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8bced8601696af0359c2002fa138441a7de970d0
xen/extras/mini-os/fs-front.c
T
Keir Fraser 453414b284 mini-os: Fix memory leaks in blkfront, netfront, pcifront, etc. 
The return value of Xenbus routines xenbus_transaction_start(),
xenbus_printf(), xenbus_transaction_end(), etc.  is a pointer of error
message.  This pointer should be passed to free() to release the
allocated memory when it is no longer needed.

Signed-off-by: Yu Zhiguo <yuzg@cn.fujitsu.com>
2009-12-14 09:51:07 +00:00

1298 lines
39 KiB
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/******************************************************************************
* fs-front.c
*
* Frontend driver for FS split device driver.
*
* Copyright (c) 2007, Grzegorz Milos, <gm281@cam.ac.uk>.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#undef NDEBUG
#include <stdint.h>
#include <mini-os/os.h>
#include <mini-os/list.h>
#include <mini-os/xmalloc.h>
#include <mini-os/xenbus.h>
#include <mini-os/gnttab.h>
#include <mini-os/events.h>
#include <xen/io/fsif.h>
#include <mini-os/fs.h>
#include <mini-os/sched.h>
#define preempt_disable()
#define preempt_enable()
#define cmpxchg(p,o,n) synch_cmpxchg(p,o,n)
#ifdef FS_DEBUG
#define DEBUG(_f, _a...) \
printk("MINI_OS(file=fs-front.c, line=%d) " _f "\n", __LINE__, ## _a)
#else
#define DEBUG(_f, _a...) ((void)0)
#endif
struct fs_request;
struct fs_import *fs_import;
void *alloc_buffer_page(struct fs_request *req, domid_t domid, grant_ref_t *gref);
void free_buffer_page(struct fs_request *req);
/******************************************************************************/
/* RING REQUEST/RESPONSES HANDLING */
/******************************************************************************/
struct fs_request
{
void *private1; /* Specific to request type */
void *private2;
struct thread *thread; /* Thread blocked on this request */
struct fsif_response shadow_rsp; /* Response copy writen by the
interrupt handler */
};
struct fs_rw_gnts
{
/* TODO 16 bit? */
int count;
grant_ref_t grefs[FSIF_NR_READ_GNTS];
void *pages[FSIF_NR_READ_GNTS];
};
/* Ring operations:
* FSIF ring is used differently to Linux-like split devices. This stems from
* the fact that no I/O request queue is present. The use of some of the macros
* defined in ring.h is not allowed, in particular:
* RING_PUSH_REQUESTS_AND_CHECK_NOTIFY cannot be used.
*
* The protocol used for FSIF ring is described below:
*
* In order to reserve a request the frontend:
* a) saves current frontend_ring->req_prod_pvt into a local variable
* b) checks that there are free request using the local req_prod_pvt
* c) tries to reserve the request using cmpxchg on frontend_ring->req_prod_pvt
* if cmpxchg fails, it means that someone reserved the request, start from
* a)
*
* In order to commit a request to the shared ring:
* a) cmpxchg shared_ring->req_prod from local req_prod_pvt to req_prod_pvt+1
* Loop if unsuccessful.
* NOTE: Request should be commited to the shared ring as quickly as possible,
* because otherwise other threads might busy loop trying to commit next
* requests. It also follows that preemption should be disabled, if
* possible, for the duration of the request construction.
*/
/* Number of free requests (for use on front side only). */
#define FS_RING_FREE_REQUESTS(_r, _req_prod_pvt) \
(RING_SIZE(_r) - (_req_prod_pvt - (_r)->rsp_cons))
static RING_IDX reserve_fsif_request(struct fs_import *import)
{
RING_IDX idx;
down(&import->reqs_sem);
preempt_disable();
again:
/* We will attempt to reserve slot idx */
idx = import->ring.req_prod_pvt;
ASSERT (FS_RING_FREE_REQUESTS(&import->ring, idx));
/* Attempt to reserve */
if(cmpxchg(&import->ring.req_prod_pvt, idx, idx+1) != idx)
goto again;
return idx;
}
static void commit_fsif_request(struct fs_import *import, RING_IDX idx)
{
while(cmpxchg(&import->ring.sring->req_prod, idx, idx+1) != idx)
{
printk("Failed to commit a request: req_prod=%d, idx=%d\n",
import->ring.sring->req_prod, idx);
}
preempt_enable();
/* NOTE: we cannot do anything clever about rsp_event, to hold off
* notifications, because we don't know if we are a single request (in which
* case we have to notify always), or a part of a larger request group
* (when, in some cases, notification isn't required) */
notify_remote_via_evtchn(import->local_port);
}
static inline void add_id_to_freelist(unsigned int id,unsigned short* freelist)
{
unsigned int old_id, new_id;
again:
old_id = freelist[0];
/* Note: temporal inconsistency, since freelist[0] can be changed by someone
* else, but we are a sole owner of freelist[id + 1], it's OK. */
freelist[id + 1] = old_id;
new_id = id;
if(cmpxchg(&freelist[0], old_id, new_id) != old_id)
{
printk("Cmpxchg on freelist add failed.\n");
goto again;
}
}
/* always call reserve_fsif_request(import) before this, to protect from
* depletion. */
static inline unsigned short get_id_from_freelist(unsigned short* freelist)
{
unsigned int old_id, new_id;
again:
old_id = freelist[0];
new_id = freelist[old_id + 1];
if(cmpxchg(&freelist[0], old_id, new_id) != old_id)
{
printk("Cmpxchg on freelist remove failed.\n");
goto again;
}
return old_id;
}
/******************************************************************************/
/* END OF RING REQUEST/RESPONSES HANDLING */
/******************************************************************************/
/******************************************************************************/
/* INDIVIDUAL FILE OPERATIONS */
/******************************************************************************/
int fs_open(struct fs_import *import, char *file)
{
struct fs_request *fsr;
unsigned short priv_req_id;
grant_ref_t gref;
void *buffer;
RING_IDX back_req_id;
struct fsif_request *req;
int fd;
if (!import)
return -1;
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_open call is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
buffer = alloc_buffer_page(fsr, import->dom_id, &gref);
DEBUG("gref id=%d\n", gref);
fsr->thread = current;
sprintf(buffer, "%s", file);
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_FILE_OPEN;
req->id = priv_req_id;
req->u.fopen.gref = gref;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
fd = (int)fsr->shadow_rsp.u.ret_val;
DEBUG("The following FD returned: %d\n", fd);
free_buffer_page(fsr);
add_id_to_freelist(priv_req_id, import->freelist);
return fd;
}
int fs_close(struct fs_import *import, int fd)
{
struct fs_request *fsr;
unsigned short priv_req_id;
RING_IDX back_req_id;
struct fsif_request *req;
int ret;
if (!import)
return -1;
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_close call is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
fsr->thread = current;
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_FILE_CLOSE;
req->id = priv_req_id;
req->u.fclose.fd = fd;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
ret = (int)fsr->shadow_rsp.u.ret_val;
DEBUG("Close returned: %d\n", ret);
add_id_to_freelist(priv_req_id, import->freelist);
return ret;
}
ssize_t fs_read(struct fs_import *import, int fd, void *buf,
ssize_t len, ssize_t offset)
{
struct fs_request *fsr;
unsigned short priv_req_id;
struct fs_rw_gnts gnts;
RING_IDX back_req_id;
struct fsif_request *req;
ssize_t ret;
int i;
if (!import)
return -1;
BUG_ON(len > PAGE_SIZE * FSIF_NR_READ_GNTS);
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_read call is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_FILE_READ;
req->id = priv_req_id;
req->u.fread.fd = fd;
req->u.fread.len = len;
req->u.fread.offset = offset;
ASSERT(len > 0);
gnts.count = ((len - 1) / PAGE_SIZE) + 1;
for(i=0; i<gnts.count; i++)
{
gnts.pages[i] = (void *)alloc_page();
gnts.grefs[i] = gnttab_grant_access(import->dom_id,
virt_to_mfn(gnts.pages[i]),
0);
memset(gnts.pages[i], 0, PAGE_SIZE);
req->u.fread.grefs[i] = gnts.grefs[i];
}
fsr->thread = current;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
ret = (ssize_t)fsr->shadow_rsp.u.ret_val;
DEBUG("The following ret value returned %d\n", ret);
if(ret > 0)
{
ssize_t to_copy = ret, current_copy;
for(i=0; i<gnts.count; i++)
{
gnttab_end_access(gnts.grefs[i]);
current_copy = to_copy > PAGE_SIZE ? PAGE_SIZE : to_copy;
if(current_copy > 0)
memcpy(buf, gnts.pages[i], current_copy);
to_copy -= current_copy;
buf = (char*) buf + current_copy;
free_page(gnts.pages[i]);
}
}
add_id_to_freelist(priv_req_id, import->freelist);
return ret;
}
ssize_t fs_write(struct fs_import *import, int fd, void *buf,
ssize_t len, ssize_t offset)
{
struct fs_request *fsr;
unsigned short priv_req_id;
struct fs_rw_gnts gnts;
RING_IDX back_req_id;
struct fsif_request *req;
ssize_t ret, to_copy;
int i;
if (!import)
return -1;
BUG_ON(len > PAGE_SIZE * FSIF_NR_WRITE_GNTS);
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_read call is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_FILE_WRITE;
req->id = priv_req_id;
req->u.fwrite.fd = fd;
req->u.fwrite.len = len;
req->u.fwrite.offset = offset;
ASSERT(len > 0);
gnts.count = ((len - 1) / PAGE_SIZE) + 1;
to_copy = len;
for(i=0; i<gnts.count; i++)
{
int current_copy = (to_copy > PAGE_SIZE ? PAGE_SIZE : to_copy);
gnts.pages[i] = (void *)alloc_page();
gnts.grefs[i] = gnttab_grant_access(import->dom_id,
virt_to_mfn(gnts.pages[i]),
0);
memcpy(gnts.pages[i], buf, current_copy);
if(current_copy < PAGE_SIZE)
memset((char *)gnts.pages[i] + current_copy,
0,
PAGE_SIZE - current_copy);
req->u.fwrite.grefs[i] = gnts.grefs[i];
to_copy -= current_copy;
buf = (char*) buf + current_copy;
}
fsr->thread = current;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
ret = (ssize_t)fsr->shadow_rsp.u.ret_val;
DEBUG("The following ret value returned %d\n", ret);
for(i=0; i<gnts.count; i++)
{
gnttab_end_access(gnts.grefs[i]);
free_page(gnts.pages[i]);
}
add_id_to_freelist(priv_req_id, import->freelist);
return ret;
}
int fs_stat(struct fs_import *import,
int fd,
struct fsif_stat_response *stat)
{
struct fs_request *fsr;
unsigned short priv_req_id;
RING_IDX back_req_id;
struct fsif_request *req;
int ret;
if (!import)
return -1;
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_stat call is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
fsr->thread = current;
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_STAT;
req->id = priv_req_id;
req->u.fstat.fd = fd;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
ret = (int)fsr->shadow_rsp.u.ret_val;
DEBUG("Following ret from fstat: %d\n", ret);
memcpy(stat,
&fsr->shadow_rsp.u.fstat,
sizeof(struct fsif_stat_response));
add_id_to_freelist(priv_req_id, import->freelist);
return ret;
}
int fs_truncate(struct fs_import *import,
int fd,
int64_t length)
{
struct fs_request *fsr;
unsigned short priv_req_id;
RING_IDX back_req_id;
struct fsif_request *req;
int ret;
if (!import)
return -1;
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_truncate call is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
fsr->thread = current;
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_FILE_TRUNCATE;
req->id = priv_req_id;
req->u.ftruncate.fd = fd;
req->u.ftruncate.length = length;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
ret = (int)fsr->shadow_rsp.u.ret_val;
DEBUG("Following ret from ftruncate: %d\n", ret);
add_id_to_freelist(priv_req_id, import->freelist);
return ret;
}
int fs_remove(struct fs_import *import, char *file)
{
struct fs_request *fsr;
unsigned short priv_req_id;
grant_ref_t gref;
void *buffer;
RING_IDX back_req_id;
struct fsif_request *req;
int ret;
if (!import)
return -1;
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_open call is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
buffer = alloc_buffer_page(fsr, import->dom_id, &gref);
DEBUG("gref=%d\n", gref);
fsr->thread = current;
sprintf(buffer, "%s", file);
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_REMOVE;
req->id = priv_req_id;
req->u.fremove.gref = gref;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
ret = (int)fsr->shadow_rsp.u.ret_val;
DEBUG("The following ret: %d\n", ret);
free_buffer_page(fsr);
add_id_to_freelist(priv_req_id, import->freelist);
return ret;
}
int fs_rename(struct fs_import *import,
char *old_file_name,
char *new_file_name)
{
struct fs_request *fsr;
unsigned short priv_req_id;
grant_ref_t gref;
void *buffer;
RING_IDX back_req_id;
struct fsif_request *req;
int ret;
char old_header[] = "old: ";
char new_header[] = "new: ";
if (!import)
return -1;
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_open call is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
buffer = alloc_buffer_page(fsr, import->dom_id, &gref);
DEBUG("gref=%d\n", gref);
fsr->thread = current;
sprintf(buffer, "%s%s%c%s%s",
old_header, old_file_name, '\0', new_header, new_file_name);
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_RENAME;
req->id = priv_req_id;
req->u.frename.gref = gref;
req->u.frename.old_name_offset = strlen(old_header);
req->u.frename.new_name_offset = strlen(old_header) +
strlen(old_file_name) +
strlen(new_header) +
1 /* Accouning for the additional
end of string character */;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
ret = (int)fsr->shadow_rsp.u.ret_val;
DEBUG("The following ret: %d\n", ret);
free_buffer_page(fsr);
add_id_to_freelist(priv_req_id, import->freelist);
return ret;
}
int fs_create(struct fs_import *import, char *name,
int8_t directory, int32_t mode)
{
struct fs_request *fsr;
unsigned short priv_req_id;
grant_ref_t gref;
void *buffer;
RING_IDX back_req_id;
struct fsif_request *req;
int ret;
if (!import)
return -1;
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_create call is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
buffer = alloc_buffer_page(fsr, import->dom_id, &gref);
DEBUG("gref=%d\n", gref);
fsr->thread = current;
sprintf(buffer, "%s", name);
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_CREATE;
req->id = priv_req_id;
req->u.fcreate.gref = gref;
req->u.fcreate.directory = directory;
req->u.fcreate.mode = mode;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
ret = (int)fsr->shadow_rsp.u.ret_val;
DEBUG("The following ret: %d\n", ret);
free_buffer_page(fsr);
add_id_to_freelist(priv_req_id, import->freelist);
return ret;
}
char** fs_list(struct fs_import *import, char *name,
int32_t offset, int32_t *nr_files, int *has_more)
{
struct fs_request *fsr;
unsigned short priv_req_id;
grant_ref_t gref;
void *buffer;
RING_IDX back_req_id;
struct fsif_request *req;
char **files, *current_file;
int i;
if (!import)
return NULL;
DEBUG("Different masks: NR_FILES=(%llx, %d), ERROR=(%llx, %d), HAS_MORE(%llx, %d)\n",
NR_FILES_MASK, NR_FILES_SHIFT, ERROR_MASK, ERROR_SHIFT, HAS_MORE_FLAG, HAS_MORE_SHIFT);
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_list call is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
buffer = alloc_buffer_page(fsr, import->dom_id, &gref);
DEBUG("gref=%d\n", gref);
fsr->thread = current;
sprintf(buffer, "%s", name);
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_DIR_LIST;
req->id = priv_req_id;
req->u.flist.gref = gref;
req->u.flist.offset = offset;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
*nr_files = (fsr->shadow_rsp.u.ret_val & NR_FILES_MASK) >> NR_FILES_SHIFT;
files = NULL;
if(*nr_files <= 0) goto exit;
files = malloc(sizeof(char*) * (*nr_files));
current_file = buffer;
for(i=0; i<*nr_files; i++)
{
files[i] = strdup(current_file);
current_file += strlen(current_file) + 1;
}
if(has_more != NULL)
*has_more = fsr->shadow_rsp.u.ret_val & HAS_MORE_FLAG;
free_buffer_page(fsr);
add_id_to_freelist(priv_req_id, import->freelist);
exit:
return files;
}
int fs_chmod(struct fs_import *import, int fd, int32_t mode)
{
struct fs_request *fsr;
unsigned short priv_req_id;
RING_IDX back_req_id;
struct fsif_request *req;
int ret;
if (!import)
return -1;
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_chmod call is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
fsr->thread = current;
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_CHMOD;
req->id = priv_req_id;
req->u.fchmod.fd = fd;
req->u.fchmod.mode = mode;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
ret = (int)fsr->shadow_rsp.u.ret_val;
DEBUG("The following returned: %d\n", ret);
add_id_to_freelist(priv_req_id, import->freelist);
return ret;
}
int64_t fs_space(struct fs_import *import, char *location)
{
struct fs_request *fsr;
unsigned short priv_req_id;
grant_ref_t gref;
void *buffer;
RING_IDX back_req_id;
struct fsif_request *req;
int64_t ret;
if (!import)
return -1;
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_space is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
buffer = alloc_buffer_page(fsr, import->dom_id, &gref);
DEBUG("gref=%d\n", gref);
fsr->thread = current;
sprintf(buffer, "%s", location);
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_FS_SPACE;
req->id = priv_req_id;
req->u.fspace.gref = gref;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
ret = (int64_t)fsr->shadow_rsp.u.ret_val;
DEBUG("The following returned: %lld\n", ret);
free_buffer_page(fsr);
add_id_to_freelist(priv_req_id, import->freelist);
return ret;
}
int fs_sync(struct fs_import *import, int fd)
{
struct fs_request *fsr;
unsigned short priv_req_id;
RING_IDX back_req_id;
struct fsif_request *req;
int ret;
if (!import)
return -1;
/* Prepare request for the backend */
back_req_id = reserve_fsif_request(import);
DEBUG("Backend request id=%d\n", back_req_id);
/* Prepare our private request structure */
priv_req_id = get_id_from_freelist(import->freelist);
DEBUG("Request id for fs_sync call is: %d\n", priv_req_id);
fsr = &import->requests[priv_req_id];
fsr->thread = current;
req = RING_GET_REQUEST(&import->ring, back_req_id);
req->type = REQ_FILE_SYNC;
req->id = priv_req_id;
req->u.fsync.fd = fd;
/* Set blocked flag before commiting the request, thus avoiding missed
* response race */
block(current);
commit_fsif_request(import, back_req_id);
schedule();
/* Read the response */
ret = (int)fsr->shadow_rsp.u.ret_val;
DEBUG("Close returned: %d\n", ret);
add_id_to_freelist(priv_req_id, import->freelist);
return ret;
}
/******************************************************************************/
/* END OF INDIVIDUAL FILE OPERATIONS */
/******************************************************************************/
void *alloc_buffer_page(struct fs_request *req, domid_t domid, grant_ref_t *gref)
{
void *page;
page = (void *)alloc_page();
*gref = gnttab_grant_access(domid, virt_to_mfn(page), 0);
req->private1 = page;
req->private2 = (void *)(uintptr_t)(*gref);
return page;
}
void free_buffer_page(struct fs_request *req)
{
gnttab_end_access((grant_ref_t)(uintptr_t)req->private2);
free_page(req->private1);
}
static void fsfront_handler(evtchn_port_t port, struct pt_regs *regs, void *data)
{
struct fs_import *import = (struct fs_import*)data;
static int in_irq = 0;
RING_IDX cons, rp;
int more;
/* Check for non-reentrance */
BUG_ON(in_irq);
in_irq = 1;
DEBUG("Event from import [%d:%d].\n", import->dom_id, import->export_id);
moretodo:
rp = import->ring.sring->rsp_prod;
rmb(); /* Ensure we see queued responses up to 'rp'. */
cons = import->ring.rsp_cons;
while (cons != rp)
{
struct fsif_response *rsp;
struct fs_request *req;
rsp = RING_GET_RESPONSE(&import->ring, cons);
DEBUG("Response at idx=%d to request id=%d, ret_val=%lx\n",
cons, rsp->id, rsp->u.ret_val);
req = &import->requests[rsp->id];
memcpy(&req->shadow_rsp, rsp, sizeof(struct fsif_response));
DEBUG("Waking up: %s\n", req->thread->name);
wake(req->thread);
cons++;
up(&import->reqs_sem);
}
import->ring.rsp_cons = rp;
RING_FINAL_CHECK_FOR_RESPONSES(&import->ring, more);
if(more) goto moretodo;
in_irq = 0;
}
static void alloc_request_table(struct fs_import *import)
{
struct fs_request *requests;
int i;
BUG_ON(import->nr_entries <= 0);
printk("Allocating request array for import %d, nr_entries = %d.\n",
import->import_id, import->nr_entries);
requests = xmalloc_array(struct fs_request, import->nr_entries);
import->freelist = xmalloc_array(unsigned short, import->nr_entries + 1);
memset(import->freelist, 0, sizeof(unsigned short) * (import->nr_entries + 1));
for(i=0; i<import->nr_entries; i++)
add_id_to_freelist(i, import->freelist);
import->requests = requests;
}
/******************************************************************************/
/* FS TESTS */
/******************************************************************************/
void test_fs_import(void *data)
{
struct fs_import *import = (struct fs_import *)data;
int ret, fd, i, repeat_count;
int32_t nr_files;
char buffer[1024];
ssize_t offset;
char **files;
long ret64;
struct fsif_stat_response stat;
repeat_count = 10;
/* Sleep for 1s and then try to open a file */
msleep(1000);
again:
ret = fs_create(import, "mini-os-created-directory", 1, 0777);
printk("Directory create: %d\n", ret);
sprintf(buffer, "mini-os-created-directory/mini-os-created-file-%d",
repeat_count);
ret = fs_create(import, buffer, 0, 0666);
printk("File create: %d\n", ret);
fd = fs_open(import, buffer);
printk("File descriptor: %d\n", fd);
if(fd < 0) return;
offset = 0;
for(i=0; i<10; i++)
{
sprintf(buffer, "Current time is: %lld\n", NOW());
ret = fs_write(import, fd, buffer, strlen(buffer), offset);
printk("Writen current time (%d)\n", ret);
if(ret < 0)
return;
offset += ret;
}
ret = fs_stat(import, fd, &stat);
printk("Ret after stat: %d\n", ret);
printk(" st_mode=%o\n", stat.stat_mode);
printk(" st_uid =%d\n", stat.stat_uid);
printk(" st_gid =%d\n", stat.stat_gid);
printk(" st_size=%ld\n", stat.stat_size);
printk(" st_atime=%ld\n", stat.stat_atime);
printk(" st_mtime=%ld\n", stat.stat_mtime);
printk(" st_ctime=%ld\n", stat.stat_ctime);
ret = fs_close(import, fd);
printk("Closed fd: %d, ret=%d\n", fd, ret);
printk("Listing files in /\n");
files = fs_list(import, "/", 0, &nr_files, NULL);
for(i=0; i<nr_files; i++)
printk(" files[%d] = %s\n", i, files[i]);
ret64 = fs_space(import, "/");
printk("Free space: %lld (=%lld Mb)\n", ret64, (ret64 >> 20));
repeat_count--;
if(repeat_count > 0)
goto again;
}
#if 0
// char *content = (char *)alloc_page();
int fd, ret;
// int read;
char write_string[] = "\"test data written from minios\"";
struct fsif_stat_response stat;
char **files;
int32_t nr_files, i;
int64_t ret64;
fd = fs_open(import, "test-export-file");
// read = fs_read(import, fd, content, PAGE_SIZE, 0);
// printk("Read: %d bytes\n", read);
// content[read] = '\0';
// printk("Value: %s\n", content);
ret = fs_write(import, fd, write_string, strlen(write_string), 0);
printk("Ret after write: %d\n", ret);
ret = fs_stat(import, fd, &stat);
printk("Ret after stat: %d\n", ret);
printk(" st_mode=%o\n", stat.stat_mode);
printk(" st_uid =%d\n", stat.stat_uid);
printk(" st_gid =%d\n", stat.stat_gid);
printk(" st_size=%ld\n", stat.stat_size);
printk(" st_atime=%ld\n", stat.stat_atime);
printk(" st_mtime=%ld\n", stat.stat_mtime);
printk(" st_ctime=%ld\n", stat.stat_ctime);
ret = fs_truncate(import, fd, 30);
printk("Ret after truncate: %d\n", ret);
ret = fs_remove(import, "test-to-remove/test-file");
printk("Ret after remove: %d\n", ret);
ret = fs_remove(import, "test-to-remove");
printk("Ret after remove: %d\n", ret);
ret = fs_chmod(import, fd, 0700);
printk("Ret after chmod: %d\n", ret);
ret = fs_sync(import, fd);
printk("Ret after sync: %d\n", ret);
ret = fs_close(import, fd);
//ret = fs_rename(import, "test-export-file", "renamed-test-export-file");
//printk("Ret after rename: %d\n", ret);
ret = fs_create(import, "created-dir", 1, 0777);
printk("Ret after dir create: %d\n", ret);
ret = fs_create(import, "created-dir/created-file", 0, 0777);
printk("Ret after file create: %d\n", ret);
files = fs_list(import, "/", 15, &nr_files, NULL);
for(i=0; i<nr_files; i++)
printk(" files[%d] = %s\n", i, files[i]);
ret64 = fs_space(import, "created-dir");
printk("Ret after space: %lld\n", ret64);
#endif
/******************************************************************************/
/* END OF FS TESTS */
/******************************************************************************/
static int init_fs_import(struct fs_import *import)
{
char *err;
xenbus_transaction_t xbt;
char nodename[1024], r_nodename[1024], token[128], *message = NULL;
struct fsif_sring *sring;
int i, retry = 0;
domid_t self_id;
xenbus_event_queue events = NULL;
printk("Initialising FS fortend to backend dom %d\n", import->dom_id);
/* Allocate page for the shared ring */
sring = (struct fsif_sring*) alloc_pages(FSIF_RING_SIZE_ORDER);
memset(sring, 0, PAGE_SIZE * FSIF_RING_SIZE_PAGES);
/* Init the shared ring */
SHARED_RING_INIT(sring);
ASSERT(FSIF_NR_READ_GNTS == FSIF_NR_WRITE_GNTS);
/* Init private frontend ring */
FRONT_RING_INIT(&import->ring, sring, PAGE_SIZE * FSIF_RING_SIZE_PAGES);
import->nr_entries = import->ring.nr_ents;
/* Allocate table of requests */
alloc_request_table(import);
init_SEMAPHORE(&import->reqs_sem, import->nr_entries);
/* Grant access to the shared ring */
for(i=0; i<FSIF_RING_SIZE_PAGES; i++)
import->gnt_refs[i] =
gnttab_grant_access(import->dom_id,
virt_to_mfn((char *)sring + i * PAGE_SIZE),
0);
/* Allocate event channel */
BUG_ON(evtchn_alloc_unbound(import->dom_id,
fsfront_handler,
//ANY_CPU,
import,
&import->local_port));
unmask_evtchn(import->local_port);
self_id = xenbus_get_self_id();
/* Write the frontend info to a node in our Xenbus */
sprintf(nodename, "/local/domain/%d/device/vfs/%d",
self_id, import->import_id);
again:
err = xenbus_transaction_start(&xbt);
if (err) {
printk("starting transaction\n");
free(err);
}
err = xenbus_printf(xbt,
nodename,
"ring-size",
"%u",
FSIF_RING_SIZE_PAGES);
if (err) {
message = "writing ring-size";
goto abort_transaction;
}
for(i=0; i<FSIF_RING_SIZE_PAGES; i++)
{
sprintf(r_nodename, "ring-ref-%d", i);
err = xenbus_printf(xbt,
nodename,
r_nodename,
"%u",
import->gnt_refs[i]);
if (err) {
message = "writing ring-refs";
goto abort_transaction;
}
}
err = xenbus_printf(xbt,
nodename,
"event-channel",
"%u",
import->local_port);
if (err) {
message = "writing event-channel";
goto abort_transaction;
}
err = xenbus_printf(xbt, nodename, "state", STATE_READY, 0xdeadbeef);
if (err) free(err);
err = xenbus_transaction_end(xbt, 0, &retry);
if (err) free(err);
if (retry) {
goto again;
printk("completing transaction\n");
}
/* Now, when our node is prepared we write request in the exporting domain
* */
printk("Our own id is %d\n", self_id);
sprintf(r_nodename,
"/local/domain/%d/backend/vfs/exports/requests/%d/%d/frontend",
import->dom_id, self_id, import->export_id);
BUG_ON(xenbus_write(XBT_NIL, r_nodename, nodename));
goto done;
abort_transaction:
free(err);
err = xenbus_transaction_end(xbt, 1, &retry);
if (err) free(err);
done:
#define WAIT_PERIOD 10 /* Wait period in ms */
#define MAX_WAIT 10 /* Max number of WAIT_PERIODs */
import->backend = NULL;
sprintf(r_nodename, "%s/backend", nodename);
for(retry = MAX_WAIT; retry > 0; retry--)
{
xenbus_read(XBT_NIL, r_nodename, &import->backend);
if(import->backend)
{
printk("Backend found at %s\n", import->backend);
break;
}
msleep(WAIT_PERIOD);
}
if(!import->backend)
{
printk("No backend available.\n");
/* TODO - cleanup datastructures/xenbus */
return 0;
}
sprintf(r_nodename, "%s/state", import->backend);
sprintf(token, "fs-front-%d", import->import_id);
/* The token will not be unique if multiple imports are inited */
xenbus_watch_path_token(XBT_NIL, r_nodename, r_nodename, &events);
err = xenbus_wait_for_value(r_nodename, STATE_READY, &events);
if (err) free(err);
xenbus_unwatch_path_token(XBT_NIL, r_nodename, r_nodename);
printk("Backend ready.\n");
//create_thread("fs-tester", test_fs_import, import);
return 1;
}
static void add_export(struct minios_list_head *exports, unsigned int domid)
{
char node[1024], **exports_list = NULL, *ret_msg;
int j = 0;
static int import_id = 0;
sprintf(node, "/local/domain/%d/backend/vfs/exports", domid);
ret_msg = xenbus_ls(XBT_NIL, node, &exports_list);
if (ret_msg && strcmp(ret_msg, "ENOENT"))
printk("couldn't read %s: %s\n", node, ret_msg);
while(exports_list && exports_list[j])
{
struct fs_import *import;
int export_id = -1;
sscanf(exports_list[j], "%d", &export_id);
if(export_id >= 0)
{
import = xmalloc(struct fs_import);
import->dom_id = domid;
import->export_id = export_id;
import->import_id = import_id++;
MINIOS_INIT_LIST_HEAD(&import->list);
minios_list_add(&import->list, exports);
}
free(exports_list[j]);
j++;
}
if(exports_list)
free(exports_list);
if(ret_msg)
free(ret_msg);
}
#if 0
static struct minios_list_head* probe_exports(void)
{
struct minios_list_head *exports;
char **node_list = NULL, *msg = NULL;
int i = 0;
exports = xmalloc(struct minios_list_head);
MINIOS_INIT_LIST_HEAD(exports);
msg = xenbus_ls(XBT_NIL, "/local/domain", &node_list);
if(msg)
{
printk("Could not list VFS exports (%s).\n", msg);
goto exit;
}
while(node_list[i])
{
add_export(exports, atoi(node_list[i]));
free(node_list[i]);
i++;
}
exit:
if(msg)
free(msg);
if(node_list)
free(node_list);
return exports;
}
#endif
MINIOS_LIST_HEAD(exports);
void init_fs_frontend(void)
{
struct minios_list_head *entry;
struct fs_import *import = NULL;
printk("Initing FS frontend(s).\n");
add_export(&exports, 0);
minios_list_for_each(entry, &exports)
{
import = minios_list_entry(entry, struct fs_import, list);
printk("FS export [dom=%d, id=%d] found\n",
import->dom_id, import->export_id);
if (init_fs_import(import) != 0) {
fs_import = import;
break;
}
}
if (!fs_import)
printk("No FS import\n");
}
/* TODO: shutdown */
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