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/*
* 9p backend
*
* Copyright IBM, Corp. 2010
*
* Authors:
* Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
* Venkateswararao Jujjuri(JV) <jvrao@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#ifndef QEMU_9P_COTH_H
#define QEMU_9P_COTH_H
#include "qemu/thread.h"
#include "qemu/coroutine.h"
#include "9p.h"
/**
* we want to use bottom half because we want to make sure the below
* sequence of events.
*
* 1. Yield the coroutine in the QEMU thread.
* 2. Submit the coroutine to a worker thread.
* 3. Enter the coroutine in the worker thread.
* we cannot swap step 1 and 2, because that would imply worker thread
* can enter coroutine while step1 is still running
*
* @b PERFORMANCE @b CONSIDERATIONS: As a rule of thumb, keep in mind
* that hopping between threads adds @b latency! So when handling a
* 9pfs request, avoid calling v9fs_co_run_in_worker() too often, because
* this might otherwise sum up to a significant, huge overall latency for
* providing the response for just a single request. For that reason it
* is highly recommended to fetch all data from fs driver with a single
* fs driver request on a background I/O thread (bottom half) in one rush
* first and then eventually assembling the final response from that data
* on main I/O thread (top half).
*/
#define v9fs_co_run_in_worker(code_block) \
do { \
QEMUBH *co_bh; \
co_bh = qemu_bh_new(co_run_in_worker_bh, \
qemu_coroutine_self()); \
qemu_bh_schedule(co_bh); \
/* \
* yield in qemu thread and re-enter back \
* in worker thread \
*/ \
qemu_coroutine_yield(); \
qemu_bh_delete(co_bh); \
code_block; \
/* re-enter back to qemu thread */ \
qemu_coroutine_yield(); \
} while (0)
void co_run_in_worker_bh(void *);
int coroutine_fn v9fs_co_readlink(V9fsPDU *, V9fsPath *, V9fsString *);
int coroutine_fn v9fs_co_readdir(V9fsPDU *, V9fsFidState *, struct dirent **);
int coroutine_fn v9fs_co_readdir_many(V9fsPDU *, V9fsFidState *,
struct V9fsDirEnt **, off_t, int32_t,
bool);
off_t coroutine_fn v9fs_co_telldir(V9fsPDU *, V9fsFidState *);
void coroutine_fn v9fs_co_seekdir(V9fsPDU *, V9fsFidState *, off_t);
void coroutine_fn v9fs_co_rewinddir(V9fsPDU *, V9fsFidState *);
int coroutine_fn v9fs_co_statfs(V9fsPDU *, V9fsPath *, struct statfs *);
int coroutine_fn v9fs_co_lstat(V9fsPDU *, V9fsPath *, struct stat *);
int coroutine_fn v9fs_co_chmod(V9fsPDU *, V9fsPath *, mode_t);
int coroutine_fn v9fs_co_utimensat(V9fsPDU *, V9fsPath *, struct timespec [2]);
int coroutine_fn v9fs_co_chown(V9fsPDU *, V9fsPath *, uid_t, gid_t);
int coroutine_fn v9fs_co_truncate(V9fsPDU *, V9fsPath *, off_t);
int coroutine_fn v9fs_co_llistxattr(V9fsPDU *, V9fsPath *, void *, size_t);
int coroutine_fn v9fs_co_lgetxattr(V9fsPDU *, V9fsPath *,
V9fsString *, void *, size_t);
int coroutine_fn v9fs_co_mknod(V9fsPDU *, V9fsFidState *, V9fsString *, uid_t,
gid_t, dev_t, mode_t, struct stat *);
int coroutine_fn v9fs_co_mkdir(V9fsPDU *, V9fsFidState *, V9fsString *,
mode_t, uid_t, gid_t, struct stat *);
int coroutine_fn v9fs_co_remove(V9fsPDU *, V9fsPath *);
int coroutine_fn v9fs_co_rename(V9fsPDU *, V9fsPath *, V9fsPath *);
int coroutine_fn v9fs_co_unlinkat(V9fsPDU *, V9fsPath *, V9fsString *,
int flags);
int coroutine_fn v9fs_co_renameat(V9fsPDU *, V9fsPath *, V9fsString *,
V9fsPath *, V9fsString *);
int coroutine_fn v9fs_co_fstat(V9fsPDU *, V9fsFidState *, struct stat *);
int coroutine_fn v9fs_co_opendir(V9fsPDU *, V9fsFidState *);
int coroutine_fn v9fs_co_open(V9fsPDU *, V9fsFidState *, int);
int coroutine_fn v9fs_co_open2(V9fsPDU *, V9fsFidState *, V9fsString *,
gid_t, int, int, struct stat *);
int coroutine_fn v9fs_co_lsetxattr(V9fsPDU *, V9fsPath *, V9fsString *,
void *, size_t, int);
int coroutine_fn v9fs_co_lremovexattr(V9fsPDU *, V9fsPath *, V9fsString *);
int coroutine_fn v9fs_co_closedir(V9fsPDU *, V9fsFidOpenState *);
int coroutine_fn v9fs_co_close(V9fsPDU *, V9fsFidOpenState *);
int coroutine_fn v9fs_co_fsync(V9fsPDU *, V9fsFidState *, int);
int coroutine_fn v9fs_co_symlink(V9fsPDU *, V9fsFidState *, V9fsString *,
const char *, gid_t, struct stat *);
int coroutine_fn v9fs_co_link(V9fsPDU *, V9fsFidState *,
V9fsFidState *, V9fsString *);
int coroutine_fn v9fs_co_pwritev(V9fsPDU *, V9fsFidState *,
struct iovec *, int, int64_t);
int coroutine_fn v9fs_co_preadv(V9fsPDU *, V9fsFidState *,
struct iovec *, int, int64_t);
int coroutine_fn v9fs_co_name_to_path(V9fsPDU *, V9fsPath *,
const char *, V9fsPath *);
int coroutine_fn v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t,
V9fsStatDotl *v9stat);
#endif
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