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coda: cleanup for upcall handling path

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Make the code that processes upcall responses more straightforward, uncovered
at least one bad assumption.  We trusted that vc_inuse would be 0 when upcalls
are aborted, however the device may have been reopened.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jan Harkes 2007-07-19 01:48:46 -07:00 committed by Linus Torvalds
parent 8706551963
commit fe71b5f387
1 changed files with 59 additions and 64 deletions
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123
fs/coda/upcall.c
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@ -687,27 +687,27 @@ static inline void coda_waitfor_upcall(struct upc_req *vmp)
* are all mapped to -EINTR, while showing a nice warning message. (jh)
*
*/
static int coda_upcall(struct coda_sb_info *sbi,
int inSize, int *outSize,
union inputArgs *buffer)
static int coda_upcall(struct coda_sb_info *sbi,
int inSize, int *outSize,
union inputArgs *buffer)
{
struct venus_comm *vcommp;
union outputArgs *out;
struct upc_req *req;
union inputArgs *sig_inputArgs;
struct upc_req *req, *sig_req;
int error = 0;
vcommp = sbi->sbi_vcomm;
if ( !vcommp->vc_inuse ) {
printk("No pseudo device in upcall comms at %p\n", vcommp);
return -ENXIO;
if (!vcommp->vc_inuse) {
printk(KERN_NOTICE "coda: Venus dead, not sending upcall\n");
return -ENXIO;
}
/* Format the request message. */
req = upc_alloc();
if (!req) {
printk("Failed to allocate upc_req structure\n");
if (!req)
return -ENOMEM;
}
req->uc_data = (void *)buffer;
req->uc_flags = 0;
req->uc_inSize = inSize;
@ -715,13 +715,13 @@ static int coda_upcall(struct coda_sb_info *sbi,
req->uc_opcode = ((union inputArgs *)buffer)->ih.opcode;
req->uc_unique = ++vcommp->vc_seq;
init_waitqueue_head(&req->uc_sleep);
/* Fill in the common input args. */
((union inputArgs *)buffer)->ih.unique = req->uc_unique;
/* Append msg to pending queue and poke Venus. */
list_add_tail(&(req->uc_chain), &vcommp->vc_pending);
list_add_tail(&req->uc_chain, &vcommp->vc_pending);
wake_up_interruptible(&vcommp->vc_waitq);
/* We can be interrupted while we wait for Venus to process
* our request. If the interrupt occurs before Venus has read
@ -735,64 +735,59 @@ static int coda_upcall(struct coda_sb_info *sbi,
/* Go to sleep. Wake up on signals only after the timeout. */
coda_waitfor_upcall(req);
if (vcommp->vc_inuse) { /* i.e. Venus is still alive */
/* Op went through, interrupt or not... */
if (req->uc_flags & REQ_WRITE) {
/* Op went through, interrupt or not... */
if (req->uc_flags & REQ_WRITE) {
out = (union outputArgs *)req->uc_data;
/* here we map positive Venus errors to kernel errors */
error = -out->oh.result;
*outSize = req->uc_outSize;
goto exit;
}
if ( !(req->uc_flags & REQ_READ) && signal_pending(current)) {
/* Interrupted before venus read it. */
list_del(&(req->uc_chain));
/* perhaps the best way to convince the app to
give up? */
error = -EINTR;
goto exit;
}
if ( (req->uc_flags & REQ_READ) && signal_pending(current) ) {
/* interrupted after Venus did its read, send signal */
union inputArgs *sig_inputArgs;
struct upc_req *sig_req;
list_del(&(req->uc_chain));
error = -ENOMEM;
sig_req = upc_alloc();
if (!sig_req) goto exit;
CODA_ALLOC((sig_req->uc_data), char *, sizeof(struct coda_in_hdr));
if (!sig_req->uc_data) {
upc_free(sig_req);
goto exit;
}
error = -EINTR;
sig_inputArgs = (union inputArgs *)sig_req->uc_data;
sig_inputArgs->ih.opcode = CODA_SIGNAL;
sig_inputArgs->ih.unique = req->uc_unique;
sig_req->uc_flags = REQ_ASYNC;
sig_req->uc_opcode = sig_inputArgs->ih.opcode;
sig_req->uc_unique = sig_inputArgs->ih.unique;
sig_req->uc_inSize = sizeof(struct coda_in_hdr);
sig_req->uc_outSize = sizeof(struct coda_in_hdr);
/* insert at head of queue! */
list_add(&(sig_req->uc_chain), &vcommp->vc_pending);
wake_up_interruptible(&vcommp->vc_waitq);
} else {
printk("Coda: Strange interruption..\n");
error = -EINTR;
}
} else { /* If venus died i.e. !VC_OPEN(vcommp) */
printk("coda_upcall: Venus dead on (op,un) (%d.%d) flags %d\n",
req->uc_opcode, req->uc_unique, req->uc_flags);
error = -ENODEV;
}
exit:
error = -EINTR;
if ((req->uc_flags & REQ_ABORT) || !signal_pending(current)) {
printk(KERN_WARNING "coda: Unexpected interruption.\n");
goto exit;
}
list_del(&(req->uc_chain));
/* Interrupted before venus read it. */
if (!(req->uc_flags & REQ_READ))
goto exit;
/* Venus saw the upcall, make sure we can send interrupt signal */
if (!vcommp->vc_inuse) {
printk(KERN_INFO "coda: Venus dead, not sending signal.\n");
goto exit;
}
error = -ENOMEM;
sig_req = upc_alloc();
if (!sig_req) goto exit;
CODA_ALLOC((sig_req->uc_data), char *, sizeof(struct coda_in_hdr));
if (!sig_req->uc_data) {
upc_free(sig_req);
goto exit;
}
error = -EINTR;
sig_inputArgs = (union inputArgs *)sig_req->uc_data;
sig_inputArgs->ih.opcode = CODA_SIGNAL;
sig_inputArgs->ih.unique = req->uc_unique;
sig_req->uc_flags = REQ_ASYNC;
sig_req->uc_opcode = sig_inputArgs->ih.opcode;
sig_req->uc_unique = sig_inputArgs->ih.unique;
sig_req->uc_inSize = sizeof(struct coda_in_hdr);
sig_req->uc_outSize = sizeof(struct coda_in_hdr);
/* insert at head of queue! */
list_add(&(sig_req->uc_chain), &vcommp->vc_pending);
wake_up_interruptible(&vcommp->vc_waitq);
exit:
upc_free(req);
return error;
}