state_purged(op);
spin_unlock(&op->lock);
}
spin_unlock(&htable_ops_in_progress_lock);
}
}

View File

@ -773,10 +773,8 @@ static int sysfs_service_op_show(char *kobj_id, char *buf, void *attr)
op_alloc_type = ORANGEFS_VFS_OP_PERF_COUNT;
new_op = op_alloc(op_alloc_type);
if (!new_op) {
rc = -ENOMEM;
goto out;
}
if (!new_op)
return -ENOMEM;
/* Can't do a service_operation if the client is not running... */
rc = is_daemon_in_service();
@ -931,11 +929,7 @@ out:
}
}
/*
* if we got ENOMEM, then op_alloc probably failed...
*/
if (rc != -ENOMEM)
op_release(new_op);
op_release(new_op);
return rc;
@ -1039,10 +1033,8 @@ static int sysfs_service_op_store(char *kobj_id, const char *buf, void *attr)
kobj_id);
new_op = op_alloc(ORANGEFS_VFS_OP_PARAM);
if (!new_op) {
rc = -ENOMEM;
goto out;
}
if (!new_op)
return -EINVAL; /* sic */
/* Can't do a service_operation if the client is not running... */
rc = is_daemon_in_service();
@ -1269,15 +1261,9 @@ static int sysfs_service_op_store(char *kobj_id, const char *buf, void *attr)
}
out:
/*
* if we got ENOMEM, then op_alloc probably failed...
*/
if (rc == -ENOMEM)
rc = 0;
else
op_release(new_op);
op_release(new_op);
if (rc == 0)
if (rc == -ENOMEM || rc == 0)
rc = -EINVAL;
return rc;

View File

@ -429,19 +429,15 @@ int orangefs_inode_setattr(struct inode *inode, struct iattr *iattr)
ret = copy_attributes_from_inode(inode,
&new_op->upcall.req.setattr.attributes,
iattr);
if (ret < 0) {
op_release(new_op);
return ret;
}
ret = service_operation(new_op, __func__,
if (ret >= 0) {
ret = service_operation(new_op, __func__,
get_interruptible_flag(inode));
gossip_debug(GOSSIP_UTILS_DEBUG,
"orangefs_inode_setattr: returning %d\n",
ret);
gossip_debug(GOSSIP_UTILS_DEBUG,
"orangefs_inode_setattr: returning %d\n",
ret);
}
/* when request is serviced properly, free req op struct */
op_release(new_op);
/*

View File

@ -279,25 +279,6 @@ retry_servicing:
return ret;
}
static inline void remove_op_from_request_list(struct orangefs_kernel_op_s *op)
{
struct list_head *tmp = NULL;
struct list_head *tmp_safe = NULL;
struct orangefs_kernel_op_s *tmp_op = NULL;
spin_lock(&orangefs_request_list_lock);
list_for_each_safe(tmp, tmp_safe, &orangefs_request_list) {
tmp_op = list_entry(tmp,
struct orangefs_kernel_op_s,
list);
if (tmp_op && (tmp_op == op)) {
list_del(&tmp_op->list);
break;
}
}
spin_unlock(&orangefs_request_list_lock);
}
static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *op)
{
/*
@ -334,6 +315,7 @@ static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s
}
spin_lock(&op->lock);
op->op_state |= OP_VFS_STATE_GIVEN_UP;
if (op_state_waiting(op)) {
/*
@ -341,7 +323,9 @@ static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s
* list.
*/
spin_unlock(&op->lock);
remove_op_from_request_list(op);
spin_lock(&orangefs_request_list_lock);
list_del(&op->list);
spin_unlock(&orangefs_request_list_lock);
gossip_debug(GOSSIP_WAIT_DEBUG,
"Interrupted: Removed op %p from request_list\n",
op);