diff options
Diffstat (limited to 'net/9p/client.c')
| -rw-r--r-- | net/9p/client.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/net/9p/client.c b/net/9p/client.c index 712d4f336ad..867031934f7 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -120,6 +120,154 @@ static int parse_opts(char *opts, struct p9_client *clnt) return ret; } +/** + * p9_tag_alloc - lookup/allocate a request by tag + * @c: client session to lookup tag within + * @tag: numeric id for transaction + * + * this is a simple array lookup, but will grow the + * request_slots as necessary to accomodate transaction + * ids which did not previously have a slot. + * + * this code relies on the client spinlock to manage locks, its + * possible we should switch to something else, but I'd rather + * stick with something low-overhead for the common case. + * + */ + +struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag) +{ + unsigned long flags; + int row, col; + + /* This looks up the original request by tag so we know which + * buffer to read the data into */ + tag++; + + if (tag >= c->max_tag) { + spin_lock_irqsave(&c->lock, flags); + /* check again since original check was outside of lock */ + while (tag >= c->max_tag) { + row = (tag / P9_ROW_MAXTAG); + c->reqs[row] = kcalloc(P9_ROW_MAXTAG, + sizeof(struct p9_req_t), GFP_ATOMIC); + + if (!c->reqs[row]) { + printk(KERN_ERR "Couldn't grow tag array\n"); + BUG(); + } + for (col = 0; col < P9_ROW_MAXTAG; col++) { + c->reqs[row][col].status = REQ_STATUS_IDLE; + c->reqs[row][col].flush_tag = P9_NOTAG; + c->reqs[row][col].wq = kmalloc( + sizeof(wait_queue_head_t), GFP_ATOMIC); + if (!c->reqs[row][col].wq) { + printk(KERN_ERR + "Couldn't grow tag array\n"); + BUG(); + } + init_waitqueue_head(c->reqs[row][col].wq); + } + c->max_tag += P9_ROW_MAXTAG; + } + spin_unlock_irqrestore(&c->lock, flags); + } + row = tag / P9_ROW_MAXTAG; + col = tag % P9_ROW_MAXTAG; + + c->reqs[row][col].status = REQ_STATUS_ALLOC; + c->reqs[row][col].flush_tag = P9_NOTAG; + + return &c->reqs[row][col]; +} +EXPORT_SYMBOL(p9_tag_alloc); + +/** + * p9_tag_lookup - lookup a request by tag + * @c: client session to lookup tag within + * @tag: numeric id for transaction + * + */ + +struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag) +{ + int row, col; + + /* This looks up the original request by tag so we know which + * buffer to read the data into */ + tag++; + + BUG_ON(tag >= c->max_tag); + + row = tag / P9_ROW_MAXTAG; + col = tag % P9_ROW_MAXTAG; + + return &c->reqs[row][col]; +} +EXPORT_SYMBOL(p9_tag_lookup); + +/** + * p9_tag_init - setup tags structure and contents + * @tags: tags structure from the client struct + * + * This initializes the tags structure for each client instance. + * + */ + +static int p9_tag_init(struct p9_client *c) +{ + int err = 0; + + c->tagpool = p9_idpool_create(); + if (IS_ERR(c->tagpool)) { + err = PTR_ERR(c->tagpool); + c->tagpool = NULL; + goto error; + } + + p9_idpool_get(c->tagpool); /* reserve tag 0 */ + + c->max_tag = 0; +error: + return err; +} + +/** + * p9_tag_cleanup - cleans up tags structure and reclaims resources + * @tags: tags structure from the client struct + * + * This frees resources associated with the tags structure + * + */ +static void p9_tag_cleanup(struct p9_client *c) +{ + int row, col; + + /* check to insure all requests are idle */ + for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) { + for (col = 0; col < P9_ROW_MAXTAG; col++) { + if (c->reqs[row][col].status != REQ_STATUS_IDLE) { + P9_DPRINTK(P9_DEBUG_MUX, + "Attempting to cleanup non-free tag %d,%d\n", + row, col); + /* TODO: delay execution of cleanup */ + return; + } + } + } + + if (c->tagpool) + p9_idpool_destroy(c->tagpool); + + /* free requests associated with tags */ + for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) { + for (col = 0; col < P9_ROW_MAXTAG; col++) + kfree(c->reqs[row][col].wq); + kfree(c->reqs[row]); + } + c->max_tag = 0; +} + static struct p9_fid *p9_fid_create(struct p9_client *clnt) { int err; @@ -209,6 +357,8 @@ struct p9_client *p9_client_create(const char *dev_name, char *options) goto error; } + p9_tag_init(clnt); + err = parse_opts(options, clnt); if (err < 0) goto error; @@ -285,6 +435,8 @@ void p9_client_destroy(struct p9_client *clnt) if (clnt->fidpool) p9_idpool_destroy(clnt->fidpool); + p9_tag_cleanup(clnt); + kfree(clnt); } EXPORT_SYMBOL(p9_client_destroy); |