diff options
| -rw-r--r-- | fs/smb/server/smb2pdu.c | 6 | ||||
| -rw-r--r-- | fs/smb/server/vfs_cache.c | 179 | ||||
| -rw-r--r-- | fs/smb/server/vfs_cache.h | 4 |
3 files changed, 164 insertions, 25 deletions
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 47b7af631f7b..62d4399a993d 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -3767,8 +3767,10 @@ err_out1: err_out2: if (!rc) { - ksmbd_update_fstate(&work->sess->file_table, fp, FP_INITED); - rc = ksmbd_iov_pin_rsp(work, (void *)rsp, iov_len); + rc = ksmbd_update_fstate(&work->sess->file_table, fp, + FP_INITED); + if (!rc) + rc = ksmbd_iov_pin_rsp(work, (void *)rsp, iov_len); } if (rc) { if (rc == -EINVAL) diff --git a/fs/smb/server/vfs_cache.c b/fs/smb/server/vfs_cache.c index 4a18107937cc..dc4037ef1834 100644 --- a/fs/smb/server/vfs_cache.c +++ b/fs/smb/server/vfs_cache.c @@ -431,13 +431,13 @@ static void ksmbd_remove_durable_fd(struct ksmbd_file *fp) static void __ksmbd_remove_fd(struct ksmbd_file_table *ft, struct ksmbd_file *fp) { - if (!has_file_id(fp->volatile_id)) - return; - down_write(&fp->f_ci->m_lock); list_del_init(&fp->node); up_write(&fp->f_ci->m_lock); + if (!has_file_id(fp->volatile_id)) + return; + write_lock(&ft->lock); idr_remove(ft->idr, fp->volatile_id); write_unlock(&ft->lock); @@ -798,15 +798,58 @@ err_out: return ERR_PTR(ret); } -void ksmbd_update_fstate(struct ksmbd_file_table *ft, struct ksmbd_file *fp, - unsigned int state) +/** + * ksmbd_update_fstate() - update an fp state under the file-table lock + * @ft: file table that publishes @fp's volatile id + * @fp: file pointer to update + * @state: new state + * + * Return: 0 on success. The FP_NEW -> FP_INITED transition is special: + * -ENOENT if teardown already unpublished @fp by advancing the state or + * clearing the volatile id. Other state updates preserve the historical + * fire-and-forget behavior. + */ +int ksmbd_update_fstate(struct ksmbd_file_table *ft, struct ksmbd_file *fp, + unsigned int state) { + int ret; + if (!fp) - return; + return -ENOENT; write_lock(&ft->lock); - fp->f_state = state; + if (state == FP_INITED && + (fp->f_state != FP_NEW || !has_file_id(fp->volatile_id))) { + ret = -ENOENT; + } else { + fp->f_state = state; + ret = 0; + } write_unlock(&ft->lock); + + return ret; +} + +/* + * ksmbd_mark_fp_closed() - mark fp closed under ft->lock and return how many + * refs the teardown path owns. + * + * FP_INITED has a normal idr-owned reference, so teardown owns both that + * reference and the transient lookup reference. FP_NEW is still owned by the + * in-flight opener/reopener, which will drop the original reference after + * ksmbd_update_fstate(..., FP_INITED) observes the cleared volatile id. + * FP_CLOSED on entry means an earlier ksmbd_close_fd() already consumed the + * idr-owned ref. + */ +static int ksmbd_mark_fp_closed(struct ksmbd_file *fp) +{ + if (fp->f_state == FP_INITED) { + set_close_state_blocked_works(fp); + fp->f_state = FP_CLOSED; + return 2; + } + + return 1; } static int @@ -814,7 +857,8 @@ __close_file_table_ids(struct ksmbd_session *sess, struct ksmbd_tree_connect *tcon, bool (*skip)(struct ksmbd_tree_connect *tcon, struct ksmbd_file *fp, - struct ksmbd_user *user)) + struct ksmbd_user *user), + bool skip_preserves_fp) { struct ksmbd_file_table *ft = &sess->file_table; struct ksmbd_file *fp; @@ -822,32 +866,120 @@ __close_file_table_ids(struct ksmbd_session *sess, int num = 0; while (1) { + int n_to_drop; + write_lock(&ft->lock); fp = idr_get_next(ft->idr, &id); if (!fp) { write_unlock(&ft->lock); break; } - - if (skip(tcon, fp, sess->user) || - !atomic_dec_and_test(&fp->refcount)) { + if (!atomic_inc_not_zero(&fp->refcount)) { id++; write_unlock(&ft->lock); continue; } - set_close_state_blocked_works(fp); - idr_remove(ft->idr, fp->volatile_id); - fp->volatile_id = KSMBD_NO_FID; - write_unlock(&ft->lock); + if (skip_preserves_fp) { + /* + * Session teardown: skip() is session_fd_check(), + * which may sleep and mutates fp->conn / fp->tcon / + * fp->volatile_id when it chooses to preserve fp + * for durable reconnect. Unpublish fp from the + * session idr here, under ft->lock, so that + * __ksmbd_lookup_fd() through this session cannot + * grant a new ksmbd_fp_get() reference to an fp + * whose fields are about to be rewritten outside + * the lock. Durable reconnect still reaches fp via + * global_ft. + */ + idr_remove(ft->idr, id); + fp->volatile_id = KSMBD_NO_FID; + write_unlock(&ft->lock); + + if (skip(tcon, fp, sess->user)) { + /* + * session_fd_check() has converted fp to + * durable-preserve state and cleared its + * per-conn fields. fp is already unpublished + * above; the original idr-owned ref keeps it + * alive for the durable scavenger. Drop only + * the transient ref. atomic_dec() is safe -- + * atomic_inc_not_zero() succeeded on a + * positive value and we added one more, so + * refcount cannot be zero here. + */ + atomic_dec(&fp->refcount); + id++; + continue; + } + + /* + * Keep the close-state decision under the same lock + * observed by ksmbd_update_fstate(), which is how an + * in-flight FP_NEW opener learns that teardown has + * cleared its volatile id. + */ + write_lock(&ft->lock); + n_to_drop = ksmbd_mark_fp_closed(fp); + write_unlock(&ft->lock); + } else { + /* + * Tree teardown: skip() is tree_conn_fd_check(), a + * cheap pointer compare that doesn't sleep and has + * no side effects, so keep the skip decision plus + * the unpublish-and-mark-closed sequence atomic + * under ft->lock. fps belonging to other tree + * connects (skip() == true) stay fully published in + * the session idr with no lock window. + */ + if (skip(tcon, fp, sess->user)) { + atomic_dec(&fp->refcount); + write_unlock(&ft->lock); + id++; + continue; + } + idr_remove(ft->idr, id); + fp->volatile_id = KSMBD_NO_FID; + n_to_drop = ksmbd_mark_fp_closed(fp); + write_unlock(&ft->lock); + } + /* + * fp->volatile_id is already cleared to prevent stale idr + * removal from a deferred final close. Remove fp from + * m_fp_list here because __ksmbd_remove_fd() will skip the + * list unlink when volatile_id is KSMBD_NO_FID. + */ down_write(&fp->f_ci->m_lock); list_del_init(&fp->node); up_write(&fp->f_ci->m_lock); - __ksmbd_close_fd(ft, fp); - - num++; + /* + * Drop the references this iteration owns: + * + * n_to_drop == 2: we observed FP_INITED and committed + * the FP_CLOSED transition ourselves, so we own the + * transient (+1) and the still-intact idr-owned ref. + * + * n_to_drop == 1: either a prior ksmbd_close_fd() + * already consumed the idr-owned ref, or fp was still + * FP_NEW and the in-flight opener/reopener must keep + * the original reference until ksmbd_update_fstate() + * observes the cleared volatile id. + * + * If we end up as the final putter, finalize fp and + * account the open_files_count decrement via the caller's + * atomic_sub(num, ...). Otherwise the remaining user's + * ksmbd_fd_put() reaches __put_fd_final(), which does its + * own atomic_dec(&open_files_count), so we must not count + * this fp here -- doing so would double-decrement the + * connection-wide counter. + */ + if (atomic_sub_and_test(n_to_drop, &fp->refcount)) { + __ksmbd_close_fd(NULL, fp); + num++; + } id++; } @@ -1082,6 +1214,9 @@ static bool session_fd_check(struct ksmbd_tree_connect *tcon, if (!is_reconnectable(fp)) return false; + if (fp->f_state != FP_INITED) + return false; + if (WARN_ON_ONCE(!fp->conn)) return false; @@ -1127,7 +1262,8 @@ void ksmbd_close_tree_conn_fds(struct ksmbd_work *work) { int num = __close_file_table_ids(work->sess, work->tcon, - tree_conn_fd_check); + tree_conn_fd_check, + false); atomic_sub(num, &work->conn->stats.open_files_count); } @@ -1136,7 +1272,8 @@ void ksmbd_close_session_fds(struct ksmbd_work *work) { int num = __close_file_table_ids(work->sess, work->tcon, - session_fd_check); + session_fd_check, + true); atomic_sub(num, &work->conn->stats.open_files_count); } @@ -1268,7 +1405,7 @@ void ksmbd_destroy_file_table(struct ksmbd_session *sess) if (!ft->idr) return; - __close_file_table_ids(sess, NULL, session_fd_check); + __close_file_table_ids(sess, NULL, session_fd_check, true); idr_destroy(ft->idr); kfree(ft->idr); ft->idr = NULL; diff --git a/fs/smb/server/vfs_cache.h b/fs/smb/server/vfs_cache.h index 866f32c10d4d..e6871266a94b 100644 --- a/fs/smb/server/vfs_cache.h +++ b/fs/smb/server/vfs_cache.h @@ -172,8 +172,8 @@ int ksmbd_close_inode_fds(struct ksmbd_work *work, struct inode *inode); int ksmbd_init_global_file_table(void); void ksmbd_free_global_file_table(void); void ksmbd_set_fd_limit(unsigned long limit); -void ksmbd_update_fstate(struct ksmbd_file_table *ft, struct ksmbd_file *fp, - unsigned int state); +int ksmbd_update_fstate(struct ksmbd_file_table *ft, struct ksmbd_file *fp, + unsigned int state); bool ksmbd_vfs_compare_durable_owner(struct ksmbd_file *fp, struct ksmbd_user *user); |