From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/fs/9p/fid.c | 306 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 306 insertions(+) create mode 100644 kernel/fs/9p/fid.c (limited to 'kernel/fs/9p/fid.c') diff --git a/kernel/fs/9p/fid.c b/kernel/fs/9p/fid.c new file mode 100644 index 000000000..47db55aee --- /dev/null +++ b/kernel/fs/9p/fid.c @@ -0,0 +1,306 @@ +/* + * V9FS FID Management + * + * Copyright (C) 2007 by Latchesar Ionkov + * Copyright (C) 2005, 2006 by Eric Van Hensbergen + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to: + * Free Software Foundation + * 51 Franklin Street, Fifth Floor + * Boston, MA 02111-1301 USA + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "v9fs.h" +#include "v9fs_vfs.h" +#include "fid.h" + +/** + * v9fs_fid_add - add a fid to a dentry + * @dentry: dentry that the fid is being added to + * @fid: fid to add + * + */ + +static inline void __add_fid(struct dentry *dentry, struct p9_fid *fid) +{ + hlist_add_head(&fid->dlist, (struct hlist_head *)&dentry->d_fsdata); +} + +void v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid) +{ + spin_lock(&dentry->d_lock); + __add_fid(dentry, fid); + spin_unlock(&dentry->d_lock); +} + +/** + * v9fs_fid_find - retrieve a fid that belongs to the specified uid + * @dentry: dentry to look for fid in + * @uid: return fid that belongs to the specified user + * @any: if non-zero, return any fid associated with the dentry + * + */ + +static struct p9_fid *v9fs_fid_find(struct dentry *dentry, kuid_t uid, int any) +{ + struct p9_fid *fid, *ret; + + p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p) uid %d any %d\n", + dentry, dentry, from_kuid(&init_user_ns, uid), + any); + ret = NULL; + /* we'll recheck under lock if there's anything to look in */ + if (dentry->d_fsdata) { + struct hlist_head *h = (struct hlist_head *)&dentry->d_fsdata; + spin_lock(&dentry->d_lock); + hlist_for_each_entry(fid, h, dlist) { + if (any || uid_eq(fid->uid, uid)) { + ret = fid; + break; + } + } + spin_unlock(&dentry->d_lock); + } + + return ret; +} + +/* + * We need to hold v9ses->rename_sem as long as we hold references + * to returned path array. Array element contain pointers to + * dentry names. + */ +static int build_path_from_dentry(struct v9fs_session_info *v9ses, + struct dentry *dentry, char ***names) +{ + int n = 0, i; + char **wnames; + struct dentry *ds; + + for (ds = dentry; !IS_ROOT(ds); ds = ds->d_parent) + n++; + + wnames = kmalloc(sizeof(char *) * n, GFP_KERNEL); + if (!wnames) + goto err_out; + + for (ds = dentry, i = (n-1); i >= 0; i--, ds = ds->d_parent) + wnames[i] = (char *)ds->d_name.name; + + *names = wnames; + return n; +err_out: + return -ENOMEM; +} + +static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry, + kuid_t uid, int any) +{ + struct dentry *ds; + char **wnames, *uname; + int i, n, l, clone, access; + struct v9fs_session_info *v9ses; + struct p9_fid *fid, *old_fid = NULL; + + v9ses = v9fs_dentry2v9ses(dentry); + access = v9ses->flags & V9FS_ACCESS_MASK; + fid = v9fs_fid_find(dentry, uid, any); + if (fid) + return fid; + /* + * we don't have a matching fid. To do a TWALK we need + * parent fid. We need to prevent rename when we want to + * look at the parent. + */ + down_read(&v9ses->rename_sem); + ds = dentry->d_parent; + fid = v9fs_fid_find(ds, uid, any); + if (fid) { + /* Found the parent fid do a lookup with that */ + fid = p9_client_walk(fid, 1, (char **)&dentry->d_name.name, 1); + goto fid_out; + } + up_read(&v9ses->rename_sem); + + /* start from the root and try to do a lookup */ + fid = v9fs_fid_find(dentry->d_sb->s_root, uid, any); + if (!fid) { + /* the user is not attached to the fs yet */ + if (access == V9FS_ACCESS_SINGLE) + return ERR_PTR(-EPERM); + + if (v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) + uname = NULL; + else + uname = v9ses->uname; + + fid = p9_client_attach(v9ses->clnt, NULL, uname, uid, + v9ses->aname); + if (IS_ERR(fid)) + return fid; + + v9fs_fid_add(dentry->d_sb->s_root, fid); + } + /* If we are root ourself just return that */ + if (dentry->d_sb->s_root == dentry) + return fid; + /* + * Do a multipath walk with attached root. + * When walking parent we need to make sure we + * don't have a parallel rename happening + */ + down_read(&v9ses->rename_sem); + n = build_path_from_dentry(v9ses, dentry, &wnames); + if (n < 0) { + fid = ERR_PTR(n); + goto err_out; + } + clone = 1; + i = 0; + while (i < n) { + l = min(n - i, P9_MAXWELEM); + /* + * We need to hold rename lock when doing a multipath + * walk to ensure none of the patch component change + */ + fid = p9_client_walk(fid, l, &wnames[i], clone); + if (IS_ERR(fid)) { + if (old_fid) { + /* + * If we fail, clunk fid which are mapping + * to path component and not the last component + * of the path. + */ + p9_client_clunk(old_fid); + } + kfree(wnames); + goto err_out; + } + old_fid = fid; + i += l; + clone = 0; + } + kfree(wnames); +fid_out: + if (!IS_ERR(fid)) { + spin_lock(&dentry->d_lock); + if (d_unhashed(dentry)) { + spin_unlock(&dentry->d_lock); + p9_client_clunk(fid); + fid = ERR_PTR(-ENOENT); + } else { + __add_fid(dentry, fid); + spin_unlock(&dentry->d_lock); + } + } +err_out: + up_read(&v9ses->rename_sem); + return fid; +} + +/** + * v9fs_fid_lookup - lookup for a fid, try to walk if not found + * @dentry: dentry to look for fid in + * + * Look for a fid in the specified dentry for the current user. + * If no fid is found, try to create one walking from a fid from the parent + * dentry (if it has one), or the root dentry. If the user haven't accessed + * the fs yet, attach now and walk from the root. + */ + +struct p9_fid *v9fs_fid_lookup(struct dentry *dentry) +{ + kuid_t uid; + int any, access; + struct v9fs_session_info *v9ses; + + v9ses = v9fs_dentry2v9ses(dentry); + access = v9ses->flags & V9FS_ACCESS_MASK; + switch (access) { + case V9FS_ACCESS_SINGLE: + case V9FS_ACCESS_USER: + case V9FS_ACCESS_CLIENT: + uid = current_fsuid(); + any = 0; + break; + + case V9FS_ACCESS_ANY: + uid = v9ses->uid; + any = 1; + break; + + default: + uid = INVALID_UID; + any = 0; + break; + } + return v9fs_fid_lookup_with_uid(dentry, uid, any); +} + +struct p9_fid *v9fs_fid_clone(struct dentry *dentry) +{ + struct p9_fid *fid, *ret; + + fid = v9fs_fid_lookup(dentry); + if (IS_ERR(fid)) + return fid; + + ret = p9_client_walk(fid, 0, NULL, 1); + return ret; +} + +static struct p9_fid *v9fs_fid_clone_with_uid(struct dentry *dentry, kuid_t uid) +{ + struct p9_fid *fid, *ret; + + fid = v9fs_fid_lookup_with_uid(dentry, uid, 0); + if (IS_ERR(fid)) + return fid; + + ret = p9_client_walk(fid, 0, NULL, 1); + return ret; +} + +struct p9_fid *v9fs_writeback_fid(struct dentry *dentry) +{ + int err; + struct p9_fid *fid; + + fid = v9fs_fid_clone_with_uid(dentry, GLOBAL_ROOT_UID); + if (IS_ERR(fid)) + goto error_out; + /* + * writeback fid will only be used to write back the + * dirty pages. We always request for the open fid in read-write + * mode so that a partial page write which result in page + * read can work. + */ + err = p9_client_open(fid, O_RDWR); + if (err < 0) { + p9_client_clunk(fid); + fid = ERR_PTR(err); + goto error_out; + } +error_out: + return fid; +} -- cgit 1.2.3-korg