From 3c86794ac0e6582eea7733619d58ea150198502f Mon Sep 17 00:00:00 2001 From: Murphy Zhou Date: Thu, 4 Apr 2019 14:57:11 +0800 Subject: nfsd/nfsd3_proc_readdir: fix buffer count and page pointers After this commit f875a79 nfsd: allow nfsv3 readdir request to be larger. nfsv3 readdir request size can be larger than PAGE_SIZE. So if the directory been read is large enough, we can use multiple pages in rq_respages. Update buffer count and page pointers like we do in readdirplus to make this happen. Now listing a directory within 3000 files will panic because we are counting in a wrong way and would write on random page. Fixes: f875a79 "nfsd: allow nfsv3 readdir request to be larger" Signed-off-by: Murphy Zhou Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs3proc.c | 17 +++++++++++++++-- fs/nfsd/nfs3xdr.c | 11 +++++++++-- 2 files changed, 24 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c index 8f933e84cec1..9bc32af4e2da 100644 --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -442,7 +442,9 @@ nfsd3_proc_readdir(struct svc_rqst *rqstp) struct nfsd3_readdirargs *argp = rqstp->rq_argp; struct nfsd3_readdirres *resp = rqstp->rq_resp; __be32 nfserr; - int count; + int count = 0; + struct page **p; + caddr_t page_addr = NULL; dprintk("nfsd: READDIR(3) %s %d bytes at %d\n", SVCFH_fmt(&argp->fh), @@ -462,7 +464,18 @@ nfsd3_proc_readdir(struct svc_rqst *rqstp) nfserr = nfsd_readdir(rqstp, &resp->fh, (loff_t*) &argp->cookie, &resp->common, nfs3svc_encode_entry); memcpy(resp->verf, argp->verf, 8); - resp->count = resp->buffer - argp->buffer; + count = 0; + for (p = rqstp->rq_respages + 1; p < rqstp->rq_next_page; p++) { + page_addr = page_address(*p); + + if (((caddr_t)resp->buffer >= page_addr) && + ((caddr_t)resp->buffer < page_addr + PAGE_SIZE)) { + count += (caddr_t)resp->buffer - page_addr; + break; + } + count += PAGE_SIZE; + } + resp->count = count >> 2; if (resp->offset) { loff_t offset = argp->cookie; diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 93fea246f676..8d789124ed3c 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -573,6 +573,7 @@ int nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p) { struct nfsd3_readdirargs *args = rqstp->rq_argp; + int len; u32 max_blocksize = svc_max_payload(rqstp); p = decode_fh(p, &args->fh); @@ -582,8 +583,14 @@ nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p) args->verf = p; p += 2; args->dircount = ~0; args->count = ntohl(*p++); - args->count = min_t(u32, args->count, max_blocksize); - args->buffer = page_address(*(rqstp->rq_next_page++)); + len = args->count = min_t(u32, args->count, max_blocksize); + + while (len > 0) { + struct page *p = *(rqstp->rq_next_page++); + if (!args->buffer) + args->buffer = page_address(p); + len -= PAGE_SIZE; + } return xdr_argsize_check(rqstp, p); } -- cgit v1.2.3 From e6abc8caa6deb14be2a206253f7e1c5e37e9515b Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 5 Apr 2019 08:54:37 -0700 Subject: nfsd: Don't release the callback slot unless it was actually held If there are multiple callbacks queued, waiting for the callback slot when the callback gets shut down, then they all currently end up acting as if they hold the slot, and call nfsd4_cb_sequence_done() resulting in interesting side-effects. In addition, the 'retry_nowait' path in nfsd4_cb_sequence_done() causes a loop back to nfsd4_cb_prepare() without first freeing the slot, which causes a deadlock when nfsd41_cb_get_slot() gets called a second time. This patch therefore adds a boolean to track whether or not the callback did pick up the slot, so that it can do the right thing in these 2 cases. Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4callback.c | 8 +++++++- fs/nfsd/state.h | 1 + 2 files changed, 8 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index d219159b98af..7caa3801ce72 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1010,8 +1010,9 @@ static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata) cb->cb_seq_status = 1; cb->cb_status = 0; if (minorversion) { - if (!nfsd41_cb_get_slot(clp, task)) + if (!cb->cb_holds_slot && !nfsd41_cb_get_slot(clp, task)) return; + cb->cb_holds_slot = true; } rpc_call_start(task); } @@ -1038,6 +1039,9 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback return true; } + if (!cb->cb_holds_slot) + goto need_restart; + switch (cb->cb_seq_status) { case 0: /* @@ -1076,6 +1080,7 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback cb->cb_seq_status); } + cb->cb_holds_slot = false; clear_bit(0, &clp->cl_cb_slot_busy); rpc_wake_up_next(&clp->cl_cb_waitq); dprintk("%s: freed slot, new seqid=%d\n", __func__, @@ -1283,6 +1288,7 @@ void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp, cb->cb_seq_status = 1; cb->cb_status = 0; cb->cb_need_restart = false; + cb->cb_holds_slot = false; } void nfsd4_run_cb(struct nfsd4_callback *cb) diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 396c76755b03..9d6cb246c6c5 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -70,6 +70,7 @@ struct nfsd4_callback { int cb_seq_status; int cb_status; bool cb_need_restart; + bool cb_holds_slot; }; struct nfsd4_callback_ops { -- cgit v1.2.3 From 6aaafc43a4ecc5bc8a3f6a2811d5eddc996a97f3 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 22 Apr 2019 12:34:23 -0400 Subject: nfsd: wake waiters blocked on file_lock before deleting it After a blocked nfsd file_lock request is deleted, knfsd will send a callback to the client and then free the request. Commit 16306a61d3b7 ("fs/locks: always delete_block after waiting.") changed it such that locks_delete_block is always called on a request after it is awoken, but that patch missed fixing up blocked nfsd request handling. Call locks_delete_block on the block to wake up any locks still blocked on the nfsd lock request before freeing it. Some of its callers already do this however, so just remove those calls. URL: https://bugzilla.kernel.org/show_bug.cgi?id=203363 Fixes: 16306a61d3b7 ("fs/locks: always delete_block after waiting.") Reported-by: Slawomir Pryczek Cc: Neil Brown Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'fs') diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 6a45fb00c5fc..e87e15df2044 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -265,6 +265,7 @@ find_or_allocate_block(struct nfs4_lockowner *lo, struct knfsd_fh *fh, static void free_blocked_lock(struct nfsd4_blocked_lock *nbl) { + locks_delete_block(&nbl->nbl_lock); locks_release_private(&nbl->nbl_lock); kfree(nbl); } @@ -293,7 +294,6 @@ remove_blocked_locks(struct nfs4_lockowner *lo) nbl = list_first_entry(&reaplist, struct nfsd4_blocked_lock, nbl_lru); list_del_init(&nbl->nbl_lru); - locks_delete_block(&nbl->nbl_lock); free_blocked_lock(nbl); } } @@ -4863,7 +4863,6 @@ nfs4_laundromat(struct nfsd_net *nn) nbl = list_first_entry(&reaplist, struct nfsd4_blocked_lock, nbl_lru); list_del_init(&nbl->nbl_lru); - locks_delete_block(&nbl->nbl_lock); free_blocked_lock(nbl); } out: -- cgit v1.2.3 From f456458e4d25a8962d0946891617c76cc3ff5fb9 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Mon, 22 Apr 2019 12:34:24 -0400 Subject: nfsd: wake blocked file lock waiters before sending callback When a blocked NFS lock is "awoken" we send a callback to the server and then wake any hosts waiting on it. If a client attempts to get a lock and then drops off the net, we could end up waiting for a long time until we end up waking locks blocked on that request. So, wake any other waiting lock requests before sending the callback. Do this by calling locks_delete_block in a new "prepare" phase for CB_NOTIFY_LOCK callbacks. URL: https://bugzilla.kernel.org/show_bug.cgi?id=203363 Fixes: 16306a61d3b7 ("fs/locks: always delete_block after waiting.") Reported-by: Slawomir Pryczek Cc: Neil Brown Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'fs') diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index e87e15df2044..f056b1d3fecd 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -298,6 +298,14 @@ remove_blocked_locks(struct nfs4_lockowner *lo) } } +static void +nfsd4_cb_notify_lock_prepare(struct nfsd4_callback *cb) +{ + struct nfsd4_blocked_lock *nbl = container_of(cb, + struct nfsd4_blocked_lock, nbl_cb); + locks_delete_block(&nbl->nbl_lock); +} + static int nfsd4_cb_notify_lock_done(struct nfsd4_callback *cb, struct rpc_task *task) { @@ -325,6 +333,7 @@ nfsd4_cb_notify_lock_release(struct nfsd4_callback *cb) } static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops = { + .prepare = nfsd4_cb_notify_lock_prepare, .done = nfsd4_cb_notify_lock_done, .release = nfsd4_cb_notify_lock_release, }; -- cgit v1.2.3