From acef3f8b47060f05e13de5b615268c39b274aab0 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Mon, 11 Jan 2021 10:49:56 +0100 Subject: 9pfs/proxy: Check return value of proxy_marshal() This should always successfully write exactly two 32-bit integers. Make it clear with an assert(), like v9fs_receive_status() and v9fs_receive_response() already do when unmarshalling the same header. Fixes: Coverity CID 1438968 Reviewed-by: Christian Schoenebeck Message-Id: <161035859647.1221144.4691749806675653934.stgit@bahia.lan> Signed-off-by: Greg Kurz --- hw/9pfs/9p-proxy.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c index 6f598a0f11..4aa4e0a3ba 100644 --- a/hw/9pfs/9p-proxy.c +++ b/hw/9pfs/9p-proxy.c @@ -537,7 +537,8 @@ static int v9fs_request(V9fsProxy *proxy, int type, void *response, ...) } /* marshal the header details */ - proxy_marshal(iovec, 0, "dd", header.type, header.size); + retval = proxy_marshal(iovec, 0, "dd", header.type, header.size); + assert(retval == 4 * 2); header.size += PROXY_HDR_SZ; retval = qemu_write_full(proxy->sockfd, iovec->iov_base, header.size); -- cgit v1.2.3 From 2e53160fc62d4d59c76bf93c7a90bd739b8b8157 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Mon, 18 Jan 2021 15:22:58 +0100 Subject: 9pfs: Convert V9fsFidState::clunked to bool This can only be 0 or 1. Reviewed-by: Christian Schoenebeck Message-Id: <20210118142300.801516-2-groug@kaod.org> Signed-off-by: Greg Kurz --- hw/9pfs/9p.c | 4 ++-- hw/9pfs/9p.h | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 6026b51a1c..37c3379b74 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -413,7 +413,7 @@ static V9fsFidState *clunk_fid(V9fsState *s, int32_t fid) } fidp = *fidpp; *fidpp = fidp->next; - fidp->clunked = 1; + fidp->clunked = true; return fidp; } @@ -544,7 +544,7 @@ static void coroutine_fn virtfs_reset(V9fsPDU *pdu) /* Clunk fid */ s->fid_list = fidp->next; - fidp->clunked = 1; + fidp->clunked = true; put_fid(pdu, fidp); } diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h index 32df81f360..93656323d1 100644 --- a/hw/9pfs/9p.h +++ b/hw/9pfs/9p.h @@ -279,7 +279,7 @@ struct V9fsFidState { int open_flags; uid_t uid; int ref; - int clunked; + bool clunked; V9fsFidState *next; V9fsFidState *rclm_lst; }; -- cgit v1.2.3 From feabd6cf78ca3b57da2ce48e95b704e72147bf2c Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Mon, 18 Jan 2021 15:22:59 +0100 Subject: 9pfs: Convert V9fsFidState::fid_list to QSIMPLEQ The fid_list is currently open-coded. This doesn't seem to serve any purpose that cannot be met with QEMU's generic lists. Let's go for a QSIMPLEQ : this will allow to add new fids at the end of the list and to improve the logic in v9fs_mark_fids_unreclaim(). Reviewed-by: Christian Schoenebeck Message-Id: <20210118142300.801516-3-groug@kaod.org> Signed-off-by: Greg Kurz --- hw/9pfs/9p.c | 41 ++++++++++++++++++----------------------- hw/9pfs/9p.h | 4 ++-- 2 files changed, 20 insertions(+), 25 deletions(-) diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 37c3379b74..b65f320e65 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -260,7 +260,7 @@ static V9fsFidState *coroutine_fn get_fid(V9fsPDU *pdu, int32_t fid) V9fsFidState *f; V9fsState *s = pdu->s; - for (f = s->fid_list; f; f = f->next) { + QSIMPLEQ_FOREACH(f, &s->fid_list, next) { BUG_ON(f->clunked); if (f->fid == fid) { /* @@ -295,7 +295,7 @@ static V9fsFidState *alloc_fid(V9fsState *s, int32_t fid) { V9fsFidState *f; - for (f = s->fid_list; f; f = f->next) { + QSIMPLEQ_FOREACH(f, &s->fid_list, next) { /* If fid is already there return NULL */ BUG_ON(f->clunked); if (f->fid == fid) { @@ -311,8 +311,7 @@ static V9fsFidState *alloc_fid(V9fsState *s, int32_t fid) * reclaim won't close the file descriptor */ f->flags |= FID_REFERENCED; - f->next = s->fid_list; - s->fid_list = f; + QSIMPLEQ_INSERT_HEAD(&s->fid_list, f, next); v9fs_readdir_init(s->proto_version, &f->fs.dir); v9fs_readdir_init(s->proto_version, &f->fs_reclaim.dir); @@ -401,20 +400,16 @@ static int coroutine_fn put_fid(V9fsPDU *pdu, V9fsFidState *fidp) static V9fsFidState *clunk_fid(V9fsState *s, int32_t fid) { - V9fsFidState **fidpp, *fidp; + V9fsFidState *fidp; - for (fidpp = &s->fid_list; *fidpp; fidpp = &(*fidpp)->next) { - if ((*fidpp)->fid == fid) { - break; + QSIMPLEQ_FOREACH(fidp, &s->fid_list, next) { + if (fidp->fid == fid) { + QSIMPLEQ_REMOVE(&s->fid_list, fidp, V9fsFidState, next); + fidp->clunked = true; + return fidp; } } - if (*fidpp == NULL) { - return NULL; - } - fidp = *fidpp; - *fidpp = fidp->next; - fidp->clunked = true; - return fidp; + return NULL; } void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu) @@ -423,7 +418,7 @@ void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu) V9fsState *s = pdu->s; V9fsFidState *f, *reclaim_list = NULL; - for (f = s->fid_list; f; f = f->next) { + QSIMPLEQ_FOREACH(f, &s->fid_list, next) { /* * Unlink fids cannot be reclaimed. Check * for them and skip them. Also skip fids @@ -505,7 +500,7 @@ static int coroutine_fn v9fs_mark_fids_unreclaim(V9fsPDU *pdu, V9fsPath *path) V9fsFidState *fidp; again: - for (fidp = s->fid_list; fidp; fidp = fidp->next) { + QSIMPLEQ_FOREACH(fidp, &s->fid_list, next) { if (fidp->path.size != path->size) { continue; } @@ -537,13 +532,13 @@ static void coroutine_fn virtfs_reset(V9fsPDU *pdu) V9fsFidState *fidp; /* Free all fids */ - while (s->fid_list) { + while (!QSIMPLEQ_EMPTY(&s->fid_list)) { /* Get fid */ - fidp = s->fid_list; + fidp = QSIMPLEQ_FIRST(&s->fid_list); fidp->ref++; /* Clunk fid */ - s->fid_list = fidp->next; + QSIMPLEQ_REMOVE(&s->fid_list, fidp, V9fsFidState, next); fidp->clunked = true; put_fid(pdu, fidp); @@ -3121,7 +3116,7 @@ static int coroutine_fn v9fs_complete_rename(V9fsPDU *pdu, V9fsFidState *fidp, * Fixup fid's pointing to the old name to * start pointing to the new name */ - for (tfidp = s->fid_list; tfidp; tfidp = tfidp->next) { + QSIMPLEQ_FOREACH(tfidp, &s->fid_list, next) { if (v9fs_path_is_ancestor(&fidp->path, &tfidp->path)) { /* replace the name */ v9fs_fix_path(&tfidp->path, &new_path, strlen(fidp->path.data)); @@ -3215,7 +3210,7 @@ static int coroutine_fn v9fs_fix_fid_paths(V9fsPDU *pdu, V9fsPath *olddir, * Fixup fid's pointing to the old name to * start pointing to the new name */ - for (tfidp = s->fid_list; tfidp; tfidp = tfidp->next) { + QSIMPLEQ_FOREACH(tfidp, &s->fid_list, next) { if (v9fs_path_is_ancestor(&oldpath, &tfidp->path)) { /* replace the name */ v9fs_fix_path(&tfidp->path, &newpath, strlen(oldpath.data)); @@ -4081,7 +4076,7 @@ int v9fs_device_realize_common(V9fsState *s, const V9fsTransport *t, s->ctx.fmode = fse->fmode; s->ctx.dmode = fse->dmode; - s->fid_list = NULL; + QSIMPLEQ_INIT(&s->fid_list); qemu_co_rwlock_init(&s->rename_lock); if (s->ops->init(&s->ctx, errp) < 0) { diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h index 93656323d1..85fb6930b0 100644 --- a/hw/9pfs/9p.h +++ b/hw/9pfs/9p.h @@ -280,7 +280,7 @@ struct V9fsFidState { uid_t uid; int ref; bool clunked; - V9fsFidState *next; + QSIMPLEQ_ENTRY(V9fsFidState) next; V9fsFidState *rclm_lst; }; @@ -339,7 +339,7 @@ typedef struct { struct V9fsState { QLIST_HEAD(, V9fsPDU) free_list; QLIST_HEAD(, V9fsPDU) active_list; - V9fsFidState *fid_list; + QSIMPLEQ_HEAD(, V9fsFidState) fid_list; FileOperations *ops; FsContext ctx; char *tag; -- cgit v1.2.3 From 20b7f45b22c3c00dc6f8bc73a66dffb6d436aa85 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Thu, 21 Jan 2021 19:15:10 +0100 Subject: 9pfs: Improve unreclaim loop If a fid was actually re-opened by v9fs_reopen_fid(), we re-traverse the fid list from the head in case some other request created a fid that needs to be marked unreclaimable as well (i.e. the client opened a new handle on the path that is being unlinked). This is suboptimal since most if not all fids that require it have likely been taken care of already. This is mostly the result of new fids being added to the head of the list. Since the list is now a QSIMPLEQ, add new fids at the end instead to avoid the need to rewind. Take a reference on the fid to ensure it doesn't go away during v9fs_reopen_fid() and that it can be safely passed to QSIMPLEQ_NEXT() afterwards. Since the associated put_fid() can also yield, same is done with the next fid. So the logic here is to get a reference on a fid and only put it back during the next iteration after we could get a reference on the next fid. Reviewed-by: Christian Schoenebeck Message-Id: <20210121181510.1459390-1-groug@kaod.org> Signed-off-by: Greg Kurz --- hw/9pfs/9p.c | 46 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 14 deletions(-) diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index b65f320e65..3864d014b4 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -311,7 +311,7 @@ static V9fsFidState *alloc_fid(V9fsState *s, int32_t fid) * reclaim won't close the file descriptor */ f->flags |= FID_REFERENCED; - QSIMPLEQ_INSERT_HEAD(&s->fid_list, f, next); + QSIMPLEQ_INSERT_TAIL(&s->fid_list, f, next); v9fs_readdir_init(s->proto_version, &f->fs.dir); v9fs_readdir_init(s->proto_version, &f->fs_reclaim.dir); @@ -497,32 +497,50 @@ static int coroutine_fn v9fs_mark_fids_unreclaim(V9fsPDU *pdu, V9fsPath *path) { int err; V9fsState *s = pdu->s; - V9fsFidState *fidp; + V9fsFidState *fidp, *fidp_next; -again: - QSIMPLEQ_FOREACH(fidp, &s->fid_list, next) { - if (fidp->path.size != path->size) { - continue; - } - if (!memcmp(fidp->path.data, path->data, path->size)) { + fidp = QSIMPLEQ_FIRST(&s->fid_list); + if (!fidp) { + return 0; + } + + /* + * v9fs_reopen_fid() can yield : a reference on the fid must be held + * to ensure its pointer remains valid and we can safely pass it to + * QSIMPLEQ_NEXT(). The corresponding put_fid() can also yield so + * we must keep a reference on the next fid as well. So the logic here + * is to get a reference on a fid and only put it back during the next + * iteration after we could get a reference on the next fid. Start with + * the first one. + */ + for (fidp->ref++; fidp; fidp = fidp_next) { + if (fidp->path.size == path->size && + !memcmp(fidp->path.data, path->data, path->size)) { /* Mark the fid non reclaimable. */ fidp->flags |= FID_NON_RECLAIMABLE; /* reopen the file/dir if already closed */ err = v9fs_reopen_fid(pdu, fidp); if (err < 0) { + put_fid(pdu, fidp); return err; } + } + + fidp_next = QSIMPLEQ_NEXT(fidp, next); + + if (fidp_next) { /* - * Go back to head of fid list because - * the list could have got updated when - * switched to the worker thread + * Ensure the next fid survives a potential clunk request during + * put_fid() below and v9fs_reopen_fid() in the next iteration. */ - if (err == 0) { - goto again; - } + fidp_next->ref++; } + + /* We're done with this fid */ + put_fid(pdu, fidp); } + return 0; } -- cgit v1.2.3 From 81f9766b7a16ccfcfd19e0b4525a5eeba862c851 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Fri, 22 Jan 2021 15:35:14 +0100 Subject: 9pfs: Convert reclaim list to QSLIST Use QSLIST instead of open-coding for a slightly improved readability. No behavioral change. Reviewed-by: Christian Schoenebeck Message-Id: <20210122143514.215780-1-groug@kaod.org> Signed-off-by: Greg Kurz --- hw/9pfs/9p.c | 17 ++++++++--------- hw/9pfs/9p.h | 2 +- 2 files changed, 9 insertions(+), 10 deletions(-) diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 3864d014b4..5a6e2c9d3d 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -416,7 +416,9 @@ void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu) { int reclaim_count = 0; V9fsState *s = pdu->s; - V9fsFidState *f, *reclaim_list = NULL; + V9fsFidState *f; + QSLIST_HEAD(, V9fsFidState) reclaim_list = + QSLIST_HEAD_INITIALIZER(reclaim_list); QSIMPLEQ_FOREACH(f, &s->fid_list, next) { /* @@ -448,8 +450,7 @@ void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu) * a clunk request won't free this fid */ f->ref++; - f->rclm_lst = reclaim_list; - reclaim_list = f; + QSLIST_INSERT_HEAD(&reclaim_list, f, reclaim_next); f->fs_reclaim.fd = f->fs.fd; f->fs.fd = -1; reclaim_count++; @@ -461,8 +462,7 @@ void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu) * a clunk request won't free this fid */ f->ref++; - f->rclm_lst = reclaim_list; - reclaim_list = f; + QSLIST_INSERT_HEAD(&reclaim_list, f, reclaim_next); f->fs_reclaim.dir.stream = f->fs.dir.stream; f->fs.dir.stream = NULL; reclaim_count++; @@ -476,15 +476,14 @@ void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu) * Now close the fid in reclaim list. Free them if they * are already clunked. */ - while (reclaim_list) { - f = reclaim_list; - reclaim_list = f->rclm_lst; + while (!QSLIST_EMPTY(&reclaim_list)) { + f = QSLIST_FIRST(&reclaim_list); + QSLIST_REMOVE(&reclaim_list, f, V9fsFidState, reclaim_next); if (f->fid_type == P9_FID_FILE) { v9fs_co_close(pdu, &f->fs_reclaim); } else if (f->fid_type == P9_FID_DIR) { v9fs_co_closedir(pdu, &f->fs_reclaim); } - f->rclm_lst = NULL; /* * Now drop the fid reference, free it * if clunked. diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h index 85fb6930b0..00381591ff 100644 --- a/hw/9pfs/9p.h +++ b/hw/9pfs/9p.h @@ -281,7 +281,7 @@ struct V9fsFidState { int ref; bool clunked; QSIMPLEQ_ENTRY(V9fsFidState) next; - V9fsFidState *rclm_lst; + QSLIST_ENTRY(V9fsFidState) reclaim_next; }; typedef enum AffixType_t { -- cgit v1.2.3