terom@29: #include <stdlib.h>
terom@29: #include <assert.h>
terom@29: 
terom@29: #include "op_base.h"
terom@29: #include "../lib/log.h"
terom@29: 
terom@29: /*
terom@29:  * Free the op.
terom@29:  *
terom@29:  * The op must any oustanding request responded to first, must not be open, and must not have a transaction.
terom@29:  *
terom@29:  * The op will be free'd.
terom@29:  */
terom@29: static void dbfs_op_free (struct dbfs_op *op) {
terom@29:     assert(op);
terom@29:     assert(!op->open);
terom@29:     assert(!op->req);
terom@29:     assert(!op->trans);
terom@29: 
terom@29:     // free_fn
terom@29:     if (op->free_fn)
terom@29:         op->free_fn(op);
terom@29:     
terom@29:     // and then free the op
terom@29:     free(op);
terom@29: }
terom@29: 
terom@29: void dbfs_op_fail (struct dbfs_op *op, int err) {
terom@29:     assert(op->req);
terom@29:     
terom@29:     if (op->trans) {
terom@29:         // abort the trans
terom@29:         evsql_trans_abort(op->trans);
terom@29:         
terom@29:         op->trans = NULL;
terom@29:     }
terom@29: 
terom@29:     // send an error reply
terom@29:     if ((err = fuse_reply_err(op->req, err)))
terom@29:         // XXX: handle these failures /somehow/, or requests will hang and interrupts might handle invalid ops
terom@29:         EFATAL(err, "\tdbfs_op.fail %p:%p -> reply with fuse_reply_err", op, op->req);
terom@29:    
terom@29:     // drop the req
terom@29:     op->req = NULL;
terom@29: 
terom@29:     // is it open?
terom@29:     if (!op->open) {
terom@29:         // no, we can free it now and then forget about the whole thing
terom@29:         dbfs_op_free(op);
terom@29: 
terom@29:     } else {
terom@29:         // we need to wait for release
terom@29: 
terom@29:     }
terom@29: }
terom@29: 
terom@29: /*
terom@29:  * The op_open transaction is ready for use.
terom@29:  */
terom@29: static void dbfs_op_ready (struct evsql_trans *trans, void *arg) {
terom@29:     struct dbfs_op *op = arg;
terom@29:     
terom@29:     assert(trans == op->trans);
terom@29:     assert(op->req);
terom@29:     assert(!op->open);
terom@29: 
terom@29:     INFO("\tdbfs_op.ready %p:%p -> trans=%p", op, op->req, trans);
terom@29: 
terom@29:     // remember the transaction
terom@29:     op->trans = trans;
terom@29: 
terom@29:     // ready
terom@29:     op->open_fn(op);
terom@29:     
terom@29:     // good
terom@29:     return;
terom@29: }
terom@29: 
terom@29: /*
terom@29:  * The op trans was committed, i.e. release has completed
terom@29:  */
terom@29: static void dbfs_op_done (struct evsql_trans *trans, void *arg) {
terom@29:     struct dbfs_op *op = arg;
terom@29:     int err;
terom@29:     
terom@29:     assert(trans == op->trans);
terom@29:     assert(op->req);
terom@29:     assert(!op->open);   // should not be considered as open anymore at this point, as errors should release
terom@29: 
terom@29:     INFO("\tdbfs_op.done %p:%p -> OK", op, op->req);
terom@29: 
terom@29:     // forget trans
terom@29:     op->trans = NULL;
terom@29:     
terom@29:     // just reply
terom@29:     if ((err = fuse_reply_err(op->req, 0)))
terom@29:         // XXX: handle these failures /somehow/, or requests will hang and interrupts might handle invalid ops
terom@29:         EFATAL(err, "dbfs_op.done %p:%p -> reply with fuse_reply_err", op, op->req);
terom@29:     
terom@29:     // req is done
terom@29:     op->req = NULL;
terom@29: 
terom@29:     // then we can just free op
terom@29:     dbfs_op_free(op);
terom@29: }
terom@29: 
terom@29: /*
terom@29:  * The op trans has failed, somehow, at some point, some where.
terom@29:  *
terom@29:  * This might happend during the open evsql_trans, during a read evsql_query, during the release
terom@29:  * evsql_trans_commit, or at any point in between.
terom@29:  *
terom@29:  * 1) loose the transaction
terom@29:  * 2) if op has a req, we handle failing it
terom@29:  */
terom@29: static void dbfs_op_error (struct evsql_trans *trans, void *arg) {
terom@29:     struct dbfs_op *op = arg;
terom@29:     
terom@29:     // unless we fail 
terom@29:     assert(trans == op->trans);
terom@29: 
terom@29:     INFO("\tdbfs_op.error %p:%p -> evsql transaction error: %s", op, op->req, evsql_trans_error(trans));
terom@29:     
terom@29:     // deassociate the trans
terom@29:     op->trans = NULL;
terom@29:     
terom@29:     // if we were answering a req, error it out, and if the op isn't open, free
terom@29:     // if we didn't have a req outstanding, the op must be open, so we wouldn't free it in any case, and must wait
terom@29:     // for the next read/release to detect this and return an error reply
terom@29:     if (op->req)
terom@29:         dbfs_op_fail(op, EIO);
terom@29:     else
terom@29:         assert(op->open);
terom@29: }
terom@29: 
terom@29: int dbfs_op_open (struct dbfs *ctx, struct dbfs_op *op, struct fuse_req *req, fuse_ino_t ino, struct fuse_file_info *fi, dbfs_op_free_cb free_fn, dbfs_op_open_cb open_fn) {
terom@29:     int err;
terom@29: 
terom@29:     assert(op && req && ino && fi);
terom@29:     assert(!(op->req || op->ino));
terom@29: 
terom@29:     // initialize the op
terom@29:     op->req = req;
terom@29:     op->ino = ino;
terom@29:     // copy *fi since it's on the stack
terom@29:     op->fi = *fi;
terom@29:     op->fi.fh = (uint64_t) op;
terom@29:     op->free_fn = free_fn;
terom@29:     op->open_fn = open_fn;
terom@29: 
terom@29:     // start a new transaction
terom@29:     if ((op->trans = evsql_trans(ctx->db, EVSQL_TRANS_SERIALIZABLE, dbfs_op_error, dbfs_op_ready, dbfs_op_done, op)) == NULL)
terom@29:         SERROR(err = EIO);
terom@29:     
terom@29:     // XXX: handle interrupts
terom@29:     
terom@29:     // good
terom@29:     return 0;
terom@29: 
terom@29: error:
terom@29:     // nothing of ours to cleanup
terom@29:     return err;
terom@29: }
terom@29: 
terom@29: int dbfs_op_open_reply (struct dbfs_op *op) {
terom@29:     int err;
terom@29:     
terom@29:     // detect earlier failures
terom@29:     if (!op->trans && (err = EIO))
terom@29:         ERROR("op trans has failed");
terom@29: 
terom@29:     // send the openddir reply
terom@29:     if ((err = fuse_reply_open(op->req, &op->fi)))
terom@29:         EERROR(err, "fuse_reply_open");
terom@29:     
terom@29:     // req is done
terom@29:     op->req = NULL;
terom@29: 
terom@29:     // op is now open
terom@29:     op->open = 1;
terom@29:  
terom@29:     // good
terom@29:     return 0;
terom@29: 
terom@29: error:
terom@29:     return err;
terom@29: }
terom@29: 
terom@29: struct dbfs_op *dbfs_op_req (struct fuse_req *req, fuse_ino_t ino, struct fuse_file_info *fi) {
terom@29:     struct dbfs_op *op = (struct dbfs_op *) fi->fh;
terom@29:     int err;
terom@29:     
terom@29:     // validate
terom@29:     assert(op);
terom@29:     assert(op->open);
terom@29:     assert(op->ino == ino);
terom@40:     
terom@40:     // detect concurrent requests
terom@40:     if (op->req) {
terom@40:         // must handle req ourself, shouldn't fail the other req
terom@40:         WARNING("op.%p: concurrent req: %p -> %p", op, op->req, req);
terom@40:         
terom@40:         // XXX: ignore error errors...
terom@40:         fuse_reply_err(req, EBUSY);
terom@29: 
terom@40:         return NULL;
terom@40: 
terom@40:     } else
terom@40:         // store the new req
terom@40:         op->req = req;
terom@40:     
terom@40:     // inodes change?
terom@40:     if (op->ino != ino)
terom@40:         XERROR(err = EBADF, "op.%p: wrong ino: %u -> %lu", op, op->ino, ino);
terom@29:     
terom@29:     // detect earlier failures
terom@29:     if (!op->trans && (err = EIO))
terom@29:         ERROR("op trans has failed");
terom@29: 
terom@29:     // good
terom@29:     return op;
terom@29: 
terom@29: error:
terom@29:     dbfs_op_fail(op, err);
terom@29:     
terom@29:     return NULL;
terom@29: }
terom@29: 
terom@29: int dbfs_op_req_done (struct dbfs_op *op) {
terom@29:     // validate
terom@29:     assert(op);
terom@29:     assert(op->req);
terom@29:     assert(op->open);
terom@29: 
terom@29:     // unassign the req
terom@29:     op->req = NULL;
terom@29: 
terom@29:     // k
terom@29:     return 0;
terom@29: }
terom@29: 
terom@29: void dbfs_op_release (struct fuse_req *req, fuse_ino_t ino, struct fuse_file_info *fi) {
terom@29:     struct dbfs_op *op = (struct dbfs_op *) fi->fh;
terom@29:     int err;
terom@29:     
terom@29:     assert(op);
terom@29:     assert(!op->req);
terom@29:     assert(op->ino == ino);
terom@29:     
terom@29:     // update to this req
terom@29:     op->req = req;
terom@29: 
terom@29:     // fi is irrelevant, we don't touch the flags anyways
terom@29:     (void) fi;
terom@29: 
terom@29:     // handle failed trans
terom@29:     if (!op->trans && (err = EIO))
terom@29:         ERROR("trans has failed");
terom@29:     
terom@29:     // log
terom@29:     INFO("\tdbfs_op.release %p:%p : ino=%lu, fi=%p : trans=%p", op, req, ino, fi, op->trans);
terom@29:     
terom@29:     // we must commit the transaction.
terom@29:     // Note that this might cause dbfs_op_error to be called, we can tell if that happaned by looking at op->req
terom@29:     // or op->trans - this means that we need to keep the op open when calling trans_commit, so that op_error
terom@29:     // doesn't free it out from underneath us.
terom@29:     if (evsql_trans_commit(op->trans))
terom@29:         SERROR(err = EIO);
terom@29: 
terom@29:     // fall-through to cleanup
terom@29:     err = 0;
terom@29: 
terom@29: error:
terom@29:     // the op is not open anymore and can be free'd next, because we either:
terom@29:     // a) already caught an error
terom@29:     // b) we get+send an error later on
terom@29:     // c) we get+send the done/no-error later on
terom@29:     op->open = 0;
terom@29: 
terom@29:     // did the commit/pre-commit-checks fail?
terom@29:     if (err) {
terom@29:         // a) the trans failed earlier (read), so we have a req but no trans
terom@29:         // b) the trans commit failed, op_error got called -> no req and no trans
terom@29:         // c) the trans commit failed, op_error did not get called -> have req and trans
terom@29:         // we either have a req (may or may not have trans), or we don't have a trans either
terom@29:         // i.e. there is no situation where we don't have a req but do have a trans
terom@29: 
terom@29:         if (op->req)
terom@29:             dbfs_op_fail(op, err);
terom@29:         else
terom@29:             assert(!op->trans);
terom@29: 
terom@29:     } else {
terom@29:         // shouldn't slip by, op_done should not get called directly. Once it does, it will handle both.
terom@29:         assert(op->req);
terom@29:         assert(op->trans);
terom@29:     }
terom@29: }
terom@29: