/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2011 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License version 2.
 */

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/namei.h>
#include <linux/mm.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>
#include <linux/fiemap.h>
#include <linux/security.h>
#include <asm/uaccess.h>

#include "gfs2.h"
#include "incore.h"
#include "acl.h"
#include "bmap.h"
#include "dir.h"
#include "xattr.h"
#include "glock.h"
#include "inode.h"
#include "meta_io.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"
#include "super.h"
#include "glops.h"

static int iget_test(struct inode *inode, void *opaque)
{
        u64 no_addr = *(u64 *)opaque;

        return GFS2_I(inode)->i_no_addr == no_addr;
}

static int iget_set(struct inode *inode, void *opaque)
{
        u64 no_addr = *(u64 *)opaque;

        GFS2_I(inode)->i_no_addr = no_addr;
        inode->i_ino = no_addr;
        return 0;
}

static struct inode *gfs2_iget(struct super_block *sb, u64 no_addr)
{
        struct inode *inode;

repeat:
        inode = iget5_locked(sb, no_addr, iget_test, iget_set, &no_addr);
        if (!inode)
                return inode;
        if (is_bad_inode(inode)) {
                iput(inode);
                goto repeat;
        }
        return inode;
}

/**
 * gfs2_set_iop - Sets inode operations
 * @inode: The inode with correct i_mode filled in
 *
 * GFS2 lookup code fills in vfs inode contents based on info obtained
 * from directory entry inside gfs2_inode_lookup().
 */

static void gfs2_set_iop(struct inode *inode)
{
        struct gfs2_sbd *sdp = GFS2_SB(inode);
        umode_t mode = inode->i_mode;

        if (S_ISREG(mode)) {
                inode->i_op = &gfs2_file_iops;
                if (gfs2_localflocks(sdp))
                        inode->i_fop = &gfs2_file_fops_nolock;
                else
                        inode->i_fop = &gfs2_file_fops;
        } else if (S_ISDIR(mode)) {
                inode->i_flags |= S_IOPS_WRAPPER;
                inode->i_op = &gfs2_dir_iops.ops;
                if (gfs2_localflocks(sdp))
                        inode->i_fop = &gfs2_dir_fops_nolock;
                else
                        inode->i_fop = &gfs2_dir_fops;
        } else if (S_ISLNK(mode)) {
                inode->i_op = &gfs2_symlink_iops;
        } else {
                inode->i_op = &gfs2_file_iops;
                init_special_inode(inode, inode->i_mode, inode->i_rdev);
        }
}

/**
 * gfs2_inode_lookup - Lookup an inode
 * @sb: The super block
 * @type: The type of the inode
 * @no_addr: The inode number
 * @no_formal_ino: The inode generation number
 * @blktype: Requested block type (GFS2_BLKST_DINODE or GFS2_BLKST_UNLINKED;
 *           GFS2_BLKST_FREE do indicate not to verify)
 *
 * If @type is DT_UNKNOWN, the inode type is fetched from disk.
 *
 * If @blktype is anything other than GFS2_BLKST_FREE (which is used as a
 * placeholder because it doesn't otherwise make sense), the on-disk block type
 * is verified to be @blktype.
 *
 * Returns: A VFS inode, or an error
 */

struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned int type,
                                u64 no_addr, u64 no_formal_ino,
                                unsigned int blktype)
{
        struct inode *inode;
        struct gfs2_inode *ip;
        struct gfs2_glock *io_gl = NULL;
        struct gfs2_holder i_gh;
        int error;

        gfs2_holder_mark_uninitialized(&i_gh);
        inode = gfs2_iget(sb, no_addr);
        if (!inode)
                return ERR_PTR(-ENOMEM);

        ip = GFS2_I(inode);

        if (inode->i_state & I_NEW) {
                struct gfs2_sbd *sdp = GFS2_SB(inode);
                ip->i_no_formal_ino = no_formal_ino;

                error = gfs2_glock_get(sdp, no_addr, &gfs2_inode_glops, CREATE, &ip->i_gl);
                if (unlikely(error))
                        goto fail;
                ip->i_gl->gl_object = ip;

                error = gfs2_glock_get(sdp, no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
                if (unlikely(error))
                        goto fail_put;

                if (type == DT_UNKNOWN || blktype != GFS2_BLKST_FREE) {
                        /*
                         * The GL_SKIP flag indicates to skip reading the inode
                         * block.  We read the inode with gfs2_inode_refresh
                         * after possibly checking the block type.
                         */
                        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE,
                                                   GL_SKIP, &i_gh);
                        if (error)
                                goto fail_put;

                        if (blktype != GFS2_BLKST_FREE) {
                                error = gfs2_check_blk_type(sdp, no_addr,
                                                            blktype);
                                if (error)
                                        goto fail_put;
                        }
                }

                set_bit(GIF_INVALID, &ip->i_flags);
                error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
                if (unlikely(error))
                        goto fail_put;

                ip->i_iopen_gh.gh_gl->gl_object = ip;
                gfs2_glock_put(io_gl);
                io_gl = NULL;

                if (type == DT_UNKNOWN) {
                        /* Inode glock must be locked already */
                        error = gfs2_inode_refresh(GFS2_I(inode));
                        if (error)
                                goto fail_refresh;
                } else {
                        inode->i_mode = DT2IF(type);
                }

                gfs2_set_iop(inode);

                inode->i_atime.tv_sec = 0;
                inode->i_atime.tv_nsec = 0;

                unlock_new_inode(inode);
        }

        if (gfs2_holder_initialized(&i_gh))
                gfs2_glock_dq_uninit(&i_gh);
        return inode;

fail_refresh:
        ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
        ip->i_iopen_gh.gh_gl->gl_object = NULL;
        gfs2_glock_dq_wait(&ip->i_iopen_gh);
        gfs2_holder_uninit(&ip->i_iopen_gh);
fail_put:
        if (io_gl)
                gfs2_glock_put(io_gl);
        if (gfs2_holder_initialized(&i_gh))
                gfs2_glock_dq_uninit(&i_gh);
        ip->i_gl->gl_object = NULL;
fail:
        iget_failed(inode);
        return ERR_PTR(error);
}

struct inode *gfs2_lookup_by_inum(struct gfs2_sbd *sdp, u64 no_addr,
                                  u64 *no_formal_ino, unsigned int blktype)
{
        struct super_block *sb = sdp->sd_vfs;
        struct inode *inode;
        int error;

        inode = gfs2_inode_lookup(sb, DT_UNKNOWN, no_addr, 0, blktype);
        if (IS_ERR(inode))
                return inode;

        /* Two extra checks for NFS only */
        if (no_formal_ino) {
                error = -ESTALE;
                if (GFS2_I(inode)->i_no_formal_ino != *no_formal_ino)
                        goto fail_iput;

                error = -EIO;
                if (GFS2_I(inode)->i_diskflags & GFS2_DIF_SYSTEM)
                        goto fail_iput;
        }
        return inode;

fail_iput:
        iput(inode);
        return ERR_PTR(error);
}


struct inode *gfs2_lookup_simple(struct inode *dip, const char *name)
{
        struct qstr qstr;
        struct inode *inode;
        gfs2_str2qstr(&qstr, name);
        inode = gfs2_lookupi(dip, &qstr, 1);
        /* gfs2_lookupi has inconsistent callers: vfs
         * related routines expect NULL for no entry found,
         * gfs2_lookup_simple callers expect ENOENT
         * and do not check for NULL.
         */
        if (inode == NULL)
                return ERR_PTR(-ENOENT);
        else
                return inode;
}


/**
 * gfs2_lookupi - Look up a filename in a directory and return its inode
 * @d_gh: An initialized holder for the directory glock
 * @name: The name of the inode to look for
 * @is_root: If 1, ignore the caller's permissions
 * @i_gh: An uninitialized holder for the new inode glock
 *
 * This can be called via the VFS filldir function when NFS is doing
 * a readdirplus and the inode which its intending to stat isn't
 * already in cache. In this case we must not take the directory glock
 * again, since the readdir call will have already taken that lock.
 *
 * Returns: errno
 */

struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
                           int is_root)
{
        struct super_block *sb = dir->i_sb;
        struct gfs2_inode *dip = GFS2_I(dir);
        struct gfs2_holder d_gh;
        int error = 0;
        struct inode *inode = NULL;

        gfs2_holder_mark_uninitialized(&d_gh);
        if (!name->len || name->len > GFS2_FNAMESIZE)
                return ERR_PTR(-ENAMETOOLONG);

        if ((name->len == 1 && memcmp(name->name, ".", 1) == 0) ||
            (name->len == 2 && memcmp(name->name, "..", 2) == 0 &&
             dir == sb->s_root->d_inode)) {
                igrab(dir);
                return dir;
        }

        if (gfs2_glock_is_locked_by_me(dip->i_gl) == NULL) {
                error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
                if (error)
                        return ERR_PTR(error);
        }

        if (!is_root) {
                error = gfs2_permission(dir, MAY_EXEC);
                if (error)
                        goto out;
        }

        inode = gfs2_dir_search(dir, name, false);
        if (IS_ERR(inode))
                error = PTR_ERR(inode);
out:
        if (gfs2_holder_initialized(&d_gh))
                gfs2_glock_dq_uninit(&d_gh);
        if (error == -ENOENT)
                return NULL;
        return inode ? inode : ERR_PTR(error);
}

/**
 * create_ok - OK to create a new on-disk inode here?
 * @dip:  Directory in which dinode is to be created
 * @name:  Name of new dinode
 * @mode:
 *
 * Returns: errno
 */

static int create_ok(struct gfs2_inode *dip, const struct qstr *name,
                     umode_t mode)
{
        int error;

        error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);
        if (error)
                return error;

        /*  Don't create entries in an unlinked directory  */
        if (!dip->i_inode.i_nlink)
                return -ENOENT;

        if (dip->i_entries == (u32)-1)
                return -EFBIG;
        if (S_ISDIR(mode) && dip->i_inode.i_nlink == (u32)-1)
                return -EMLINK;

        return 0;
}

static void munge_mode_uid_gid(const struct gfs2_inode *dip,
                               struct inode *inode)
{
        if (GFS2_SB(&dip->i_inode)->sd_args.ar_suiddir &&
            (dip->i_inode.i_mode & S_ISUID) &&
            !uid_eq(dip->i_inode.i_uid, GLOBAL_ROOT_UID)) {
                if (S_ISDIR(inode->i_mode))
                        inode->i_mode |= S_ISUID;
                else if (!uid_eq(dip->i_inode.i_uid, current_fsuid()))
                        inode->i_mode &= ~07111;
                inode->i_uid = dip->i_inode.i_uid;
        } else
                inode->i_uid = current_fsuid();

        if (dip->i_inode.i_mode & S_ISGID) {
                if (S_ISDIR(inode->i_mode))
                        inode->i_mode |= S_ISGID;
                inode->i_gid = dip->i_inode.i_gid;
        } else
                inode->i_gid = current_fsgid();
}

static int alloc_dinode(struct gfs2_inode *ip, u32 flags)
{
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
        struct gfs2_alloc_parms ap = { .target = RES_DINODE, .aflags = flags, };
        int error;
        int dblocks = 1;

        error = gfs2_quota_lock_check(ip, &ap);
        if (error)
                goto out;

        error = gfs2_inplace_reserve(ip, &ap);
        if (error)
                goto out_quota;

        error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS + RES_QUOTA, 0);
        if (error)
                goto out_ipreserv;

        error = gfs2_alloc_blocks(ip, &ip->i_no_addr, &dblocks, 1, &ip->i_generation);
        ip->i_no_formal_ino = ip->i_generation;
        ip->i_inode.i_ino = ip->i_no_addr;
        ip->i_goal = ip->i_no_addr;

        gfs2_trans_end(sdp);

out_ipreserv:
        gfs2_inplace_release(ip);
out_quota:
        gfs2_quota_unlock(ip);
out:
        return error;
}

static void gfs2_init_dir(struct buffer_head *dibh,
                          const struct gfs2_inode *parent)
{
        struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data;
        struct gfs2_dirent *dent = (struct gfs2_dirent *)(di+1);

        gfs2_qstr2dirent(&gfs2_qdot, GFS2_DIRENT_SIZE(gfs2_qdot.len), dent);
        dent->de_inum = di->di_num; /* already GFS2 endian */
        dent->de_type = cpu_to_be16(DT_DIR);

        dent = (struct gfs2_dirent *)((char*)dent + GFS2_DIRENT_SIZE(1));
        gfs2_qstr2dirent(&gfs2_qdotdot, dibh->b_size - GFS2_DIRENT_SIZE(1) - sizeof(struct gfs2_dinode), dent);
        gfs2_inum_out(parent, dent);
        dent->de_type = cpu_to_be16(DT_DIR);
        
}

/**
 * init_dinode - Fill in a new dinode structure
 * @dip: The directory this inode is being created in
 * @ip: The inode
 * @symname: The symlink destination (if a symlink)
 * @bhp: The buffer head (returned to caller)
 *
 */

static void init_dinode(struct gfs2_inode *dip, struct gfs2_inode *ip,
                        const char *symname)
{
        struct gfs2_dinode *di;
        struct buffer_head *dibh;

        dibh = gfs2_meta_new(ip->i_gl, ip->i_no_addr);
        gfs2_trans_add_meta(ip->i_gl, dibh);
        di = (struct gfs2_dinode *)dibh->b_data;
        gfs2_dinode_out(ip, di);

        di->di_major = cpu_to_be32(MAJOR(ip->i_inode.i_rdev));
        di->di_minor = cpu_to_be32(MINOR(ip->i_inode.i_rdev));
        di->__pad1 = 0;
        di->__pad2 = 0;
        di->__pad3 = 0;
        memset(&di->__pad4, 0, sizeof(di->__pad4));
        memset(&di->di_reserved, 0, sizeof(di->di_reserved));
        gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));

        switch(ip->i_inode.i_mode & S_IFMT) {
        case S_IFDIR:
                gfs2_init_dir(dibh, dip);
                break;
        case S_IFLNK:
                memcpy(dibh->b_data + sizeof(struct gfs2_dinode), symname, ip->i_inode.i_size);
                break;
        }

        set_buffer_uptodate(dibh);
        brelse(dibh);
}

static int link_dinode(struct gfs2_inode *dip, const struct qstr *name,
                       struct gfs2_inode *ip, int arq)
{
        struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
        struct gfs2_alloc_parms ap = { .target = sdp->sd_max_dirres, };
        int error;

        if (arq) {
                error = gfs2_quota_lock_check(dip, &ap);
                if (error)
                        goto fail_quota_locks;

                error = gfs2_inplace_reserve(dip, &ap);
                if (error)
                        goto fail_quota_locks;

                error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
                                         dip->i_rgd->rd_length +
                                         2 * RES_DINODE +
                                         RES_STATFS + RES_QUOTA, 0);
                if (error)
                        goto fail_ipreserv;
        } else {
                error = gfs2_trans_begin(sdp, RES_LEAF + 2 * RES_DINODE, 0);
                if (error)
                        goto fail_quota_locks;
        }

        error = gfs2_dir_add(&dip->i_inode, name, ip);
        if (error)
                goto fail_end_trans;

fail_end_trans:
        gfs2_trans_end(sdp);
fail_ipreserv:
        gfs2_inplace_release(dip);
fail_quota_locks:
        gfs2_quota_unlock(dip);
        return error;
}

static int gfs2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
                    void *fs_info)
{
        const struct xattr *xattr;
        int err = 0;

        for (xattr = xattr_array; xattr->name != NULL; xattr++) {
                err = __gfs2_xattr_set(inode, xattr->name, xattr->value,
                                       xattr->value_len, 0,
                                       GFS2_EATYPE_SECURITY);
                if (err < 0)
                        break;
        }
        return err;
}

static int gfs2_security_init(struct gfs2_inode *dip, struct gfs2_inode *ip,
                              const struct qstr *qstr)
{
        return security_inode_init_security(&ip->i_inode, &dip->i_inode, qstr,
                                            &gfs2_initxattrs, NULL);
}

/**
 * gfs2_create_inode - Create a new inode
 * @dir: The parent directory
 * @dentry: The new dentry
 * @file: If non-NULL, the file which is being opened
 * @mode: The permissions on the new inode
 * @dev: For device nodes, this is the device number
 * @symname: For symlinks, this is the link destination
 * @size: The initial size of the inode (ignored for directories)
 *
 * Returns: 0 on success, or error code
 */

static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
                             struct file *file,
                             umode_t mode, dev_t dev, const char *symname,
                             unsigned int size, int excl, int *opened)
{
        const struct qstr *name = &dentry->d_name;
        struct gfs2_holder ghs[2];
        struct inode *inode = NULL;
        struct gfs2_inode *dip = GFS2_I(dir), *ip;
        struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
        struct gfs2_glock *io_gl = NULL;
        struct dentry *d;
        int error, free_vfs_inode = 1;
        u32 aflags = 0;
        int arq;

        if (!name->len || name->len > GFS2_FNAMESIZE)
                return -ENAMETOOLONG;

        error = gfs2_rsqa_alloc(dip);
        if (error)
                return error;

        error = gfs2_rindex_update(sdp);
        if (error)
                return error;

        error = gfs2_glock_nq_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
        if (error)
                goto fail;

        error = create_ok(dip, name, mode);
        if (error)
                goto fail_gunlock;

        inode = gfs2_dir_search(dir, &dentry->d_name, !S_ISREG(mode) || excl);
        error = PTR_ERR(inode);
        if (!IS_ERR(inode)) {
                d = d_splice_alias(inode, dentry);
                error = PTR_ERR(d);
                if (IS_ERR(d)) {
                        inode = ERR_CAST(d);
                        goto fail_gunlock;
                }
                error = 0;
                if (file) {
                        if (S_ISREG(inode->i_mode)) {
                                WARN_ON(d != NULL);
                                error = finish_open(file, dentry, gfs2_open_common, opened);
                        } else {
                                error = finish_no_open(file, d);
                        }
                } else {
                        dput(d);
                }
                gfs2_glock_dq_uninit(ghs);
                return error;
        } else if (error != -ENOENT) {
                goto fail_gunlock;
        }

        arq = error = gfs2_diradd_alloc_required(dir, name);
        if (error < 0)
                goto fail_gunlock;

        inode = new_inode(sdp->sd_vfs);
        error = -ENOMEM;
        if (!inode)
                goto fail_gunlock;

        ip = GFS2_I(inode);
        error = gfs2_rsqa_alloc(ip);
        if (error)
                goto fail_free_inode;

        inode->i_mode = mode;
        set_nlink(inode, S_ISDIR(mode) ? 2 : 1);
        inode->i_rdev = dev;
        inode->i_size = size;
        inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
        gfs2_set_inode_blocks(inode, 1);
        munge_mode_uid_gid(dip, inode);
        check_and_update_goal(dip);
        ip->i_goal = dip->i_goal;
        ip->i_diskflags = 0;
        ip->i_eattr = 0;
        ip->i_height = 0;
        ip->i_depth = 0;
        ip->i_entries = 0;

        switch(mode & S_IFMT) {
        case S_IFREG:
                if ((dip->i_diskflags & GFS2_DIF_INHERIT_JDATA) ||
                    gfs2_tune_get(sdp, gt_new_files_jdata))
                        ip->i_diskflags |= GFS2_DIF_JDATA;
                gfs2_set_aops(inode);
                break;
        case S_IFDIR:
                ip->i_diskflags |= (dip->i_diskflags & GFS2_DIF_INHERIT_JDATA);
                ip->i_diskflags |= GFS2_DIF_JDATA;
                ip->i_entries = 2;
                break;
        }

        /* Force SYSTEM flag on all files and subdirs of a SYSTEM directory */
        if (dip->i_diskflags & GFS2_DIF_SYSTEM)
                ip->i_diskflags |= GFS2_DIF_SYSTEM;

        gfs2_set_inode_flags(inode);

        if ((GFS2_I(sdp->sd_root_dir->d_inode) == dip) ||
            (dip->i_diskflags & GFS2_DIF_TOPDIR))
                aflags |= GFS2_AF_ORLOV;

        error = alloc_dinode(ip, aflags);
        if (error)
                goto fail_free_inode;

        error = gfs2_glock_get(sdp, ip->i_no_addr, &gfs2_inode_glops, CREATE, &ip->i_gl);
        if (error)
                goto fail_free_inode;

        ip->i_gl->gl_object = ip;
        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
        if (error)
                goto fail_free_inode;

        error = gfs2_trans_begin(sdp, RES_DINODE, 0);
        if (error)
                goto fail_gunlock2;

        init_dinode(dip, ip, symname);
        gfs2_trans_end(sdp);

        error = gfs2_glock_get(sdp, ip->i_no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
        if (error)
                goto fail_gunlock2;

        BUG_ON(test_and_set_bit(GLF_INODE_CREATING, &io_gl->gl_flags));

        error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
        if (error)
                goto fail_gunlock2;

        ip->i_iopen_gh.gh_gl->gl_object = ip;
        gfs2_glock_put(io_gl);
        gfs2_set_iop(inode);
        insert_inode_hash(inode);

        free_vfs_inode = 0; /* After this point, the inode is no longer
                               considered free. Any failures need to undo
                               the gfs2 structures. */

        error = gfs2_acl_create(dip, inode);
        if (error)
                goto fail_gunlock3;

        error = gfs2_security_init(dip, ip, name);
        if (error)
                goto fail_gunlock3;

        error = link_dinode(dip, name, ip, arq);
        if (error)
                goto fail_gunlock3;

        mark_inode_dirty(inode);
        d_instantiate(dentry, inode);
        if (file) {
                *opened |= FILE_CREATED;
                error = finish_open(file, dentry, gfs2_open_common, opened);
        }
        gfs2_glock_dq_uninit(ghs);
        gfs2_glock_dq_uninit(ghs + 1);
        clear_bit(GLF_INODE_CREATING, &io_gl->gl_flags);
        return error;

fail_gunlock3:
        gfs2_glock_dq_uninit(&ip->i_iopen_gh);
        gfs2_glock_put(io_gl);
fail_gunlock2:
        if (io_gl)
                clear_bit(GLF_INODE_CREATING, &io_gl->gl_flags);
        gfs2_glock_dq_uninit(ghs + 1);
fail_free_inode:
        if (ip->i_gl)
                gfs2_glock_put(ip->i_gl);
        gfs2_rsqa_delete(ip, NULL);
fail_gunlock:
        gfs2_glock_dq_uninit(ghs);
        if (inode && !IS_ERR(inode)) {
                clear_nlink(inode);
                if (!free_vfs_inode)
                        mark_inode_dirty(inode);
                set_bit(free_vfs_inode ? GIF_FREE_VFS_INODE : GIF_ALLOC_FAILED,
                        &GFS2_I(inode)->i_flags);
                iput(inode);
        }
fail:
        return error;
}

/**
 * gfs2_create - Create a file
 * @dir: The directory in which to create the file
 * @dentry: The dentry of the new file
 * @mode: The mode of the new file
 *
 * Returns: errno
 */

static int gfs2_create(struct inode *dir, struct dentry *dentry,
                       umode_t mode, bool excl)
{
        return gfs2_create_inode(dir, dentry, NULL, S_IFREG | mode, 0, NULL, 0, excl, NULL);
}

/**
 * __gfs2_lookup - Look up a filename in a directory and return its inode
 * @dir: The directory inode
 * @dentry: The dentry of the new inode
 * @file: File to be opened
 * @opened: atomic_open flags
 *
 *
 * Returns: errno
 */

static struct dentry *__gfs2_lookup(struct inode *dir, struct dentry *dentry,
                                    struct file *file, int *opened)
{
        struct inode *inode;
        struct dentry *d;
        struct gfs2_holder gh;
        struct gfs2_glock *gl;
        int error;

        inode = gfs2_lookupi(dir, &dentry->d_name, 0);
        if (inode == NULL) {
                d_add(dentry, NULL);
                return NULL;
        }
        if (IS_ERR(inode))
                return ERR_CAST(inode);

        gl = GFS2_I(inode)->i_gl;
        error = gfs2_glock_nq_init(gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
        if (error) {
                iput(inode);
                return ERR_PTR(error);
        }

        d = d_splice_alias(inode, dentry);
        if (IS_ERR(d)) {
                gfs2_glock_dq_uninit(&gh);
                return d;
        }
        if (file && S_ISREG(inode->i_mode))
                error = finish_open(file, dentry, gfs2_open_common, opened);

        gfs2_glock_dq_uninit(&gh);
        if (error) {
                dput(d);
                return ERR_PTR(error);
        }
        return d;
}

static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry,
                                  unsigned flags)
{
        return __gfs2_lookup(dir, dentry, NULL, NULL);
}

/**
 * gfs2_link - Link to a file
 * @old_dentry: The inode to link
 * @dir: Add link to this directory
 * @dentry: The name of the link
 *
 * Link the inode in "old_dentry" into the directory "dir" with the
 * name in "dentry".
 *
 * Returns: errno
 */

static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
                     struct dentry *dentry)
{
        struct gfs2_inode *dip = GFS2_I(dir);
        struct gfs2_sbd *sdp = GFS2_SB(dir);
        struct inode *inode = old_dentry->d_inode;
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_holder ghs[2];
        struct buffer_head *dibh;
        int alloc_required;
        int error;

        if (S_ISDIR(inode->i_mode))
                return -EPERM;

        error = gfs2_rsqa_alloc(dip);
        if (error)
                return error;

        gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);

        error = gfs2_glock_nq(ghs); /* parent */
        if (error)
                goto out_parent;

        error = gfs2_glock_nq(ghs + 1); /* child */
        if (error)
                goto out_child;

        error = -ENOENT;
        if (inode->i_nlink == 0)
                goto out_gunlock;

        error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC);
        if (error)
                goto out_gunlock;

        error = gfs2_dir_check(dir, &dentry->d_name, NULL);
        switch (error) {
        case -ENOENT:
                break;
        case 0:
                error = -EEXIST;
        default:
                goto out_gunlock;
        }

        error = -EINVAL;
        if (!dip->i_inode.i_nlink)
                goto out_gunlock;
        error = -EFBIG;
        if (dip->i_entries == (u32)-1)
                goto out_gunlock;
        error = -EPERM;
        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
                goto out_gunlock;
        error = -EINVAL;
        if (!ip->i_inode.i_nlink)
                goto out_gunlock;
        error = -EMLINK;
        if (ip->i_inode.i_nlink == (u32)-1)
                goto out_gunlock;

        alloc_required = error = gfs2_diradd_alloc_required(dir, &dentry->d_name);
        if (error < 0)
                goto out_gunlock;
        error = 0;

        if (alloc_required) {
                struct gfs2_alloc_parms ap = { .target = sdp->sd_max_dirres, };
                error = gfs2_quota_lock_check(dip, &ap);
                if (error)
                        goto out_gunlock;

                error = gfs2_inplace_reserve(dip, &ap);
                if (error)
                        goto out_gunlock_q;

                error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
                                         gfs2_rg_blocks(dip, sdp->sd_max_dirres) +
                                         2 * RES_DINODE + RES_STATFS +
                                         RES_QUOTA, 0);
                if (error)
                        goto out_ipres;
        } else {
                error = gfs2_trans_begin(sdp, 2 * RES_DINODE + RES_LEAF, 0);
                if (error)
                        goto out_ipres;
        }

        error = gfs2_meta_inode_buffer(ip, &dibh);
        if (error)
                goto out_end_trans;

        error = gfs2_dir_add(dir, &dentry->d_name, ip);
        if (error)
                goto out_brelse;

        gfs2_trans_add_meta(ip->i_gl, dibh);
        inc_nlink(&ip->i_inode);
        ip->i_inode.i_ctime = CURRENT_TIME;
        ihold(inode);
        d_instantiate(dentry, inode);
        mark_inode_dirty(inode);

out_brelse:
        brelse(dibh);
out_end_trans:
        gfs2_trans_end(sdp);
out_ipres:
        if (alloc_required)
                gfs2_inplace_release(dip);
out_gunlock_q:
        if (alloc_required)
                gfs2_quota_unlock(dip);
out_gunlock:
        gfs2_glock_dq(ghs + 1);
out_child:
        gfs2_glock_dq(ghs);
out_parent:
        gfs2_holder_uninit(ghs);
        gfs2_holder_uninit(ghs + 1);
        return error;
}

/*
 * gfs2_unlink_ok - check to see that a inode is still in a directory
 * @dip: the directory
 * @name: the name of the file
 * @ip: the inode
 *
 * Assumes that the lock on (at least) @dip is held.
 *
 * Returns: 0 if the parent/child relationship is correct, errno if it isn't
 */

static int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
                          const struct gfs2_inode *ip)
{
        int error;

        if (IS_IMMUTABLE(&ip->i_inode) || IS_APPEND(&ip->i_inode))
                return -EPERM;

        if ((dip->i_inode.i_mode & S_ISVTX) &&
            !uid_eq(dip->i_inode.i_uid, current_fsuid()) &&
            !uid_eq(ip->i_inode.i_uid, current_fsuid()) && !capable(CAP_FOWNER))
                return -EPERM;

        if (IS_APPEND(&dip->i_inode))
                return -EPERM;

        error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);
        if (error)
                return error;

        error = gfs2_dir_check(&dip->i_inode, name, ip);
        if (error)
                return error;

        return 0;
}

/**
 * gfs2_unlink_inode - Removes an inode from its parent dir and unlinks it
 * @dip: The parent directory
 * @name: The name of the entry in the parent directory
 * @inode: The inode to be removed
 *
 * Called with all the locks and in a transaction. This will only be

 * called for a directory after it has been checked to ensure it is empty.
 *
 * Returns: 0 on success, or an error
 */

static int gfs2_unlink_inode(struct gfs2_inode *dip,
                             const struct dentry *dentry)
{
        struct inode *inode = dentry->d_inode;
        struct gfs2_inode *ip = GFS2_I(inode);
        int error;

        error = gfs2_dir_del(dip, dentry);
        if (error)
                return error;

        ip->i_entries = 0;
        inode->i_ctime = CURRENT_TIME;
        if (S_ISDIR(inode->i_mode))
                clear_nlink(inode);
        else
                drop_nlink(inode);
        mark_inode_dirty(inode);
        if (inode->i_nlink == 0)
                gfs2_unlink_di(inode);
        return 0;
}


/**
 * gfs2_unlink - Unlink an inode (this does rmdir as well)
 * @dir: The inode of the directory containing the inode to unlink
 * @dentry: The file itself
 *
 * This routine uses the type of the inode as a flag to figure out
 * whether this is an unlink or an rmdir.
 *
 * Returns: errno
 */

static int gfs2_unlink(struct inode *dir, struct dentry *dentry)
{
        struct gfs2_inode *dip = GFS2_I(dir);
        struct gfs2_sbd *sdp = GFS2_SB(dir);
        struct inode *inode = dentry->d_inode;
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_holder ghs[3];
        struct gfs2_rgrpd *rgd;
        int error;

        error = gfs2_rindex_update(sdp);
        if (error)
                return error;

        error = -EROFS;

        gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
        gfs2_holder_init(ip->i_gl,  LM_ST_EXCLUSIVE, 0, ghs + 1);

        rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr, 1);
        if (!rgd)
                goto out_inodes;

        gfs2_holder_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + 2);


        error = gfs2_glock_nq(ghs); /* parent */
        if (error)
                goto out_parent;

        error = gfs2_glock_nq(ghs + 1); /* child */
        if (error)
                goto out_child;

        error = -ENOENT;
        if (inode->i_nlink == 0)
                goto out_rgrp;

        if (S_ISDIR(inode->i_mode)) {
                error = -ENOTEMPTY;
                if (ip->i_entries > 2 || inode->i_nlink > 2)
                        goto out_rgrp;
        }

        error = gfs2_glock_nq(ghs + 2); /* rgrp */
        if (error)
                goto out_rgrp;

        error = gfs2_unlink_ok(dip, &dentry->d_name, ip);
        if (error)
                goto out_gunlock;

        error = gfs2_trans_begin(sdp, 2*RES_DINODE + 3*RES_LEAF + RES_RG_BIT, 0);
        if (error)
                goto out_end_trans;

        error = gfs2_unlink_inode(dip, dentry);

out_end_trans:
        gfs2_trans_end(sdp);
out_gunlock:
        gfs2_glock_dq(ghs + 2);
out_rgrp:
        gfs2_glock_dq(ghs + 1);
out_child:
        gfs2_glock_dq(ghs);
out_parent:
        gfs2_holder_uninit(ghs + 2);
out_inodes:
        gfs2_holder_uninit(ghs + 1);
        gfs2_holder_uninit(ghs);
        return error;
}

/**
 * gfs2_symlink - Create a symlink
 * @dir: The directory to create the symlink in
 * @dentry: The dentry to put the symlink in
 * @symname: The thing which the link points to
 *
 * Returns: errno
 */

static int gfs2_symlink(struct inode *dir, struct dentry *dentry,
                        const char *symname)
{
        struct gfs2_sbd *sdp = GFS2_SB(dir);
        unsigned int size;

        size = strlen(symname);
        if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode) - 1)
                return -ENAMETOOLONG;

        return gfs2_create_inode(dir, dentry, NULL, S_IFLNK | S_IRWXUGO, 0, symname, size, 0, NULL);
}

/**
 * gfs2_mkdir - Make a directory
 * @dir: The parent directory of the new one
 * @dentry: The dentry of the new directory
 * @mode: The mode of the new directory
 *
 * Returns: errno
 */

static int gfs2_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
        struct gfs2_sbd *sdp = GFS2_SB(dir);
        unsigned dsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode);
        return gfs2_create_inode(dir, dentry, NULL, S_IFDIR | mode, 0, NULL, dsize, 0, NULL);
}

/**
 * gfs2_mknod - Make a special file
 * @dir: The directory in which the special file will reside
 * @dentry: The dentry of the special file
 * @mode: The mode of the special file
 * @dev: The device specification of the special file
 *
 */

static int gfs2_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
                      dev_t dev)
{
        return gfs2_create_inode(dir, dentry, NULL, mode, dev, NULL, 0, 0, NULL);
}

/**
 * gfs2_atomic_open - Atomically open a file
 * @dir: The directory
 * @dentry: The proposed new entry
 * @file: The proposed new struct file
 * @flags: open flags
 * @mode: File mode
 * @opened: Flag to say whether the file has been opened or not
 *
 * Returns: error code or 0 for success
 */

static int gfs2_atomic_open(struct inode *dir, struct dentry *dentry,
                            struct file *file, unsigned flags,
                            umode_t mode, int *opened)
{
        struct dentry *d;
        bool excl = !!(flags & O_EXCL);

        if (!d_unhashed(dentry))
                goto skip_lookup;

        d = __gfs2_lookup(dir, dentry, file, opened);
        if (IS_ERR(d))
                return PTR_ERR(d);
        if (d != NULL)
                dentry = d;
        if (dentry->d_inode) {
                if (!(*opened & FILE_OPENED)) {
                        if (d == NULL)
                                dget(dentry);
                        return finish_no_open(file, dentry);
                }
                dput(d);
                return 0;
        }

        BUG_ON(d != NULL);

skip_lookup:
        if (!(flags & O_CREAT))
                return -ENOENT;

        return gfs2_create_inode(dir, dentry, file, S_IFREG | mode, 0, NULL, 0, excl, opened);
}

/*
 * gfs2_ok_to_move - check if it's ok to move a directory to another directory
 * @this: move this
 * @to: to here
 *
 * Follow @to back to the root and make sure we don't encounter @this
 * Assumes we already hold the rename lock.
 *
 * Returns: errno
 */

static int gfs2_ok_to_move(struct gfs2_inode *this, struct gfs2_inode *to)
{
        struct inode *dir = &to->i_inode;
        struct super_block *sb = dir->i_sb;
        struct inode *tmp;
        int error = 0;

        igrab(dir);

        for (;;) {
                if (dir == &this->i_inode) {
                        error = -EINVAL;
                        break;
                }
                if (dir == sb->s_root->d_inode) {
                        error = 0;
                        break;
                }

                tmp = gfs2_lookupi(dir, &gfs2_qdotdot, 1);
                if (!tmp) {
                        error = -ENOENT;
                        break;
                }
                if (IS_ERR(tmp)) {
                        error = PTR_ERR(tmp);
                        break;
                }

                iput(dir);
                dir = tmp;
        }

        iput(dir);

        return error;
}

/**
 * update_moved_ino - Update an inode that's being moved
 * @ip: The inode being moved
 * @ndip: The parent directory of the new filename
 * @dir_rename: True of ip is a directory
 *
 * Returns: errno
 */

static int update_moved_ino(struct gfs2_inode *ip, struct gfs2_inode *ndip,
                            int dir_rename)
{
        int error;
        struct buffer_head *dibh;

        if (dir_rename)
                return gfs2_dir_mvino(ip, &gfs2_qdotdot, ndip, DT_DIR);

        error = gfs2_meta_inode_buffer(ip, &dibh);
        if (error)
                return error;
        ip->i_inode.i_ctime = CURRENT_TIME;
        gfs2_trans_add_meta(ip->i_gl, dibh);
        gfs2_dinode_out(ip, dibh->b_data);
        brelse(dibh);
        return 0;
}


/**
 * gfs2_rename - Rename a file
 * @odir: Parent directory of old file name
 * @odentry: The old dentry of the file
 * @ndir: Parent directory of new file name
 * @ndentry: The new dentry of the file
 *
 * Returns: errno
 */

static int gfs2_rename(struct inode *odir, struct dentry *odentry,
                       struct inode *ndir, struct dentry *ndentry)
{
        struct gfs2_inode *odip = GFS2_I(odir);
        struct gfs2_inode *ndip = GFS2_I(ndir);
        struct gfs2_inode *ip = GFS2_I(odentry->d_inode);
        struct gfs2_inode *nip = NULL;
        struct gfs2_sbd *sdp = GFS2_SB(odir);
        struct gfs2_holder ghs[5], r_gh;
        struct gfs2_rgrpd *nrgd;
        unsigned int num_gh;
        int dir_rename = 0;
        int alloc_required = 0;
        unsigned int x;
        int error;

        gfs2_holder_mark_uninitialized(&r_gh);
        if (ndentry->d_inode) {
                nip = GFS2_I(ndentry->d_inode);
                if (ip == nip)
                        return 0;
        }

        error = gfs2_rindex_update(sdp);
        if (error)
                return error;

        error = gfs2_rsqa_alloc(ndip);
        if (error)
                return error;

        if (odip != ndip) {
                error = gfs2_glock_nq_init(sdp->sd_rename_gl, LM_ST_EXCLUSIVE,
                                           0, &r_gh);
                if (error)
                        goto out;

                if (S_ISDIR(ip->i_inode.i_mode)) {
                        dir_rename = 1;
                        /* don't move a directory into its subdir */
                        error = gfs2_ok_to_move(ip, ndip);
                        if (error)
                                goto out_gunlock_r;
                }
        }

        num_gh = 1;
        gfs2_holder_init(odip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
        if (odip != ndip) {
                gfs2_holder_init(ndip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh);
                num_gh++;
        }
        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh);
        num_gh++;

        if (nip) {
                gfs2_holder_init(nip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh);
                num_gh++;
                /* grab the resource lock for unlink flag twiddling 
                 * this is the case of the target file already existing
                 * so we unlink before doing the rename
                 */
                nrgd = gfs2_blk2rgrpd(sdp, nip->i_no_addr, 1);
                if (nrgd)
                        gfs2_holder_init(nrgd->rd_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh++);
        }

        for (x = 0; x < num_gh; x++) {
                error = gfs2_glock_nq(ghs + x);
                if (error)
                        goto out_gunlock;
        }

        error = -ENOENT;
        if (ip->i_inode.i_nlink == 0)
                goto out_gunlock;

        /* Check out the old directory */

        error = gfs2_unlink_ok(odip, &odentry->d_name, ip);
        if (error)
                goto out_gunlock;

        /* Check out the new directory */

        if (nip) {
                error = gfs2_unlink_ok(ndip, &ndentry->d_name, nip);
                if (error)
                        goto out_gunlock;

                if (nip->i_inode.i_nlink == 0) {
                        error = -EAGAIN;
                        goto out_gunlock;
                }

                if (S_ISDIR(nip->i_inode.i_mode)) {
                        if (nip->i_entries < 2) {
                                gfs2_consist_inode(nip);
                                error = -EIO;
                                goto out_gunlock;
                        }
                        if (nip->i_entries > 2) {
                                error = -ENOTEMPTY;
                                goto out_gunlock;
                        }
                }
        } else {
                error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC);
                if (error)
                        goto out_gunlock;

                error = gfs2_dir_check(ndir, &ndentry->d_name, NULL);
                switch (error) {
                case -ENOENT:
                        error = 0;
                        break;
                case 0:
                        error = -EEXIST;
                default:
                        goto out_gunlock;
                };

                if (odip != ndip) {
                        if (!ndip->i_inode.i_nlink) {
                                error = -ENOENT;
                                goto out_gunlock;
                        }
                        if (ndip->i_entries == (u32)-1) {
                                error = -EFBIG;
                                goto out_gunlock;
                        }
                        if (S_ISDIR(ip->i_inode.i_mode) &&
                            ndip->i_inode.i_nlink == (u32)-1) {
                                error = -EMLINK;
                                goto out_gunlock;
                        }
                }
        }

        /* Check out the dir to be renamed */

        if (dir_rename) {
                error = gfs2_permission(odentry->d_inode, MAY_WRITE);
                if (error)
                        goto out_gunlock;
        }

        if (nip == NULL)
                alloc_required = gfs2_diradd_alloc_required(ndir, &ndentry->d_name);
        error = alloc_required;
        if (error < 0)
                goto out_gunlock;

        if (alloc_required) {
                struct gfs2_alloc_parms ap = { .target = sdp->sd_max_dirres, };
                error = gfs2_quota_lock_check(ndip, &ap);
                if (error)
                        goto out_gunlock;

                error = gfs2_inplace_reserve(ndip, &ap);
                if (error)
                        goto out_gunlock_q;

                error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
                                         gfs2_rg_blocks(ndip, sdp->sd_max_dirres) +
                                         4 * RES_DINODE + 4 * RES_LEAF +
                                         RES_STATFS + RES_QUOTA + 4, 0);
                if (error)
                        goto out_ipreserv;
        } else {
                error = gfs2_trans_begin(sdp, 4 * RES_DINODE +
                                         5 * RES_LEAF + 4, 0);
                if (error)
                        goto out_gunlock;
        }

        /* Remove the target file, if it exists */

        if (nip)
                error = gfs2_unlink_inode(ndip, ndentry);

        error = update_moved_ino(ip, ndip, dir_rename);
        if (error)
                goto out_end_trans;

        error = gfs2_dir_del(odip, odentry);
        if (error)
                goto out_end_trans;

        error = gfs2_dir_add(ndir, &ndentry->d_name, ip);
        if (error)
                goto out_end_trans;

out_end_trans:
        gfs2_trans_end(sdp);
out_ipreserv:
        if (alloc_required)
                gfs2_inplace_release(ndip);
out_gunlock_q:
        if (alloc_required)
                gfs2_quota_unlock(ndip);
out_gunlock:
        while (x--) {
                gfs2_glock_dq(ghs + x);
                gfs2_holder_uninit(ghs + x);
        }
out_gunlock_r:
        if (gfs2_holder_initialized(&r_gh))
                gfs2_glock_dq_uninit(&r_gh);
out:
        return error;
}

/**
 * gfs2_exchange - exchange two files
 * @odir: Parent directory of old file name
 * @odentry: The old dentry of the file
 * @ndir: Parent directory of new file name
 * @ndentry: The new dentry of the file
 * @flags: The rename flags
 *
 * Returns: errno
 */

static int gfs2_exchange(struct inode *odir, struct dentry *odentry,
                         struct inode *ndir, struct dentry *ndentry,
                         unsigned int flags)
{
        struct gfs2_inode *odip = GFS2_I(odir);
        struct gfs2_inode *ndip = GFS2_I(ndir);
        struct gfs2_inode *oip = GFS2_I(odentry->d_inode);
        struct gfs2_inode *nip = GFS2_I(ndentry->d_inode);
        struct gfs2_sbd *sdp = GFS2_SB(odir);
        struct gfs2_holder ghs[5], r_gh;
        unsigned int num_gh;
        unsigned int x;
        umode_t old_mode = oip->i_inode.i_mode;
        umode_t new_mode = nip->i_inode.i_mode;
        int error;

        gfs2_holder_mark_uninitialized(&r_gh);
        error = gfs2_rindex_update(sdp);
        if (error)
                return error;

        if (odip != ndip) {
                error = gfs2_glock_nq_init(sdp->sd_rename_gl, LM_ST_EXCLUSIVE,
                                           0, &r_gh);
                if (error)
                        goto out;

                if (S_ISDIR(old_mode)) {
                        /* don't move a directory into its subdir */
                        error = gfs2_ok_to_move(oip, ndip);
                        if (error)
                                goto out_gunlock_r;
                }

                if (S_ISDIR(new_mode)) {
                        /* don't move a directory into its subdir */
                        error = gfs2_ok_to_move(nip, odip);
                        if (error)
                                goto out_gunlock_r;
                }
        }

        num_gh = 1;
        gfs2_holder_init(odip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
        if (odip != ndip) {
                gfs2_holder_init(ndip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh);
                num_gh++;
        }
        gfs2_holder_init(oip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh);
        num_gh++;

        gfs2_holder_init(nip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + num_gh);
        num_gh++;

        for (x = 0; x < num_gh; x++) {
                error = gfs2_glock_nq(ghs + x);
                if (error)
                        goto out_gunlock;
        }

        error = -ENOENT;
        if (oip->i_inode.i_nlink == 0 || nip->i_inode.i_nlink == 0)
                goto out_gunlock;

        error = gfs2_unlink_ok(odip, &odentry->d_name, oip);
        if (error)
                goto out_gunlock;
        error = gfs2_unlink_ok(ndip, &ndentry->d_name, nip);
        if (error)
                goto out_gunlock;

        if (S_ISDIR(old_mode)) {
                error = gfs2_permission(odentry->d_inode, MAY_WRITE);
                if (error)
                        goto out_gunlock;
        }
        if (S_ISDIR(new_mode)) {
                error = gfs2_permission(ndentry->d_inode, MAY_WRITE);
                if (error)
                        goto out_gunlock;
        }
        error = gfs2_trans_begin(sdp, 4 * RES_DINODE + 4 * RES_LEAF, 0);
        if (error)
                goto out_gunlock;

        error = update_moved_ino(oip, ndip, S_ISDIR(old_mode));
        if (error)
                goto out_end_trans;

        error = update_moved_ino(nip, odip, S_ISDIR(new_mode));
        if (error)
                goto out_end_trans;

        error = gfs2_dir_mvino(ndip, &ndentry->d_name, oip,
                               IF2DT(old_mode));
        if (error)
                goto out_end_trans;

        error = gfs2_dir_mvino(odip, &odentry->d_name, nip,
                               IF2DT(new_mode));
        if (error)
                goto out_end_trans;

        if (odip != ndip) {
                if (S_ISDIR(new_mode) && !S_ISDIR(old_mode)) {
                        inc_nlink(&odip->i_inode);
                        drop_nlink(&ndip->i_inode);
                } else if (S_ISDIR(old_mode) && !S_ISDIR(new_mode)) {
                        inc_nlink(&ndip->i_inode);
                        drop_nlink(&odip->i_inode);
                }
        }
        mark_inode_dirty(&ndip->i_inode);
        if (odip != ndip)
                mark_inode_dirty(&odip->i_inode);

out_end_trans:
        gfs2_trans_end(sdp);
out_gunlock:
        while (x--) {
                gfs2_glock_dq(ghs + x);
                gfs2_holder_uninit(ghs + x);
        }
out_gunlock_r:
        if (gfs2_holder_initialized(&r_gh))
                gfs2_glock_dq_uninit(&r_gh);
out:
        return error;
}

static int gfs2_rename2(struct inode *odir, struct dentry *odentry,
                        struct inode *ndir, struct dentry *ndentry,
                        unsigned int flags)
{
        flags &= ~RENAME_NOREPLACE;

        if (flags & ~RENAME_EXCHANGE)
                return -EINVAL;

        if (flags & RENAME_EXCHANGE)
                return gfs2_exchange(odir, odentry, ndir, ndentry, flags);

        return gfs2_rename(odir, odentry, ndir, ndentry);
}

/**
 * gfs2_follow_link - Follow a symbolic link
 * @dentry: The dentry of the link
 * @nd: Data that we pass to vfs_follow_link()
 *
 * This can handle symlinks of any size.
 *
 * Returns: 0 on success or error code
 */

static void *gfs2_follow_link(struct dentry *dentry, struct nameidata *nd)
{
        struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
        struct gfs2_holder i_gh;
        struct buffer_head *dibh;
        unsigned int size;
        char *buf;
        int error;

        gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
        error = gfs2_glock_nq(&i_gh);
        if (error) {
                gfs2_holder_uninit(&i_gh);
                nd_set_link(nd, ERR_PTR(error));
                return NULL;
        }

        size = (unsigned int)i_size_read(&ip->i_inode);
        if (size == 0) {
                gfs2_consist_inode(ip);
                buf = ERR_PTR(-EIO);
                goto out;
        }

        error = gfs2_meta_inode_buffer(ip, &dibh);
        if (error) {
                buf = ERR_PTR(error);
                goto out;
        }

        buf = kzalloc(size + 1, GFP_NOFS);
        if (!buf)
                buf = ERR_PTR(-ENOMEM);
        else
                memcpy(buf, dibh->b_data + sizeof(struct gfs2_dinode), size);
        brelse(dibh);
out:
        gfs2_glock_dq_uninit(&i_gh);
        nd_set_link(nd, buf);
        return NULL;
}

/**
 * gfs2_permission -
 * @inode: The inode
 * @mask: The mask to be tested
 * @flags: Indicates whether this is an RCU path walk or not
 *
 * This may be called from the VFS directly, or from within GFS2 with the
 * inode locked, so we look to see if the glock is already locked and only
 * lock the glock if its not already been done.
 *
 * Returns: errno
 */

int gfs2_permission(struct inode *inode, int mask)
{
        struct gfs2_inode *ip;
        struct gfs2_holder i_gh;
        int error;

        gfs2_holder_mark_uninitialized(&i_gh);
        ip = GFS2_I(inode);
        if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) {
                if (mask & MAY_NOT_BLOCK)
                        return -ECHILD;
                error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
                if (error)
                        return error;
        }

        if ((mask & MAY_WRITE) && IS_IMMUTABLE(inode))
                error = -EACCES;
        else
                error = generic_permission(inode, mask);
        if (gfs2_holder_initialized(&i_gh))
                gfs2_glock_dq_uninit(&i_gh);

        return error;
}

static int __gfs2_setattr_simple(struct inode *inode, struct iattr *attr)
{
        setattr_copy(inode, attr);
        mark_inode_dirty(inode);
        return 0;
}

/**
 * gfs2_setattr_simple -
 * @ip:
 * @attr:
 *
 * Returns: errno
 */

int gfs2_setattr_simple(struct inode *inode, struct iattr *attr)
{
        int error;

        if (current->journal_info)
                return __gfs2_setattr_simple(inode, attr);

        error = gfs2_trans_begin(GFS2_SB(inode), RES_DINODE, 0);
        if (error)
                return error;

        error = __gfs2_setattr_simple(inode, attr);
        gfs2_trans_end(GFS2_SB(inode));
        return error;
}

static int setattr_chown(struct inode *inode, struct iattr *attr)
{
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_sbd *sdp = GFS2_SB(inode);
        kuid_t ouid, nuid;
        kgid_t ogid, ngid;
        int error;
        struct gfs2_alloc_parms ap;

        ouid = inode->i_uid;
        ogid = inode->i_gid;
        nuid = attr->ia_uid;
        ngid = attr->ia_gid;

        if (!(attr->ia_valid & ATTR_UID) || uid_eq(ouid, nuid))
                ouid = nuid = NO_UID_QUOTA_CHANGE;
        if (!(attr->ia_valid & ATTR_GID) || gid_eq(ogid, ngid))
                ogid = ngid = NO_GID_QUOTA_CHANGE;

        error = gfs2_rsqa_alloc(ip);
        if (error)
                goto out;

        error = gfs2_rindex_update(sdp);
        if (error)
                goto out;

        error = gfs2_quota_lock(ip, nuid, ngid);
        if (error)
                goto out;

        ap.target = gfs2_get_inode_blocks(&ip->i_inode);

        if (!uid_eq(ouid, NO_UID_QUOTA_CHANGE) ||
            !gid_eq(ogid, NO_GID_QUOTA_CHANGE)) {
                error = gfs2_quota_check(ip, nuid, ngid, &ap);
                if (error)
                        goto out_gunlock_q;
        }

        error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_QUOTA, 0);
        if (error)
                goto out_gunlock_q;

        error = gfs2_setattr_simple(inode, attr);
        if (error)
                goto out_end_trans;

        if (!uid_eq(ouid, NO_UID_QUOTA_CHANGE) ||
            !gid_eq(ogid, NO_GID_QUOTA_CHANGE)) {
                gfs2_quota_change(ip, -(s64)ap.target, ouid, ogid);
                gfs2_quota_change(ip, ap.target, nuid, ngid);
        }

out_end_trans:
        gfs2_trans_end(sdp);
out_gunlock_q:
        gfs2_quota_unlock(ip);
out:
        return error;
}

/**
 * gfs2_setattr - Change attributes on an inode
 * @dentry: The dentry which is changing
 * @attr: The structure describing the change
 *
 * The VFS layer wants to change one or more of an inodes attributes.  Write
 * that change out to disk.
 *
 * Returns: errno
 */

static int gfs2_setattr(struct dentry *dentry, struct iattr *attr)
{
        struct inode *inode = dentry->d_inode;
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_holder i_gh;
        int error;

        error = gfs2_rsqa_alloc(ip);
        if (error)
                return error;

        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
        if (error)
                return error;

        error = -EPERM;
        if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
                goto out;

        error = inode_change_ok(inode, attr);
        if (error)
                goto out;

        if (attr->ia_valid & ATTR_SIZE)
                error = gfs2_setattr_size(inode, attr->ia_size);
        else if (attr->ia_valid & (ATTR_UID | ATTR_GID))
                error = setattr_chown(inode, attr);
        else if ((attr->ia_valid & ATTR_MODE) && IS_POSIXACL(inode))
                error = gfs2_acl_chmod(ip, attr);
        else
                error = gfs2_setattr_simple(inode, attr);

out:
        if (!error)
                mark_inode_dirty(inode);
        gfs2_glock_dq_uninit(&i_gh);
        return error;
}

/**
 * gfs2_getattr - Read out an inode's attributes
 * @mnt: The vfsmount the inode is being accessed from
 * @dentry: The dentry to stat
 * @stat: The inode's stats
 *
 * This may be called from the VFS directly, or from within GFS2 with the
 * inode locked, so we look to see if the glock is already locked and only
 * lock the glock if its not already been done. Note that its the NFS
 * readdirplus operation which causes this to be called (from filldir)
 * with the glock already held.
 *
 * Returns: errno
 */

static int gfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
                        struct kstat *stat)
{
        struct inode *inode = dentry->d_inode;
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_holder gh;
        int error;

        gfs2_holder_mark_uninitialized(&gh);
        if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) {
                error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
                if (error)
                        return error;
        }

        generic_fillattr(inode, stat);
        if (gfs2_holder_initialized(&gh))
                gfs2_glock_dq_uninit(&gh);

        return 0;
}

static int gfs2_setxattr(struct dentry *dentry, const char *name,
                         const void *data, size_t size, int flags)
{
        struct inode *inode = dentry->d_inode;
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_holder gh;
        int ret;

        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
        ret = gfs2_glock_nq(&gh);
        if (ret == 0) {
                ret = gfs2_rsqa_alloc(ip);
                if (ret == 0)
                        ret = generic_setxattr(dentry, name, data, size, flags);
                gfs2_glock_dq(&gh);
        }
        gfs2_holder_uninit(&gh);
        return ret;
}

static ssize_t gfs2_getxattr(struct dentry *dentry, const char *name,
                             void *data, size_t size)
{
        struct inode *inode = dentry->d_inode;
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_holder gh;
        int ret;

        /* For selinux during lookup */
        if (gfs2_glock_is_locked_by_me(ip->i_gl))
                return generic_getxattr(dentry, name, data, size);

        gfs2_holder_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
        ret = gfs2_glock_nq(&gh);
        if (ret == 0) {
                ret = generic_getxattr(dentry, name, data, size);
                gfs2_glock_dq(&gh);
        }
        gfs2_holder_uninit(&gh);
        return ret;
}

static int gfs2_removexattr(struct dentry *dentry, const char *name)
{
        struct inode *inode = dentry->d_inode;
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_holder gh;
        int ret;

        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
        ret = gfs2_glock_nq(&gh);
        if (ret == 0) {
                ret = gfs2_rsqa_alloc(ip);
                if (ret == 0)
                        ret = generic_removexattr(dentry, name);
                gfs2_glock_dq(&gh);
        }
        gfs2_holder_uninit(&gh);
        return ret;

}

static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                       u64 start, u64 len)
{
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_holder gh;
        int ret;

        ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
        if (ret)
                return ret;

        mutex_lock(&inode->i_mutex);

        ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
        if (ret)
                goto out;

        if (gfs2_is_stuffed(ip)) {
                u64 phys = ip->i_no_addr << inode->i_blkbits;
                u64 size = i_size_read(inode);
                u32 flags = FIEMAP_EXTENT_LAST|FIEMAP_EXTENT_NOT_ALIGNED|
                            FIEMAP_EXTENT_DATA_INLINE;
                phys += sizeof(struct gfs2_dinode);
                phys += start;
                if (start + len > size)
                        len = size - start;
                if (start < size)
                        ret = fiemap_fill_next_extent(fieinfo, start, phys,
                                                      len, flags);
                if (ret == 1)
                        ret = 0;
        } else {
                ret = __generic_block_fiemap(inode, fieinfo, start, len,
                                             gfs2_block_map);
        }

        gfs2_glock_dq_uninit(&gh);
out:
        mutex_unlock(&inode->i_mutex);
        return ret;
}

const struct inode_operations gfs2_file_iops = {
        .permission = gfs2_permission,
        .setattr = gfs2_setattr,
        .getattr = gfs2_getattr,
        .setxattr = gfs2_setxattr,
        .getxattr = gfs2_getxattr,
        .listxattr = gfs2_listxattr,
        .removexattr = gfs2_removexattr,
        .fiemap = gfs2_fiemap,
        .get_acl = gfs2_get_acl,
};

const struct inode_operations_wrapper gfs2_dir_iops = {
        .ops = {
        .create = gfs2_create,
        .lookup = gfs2_lookup,
        .link = gfs2_link,
        .unlink = gfs2_unlink,
        .symlink = gfs2_symlink,
        .mkdir = gfs2_mkdir,
        .rmdir = gfs2_unlink,
        .mknod = gfs2_mknod,
        .rename = gfs2_rename,
        .permission = gfs2_permission,
        .setattr = gfs2_setattr,
        .getattr = gfs2_getattr,
        .setxattr = gfs2_setxattr,
        .getxattr = gfs2_getxattr,
        .listxattr = gfs2_listxattr,
        .removexattr = gfs2_removexattr,
        .fiemap = gfs2_fiemap,
        .get_acl = gfs2_get_acl,
        .atomic_open = gfs2_atomic_open,
        },
        .rename2 = gfs2_rename2,
};

const struct inode_operations gfs2_symlink_iops = {
        .readlink = generic_readlink,
        .follow_link = gfs2_follow_link,
        .put_link = kfree_put_link,
        .permission = gfs2_permission,
        .setattr = gfs2_setattr,
        .getattr = gfs2_getattr,
        .setxattr = gfs2_setxattr,
        .getxattr = gfs2_getxattr,
        .listxattr = gfs2_listxattr,
        .removexattr = gfs2_removexattr,
        .fiemap = gfs2_fiemap,
        .get_acl = gfs2_get_acl,
};