This removes the limit for p9 fids and the huge fid array that came along with it. Instead, it dynamically allocates fids and stores them in a rb-tree.
This is useful when the guest needs a lot of fids, such as when stress testing guests. Signed-off-by: Sasha Levin <[email protected]> --- tools/kvm/include/kvm/virtio-9p.h | 5 +- tools/kvm/virtio/9p.c | 149 ++++++++++++++++++++++++++---------- 2 files changed, 110 insertions(+), 44 deletions(-) diff --git a/tools/kvm/include/kvm/virtio-9p.h b/tools/kvm/include/kvm/virtio-9p.h index 5902701..186fe05 100644 --- a/tools/kvm/include/kvm/virtio-9p.h +++ b/tools/kvm/include/kvm/virtio-9p.h @@ -7,12 +7,12 @@ #include <sys/types.h> #include <dirent.h> #include <linux/list.h> +#include <linux/rbtree.h> #define NUM_VIRT_QUEUES 1 #define VIRTQUEUE_NUM 128 #define VIRTIO_9P_DEFAULT_TAG "kvm_9p" #define VIRTIO_9P_HDR_LEN (sizeof(u32)+sizeof(u8)+sizeof(u16)) -#define VIRTIO_9P_MAX_FID 16384 #define VIRTIO_9P_VERSION_DOTL "9P2000.L" #define MAX_TAG_LEN 32 @@ -31,6 +31,7 @@ struct p9_fid { char *path; DIR *dir; int fd; + struct rb_node node; }; struct p9_dev_job { @@ -42,6 +43,7 @@ struct p9_dev_job { struct p9_dev { struct list_head list; struct virtio_device vdev; + struct rb_root fids; struct virtio_9p_config *config; u32 features; @@ -49,7 +51,6 @@ struct p9_dev { /* virtio queue */ struct virt_queue vqs[NUM_VIRT_QUEUES]; struct p9_dev_job jobs[NUM_VIRT_QUEUES]; - struct p9_fid fids[VIRTIO_9P_MAX_FID]; char root_dir[PATH_MAX]; }; diff --git a/tools/kvm/virtio/9p.c b/tools/kvm/virtio/9p.c index 830fc50..201ea95 100644 --- a/tools/kvm/virtio/9p.c +++ b/tools/kvm/virtio/9p.c @@ -22,12 +22,65 @@ static LIST_HEAD(devs); static int compat_id = -1; +static int insert_new_fid(struct p9_dev *dev, struct p9_fid *fid); +static struct p9_fid *find_or_create_fid(struct p9_dev *dev, u32 fid) +{ + struct rb_node *node = dev->fids.rb_node; + struct p9_fid *pfid = NULL; + + while (node) { + struct p9_fid *cur = rb_entry(node, struct p9_fid, node); + + if (fid < cur->fid) { + node = node->rb_left; + } else if (fid > cur->fid) { + node = node->rb_right; + } else { + return cur; + } + } + + pfid = calloc(sizeof(*pfid), 1); + if (!pfid) + return NULL; + + pfid->fid = fid; + strcpy(pfid->abs_path, dev->root_dir); + pfid->path = pfid->abs_path + strlen(dev->root_dir); + + insert_new_fid(dev, pfid); + + return pfid; +} + +static int insert_new_fid(struct p9_dev *dev, struct p9_fid *fid) +{ + struct rb_node **node = &(dev->fids.rb_node), *parent = NULL; + + while (*node) { + int result = fid->fid - rb_entry(*node, struct p9_fid, node)->fid; + + parent = *node; + if (result < 0) + node = &((*node)->rb_left); + else if (result > 0) + node = &((*node)->rb_right); + else + return -EEXIST; + } + + rb_link_node(&fid->node, parent, node); + rb_insert_color(&fid->node, &dev->fids); + return 0; +} + static struct p9_fid *get_fid(struct p9_dev *p9dev, int fid) { - if (fid >= VIRTIO_9P_MAX_FID) - die("virtio-9p max FID (%u) reached!", VIRTIO_9P_MAX_FID); + struct p9_fid *new; + + new = find_or_create_fid(p9dev, fid); - return &p9dev->fids[fid]; + return new; } /* Warning: Immediately use value returned from this function */ @@ -52,15 +105,36 @@ static void stat2qid(struct stat *st, struct p9_qid *qid) static void close_fid(struct p9_dev *p9dev, u32 fid) { - if (p9dev->fids[fid].fd > 0) { - close(p9dev->fids[fid].fd); - p9dev->fids[fid].fd = -1; - } - if (p9dev->fids[fid].dir) { - closedir(p9dev->fids[fid].dir); - p9dev->fids[fid].dir = NULL; + struct p9_fid *pfid = get_fid(p9dev, fid); + + if (pfid->fd > 0) + close(pfid->fd); + + if (pfid->dir) + closedir(pfid->dir); + + rb_erase(&pfid->node, &p9dev->fids); + free(pfid); +} + +static void clear_all_fids(struct p9_dev *p9dev) +{ + struct rb_node *node = rb_first(&p9dev->fids); + + while (node) { + struct p9_fid *fid = rb_entry(node, struct p9_fid, node); + + if (fid->fd > 0) + close(fid->fd); + + if (fid->dir) + closedir(fid->dir); + + rb_erase(&fid->node, &p9dev->fids); + free(fid); + + node = rb_first(&p9dev->fids); } - p9dev->fids[fid].fid = P9_NOFID; } static void virtio_p9_set_reply_header(struct p9_pdu *pdu, u32 size) @@ -213,7 +287,6 @@ static void virtio_p9_create(struct p9_dev *p9dev, fd = open(full_path, flags | O_CREAT, mode); if (fd < 0) goto err_out; - close_fid(p9dev, dfid_val); dfid->fd = fd; if (lstat(full_path, &st) < 0) @@ -290,7 +363,7 @@ static void virtio_p9_walk(struct p9_dev *p9dev, u16 nwqid; u16 nwname; struct p9_qid wqid; - struct p9_fid *new_fid; + struct p9_fid *new_fid, *old_fid; u32 fid_val, newfid_val; @@ -323,7 +396,6 @@ static void virtio_p9_walk(struct p9_dev *p9dev, stat2qid(&st, &wqid); new_fid->is_dir = S_ISDIR(st.st_mode); strcpy(new_fid->path, tmp); - new_fid->fid = newfid_val; new_fid->uid = fid->uid; nwqid++; virtio_p9_pdu_writef(pdu, "Q", &wqid); @@ -333,10 +405,10 @@ static void virtio_p9_walk(struct p9_dev *p9dev, * update write_offset so our outlen get correct value */ pdu->write_offset += sizeof(u16); - new_fid->is_dir = p9dev->fids[fid_val].is_dir; - strcpy(new_fid->path, p9dev->fids[fid_val].path); - new_fid->fid = newfid_val; - new_fid->uid = p9dev->fids[fid_val].uid; + old_fid = get_fid(p9dev, fid_val); + new_fid->is_dir = old_fid->is_dir; + strcpy(new_fid->path, old_fid->path); + new_fid->uid = old_fid->uid; } *outlen = pdu->write_offset; pdu->write_offset = VIRTIO_9P_HDR_LEN; @@ -351,7 +423,6 @@ err_out: static void virtio_p9_attach(struct p9_dev *p9dev, struct p9_pdu *pdu, u32 *outlen) { - int i; char *uname; char *aname; struct stat st; @@ -365,9 +436,7 @@ static void virtio_p9_attach(struct p9_dev *p9dev, free(uname); free(aname); - /* Reset everything */ - for (i = 0; i < VIRTIO_9P_MAX_FID; i++) - p9dev->fids[i].fid = P9_NOFID; + clear_all_fids(p9dev); if (lstat(p9dev->root_dir, &st) < 0) goto err_out; @@ -375,7 +444,6 @@ static void virtio_p9_attach(struct p9_dev *p9dev, stat2qid(&st, &qid); fid = get_fid(p9dev, fid_val); - fid->fid = fid_val; fid->uid = uid; fid->is_dir = 1; strcpy(fid->path, "/"); @@ -729,7 +797,6 @@ static void virtio_p9_rename(struct p9_dev *p9dev, ret = rename(fid->abs_path, full_path); if (ret < 0) goto err_out; - close_fid(p9dev, fid_val); *outlen = pdu->write_offset; virtio_p9_set_reply_header(pdu, *outlen); return; @@ -1001,10 +1068,24 @@ static void virtio_p9_fix_path(char *fid_path, char *old_name, char *new_name) return; } +static void rename_fids(struct p9_dev *p9dev, char *old_name, char *new_name) +{ + struct rb_node *node = rb_first(&p9dev->fids); + + while (node) { + struct p9_fid *fid = rb_entry(node, struct p9_fid, node); + + if (fid->fid != P9_NOFID && virtio_p9_ancestor(fid->path, old_name)) { + virtio_p9_fix_path(fid->path, old_name, new_name); + } + node = rb_next(node); + } +} + static void virtio_p9_renameat(struct p9_dev *p9dev, struct p9_pdu *pdu, u32 *outlen) { - int i, ret; + int ret; char *old_name, *new_name; u32 old_dfid_val, new_dfid_val; struct p9_fid *old_dfid, *new_dfid; @@ -1026,13 +1107,7 @@ static void virtio_p9_renameat(struct p9_dev *p9dev, * Now fix path in other fids, if the renamed path is part of * that. */ - for (i = 0; i < VIRTIO_9P_MAX_FID; i++) { - if (get_fid(p9dev, i)->fid != P9_NOFID && - virtio_p9_ancestor(get_fid(p9dev, i)->path, old_name)) { - virtio_p9_fix_path(get_fid(p9dev, i)->path, old_name, - new_name); - } - } + rename_fids(p9dev, old_name, new_name); free(old_name); free(new_name); *outlen = pdu->write_offset; @@ -1289,7 +1364,6 @@ int virtio_9p__init(struct kvm *kvm) int virtio_9p__register(struct kvm *kvm, const char *root, const char *tag_name) { struct p9_dev *p9dev; - u32 i, root_len; int err = 0; p9dev = calloc(1, sizeof(*p9dev)); @@ -1306,15 +1380,6 @@ int virtio_9p__register(struct kvm *kvm, const char *root, const char *tag_name) } strcpy(p9dev->root_dir, root); - root_len = strlen(root); - /* - * We prefix the full path in all fids, This allows us to get the - * absolute path of an fid without playing with strings. - */ - for (i = 0; i < VIRTIO_9P_MAX_FID; i++) { - strcpy(get_fid(p9dev, i)->abs_path, root); - get_fid(p9dev, i)->path = get_fid(p9dev, i)->abs_path + root_len; - } p9dev->config->tag_len = strlen(tag_name); if (p9dev->config->tag_len > MAX_TAG_LEN) { err = -EINVAL; -- 1.7.8.6 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
