Date: Thu, 12 Aug 2021 17:02:30 GMT From: John Baldwin <jhb@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 0f01337e3af4 - stable/13 - bhyve: Add support for handling disk resize events to block_if. Message-ID: <202108121702.17CH2Urj018332@gitrepo.freebsd.org>
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The branch stable/13 has been updated by jhb: URL: https://cgit.FreeBSD.org/src/commit/?id=0f01337e3af4c013f3ef81401a56d420fa4de997 commit 0f01337e3af4c013f3ef81401a56d420fa4de997 Author: John Baldwin <jhb@FreeBSD.org> AuthorDate: 2021-06-12 00:59:25 +0000 Commit: John Baldwin <jhb@FreeBSD.org> CommitDate: 2021-08-12 15:56:23 +0000 bhyve: Add support for handling disk resize events to block_if. Allow clients of blockif to register a resize callback handler. When a callback is registered, register an EVFILT_VNODE kevent watching the backing store for a change in the file's attributes. If the size has changed when the kevent fires, invoke the clients' callback. Currently resize detection is limited to backing stores that support EVFILT_VNODE kevents such as regular files. Reviewed by: grehan, markj MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D30504 (cherry picked from commit 8794846a91c5429c612ba939c61ebf8f1ff1a628) --- usr.sbin/bhyve/block_if.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++- usr.sbin/bhyve/block_if.h | 5 ++++ 2 files changed, 67 insertions(+), 1 deletion(-) diff --git a/usr.sbin/bhyve/block_if.c b/usr.sbin/bhyve/block_if.c index ae09bc71d622..98c0f9f5f38b 100644 --- a/usr.sbin/bhyve/block_if.c +++ b/usr.sbin/bhyve/block_if.c @@ -115,6 +115,9 @@ struct blockif_ctxt { pthread_cond_t bc_cond; pthread_cond_t bc_paused_cond; pthread_cond_t bc_work_done_cond; + blockif_resize_cb *bc_resize_cb; + void *bc_resize_cb_arg; + struct mevent *bc_resize_event; /* Request elements and free/pending/busy queues */ TAILQ_HEAD(, blockif_elem) bc_freeq; @@ -532,7 +535,7 @@ blockif_open(nvlist_t *nvl, const char *ident) #ifndef WITHOUT_CAPSICUM cap_rights_init(&rights, CAP_FSYNC, CAP_IOCTL, CAP_READ, CAP_SEEK, - CAP_WRITE); + CAP_WRITE, CAP_FSTAT, CAP_EVENT); if (ro) cap_rights_clear(&rights, CAP_FSYNC, CAP_WRITE); @@ -643,6 +646,62 @@ err: return (NULL); } +static void +blockif_resized(int fd, enum ev_type type, void *arg) +{ + struct blockif_ctxt *bc; + struct stat sb; + + if (fstat(fd, &sb) != 0) + return; + + bc = arg; + pthread_mutex_lock(&bc->bc_mtx); + if (sb.st_size != bc->bc_size) { + bc->bc_size = sb.st_size; + bc->bc_resize_cb(bc, bc->bc_resize_cb_arg, bc->bc_size); + } + pthread_mutex_unlock(&bc->bc_mtx); +} + +int +blockif_register_resize_callback(struct blockif_ctxt *bc, blockif_resize_cb *cb, + void *cb_arg) +{ + struct stat sb; + int err; + + if (cb == NULL) + return (EINVAL); + + pthread_mutex_lock(&bc->bc_mtx); + if (bc->bc_resize_cb != NULL) { + err = EBUSY; + goto out; + } + + assert(bc->bc_closing == 0); + + if (fstat(bc->bc_fd, &sb) != 0) { + err = errno; + goto out; + } + + bc->bc_resize_event = mevent_add_flags(bc->bc_fd, EVF_VNODE, + EVFF_ATTRIB, blockif_resized, bc); + if (bc->bc_resize_event == NULL) { + err = ENXIO; + goto out; + } + + bc->bc_resize_cb = cb; + bc->bc_resize_cb_arg = cb_arg; +out: + pthread_mutex_unlock(&bc->bc_mtx); + + return (err); +} + static int blockif_request(struct blockif_ctxt *bc, struct blockif_req *breq, enum blockop op) @@ -796,6 +855,8 @@ blockif_close(struct blockif_ctxt *bc) */ pthread_mutex_lock(&bc->bc_mtx); bc->bc_closing = 1; + if (bc->bc_resize_event != NULL) + mevent_disable(bc->bc_resize_event); pthread_mutex_unlock(&bc->bc_mtx); pthread_cond_broadcast(&bc->bc_cond); for (i = 0; i < BLOCKIF_NUMTHR; i++) diff --git a/usr.sbin/bhyve/block_if.h b/usr.sbin/bhyve/block_if.h index 87ae4d169969..0407ff43cf94 100644 --- a/usr.sbin/bhyve/block_if.h +++ b/usr.sbin/bhyve/block_if.h @@ -63,8 +63,13 @@ struct blockif_req { }; struct blockif_ctxt; + +typedef void blockif_resize_cb(struct blockif_ctxt *, void *, size_t); + int blockif_legacy_config(nvlist_t *nvl, const char *opts); struct blockif_ctxt *blockif_open(nvlist_t *nvl, const char *ident); +int blockif_register_resize_callback(struct blockif_ctxt *bc, + blockif_resize_cb *cb, void *cb_arg); off_t blockif_size(struct blockif_ctxt *bc); void blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h, uint8_t *s);
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