mainline inclusion from mainline-v6.15-rc1 commit a091d9711bdee46a76fa14fad31cb261a6dad74a category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IC1OPD CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Currently, when a SMB connection is reset and renegotiated with the server, there's no way to update all related mount points with new negotiated sizes. This is because while superblocks (cifs_sb_info) maintain references to tree connections (tcon) through tcon_link structures, there is no reverse mapping from a tcon back to all the superblocks using it. This patch adds a bidirectional relationship between tcon and cifs_sb_info structures by: 1. Adding a cifs_sb_list to tcon structure with appropriate locking 2. Adding tcon_sb_link to cifs_sb_info to join the list 3. Managing the list entries during mount and umount operations The bidirectional relationship enables future functionality to locate and update all superblocks connected to a specific tree connection, such as: - Updating negotiated parameters after reconnection - Efficiently notifying all affected mounts of capability changes This is the first part of a series to improve connection resilience by keeping all mount parameters in sync with server capabilities after reconnection. Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com> Conflicts: fs/cifs/cifs_fs_sb.h fs/cifs/cifsglob.h fs/cifs/connect.c fs/cifs/misc.c fs/smb/client/cifs_fs_sb.h fs/smb/client/cifsglob.h fs/smb/client/connect.c fs/smb/client/misc.c [The mainline code has already undergone multiple refactoring sessions.] Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com> --- fs/cifs/cifs_fs_sb.h | 1 + fs/cifs/cifsglob.h | 3 ++- fs/cifs/connect.c | 15 +++++++++++++++ fs/cifs/misc.c | 2 ++ 4 files changed, 20 insertions(+), 1 deletion(-) diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h index aba2b48d4da1..790347e16841 100644 --- a/fs/cifs/cifs_fs_sb.h +++ b/fs/cifs/cifs_fs_sb.h @@ -52,10 +52,11 @@ #define CIFS_MOUNT_UID_FROM_ACL 0x2000000 /* try to get UID via special SID */ #define CIFS_MOUNT_NO_HANDLE_CACHE 0x4000000 /* disable caching dir handles */ struct cifs_sb_info { struct rb_root tlink_tree; + struct list_head tcon_sb_link; spinlock_t tlink_tree_lock; struct tcon_link *master_tlink; struct nls_table *local_nls; unsigned int rsize; unsigned int wsize; diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index f9abe37c549c..3bd4e369f91a 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -1021,11 +1021,12 @@ struct cifs_tcon { u64 resource_id; /* server resource id */ struct fscache_cookie *fscache; /* cookie for share */ #endif struct list_head pending_opens; /* list of incomplete opens */ struct cached_fid crfid; /* Cached root fid */ - /* BB add field for back pointer to sb struct(s)? */ + struct list_head cifs_sb_list; + spinlock_t sb_list_lock; }; /* * This is a refcounted and timestamped container for a tcon pointer. The * container holds a tcon reference. It is considered safe to free one of diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index fd4ec5bd35f6..2861dd569d41 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -3835,10 +3835,11 @@ void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon, int cifs_setup_cifs_sb(struct smb_vol *pvolume_info, struct cifs_sb_info *cifs_sb) { INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks); + INIT_LIST_HEAD(&cifs_sb->tcon_sb_link); spin_lock_init(&cifs_sb->tlink_tree_lock); cifs_sb->tlink_tree = RB_ROOT; /* @@ -4345,10 +4346,14 @@ cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info) cifs_sb->master_tlink = tlink; spin_lock(&cifs_sb->tlink_tree_lock); tlink_rb_insert(&cifs_sb->tlink_tree, tlink); spin_unlock(&cifs_sb->tlink_tree_lock); + spin_lock(&tcon->sb_list_lock); + list_add(&cifs_sb->tcon_sb_link, &tcon->cifs_sb_list); + spin_unlock(&tcon->sb_list_lock); + queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks, TLINK_IDLE_EXPIRE); mount_fail_check: /* on error free sesinfo and tcon struct if needed */ @@ -4542,13 +4547,23 @@ void cifs_umount(struct cifs_sb_info *cifs_sb) { struct rb_root *root = &cifs_sb->tlink_tree; struct rb_node *node; struct tcon_link *tlink; + struct cifs_tcon *tcon = NULL; cancel_delayed_work_sync(&cifs_sb->prune_tlinks); + if (cifs_sb->master_tlink) { + tcon = cifs_sb->master_tlink->tl_tcon; + if (tcon) { + spin_lock(&tcon->sb_list_lock); + list_del_init(&cifs_sb->tcon_sb_link); + spin_unlock(&tcon->sb_list_lock); + } + } + spin_lock(&cifs_sb->tlink_tree_lock); while ((node = rb_first(root))) { tlink = rb_entry(node, struct tcon_link, tl_rbnode); cifs_get_tlink(tlink); clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags); diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index a1563987de48..006f05ad2b80 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -124,11 +124,13 @@ tconInfoAlloc(void) atomic_inc(&tconInfoAllocCount); ret_buf->tidStatus = CifsNew; ++ret_buf->tc_count; INIT_LIST_HEAD(&ret_buf->openFileList); INIT_LIST_HEAD(&ret_buf->tcon_list); + INIT_LIST_HEAD(&ret_buf->cifs_sb_list); spin_lock_init(&ret_buf->open_file_lock); + spin_lock_init(&ret_buf->sb_list_lock); mutex_init(&ret_buf->crfid.fid_mutex); spin_lock_init(&ret_buf->stat_lock); return ret_buf; } -- 2.39.2