From d9ee65539d3eabd9ade46cca1780e3309ad0f907 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Tue, 6 Mar 2018 12:47:08 -0500 Subject: NFS: Fix an incorrect type in struct nfs_direct_req The start offset needs to be of type loff_t. Fixed: 5fadeb47dcc5c ("nfs: count DIO good bytes correctly with mirroring") Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Trond Myklebust --- fs/nfs/direct.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/nfs') diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 8c10b0562e75..621c517b325c 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -86,10 +86,10 @@ struct nfs_direct_req { struct nfs_direct_mirror mirrors[NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX]; int mirror_count; + loff_t io_start; /* Start offset for I/O */ ssize_t count, /* bytes actually processed */ max_count, /* max expected count */ bytes_left, /* bytes left to be sent */ - io_start, /* start of IO */ error; /* any reported error */ struct completion completion; /* wait for i/o completion */ -- cgit v1.2.1 From 9c6376ebddad585da4238532dd6d90ae23ffee67 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 7 Mar 2018 14:49:06 -0500 Subject: pNFS: Prevent the layout header refcount going to zero in pnfs_roc() Ensure that we hold a reference to the layout header when processing the pNFS return-on-close so that the refcount value does not inadvertently go to zero. Reported-by: Tigran Mkrtchyan Signed-off-by: Trond Myklebust Cc: stable@vger.kernel.org # v4.10+ Tested-by: Tigran Mkrtchyan --- fs/nfs/pnfs.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index c13e826614b5..ee723aa153a3 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -292,8 +292,11 @@ pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo) void pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo) { - struct inode *inode = lo->plh_inode; + struct inode *inode; + if (!lo) + return; + inode = lo->plh_inode; pnfs_layoutreturn_before_put_layout_hdr(lo); if (refcount_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) { @@ -1241,10 +1244,12 @@ retry: spin_lock(&ino->i_lock); lo = nfsi->layout; if (!lo || !pnfs_layout_is_valid(lo) || - test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) + test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) { + lo = NULL; goto out_noroc; + } + pnfs_get_layout_hdr(lo); if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) { - pnfs_get_layout_hdr(lo); spin_unlock(&ino->i_lock); wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN, TASK_UNINTERRUPTIBLE); @@ -1312,10 +1317,12 @@ out_noroc: struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld; if (ld->prepare_layoutreturn) ld->prepare_layoutreturn(args); + pnfs_put_layout_hdr(lo); return true; } if (layoutreturn) pnfs_send_layoutreturn(lo, &stateid, iomode, true); + pnfs_put_layout_hdr(lo); return false; } -- cgit v1.2.1 From c4f24df942a181699c5bab01b8e5e82b925f77f3 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 7 Mar 2018 15:22:31 -0500 Subject: NFS: Fix unstable write completion We do want to respect the FLUSH_SYNC argument to nfs_commit_inode() to ensure that all outstanding COMMIT requests to the inode in question are complete. Currently we may exit early from both nfs_commit_inode() and nfs_write_inode() even if there are COMMIT requests in flight, or unstable writes on the commit list. In order to get the right semantics w.r.t. sync_inode(), we don't need to have nfs_commit_inode() reset the inode dirty flags when called from nfs_wb_page() and/or nfs_wb_all(). We just need to ensure that nfs_write_inode() leaves them in the right state if there are outstanding commits, or stable pages. Reported-by: Scott Mayhew Fixes: dc4fd9ab01ab ("nfs: don't wait on commit in nfs_commit_inode()...") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 83 ++++++++++++++++++++++++++++++---------------------------- 1 file changed, 43 insertions(+), 40 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 7428a669d7a7..e7d8ceae8f26 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1876,40 +1876,43 @@ int nfs_generic_commit_list(struct inode *inode, struct list_head *head, return status; } -int nfs_commit_inode(struct inode *inode, int how) +static int __nfs_commit_inode(struct inode *inode, int how, + struct writeback_control *wbc) { LIST_HEAD(head); struct nfs_commit_info cinfo; int may_wait = how & FLUSH_SYNC; - int error = 0; - int res; + int ret, nscan; nfs_init_cinfo_from_inode(&cinfo, inode); nfs_commit_begin(cinfo.mds); - res = nfs_scan_commit(inode, &head, &cinfo); - if (res) - error = nfs_generic_commit_list(inode, &head, how, &cinfo); + for (;;) { + ret = nscan = nfs_scan_commit(inode, &head, &cinfo); + if (ret <= 0) + break; + ret = nfs_generic_commit_list(inode, &head, how, &cinfo); + if (ret < 0) + break; + ret = 0; + if (wbc && wbc->sync_mode == WB_SYNC_NONE) { + if (nscan < wbc->nr_to_write) + wbc->nr_to_write -= nscan; + else + wbc->nr_to_write = 0; + } + if (nscan < INT_MAX) + break; + cond_resched(); + } nfs_commit_end(cinfo.mds); - if (res == 0) - return res; - if (error < 0) - goto out_error; - if (!may_wait) - goto out_mark_dirty; - error = wait_on_commit(cinfo.mds); - if (error < 0) - return error; - return res; -out_error: - res = error; - /* Note: If we exit without ensuring that the commit is complete, - * we must mark the inode as dirty. Otherwise, future calls to - * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure - * that the data is on the disk. - */ -out_mark_dirty: - __mark_inode_dirty(inode, I_DIRTY_DATASYNC); - return res; + if (ret || !may_wait) + return ret; + return wait_on_commit(cinfo.mds); +} + +int nfs_commit_inode(struct inode *inode, int how) +{ + return __nfs_commit_inode(inode, how, NULL); } EXPORT_SYMBOL_GPL(nfs_commit_inode); @@ -1919,11 +1922,11 @@ int nfs_write_inode(struct inode *inode, struct writeback_control *wbc) int flags = FLUSH_SYNC; int ret = 0; - /* no commits means nothing needs to be done */ - if (!atomic_long_read(&nfsi->commit_info.ncommit)) - return ret; - if (wbc->sync_mode == WB_SYNC_NONE) { + /* no commits means nothing needs to be done */ + if (!atomic_long_read(&nfsi->commit_info.ncommit)) + goto check_requests_outstanding; + /* Don't commit yet if this is a non-blocking flush and there * are a lot of outstanding writes for this mapping. */ @@ -1934,16 +1937,16 @@ int nfs_write_inode(struct inode *inode, struct writeback_control *wbc) flags = 0; } - ret = nfs_commit_inode(inode, flags); - if (ret >= 0) { - if (wbc->sync_mode == WB_SYNC_NONE) { - if (ret < wbc->nr_to_write) - wbc->nr_to_write -= ret; - else - wbc->nr_to_write = 0; - } - return 0; - } + ret = __nfs_commit_inode(inode, flags, wbc); + if (!ret) { + if (flags & FLUSH_SYNC) + return 0; + } else if (atomic_long_read(&nfsi->commit_info.ncommit)) + goto out_mark_dirty; + +check_requests_outstanding: + if (!atomic_read(&nfsi->commit_info.rpcs_out)) + return ret; out_mark_dirty: __mark_inode_dirty(inode, I_DIRTY_DATASYNC); return ret; -- cgit v1.2.1 From 95dd77580ccd66a0da96e6d4696945b8cea39431 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 14 Mar 2018 18:20:29 -0500 Subject: fs: Teach path_connected to handle nfs filesystems with multiple roots. On nfsv2 and nfsv3 the nfs server can export subsets of the same filesystem and report the same filesystem identifier, so that the nfs client can know they are the same filesystem. The subsets can be from disjoint directory trees. The nfsv2 and nfsv3 filesystems provides no way to find the common root of all directory trees exported form the server with the same filesystem identifier. The practical result is that in struct super s_root for nfs s_root is not necessarily the root of the filesystem. The nfs mount code sets s_root to the root of the first subset of the nfs filesystem that the kernel mounts. This effects the dcache invalidation code in generic_shutdown_super currently called shrunk_dcache_for_umount and that code for years has gone through an additional list of dentries that might be dentry trees that need to be freed to accomodate nfs. When I wrote path_connected I did not realize nfs was so special, and it's hueristic for avoiding calling is_subdir can fail. The practical case where this fails is when there is a move of a directory from the subtree exposed by one nfs mount to the subtree exposed by another nfs mount. This move can happen either locally or remotely. With the remote case requiring that the move directory be cached before the move and that after the move someone walks the path to where the move directory now exists and in so doing causes the already cached directory to be moved in the dcache through the magic of d_splice_alias. If someone whose working directory is in the move directory or a subdirectory and now starts calling .. from the initial mount of nfs (where s_root == mnt_root), then path_connected as a heuristic will not bother with the is_subdir check. As s_root really is not the root of the nfs filesystem this heuristic is wrong, and the path may actually not be connected and path_connected can fail. The is_subdir function might be cheap enough that we can call it unconditionally. Verifying that will take some benchmarking and the result may not be the same on all kernels this fix needs to be backported to. So I am avoiding that for now. Filesystems with snapshots such as nilfs and btrfs do something similar. But as the directory tree of the snapshots are disjoint from one another and from the main directory tree rename won't move things between them and this problem will not occur. Cc: stable@vger.kernel.org Reported-by: Al Viro Fixes: 397d425dc26d ("vfs: Test for and handle paths that are unreachable from their mnt_root") Signed-off-by: "Eric W. Biederman" Signed-off-by: Al Viro --- fs/nfs/super.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/nfs') diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 29bacdc56f6a..5e470e233c83 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -2631,6 +2631,8 @@ struct dentry *nfs_fs_mount_common(struct nfs_server *server, /* initial superblock/root creation */ mount_info->fill_super(s, mount_info); nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned); + if (!(server->flags & NFS_MOUNT_UNSHARED)) + s->s_iflags |= SB_I_MULTIROOT; } mntroot = nfs_get_root(s, mount_info->mntfh, dev_name); -- cgit v1.2.1