/*
 *  linux/fs/9p/vfs_inode_dotl.c
 *
 * This file contains vfs inode ops for the 9P2000.L protocol.
 *
 *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
 *
 *  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 <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/pagemap.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/namei.h>
#include <linux/idr.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>

#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
#include "cache.h"
#include "xattr.h"
#include "acl.h"

static int
v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
                    dev_t rdev);

/**
 * v9fs_get_fsgid_for_create - Helper function to get the gid for creating a
 * new file system object. This checks the S_ISGID to determine the owning
 * group of the new file system object.
 */

static kgid_t v9fs_get_fsgid_for_create(struct inode *dir_inode)
{
        BUG_ON(dir_inode == NULL);

        if (dir_inode->i_mode & S_ISGID) {
                /* set_gid bit is set.*/
                return dir_inode->i_gid;
        }
        return current_fsgid();
}

static int v9fs_test_inode_dotl(struct inode *inode, void *data)
{
        struct v9fs_inode *v9inode = V9FS_I(inode);
        struct p9_stat_dotl *st = (struct p9_stat_dotl *)data;

        /* don't match inode of different type */
        if ((inode->i_mode & S_IFMT) != (st->st_mode & S_IFMT))
                return 0;

        if (inode->i_generation != st->st_gen)
                return 0;

        /* compare qid details */
        if (memcmp(&v9inode->qid.version,
                   &st->qid.version, sizeof(v9inode->qid.version)))
                return 0;

        if (v9inode->qid.type != st->qid.type)
                return 0;
        return 1;
}

/* Always get a new inode */
static int v9fs_test_new_inode_dotl(struct inode *inode, void *data)
{
        return 0;
}

static int v9fs_set_inode_dotl(struct inode *inode,  void *data)
{
        struct v9fs_inode *v9inode = V9FS_I(inode);
        struct p9_stat_dotl *st = (struct p9_stat_dotl *)data;

        memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
        inode->i_generation = st->st_gen;
        return 0;
}

static struct inode *v9fs_qid_iget_dotl(struct super_block *sb,
                                        struct p9_qid *qid,
                                        struct p9_fid *fid,
                                        struct p9_stat_dotl *st,
                                        int new)
{
        int retval;
        unsigned long i_ino;
        struct inode *inode;
        struct v9fs_session_info *v9ses = sb->s_fs_info;
        int (*test)(struct inode *, void *);

        if (new)
                test = v9fs_test_new_inode_dotl;
        else
                test = v9fs_test_inode_dotl;

        i_ino = v9fs_qid2ino(qid);
        inode = iget5_locked(sb, i_ino, test, v9fs_set_inode_dotl, st);
        if (!inode)
                return ERR_PTR(-ENOMEM);
        if (!(inode->i_state & I_NEW))
                return inode;
        /*
         * initialize the inode with the stat info
         * FIXME!! we may need support for stale inodes
         * later.
         */
        inode->i_ino = i_ino;
        retval = v9fs_init_inode(v9ses, inode,
                                 st->st_mode, new_decode_dev(st->st_rdev));
        if (retval)
                goto error;

        v9fs_stat2inode_dotl(st, inode);
#ifdef CONFIG_9P_FSCACHE
        v9fs_cache_inode_get_cookie(inode);
#endif
        retval = v9fs_get_acl(inode, fid);
        if (retval)
                goto error;

        unlock_new_inode(inode);
        return inode;
error:
        unlock_new_inode(inode);
        iput(inode);
        return ERR_PTR(retval);

}

struct inode *
v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses, struct p9_fid *fid,
                         struct super_block *sb, int new)
{
        struct p9_stat_dotl *st;
        struct inode *inode = NULL;

        st = p9_client_getattr_dotl(fid, P9_STATS_BASIC | P9_STATS_GEN);
        if (IS_ERR(st))
                return ERR_CAST(st);

        inode = v9fs_qid_iget_dotl(sb, &st->qid, fid, st, new);
        kfree(st);
        return inode;
}

struct dotl_openflag_map {
        int open_flag;
        int dotl_flag;
};

static int v9fs_mapped_dotl_flags(int flags)
{
        int i;
        int rflags = 0;
        struct dotl_openflag_map dotl_oflag_map[] = {
                { O_CREAT,      P9_DOTL_CREATE },
                { O_EXCL,       P9_DOTL_EXCL },
                { O_NOCTTY,     P9_DOTL_NOCTTY },
                { O_APPEND,     P9_DOTL_APPEND },
                { O_NONBLOCK,   P9_DOTL_NONBLOCK },
                { O_DSYNC,      P9_DOTL_DSYNC },
                { FASYNC,       P9_DOTL_FASYNC },
                { O_DIRECT,     P9_DOTL_DIRECT },
                { O_LARGEFILE,  P9_DOTL_LARGEFILE },
                { O_DIRECTORY,  P9_DOTL_DIRECTORY },
                { O_NOFOLLOW,   P9_DOTL_NOFOLLOW },
                { O_NOATIME,    P9_DOTL_NOATIME },
                { O_CLOEXEC,    P9_DOTL_CLOEXEC },
                { O_SYNC,       P9_DOTL_SYNC},
        };
        for (i = 0; i < ARRAY_SIZE(dotl_oflag_map); i++) {
                if (flags & dotl_oflag_map[i].open_flag)
                        rflags |= dotl_oflag_map[i].dotl_flag;
        }
        return rflags;
}

/**
 * v9fs_open_to_dotl_flags- convert Linux specific open flags to
 * plan 9 open flag.
 * @flags: flags to convert
 */
int v9fs_open_to_dotl_flags(int flags)
{
        int rflags = 0;

        /*
         * We have same bits for P9_DOTL_READONLY, P9_DOTL_WRONLY
         * and P9_DOTL_NOACCESS
         */
        rflags |= flags & O_ACCMODE;
        rflags |= v9fs_mapped_dotl_flags(flags);

        return rflags;
}

/**
 * v9fs_vfs_create_dotl - VFS hook to create files for 9P2000.L protocol.
 * @dir: directory inode that is being created
 * @dentry:  dentry that is being deleted
 * @mode: create permissions
 *
 */

static int
v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
                bool excl)
{
        return v9fs_vfs_mknod_dotl(dir, dentry, omode, 0);
}

static int
v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
                          struct file *file, unsigned flags, umode_t omode,
                          int *opened)
{
        int err = 0;
        kgid_t gid;
        umode_t mode;
        char *name = NULL;
        struct p9_qid qid;
        struct inode *inode;
        struct p9_fid *fid = NULL;
        struct v9fs_inode *v9inode;
        struct p9_fid *dfid, *ofid, *inode_fid;
        struct v9fs_session_info *v9ses;
        struct posix_acl *pacl = NULL, *dacl = NULL;
        struct dentry *res = NULL;

        if (d_unhashed(dentry)) {
                res = v9fs_vfs_lookup(dir, dentry, 0);
                if (IS_ERR(res))
                        return PTR_ERR(res);

                if (res)
                        dentry = res;
        }

        /* Only creates */
        if (!(flags & O_CREAT))
                return  finish_no_open(file, res);
        else if (dentry->d_inode) {
                if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
                        return -EEXIST;
                else
                        return finish_no_open(file, res);
        }

        v9ses = v9fs_inode2v9ses(dir);

        name = (char *) dentry->d_name.name;
        p9_debug(P9_DEBUG_VFS, "name:%s flags:0x%x mode:0x%hx\n",
                 name, flags, omode);

        dfid = v9fs_fid_lookup(dentry->d_parent);
        if (IS_ERR(dfid)) {
                err = PTR_ERR(dfid);
                p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
                goto out;
        }

        /* clone a fid to use for creation */
        ofid = p9_client_walk(dfid, 0, NULL, 1);
        if (IS_ERR(ofid)) {
                err = PTR_ERR(ofid);
                p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
                goto out;
        }

        gid = v9fs_get_fsgid_for_create(dir);

        mode = omode;
        /* Update mode based on ACL value */
        err = v9fs_acl_mode(dir, &mode, &dacl, &pacl);
        if (err) {
                p9_debug(P9_DEBUG_VFS, "Failed to get acl values in creat %d\n",
                         err);
                goto error;
        }
        err = p9_client_create_dotl(ofid, name, v9fs_open_to_dotl_flags(flags),
                                    mode, gid, &qid);
        if (err < 0) {
                p9_debug(P9_DEBUG_VFS, "p9_client_open_dotl failed in creat %d\n",
                         err);
                goto error;
        }
        v9fs_invalidate_inode_attr(dir);

        /* instantiate inode and assign the unopened fid to the dentry */
        fid = p9_client_walk(dfid, 1, &name, 1);
        if (IS_ERR(fid)) {
                err = PTR_ERR(fid);
                p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
                fid = NULL;
                goto error;
        }
        inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
        if (IS_ERR(inode)) {
                err = PTR_ERR(inode);
                p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n", err);
                goto error;
        }
        /* Now set the ACL based on the default value */
        v9fs_set_create_acl(inode, fid, dacl, pacl);

        v9fs_fid_add(dentry, fid);
        d_instantiate(dentry, inode);

        v9inode = V9FS_I(inode);
        mutex_lock(&v9inode->v_mutex);
        if (v9ses->cache && !v9inode->writeback_fid &&
            ((flags & O_ACCMODE) != O_RDONLY)) {
                /*
                 * clone a fid and add it to writeback_fid
                 * we do it during open time instead of
                 * page dirty time via write_begin/page_mkwrite
                 * because we want write after unlink usecase
                 * to work.
                 */
                inode_fid = v9fs_writeback_fid(dentry);
                if (IS_ERR(inode_fid)) {
                        err = PTR_ERR(inode_fid);
                        mutex_unlock(&v9inode->v_mutex);
                        goto err_clunk_old_fid;
                }
                v9inode->writeback_fid = (void *) inode_fid;
        }
        mutex_unlock(&v9inode->v_mutex);
        /* Since we are opening a file, assign the open fid to the file */
        err = finish_open(file, dentry, generic_file_open, opened);
        if (err)
                goto err_clunk_old_fid;
        file->private_data = ofid;
#ifdef CONFIG_9P_FSCACHE
        if (v9ses->cache)
                v9fs_cache_inode_set_cookie(inode, file);
#endif
        *opened |= FILE_CREATED;
out:
        v9fs_put_acl(dacl, pacl);
        dput(res);
        return err;

error:
        if (fid)
                p9_client_clunk(fid);
err_clunk_old_fid:
        if (ofid)
                p9_client_clunk(ofid);
        goto out;
}

/**
 * v9fs_vfs_mkdir_dotl - VFS mkdir hook to create a directory
 * @dir:  inode that is being unlinked
 * @dentry: dentry that is being unlinked
 * @mode: mode for new directory
 *
 */

static int v9fs_vfs_mkdir_dotl(struct inode *dir,
                               struct dentry *dentry, umode_t omode)
{
        int err;
        struct v9fs_session_info *v9ses;
        struct p9_fid *fid = NULL, *dfid = NULL;
        kgid_t gid;
        char *name;
        umode_t mode;
        struct inode *inode;
        struct p9_qid qid;
        struct dentry *dir_dentry;
        struct posix_acl *dacl = NULL, *pacl = NULL;

        p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
        err = 0;
        v9ses = v9fs_inode2v9ses(dir);

        omode |= S_IFDIR;
        if (dir->i_mode & S_ISGID)
                omode |= S_ISGID;

        dir_dentry = dentry->d_parent;
        dfid = v9fs_fid_lookup(dir_dentry);
        if (IS_ERR(dfid)) {
                err = PTR_ERR(dfid);
                p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
                dfid = NULL;
                goto error;
        }

        gid = v9fs_get_fsgid_for_create(dir);
        mode = omode;
        /* Update mode based on ACL value */
        err = v9fs_acl_mode(dir, &mode, &dacl, &pacl);
        if (err) {
                p9_debug(P9_DEBUG_VFS, "Failed to get acl values in mkdir %d\n",
                         err);
                goto error;
        }
        name = (char *) dentry->d_name.name;
        err = p9_client_mkdir_dotl(dfid, name, mode, gid, &qid);
        if (err < 0)
                goto error;

        fid = p9_client_walk(dfid, 1, &name, 1);
        if (IS_ERR(fid)) {
                err = PTR_ERR(fid);
                p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
                         err);
                fid = NULL;
                goto error;
        }

        /* instantiate inode and assign the unopened fid to the dentry */
        if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
                inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
                if (IS_ERR(inode)) {
                        err = PTR_ERR(inode);
                        p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
                                 err);
                        goto error;
                }
                v9fs_fid_add(dentry, fid);
                v9fs_set_create_acl(inode, fid, dacl, pacl);
                d_instantiate(dentry, inode);
                fid = NULL;
                err = 0;
        } else {
                /*
                 * Not in cached mode. No need to populate
                 * inode with stat. We need to get an inode
                 * so that we can set the acl with dentry
                 */
                inode = v9fs_get_inode(dir->i_sb, mode, 0);
                if (IS_ERR(inode)) {
                        err = PTR_ERR(inode);
                        goto error;
                }
                v9fs_set_create_acl(inode, fid, dacl, pacl);
                d_instantiate(dentry, inode);
        }
        inc_nlink(dir);
        v9fs_invalidate_inode_attr(dir);
error:
        if (fid)
                p9_client_clunk(fid);
        v9fs_put_acl(dacl, pacl);
        return err;
}

static int
v9fs_vfs_getattr_dotl(struct vfsmount *mnt, struct dentry *dentry,
                 struct kstat *stat)
{
        int err;
        struct v9fs_session_info *v9ses;
        struct p9_fid *fid;
        struct p9_stat_dotl *st;

        p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
        err = -EPERM;
        v9ses = v9fs_dentry2v9ses(dentry);
        if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
                generic_fillattr(dentry->d_inode, stat);
                return 0;
        }
        fid = v9fs_fid_lookup(dentry);
        if (IS_ERR(fid))
                return PTR_ERR(fid);

        /* Ask for all the fields in stat structure. Server will return
         * whatever it supports
         */

        st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
        if (IS_ERR(st))
                return PTR_ERR(st);

        v9fs_stat2inode_dotl(st, dentry->d_inode);
        generic_fillattr(dentry->d_inode, stat);
        /* Change block size to what the server returned */
        stat->blksize = st->st_blksize;

        kfree(st);
        return 0;
}

/*
 * Attribute flags.
 */
#define P9_ATTR_MODE            (1 << 0)
#define P9_ATTR_UID             (1 << 1)
#define P9_ATTR_GID             (1 << 2)
#define P9_ATTR_SIZE            (1 << 3)
#define P9_ATTR_ATIME           (1 << 4)
#define P9_ATTR_MTIME           (1 << 5)
#define P9_ATTR_CTIME           (1 << 6)
#define P9_ATTR_ATIME_SET       (1 << 7)
#define P9_ATTR_MTIME_SET       (1 << 8)

struct dotl_iattr_map {
        int iattr_valid;
        int p9_iattr_valid;
};

static int v9fs_mapped_iattr_valid(int iattr_valid)
{
        int i;
        int p9_iattr_valid = 0;
        struct dotl_iattr_map dotl_iattr_map[] = {
                { ATTR_MODE,            P9_ATTR_MODE },
                { ATTR_UID,             P9_ATTR_UID },
                { ATTR_GID,             P9_ATTR_GID },
                { ATTR_SIZE,            P9_ATTR_SIZE },
                { ATTR_ATIME,           P9_ATTR_ATIME },
                { ATTR_MTIME,           P9_ATTR_MTIME },
                { ATTR_CTIME,           P9_ATTR_CTIME },
                { ATTR_ATIME_SET,       P9_ATTR_ATIME_SET },
                { ATTR_MTIME_SET,       P9_ATTR_MTIME_SET },
        };
        for (i = 0; i < ARRAY_SIZE(dotl_iattr_map); i++) {
                if (iattr_valid & dotl_iattr_map[i].iattr_valid)
                        p9_iattr_valid |= dotl_iattr_map[i].p9_iattr_valid;
        }
        return p9_iattr_valid;
}

/**
 * v9fs_vfs_setattr_dotl - set file metadata
 * @dentry: file whose metadata to set
 * @iattr: metadata assignment structure
 *
 */

int v9fs_vfs_setattr_dotl(struct dentry *dentry, struct iattr *iattr)
{
        int retval;
        struct v9fs_session_info *v9ses;
        struct p9_fid *fid;
        struct p9_iattr_dotl p9attr;
        struct inode *inode = dentry->d_inode;

        p9_debug(P9_DEBUG_VFS, "\n");

        retval = inode_change_ok(inode, iattr);
        if (retval)
                return retval;

        p9attr.valid = v9fs_mapped_iattr_valid(iattr->ia_valid);
        p9attr.mode = iattr->ia_mode;
        p9attr.uid = iattr->ia_uid;
        p9attr.gid = iattr->ia_gid;
        p9attr.size = iattr->ia_size;
        p9attr.atime_sec = iattr->ia_atime.tv_sec;
        p9attr.atime_nsec = iattr->ia_atime.tv_nsec;
        p9attr.mtime_sec = iattr->ia_mtime.tv_sec;
        p9attr.mtime_nsec = iattr->ia_mtime.tv_nsec;

        retval = -EPERM;
        v9ses = v9fs_dentry2v9ses(dentry);
        fid = v9fs_fid_lookup(dentry);
        if (IS_ERR(fid))
                return PTR_ERR(fid);

        /* Write all dirty data */
        if (S_ISREG(inode->i_mode))
                filemap_write_and_wait(inode->i_mapping);

        retval = p9_client_setattr(fid, &p9attr);
        if (retval < 0)
                return retval;

        if ((iattr->ia_valid & ATTR_SIZE) &&
            iattr->ia_size != i_size_read(inode))
                truncate_setsize(inode, iattr->ia_size);

        v9fs_invalidate_inode_attr(inode);
        setattr_copy(inode, iattr);
        mark_inode_dirty(inode);
        if (iattr->ia_valid & ATTR_MODE) {
                /* We also want to update ACL when we update mode bits */
                retval = v9fs_acl_chmod(inode, fid);
                if (retval < 0)
                        return retval;
        }
        return 0;
}

/**
 * v9fs_stat2inode_dotl - populate an inode structure with stat info
 * @stat: stat structure
 * @inode: inode to populate
 * @sb: superblock of filesystem
 *
 */

void
v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
{
        umode_t mode;
        struct v9fs_inode *v9inode = V9FS_I(inode);

        if ((stat->st_result_mask & P9_STATS_BASIC) == P9_STATS_BASIC) {
                inode->i_atime.tv_sec = stat->st_atime_sec;
                inode->i_atime.tv_nsec = stat->st_atime_nsec;
                inode->i_mtime.tv_sec = stat->st_mtime_sec;
                inode->i_mtime.tv_nsec = stat->st_mtime_nsec;
                inode->i_ctime.tv_sec = stat->st_ctime_sec;
                inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
                inode->i_uid = stat->st_uid;
                inode->i_gid = stat->st_gid;
                set_nlink(inode, stat->st_nlink);

                mode = stat->st_mode & S_IALLUGO;
                mode |= inode->i_mode & ~S_IALLUGO;
                inode->i_mode = mode;

                i_size_write(inode, stat->st_size);
                inode->i_blocks = stat->st_blocks;
        } else {
                if (stat->st_result_mask & P9_STATS_ATIME) {
                        inode->i_atime.tv_sec = stat->st_atime_sec;
                        inode->i_atime.tv_nsec = stat->st_atime_nsec;
                }
                if (stat->st_result_mask & P9_STATS_MTIME) {
                        inode->i_mtime.tv_sec = stat->st_mtime_sec;
                        inode->i_mtime.tv_nsec = stat->st_mtime_nsec;
                }
                if (stat->st_result_mask & P9_STATS_CTIME) {
                        inode->i_ctime.tv_sec = stat->st_ctime_sec;
                        inode->i_ctime.tv_nsec = stat->st_ctime_nsec;
                }
                if (stat->st_result_mask & P9_STATS_UID)
                        inode->i_uid = stat->st_uid;
                if (stat->st_result_mask & P9_STATS_GID)
                        inode->i_gid = stat->st_gid;
                if (stat->st_result_mask & P9_STATS_NLINK)
                        set_nlink(inode, stat->st_nlink);
                if (stat->st_result_mask & P9_STATS_MODE) {
                        inode->i_mode = stat->st_mode;
                        if ((S_ISBLK(inode->i_mode)) ||
                                                (S_ISCHR(inode->i_mode)))
                                init_special_inode(inode, inode->i_mode,
                                                                inode->i_rdev);
                }
                if (stat->st_result_mask & P9_STATS_RDEV)
                        inode->i_rdev = new_decode_dev(stat->st_rdev);
                if (stat->st_result_mask & P9_STATS_SIZE)
                        i_size_write(inode, stat->st_size);
                if (stat->st_result_mask & P9_STATS_BLOCKS)
                        inode->i_blocks = stat->st_blocks;
        }
        if (stat->st_result_mask & P9_STATS_GEN)
                inode->i_generation = stat->st_gen;

        /* Currently we don't support P9_STATS_BTIME and P9_STATS_DATA_VERSION
         * because the inode structure does not have fields for them.
         */
        v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
}

static int
v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry,
                const char *symname)
{
        int err;
        kgid_t gid;
        char *name;
        struct p9_qid qid;
        struct inode *inode;
        struct p9_fid *dfid;
        struct p9_fid *fid = NULL;
        struct v9fs_session_info *v9ses;

        name = (char *) dentry->d_name.name;
        p9_debug(P9_DEBUG_VFS, "%lu,%s,%s\n", dir->i_ino, name, symname);
        v9ses = v9fs_inode2v9ses(dir);

        dfid = v9fs_fid_lookup(dentry->d_parent);
        if (IS_ERR(dfid)) {
                err = PTR_ERR(dfid);
                p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
                return err;
        }

        gid = v9fs_get_fsgid_for_create(dir);

        /* Server doesn't alter fid on TSYMLINK. Hence no need to clone it. */
        err = p9_client_symlink(dfid, name, (char *)symname, gid, &qid);

        if (err < 0) {
                p9_debug(P9_DEBUG_VFS, "p9_client_symlink failed %d\n", err);
                goto error;
        }

        v9fs_invalidate_inode_attr(dir);
        if (v9ses->cache) {
                /* Now walk from the parent so we can get an unopened fid. */
                fid = p9_client_walk(dfid, 1, &name, 1);
                if (IS_ERR(fid)) {
                        err = PTR_ERR(fid);
                        p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
                                 err);
                        fid = NULL;
                        goto error;
                }

                /* instantiate inode and assign the unopened fid to dentry */
                inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
                if (IS_ERR(inode)) {
                        err = PTR_ERR(inode);
                        p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
                                 err);
                        goto error;
                }
                v9fs_fid_add(dentry, fid);
                d_instantiate(dentry, inode);
                fid = NULL;
                err = 0;
        } else {
                /* Not in cached mode. No need to populate inode with stat */
                inode = v9fs_get_inode(dir->i_sb, S_IFLNK, 0);
                if (IS_ERR(inode)) {
                        err = PTR_ERR(inode);
                        goto error;
                }
                d_instantiate(dentry, inode);
        }

error:
        if (fid)
                p9_client_clunk(fid);

        return err;
}

/**
 * v9fs_vfs_link_dotl - create a hardlink for dotl
 * @old_dentry: dentry for file to link to
 * @dir: inode destination for new link
 * @dentry: dentry for link
 *
 */

static int
v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir,
                struct dentry *dentry)
{
        int err;
        char *name;
        struct dentry *dir_dentry;
        struct p9_fid *dfid, *oldfid;
        struct v9fs_session_info *v9ses;

        p9_debug(P9_DEBUG_VFS, "dir ino: %lu, old_name: %s, new_name: %s\n",
                 dir->i_ino, old_dentry->d_name.name, dentry->d_name.name);

        v9ses = v9fs_inode2v9ses(dir);
        dir_dentry = dentry->d_parent;
        dfid = v9fs_fid_lookup(dir_dentry);
        if (IS_ERR(dfid))
                return PTR_ERR(dfid);

        oldfid = v9fs_fid_lookup(old_dentry);
        if (IS_ERR(oldfid))
                return PTR_ERR(oldfid);

        name = (char *) dentry->d_name.name;

        err = p9_client_link(dfid, oldfid, (char *)dentry->d_name.name);

        if (err < 0) {
                p9_debug(P9_DEBUG_VFS, "p9_client_link failed %d\n", err);
                return err;
        }

        v9fs_invalidate_inode_attr(dir);
        if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
                /* Get the latest stat info from server. */
                struct p9_fid *fid;
                fid = v9fs_fid_lookup(old_dentry);
                if (IS_ERR(fid))
                        return PTR_ERR(fid);

                v9fs_refresh_inode_dotl(fid, old_dentry->d_inode);
        }
        ihold(old_dentry->d_inode);
        d_instantiate(dentry, old_dentry->d_inode);

        return err;
}

/**
 * v9fs_vfs_mknod_dotl - create a special file
 * @dir: inode destination for new link
 * @dentry: dentry for file
 * @mode: mode for creation
 * @rdev: device associated with special file
 *
 */
static int
v9fs_vfs_mknod_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
                dev_t rdev)
{
        int err;
        kgid_t gid;
        char *name;
        umode_t mode;
        struct v9fs_session_info *v9ses;
        struct p9_fid *fid = NULL, *dfid = NULL;
        struct inode *inode;
        struct p9_qid qid;
        struct dentry *dir_dentry;
        struct posix_acl *dacl = NULL, *pacl = NULL;

        p9_debug(P9_DEBUG_VFS, " %lu,%s mode: %hx MAJOR: %u MINOR: %u\n",
                 dir->i_ino, dentry->d_name.name, omode,
                 MAJOR(rdev), MINOR(rdev));

        if (!new_valid_dev(rdev))
                return -EINVAL;

        v9ses = v9fs_inode2v9ses(dir);
        dir_dentry = dentry->d_parent;
        dfid = v9fs_fid_lookup(dir_dentry);
        if (IS_ERR(dfid)) {
                err = PTR_ERR(dfid);
                p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
                dfid = NULL;
                goto error;
        }

        gid = v9fs_get_fsgid_for_create(dir);
        mode = omode;
        /* Update mode based on ACL value */
        err = v9fs_acl_mode(dir, &mode, &dacl, &pacl);
        if (err) {
                p9_debug(P9_DEBUG_VFS, "Failed to get acl values in mknod %d\n",
                         err);
                goto error;
        }
        name = (char *) dentry->d_name.name;

        err = p9_client_mknod_dotl(dfid, name, mode, rdev, gid, &qid);
        if (err < 0)
                goto error;

        v9fs_invalidate_inode_attr(dir);
        fid = p9_client_walk(dfid, 1, &name, 1);
        if (IS_ERR(fid)) {
                err = PTR_ERR(fid);
                p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
                         err);
                fid = NULL;
                goto error;
        }

        /* instantiate inode and assign the unopened fid to the dentry */
        if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
                inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
                if (IS_ERR(inode)) {
                        err = PTR_ERR(inode);
                        p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
                                 err);
                        goto error;
                }
                v9fs_set_create_acl(inode, fid, dacl, pacl);
                v9fs_fid_add(dentry, fid);
                d_instantiate(dentry, inode);
                fid = NULL;
                err = 0;
        } else {
                /*
                 * Not in cached mode. No need to populate inode with stat.
                 * socket syscall returns a fd, so we need instantiate
                 */
                inode = v9fs_get_inode(dir->i_sb, mode, rdev);
                if (IS_ERR(inode)) {
                        err = PTR_ERR(inode);
                        goto error;
                }
                v9fs_set_create_acl(inode, fid, dacl, pacl);
                d_instantiate(dentry, inode);
        }
error:
        if (fid)
                p9_client_clunk(fid);
        v9fs_put_acl(dacl, pacl);
        return err;
}

/**
 * v9fs_vfs_follow_link_dotl - follow a symlink path
 * @dentry: dentry for symlink
 * @nd: nameidata
 *
 */

static void *
v9fs_vfs_follow_link_dotl(struct dentry *dentry, struct nameidata *nd)
{
        int retval;
        struct p9_fid *fid;
        char *link = __getname();
        char *target;

        p9_debug(P9_DEBUG_VFS, "%s\n", dentry->d_name.name);

        if (!link) {
                link = ERR_PTR(-ENOMEM);
                goto ndset;
        }
        fid = v9fs_fid_lookup(dentry);
        if (IS_ERR(fid)) {
                __putname(link);
                link = ERR_CAST(fid);
                goto ndset;
        }
        retval = p9_client_readlink(fid, &target);
        if (!retval) {
                strcpy(link, target);
                kfree(target);
                goto ndset;
        }
        __putname(link);
        link = ERR_PTR(retval);
ndset:
        nd_set_link(nd, link);
        return NULL;
}

int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
{
        loff_t i_size;
        struct p9_stat_dotl *st;
        struct v9fs_session_info *v9ses;

        v9ses = v9fs_inode2v9ses(inode);
        st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
        if (IS_ERR(st))
                return PTR_ERR(st);
        /*
         * Don't update inode if the file type is different
         */
        if ((inode->i_mode & S_IFMT) != (st->st_mode & S_IFMT))
                goto out;

        spin_lock(&inode->i_lock);
        /*
         * We don't want to refresh inode->i_size,
         * because we may have cached data
         */
        i_size = inode->i_size;
        v9fs_stat2inode_dotl(st, inode);
        if (v9ses->cache)
                inode->i_size = i_size;
        spin_unlock(&inode->i_lock);
out:
        kfree(st);
        return 0;
}

const struct inode_operations v9fs_dir_inode_operations_dotl = {
        .create = v9fs_vfs_create_dotl,
        .atomic_open = v9fs_vfs_atomic_open_dotl,
        .lookup = v9fs_vfs_lookup,
        .link = v9fs_vfs_link_dotl,
        .symlink = v9fs_vfs_symlink_dotl,
        .unlink = v9fs_vfs_unlink,

        .mkdir = v9fs_vfs_mkdir_dotl,
        .rmdir = v9fs_vfs_rmdir,
        .mknod = v9fs_vfs_mknod_dotl,
        .rename = v9fs_vfs_rename,
        .getattr = v9fs_vfs_getattr_dotl,
        .setattr = v9fs_vfs_setattr_dotl,
        .setxattr = generic_setxattr,
        .getxattr = generic_getxattr,
        .removexattr = generic_removexattr,
        .listxattr = v9fs_listxattr,
        .get_acl = v9fs_iop_get_acl,
};

const struct inode_operations v9fs_file_inode_operations_dotl = {
        .getattr = v9fs_vfs_getattr_dotl,
        .setattr = v9fs_vfs_setattr_dotl,
        .setxattr = generic_setxattr,
        .getxattr = generic_getxattr,
        .removexattr = generic_removexattr,
        .listxattr = v9fs_listxattr,
        .get_acl = v9fs_iop_get_acl,
};

const struct inode_operations v9fs_symlink_inode_operations_dotl = {
        .readlink = generic_readlink,
        .follow_link = v9fs_vfs_follow_link_dotl,
        .put_link = v9fs_vfs_put_link,
        .getattr = v9fs_vfs_getattr_dotl,
        .setattr = v9fs_vfs_setattr_dotl,
        .setxattr = generic_setxattr,
        .getxattr = generic_getxattr,
        .removexattr = generic_removexattr,
        .listxattr = v9fs_listxattr,
};