From aa45dadd34e44fcd6a9df4b395bee5b5633b4cec Mon Sep 17 00:00:00 2001 From: Shyam Prasad N Date: Sat, 1 Jan 2022 12:50:21 +0000 Subject: [PATCH] cifs: change iface_list from array to sorted linked list A server's published interface list can change over time, and needs to be updated. We've storing iface_list as a simple array, which makes it difficult to manipulate an existing list. With this change, iface_list is modified into a linked list of interfaces, which is kept sorted by speed. Also added a reference counter for an iface entry, so that each channel can maintain a backpointer to the iface and drop it easily when needed. Signed-off-by: Shyam Prasad N Signed-off-by: Steve French --- fs/cifs/cifs_debug.c | 12 ++-- fs/cifs/cifsglob.h | 54 +++++++++++++++- fs/cifs/connect.c | 6 +- fs/cifs/misc.c | 9 ++- fs/cifs/sess.c | 78 +++++++++++------------ fs/cifs/smb2ops.c | 171 +++++++++++++++++++++++++++------------------------ 6 files changed, 201 insertions(+), 129 deletions(-) diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c index 1dd995e..2cfbac8b 100644 --- a/fs/cifs/cifs_debug.c +++ b/fs/cifs/cifs_debug.c @@ -162,6 +162,8 @@ cifs_dump_iface(struct seq_file *m, struct cifs_server_iface *iface) seq_printf(m, "\t\tIPv4: %pI4\n", &ipv4->sin_addr); else if (iface->sockaddr.ss_family == AF_INET6) seq_printf(m, "\t\tIPv6: %pI6\n", &ipv6->sin6_addr); + if (!iface->is_active) + seq_puts(m, "\t\t[for-cleanup]\n"); } static int cifs_debug_files_proc_show(struct seq_file *m, void *v) @@ -221,6 +223,7 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v) struct TCP_Server_Info *server; struct cifs_ses *ses; struct cifs_tcon *tcon; + struct cifs_server_iface *iface; int c, i, j; seq_puts(m, @@ -456,11 +459,10 @@ skip_rdma: if (ses->iface_count) seq_printf(m, "\n\n\tServer interfaces: %zu", ses->iface_count); - for (j = 0; j < ses->iface_count; j++) { - struct cifs_server_iface *iface; - - iface = &ses->iface_list[j]; - seq_printf(m, "\n\t%d)", j+1); + j = 0; + list_for_each_entry(iface, &ses->iface_list, + iface_head) { + seq_printf(m, "\n\t%d)", ++j); cifs_dump_iface(m, iface); if (is_ses_using_iface(ses, iface)) seq_puts(m, "\t\t[CONNECTED]\n"); diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index e773716..7fc2add 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -933,15 +933,67 @@ static inline void cifs_set_net_ns(struct TCP_Server_Info *srv, struct net *net) #endif struct cifs_server_iface { + struct list_head iface_head; + struct kref refcount; size_t speed; unsigned int rdma_capable : 1; unsigned int rss_capable : 1; + unsigned int is_active : 1; /* unset if non existent */ struct sockaddr_storage sockaddr; }; +/* release iface when last ref is dropped */ +static inline void +release_iface(struct kref *ref) +{ + struct cifs_server_iface *iface = container_of(ref, + struct cifs_server_iface, + refcount); + list_del_init(&iface->iface_head); + kfree(iface); +} + +/* + * compare two interfaces a and b + * return 0 if everything matches. + * return 1 if a has higher link speed, or rdma capable, or rss capable + * return -1 otherwise. + */ +static inline int +iface_cmp(struct cifs_server_iface *a, struct cifs_server_iface *b) +{ + int cmp_ret = 0; + + WARN_ON(!a || !b); + if (a->speed == b->speed) { + if (a->rdma_capable == b->rdma_capable) { + if (a->rss_capable == b->rss_capable) { + cmp_ret = memcmp(&a->sockaddr, &b->sockaddr, + sizeof(a->sockaddr)); + if (!cmp_ret) + return 0; + else if (cmp_ret > 0) + return 1; + else + return -1; + } else if (a->rss_capable > b->rss_capable) + return 1; + else + return -1; + } else if (a->rdma_capable > b->rdma_capable) + return 1; + else + return -1; + } else if (a->speed > b->speed) + return 1; + else + return -1; +} + struct cifs_chan { unsigned int in_reconnect : 1; /* if session setup in progress for this channel */ struct TCP_Server_Info *server; + struct cifs_server_iface *iface; /* interface in use */ __u8 signkey[SMB3_SIGN_KEY_SIZE]; }; @@ -993,7 +1045,7 @@ struct cifs_ses { */ spinlock_t iface_lock; /* ========= begin: protected by iface_lock ======== */ - struct cifs_server_iface *iface_list; + struct list_head iface_list; size_t iface_count; unsigned long iface_last_update; /* jiffies */ /* ========= end: protected by iface_lock ======== */ diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 1849e341..248fe18 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1894,9 +1894,11 @@ void cifs_put_smb_ses(struct cifs_ses *ses) int i; for (i = 1; i < chan_count; i++) { - spin_unlock(&ses->chan_lock); + if (ses->chans[i].iface) { + kref_put(&ses->chans[i].iface->refcount, release_iface); + ses->chans[i].iface = NULL; + } cifs_put_tcp_session(ses->chans[i].server, 0); - spin_lock(&ses->chan_lock); ses->chans[i].server = NULL; } } diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index c69e1240d..0e84e6f 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -75,6 +75,7 @@ sesInfoAlloc(void) INIT_LIST_HEAD(&ret_buf->tcon_list); mutex_init(&ret_buf->session_mutex); spin_lock_init(&ret_buf->iface_lock); + INIT_LIST_HEAD(&ret_buf->iface_list); spin_lock_init(&ret_buf->chan_lock); } return ret_buf; @@ -83,6 +84,8 @@ sesInfoAlloc(void) void sesInfoFree(struct cifs_ses *buf_to_free) { + struct cifs_server_iface *iface = NULL, *niface = NULL; + if (buf_to_free == NULL) { cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n"); return; @@ -96,7 +99,11 @@ sesInfoFree(struct cifs_ses *buf_to_free) kfree(buf_to_free->user_name); kfree(buf_to_free->domainName); kfree_sensitive(buf_to_free->auth_key.response); - kfree(buf_to_free->iface_list); + spin_lock(&buf_to_free->iface_lock); + list_for_each_entry_safe(iface, niface, &buf_to_free->iface_list, + iface_head) + kref_put(&iface->refcount, release_iface); + spin_unlock(&buf_to_free->iface_lock); kfree_sensitive(buf_to_free); } diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c index d417de3..d7b6e56 100644 --- a/fs/cifs/sess.c +++ b/fs/cifs/sess.c @@ -58,7 +58,7 @@ bool is_ses_using_iface(struct cifs_ses *ses, struct cifs_server_iface *iface) spin_lock(&ses->chan_lock); for (i = 0; i < ses->chan_count; i++) { - if (is_server_using_iface(ses->chans[i].server, iface)) { + if (ses->chans[i].iface == iface) { spin_unlock(&ses->chan_lock); return true; } @@ -151,11 +151,9 @@ int cifs_try_adding_channels(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses) { int old_chan_count, new_chan_count; int left; - int i = 0; int rc = 0; int tries = 0; - struct cifs_server_iface *ifaces = NULL; - size_t iface_count; + struct cifs_server_iface *iface = NULL, *niface = NULL; spin_lock(&ses->chan_lock); @@ -185,32 +183,16 @@ int cifs_try_adding_channels(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses) spin_unlock(&ses->chan_lock); /* - * Make a copy of the iface list at the time and use that - * instead so as to not hold the iface spinlock for opening - * channels - */ - spin_lock(&ses->iface_lock); - iface_count = ses->iface_count; - if (iface_count <= 0) { - spin_unlock(&ses->iface_lock); - cifs_dbg(VFS, "no iface list available to open channels\n"); - return 0; - } - ifaces = kmemdup(ses->iface_list, iface_count*sizeof(*ifaces), - GFP_ATOMIC); - if (!ifaces) { - spin_unlock(&ses->iface_lock); - return 0; - } - spin_unlock(&ses->iface_lock); - - /* * Keep connecting to same, fastest, iface for all channels as * long as its RSS. Try next fastest one if not RSS or channel * creation fails. */ + spin_lock(&ses->iface_lock); + iface = list_first_entry(&ses->iface_list, struct cifs_server_iface, + iface_head); + spin_unlock(&ses->iface_lock); + while (left > 0) { - struct cifs_server_iface *iface; tries++; if (tries > 3*ses->chan_max) { @@ -219,27 +201,46 @@ int cifs_try_adding_channels(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses) break; } - iface = &ifaces[i]; - if (is_ses_using_iface(ses, iface) && !iface->rss_capable) { - i = (i+1) % iface_count; - continue; + spin_lock(&ses->iface_lock); + if (!ses->iface_count) { + spin_unlock(&ses->iface_lock); + break; } - rc = cifs_ses_add_channel(cifs_sb, ses, iface); - if (rc) { - cifs_dbg(FYI, "failed to open extra channel on iface#%d rc=%d\n", - i, rc); - i = (i+1) % iface_count; - continue; + list_for_each_entry_safe_from(iface, niface, &ses->iface_list, + iface_head) { + /* skip ifaces that are unusable */ + if (!iface->is_active || + (is_ses_using_iface(ses, iface) && + !iface->rss_capable)) { + continue; + } + + /* take ref before unlock */ + kref_get(&iface->refcount); + + spin_unlock(&ses->iface_lock); + rc = cifs_ses_add_channel(cifs_sb, ses, iface); + spin_lock(&ses->iface_lock); + + if (rc) { + cifs_dbg(VFS, "failed to open extra channel on iface:%pIS rc=%d\n", + &iface->sockaddr, + rc); + kref_put(&iface->refcount, release_iface); + continue; + } + + cifs_dbg(FYI, "successfully opened new channel on iface:%pIS\n", + &iface->sockaddr); + break; } + spin_unlock(&ses->iface_lock); - cifs_dbg(FYI, "successfully opened new channel on iface#%d\n", - i); left--; new_chan_count++; } - kfree(ifaces); return new_chan_count - old_chan_count; } @@ -355,6 +356,7 @@ cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses, spin_unlock(&ses->chan_lock); goto out; } + chan->iface = iface; ses->chan_count++; atomic_set(&ses->chan_seq, 0); diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 8543caf..db4ccf1 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -512,73 +512,41 @@ smb3_negotiate_rsize(struct cifs_tcon *tcon, struct smb3_fs_context *ctx) static int parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf, size_t buf_len, - struct cifs_server_iface **iface_list, - size_t *iface_count) + struct cifs_ses *ses) { struct network_interface_info_ioctl_rsp *p; struct sockaddr_in *addr4; struct sockaddr_in6 *addr6; struct iface_info_ipv4 *p4; struct iface_info_ipv6 *p6; - struct cifs_server_iface *info; + struct cifs_server_iface *info = NULL, *iface = NULL, *niface = NULL; + struct cifs_server_iface tmp_iface; ssize_t bytes_left; size_t next = 0; int nb_iface = 0; - int rc = 0; - - *iface_list = NULL; - *iface_count = 0; - - /* - * Fist pass: count and sanity check - */ + int rc = 0, ret = 0; bytes_left = buf_len; p = buf; - while (bytes_left >= sizeof(*p)) { - nb_iface++; - next = le32_to_cpu(p->Next); - if (!next) { - bytes_left -= sizeof(*p); - break; - } - p = (struct network_interface_info_ioctl_rsp *)((u8 *)p+next); - bytes_left -= next; - } - - if (!nb_iface) { - cifs_dbg(VFS, "%s: malformed interface info\n", __func__); - rc = -EINVAL; - goto out; - } - - /* Azure rounds the buffer size up 8, to a 16 byte boundary */ - if ((bytes_left > 8) || p->Next) - cifs_dbg(VFS, "%s: incomplete interface info\n", __func__); - + spin_lock(&ses->iface_lock); /* - * Second pass: extract info to internal structure + * Go through iface_list and do kref_put to remove + * any unused ifaces. ifaces in use will be removed + * when the last user calls a kref_put on it */ - - *iface_list = kcalloc(nb_iface, sizeof(**iface_list), GFP_KERNEL); - if (!*iface_list) { - rc = -ENOMEM; - goto out; + list_for_each_entry_safe(iface, niface, &ses->iface_list, + iface_head) { + iface->is_active = 0; + kref_put(&iface->refcount, release_iface); } + spin_unlock(&ses->iface_lock); - info = *iface_list; - bytes_left = buf_len; - p = buf; while (bytes_left >= sizeof(*p)) { - info->speed = le64_to_cpu(p->LinkSpeed); - info->rdma_capable = le32_to_cpu(p->Capability & RDMA_CAPABLE) ? 1 : 0; - info->rss_capable = le32_to_cpu(p->Capability & RSS_CAPABLE) ? 1 : 0; - - cifs_dbg(FYI, "%s: adding iface %zu\n", __func__, *iface_count); - cifs_dbg(FYI, "%s: speed %zu bps\n", __func__, info->speed); - cifs_dbg(FYI, "%s: capabilities 0x%08x\n", __func__, - le32_to_cpu(p->Capability)); + memset(&tmp_iface, 0, sizeof(tmp_iface)); + tmp_iface.speed = le64_to_cpu(p->LinkSpeed); + tmp_iface.rdma_capable = le32_to_cpu(p->Capability & RDMA_CAPABLE) ? 1 : 0; + tmp_iface.rss_capable = le32_to_cpu(p->Capability & RSS_CAPABLE) ? 1 : 0; switch (p->Family) { /* @@ -587,7 +555,7 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf, * conversion explicit in case either one changes. */ case INTERNETWORK: - addr4 = (struct sockaddr_in *)&info->sockaddr; + addr4 = (struct sockaddr_in *)&tmp_iface.sockaddr; p4 = (struct iface_info_ipv4 *)p->Buffer; addr4->sin_family = AF_INET; memcpy(&addr4->sin_addr, &p4->IPv4Address, 4); @@ -599,7 +567,7 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf, &addr4->sin_addr); break; case INTERNETWORKV6: - addr6 = (struct sockaddr_in6 *)&info->sockaddr; + addr6 = (struct sockaddr_in6 *)&tmp_iface.sockaddr; p6 = (struct iface_info_ipv6 *)p->Buffer; addr6->sin6_family = AF_INET6; memcpy(&addr6->sin6_addr, &p6->IPv6Address, 16); @@ -619,36 +587,88 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf, goto next_iface; } - (*iface_count)++; - info++; + /* + * The iface_list is assumed to be sorted by speed. + * Check if the new interface exists in that list. + * NEVER change iface. it could be in use. + * Add a new one instead + */ + spin_lock(&ses->iface_lock); + iface = niface = NULL; + list_for_each_entry_safe(iface, niface, &ses->iface_list, + iface_head) { + ret = iface_cmp(iface, &tmp_iface); + if (!ret) { + /* just get a ref so that it doesn't get picked/freed */ + iface->is_active = 1; + kref_get(&iface->refcount); + spin_unlock(&ses->iface_lock); + goto next_iface; + } else if (ret < 0) { + /* all remaining ifaces are slower */ + kref_get(&iface->refcount); + break; + } + } + spin_unlock(&ses->iface_lock); + + /* no match. insert the entry in the list */ + info = kmalloc(sizeof(struct cifs_server_iface), + GFP_KERNEL); + if (!info) { + rc = -ENOMEM; + goto out; + } + memcpy(info, &tmp_iface, sizeof(tmp_iface)); + + /* add this new entry to the list */ + kref_init(&info->refcount); + info->is_active = 1; + + cifs_dbg(FYI, "%s: adding iface %zu\n", __func__, ses->iface_count); + cifs_dbg(FYI, "%s: speed %zu bps\n", __func__, info->speed); + cifs_dbg(FYI, "%s: capabilities 0x%08x\n", __func__, + le32_to_cpu(p->Capability)); + + spin_lock(&ses->iface_lock); + if (!list_entry_is_head(iface, &ses->iface_list, iface_head)) { + list_add_tail(&info->iface_head, &iface->iface_head); + kref_put(&iface->refcount, release_iface); + } else + list_add_tail(&info->iface_head, &ses->iface_list); + spin_unlock(&ses->iface_lock); + + ses->iface_count++; + ses->iface_last_update = jiffies; next_iface: + nb_iface++; next = le32_to_cpu(p->Next); - if (!next) + if (!next) { + bytes_left -= sizeof(*p); break; + } p = (struct network_interface_info_ioctl_rsp *)((u8 *)p+next); bytes_left -= next; } - if (!*iface_count) { + if (!nb_iface) { + cifs_dbg(VFS, "%s: malformed interface info\n", __func__); rc = -EINVAL; goto out; } -out: - if (rc) { - kfree(*iface_list); - *iface_count = 0; - *iface_list = NULL; - } - return rc; -} + /* Azure rounds the buffer size up 8, to a 16 byte boundary */ + if ((bytes_left > 8) || p->Next) + cifs_dbg(VFS, "%s: incomplete interface info\n", __func__); -static int compare_iface(const void *ia, const void *ib) -{ - const struct cifs_server_iface *a = (struct cifs_server_iface *)ia; - const struct cifs_server_iface *b = (struct cifs_server_iface *)ib; - return a->speed == b->speed ? 0 : (a->speed > b->speed ? -1 : 1); + if (!ses->iface_count) { + rc = -EINVAL; + goto out; + } + +out: + return rc; } static int @@ -657,8 +677,6 @@ SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon) int rc; unsigned int ret_data_len = 0; struct network_interface_info_ioctl_rsp *out_buf = NULL; - struct cifs_server_iface *iface_list; - size_t iface_count; struct cifs_ses *ses = tcon->ses; rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID, @@ -674,21 +692,10 @@ SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon) goto out; } - rc = parse_server_interfaces(out_buf, ret_data_len, - &iface_list, &iface_count); + rc = parse_server_interfaces(out_buf, ret_data_len, ses); if (rc) goto out; - /* sort interfaces from fastest to slowest */ - sort(iface_list, iface_count, sizeof(*iface_list), compare_iface, NULL); - - spin_lock(&ses->iface_lock); - kfree(ses->iface_list); - ses->iface_list = iface_list; - ses->iface_count = iface_count; - ses->iface_last_update = jiffies; - spin_unlock(&ses->iface_lock); - out: kfree(out_buf); return rc; -- 2.7.4