search for: backend_ext

...39; can_extents='exit 0' extents='printf "0 3\n3 4 hole,zero\n7 1\n"' --run 'qemu-img map -f raw --output=json $uri' > > except it's currently failing: > nbdkit: eval[1]: error: swab: requests to this filter must be aligned > nbdkit: backend.c:621: backend_extents: Assertion `*err' failed. > qemu-img: Could not read file metadata: Input/output error I would add -v to the command line, as it will show you exactly what requests qemu-img is making. The assert failure seems to be a separate and worrying problem. Rich. > filters/swab/swab.c | 1...

...ero (struct backend *b, struct connection *conn, + __attribute__((__nonnull__ (1, 5))); +extern int backend_zero (struct backend *b, uint32_t count, uint64_t offset, uint32_t flags, int *err) - __attribute__((__nonnull__ (1, 2, 6))); -extern int backend_extents (struct backend *b, struct connection *conn, + __attribute__((__nonnull__ (1, 5))); +extern int backend_extents (struct backend *b, uint32_t count, uint64_t offset, uint32_t flags, struct nbdkit_extents *extents, int *err) - __attribut...

...t_size='echo 8' can_extents='exit 0' extents='printf "0 3\n3 4 hole,zero\n7 1\n"' --run 'qemu-img map -f raw --output=json $uri' except it's currently failing: nbdkit: eval[1]: error: swab: requests to this filter must be aligned nbdkit: backend.c:621: backend_extents: Assertion `*err' failed. qemu-img: Could not read file metadata: Input/output error --- filters/swab/swab.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/filters/swab/swab.c b/filters/swab/swab.c index 57a51aee..2e423bbf 100644 --- a/filters/swab/swa...

v1 was here: https://www.redhat.com/archives/libguestfs/2020-February/msg00081.html v2 replaces struct connection *conn = GET_CONN; with GET_CONN; which sets conn implicitly and asserts that it is non-NULL. If we actually want to test if conn is non-NULL or behave differently, then you must use threadlocal_get_conn() instead, and some existing uses do that. Rich.

...BDKIT_FLAG_FAST_ZERO; - if (backend_zero (backend, count, offset, f, &err) == -1) + if (backend_zero (top, count, offset, f, &err) == -1) return err; break; case NBD_CMD_BLOCK_STATUS: if (flags & NBD_CMD_FLAG_REQ_ONE) f |= NBDKIT_FLAG_REQ_ONE; - if (backend_extents (backend, count, offset, f, + if (backend_extents (top, count, offset, f, extents, &err) == -1) return err; break; @@ -683,7 +683,7 @@ protocol_recv_request_send_reply (void) /* Allocate the extents list for block status only. */ if (cmd...

The third patch is a large but mechanical change which gets rid of passing around struct connection * entirely within the server, preferring instead to reference the connection through thread-local storage. I hope this is a gateway to simplifying other parts of the code. Rich.

...-{ - struct backend *b_next = nxdata; - return backend_zero (b_next, count, offset, flags, err); -} - -static int -next_extents (void *nxdata, uint32_t count, uint64_t offset, uint32_t flags, - struct nbdkit_extents *extents, int *err) -{ - struct backend *b_next = nxdata; - return backend_extents (b_next, count, offset, flags, extents, err); -} - -static int -next_cache (void *nxdata, uint32_t count, uint64_t offset, - uint32_t flags, int *err) -{ - struct backend *b_next = nxdata; - return backend_cache (b_next, count, offset, flags, err); -} - static struct nbdkit_next_o...

...gs, err); + struct backend *b_next = nxdata; + return backend_zero (b_next, count, offset, flags, err); } static int next_extents (void *nxdata, uint32_t count, uint64_t offset, uint32_t flags, struct nbdkit_extents *extents, int *err) { - struct b_h *b_h = nxdata; - return backend_extents (b_h->b, count, offset, flags, - extents, err); + struct backend *b_next = nxdata; + return backend_extents (b_next, count, offset, flags, extents, err); } static int next_cache (void *nxdata, uint32_t count, uint64_t offset, uint32_t flags, int *...

Ultimately, both the blocksize and swab filters want to return aligned extents to the client. I'm posting this as a snapshot of my work in progress on how I plan to get there (it's not quite working yet, but I'm done for today and wanted to at least document my ideas). I might also add a convenience function for nbdkit_extents_offset, since we have a number of filters that repeat the

It's easy to use the sh script to demonstrate that nbdkit is inefficiently calling into .get_size, .can_fua, and friends more than necessary. We've also commented on the list in the past that it would be nice to ensure that when filters call into next_ops, they are not violating constraints (as we've have to fix several bugs in the past where we did not have such checking to protect

...ruct backend *b, int *err) { GET_CONN; - struct b_conn_handle *h = &conn->handles[b->i]; + struct handle *h = get_handle (conn, b->i); bool fua = !!(flags & NBDKIT_FLAG_FUA); bool fast = !!(flags & NBDKIT_FLAG_FAST_ZERO); int r; @@ -601,7 +601,7 @@ backend_extents (struct backend *b, struct nbdkit_extents *extents, int *err) { GET_CONN; - struct b_conn_handle *h = &conn->handles[b->i]; + struct handle *h = get_handle (conn, b->i); int r; assert (h->handle && (h->state & HANDLE_CONNECTED)); @@...

...{ + nbdkit_error ("invalid request: write zeroes operation not supported"); + *err = EINVAL; + return -1; + } r = b->zero (b, conn, count, offset, flags, err); if (r == -1) assert (*err && *err != ENOTSUP && *err != EOPNOTSUPP); @@ -368,6 +454,10 @@ backend_extents (struct backend *b, struct connection *conn, debug ("%s: extents count=%" PRIu32 " offset=%" PRIu64 " req_one=%d", b->name, count, offset, !!(flags & NBDKIT_FLAG_REQ_ONE)); + if (invalid_range (b, conn, "extents", offset, count)) { +...

...der to perform a fallback when needed. */ - if (conn->can_extents) { + r = backend_can_extents (backend, conn); + assert (r >= 0); /* Guaranteed during eflags computation */ + if (r) { if (flags & NBD_CMD_FLAG_REQ_ONE) f |= NBDKIT_FLAG_REQ_ONE; if (backend_extents (backend, conn, count, offset, f, @@ -304,8 +334,6 @@ handle_request (struct connection *conn, return err; } else { - int r; - /* By default it is safe assume that everything in the range is * allocated. */ diff --git a/filters/blocksize/blocksize....

I think this is my last round of patches for issues I identified with the retry filter. With this in place, it should be safe to interject another filter in between retry and the plugin. Eric Blake (5): retry: Don't call into closed plugin tests: Refactor test-retry-reopen-fail.sh tests: Enhance retry test to cover failed reopen server: Move prepare/finalize/close recursion to

The immediate reason for this patch is to reduce the amount of debugging in virt-v2v with using the virt-v2v -v option (because this implies running nbdkit in verbose mode too). Most of the messages are datapath ones about pread/pwrite requests, and in fact as we've added more filters on top of nbdkit these messages have got more and more verbose. However they are not particularly

I still don't have .prepare/.finalize working cleanly across reopen, but did find a nasty bug where a botched assertion means we failed to notice reads beyond EOF in both the xz and retry filter. Refactoring backend.c will make .finalize work easier. Eric Blake (5): xz: Avoid reading beyond EOF retry: Check size before transactions tests: Test retry when get_size values change