GFS2: Reduce file fragmentation

[deliverable/linux.git] / fs / gfs2 / inode.c

/*
 * 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"

struct gfs2_skip_data {
        u64 no_addr;
        int skipped;
        int non_block;
};

static int iget_test(struct inode *inode, void *opaque)
{
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_skip_data *data = opaque;

        if (ip->i_no_addr == data->no_addr) {
                if (data->non_block &&
                    inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) {
                        data->skipped = 1;
                        return 0;
                }
                return 1;
        }
        return 0;
}

static int iget_set(struct inode *inode, void *opaque)
{
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_skip_data *data = opaque;

        if (data->skipped)
                return -ENOENT;
        inode->i_ino = (unsigned long)(data->no_addr);
        ip->i_no_addr = data->no_addr;
        return 0;
}

struct inode *gfs2_ilookup(struct super_block *sb, u64 no_addr, int non_block)
{
        unsigned long hash = (unsigned long)no_addr;
        struct gfs2_skip_data data;

        data.no_addr = no_addr;
        data.skipped = 0;
        data.non_block = non_block;
        return ilookup5(sb, hash, iget_test, &data);
}

static struct inode *gfs2_iget(struct super_block *sb, u64 no_addr,
                               int non_block)
{
        struct gfs2_skip_data data;
        unsigned long hash = (unsigned long)no_addr;

        data.no_addr = no_addr;
        data.skipped = 0;
        data.non_block = non_block;
        return iget5_locked(sb, hash, iget_test, iget_set, &data);
}

/**
 * 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_op = &gfs2_dir_iops;
                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
 * @no_addr: The inode number
 * @type: The type of the inode
 * non_block: Can we block on inodes that are being freed?
 *
 * 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, int non_block)
{
        struct inode *inode;
        struct gfs2_inode *ip;
        struct gfs2_glock *io_gl = NULL;
        int error;

        inode = gfs2_iget(sb, no_addr, non_block);
        ip = GFS2_I(inode);

        if (!inode)
                return ERR_PTR(-ENOBUFS);

        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;

                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_iopen;

                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);
                unlock_new_inode(inode);
        }

        return inode;

fail_refresh:
        ip->i_iopen_gh.gh_gl->gl_object = NULL;
        gfs2_glock_dq_uninit(&ip->i_iopen_gh);
fail_iopen:
        if (io_gl)
                gfs2_glock_put(io_gl);
fail_put:
        ip->i_gl->gl_object = NULL;
        gfs2_glock_put(ip->i_gl);
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 gfs2_holder i_gh;
        struct inode *inode = NULL;
        int error;

        /* Must not read in block until block type is verified */
        error = gfs2_glock_nq_num(sdp, no_addr, &gfs2_inode_glops,
                                  LM_ST_EXCLUSIVE, GL_SKIP, &i_gh);
        if (error)
                return ERR_PTR(error);

        error = gfs2_check_blk_type(sdp, no_addr, blktype);
        if (error)
                goto fail;

        inode = gfs2_inode_lookup(sb, DT_UNKNOWN, no_addr, 0, 1);
        if (IS_ERR(inode))
                goto fail;

        /* 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;

                error = 0;
        }

fail:
        gfs2_glock_dq_uninit(&i_gh);
        return error ? ERR_PTR(error) : inode;
fail_iput:
        iput(inode);
        goto fail;
}


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;
        int unlock = 0;

        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);
                unlock = 1;
        }

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

        inode = gfs2_dir_search(dir, name);
        if (IS_ERR(inode))
                error = PTR_ERR(inode);
out:
        if (unlock)
                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;

        error = gfs2_dir_check(&dip->i_inode, name, NULL);
        switch (error) {
        case -ENOENT:
                error = 0;
                break;
        case 0:
                return -EEXIST;
        default:
                return error;
        }

        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(struct gfs2_inode *dip, umode_t *mode,
                               unsigned int *uid, unsigned int *gid)
{
        if (GFS2_SB(&dip->i_inode)->sd_args.ar_suiddir &&
            (dip->i_inode.i_mode & S_ISUID) && dip->i_inode.i_uid) {
                if (S_ISDIR(*mode))
                        *mode |= S_ISUID;
                else if (dip->i_inode.i_uid != current_fsuid())
                        *mode &= ~07111;
                *uid = dip->i_inode.i_uid;
        } else
                *uid = current_fsuid();

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

static int alloc_dinode(struct gfs2_inode *dip, u64 *no_addr, u64 *generation)
{
        struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
        int error;
        int dblocks = 1;

        error = gfs2_inplace_reserve(dip, RES_DINODE);
        if (error)
                goto out;

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

        error = gfs2_alloc_blocks(dip, no_addr, &dblocks, 1, generation);

        gfs2_trans_end(sdp);

out_ipreserv:
        gfs2_inplace_release(dip);
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
 * @gl: The glock covering the new inode
 * @inum: The inode number
 * @mode: The file permissions
 * @uid: The uid of the new inode
 * @gid: The gid of the new inode
 * @generation: The generation number of the new inode
 * @dev: The device number (if a device node)
 * @symname: The symlink destination (if a symlink)
 * @size: The inode size (ignored for directories)
 * @bhp: The buffer head (returned to caller)
 *
 */

static void init_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
                        const struct gfs2_inum_host *inum, umode_t mode,
                        unsigned int uid, unsigned int gid,
                        const u64 *generation, dev_t dev, const char *symname,
                        unsigned size, struct buffer_head **bhp)
{
        struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
        struct gfs2_dinode *di;
        struct buffer_head *dibh;
        struct timespec tv = CURRENT_TIME;

        dibh = gfs2_meta_new(gl, inum->no_addr);
        gfs2_trans_add_bh(gl, dibh, 1);
        gfs2_metatype_set(dibh, GFS2_METATYPE_DI, GFS2_FORMAT_DI);
        gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
        di = (struct gfs2_dinode *)dibh->b_data;

        di->di_num.no_formal_ino = cpu_to_be64(inum->no_formal_ino);
        di->di_num.no_addr = cpu_to_be64(inum->no_addr);
        di->di_mode = cpu_to_be32(mode);
        di->di_uid = cpu_to_be32(uid);
        di->di_gid = cpu_to_be32(gid);
        di->di_nlink = 0;
        di->di_size = cpu_to_be64(size);
        di->di_blocks = cpu_to_be64(1);
        di->di_atime = di->di_mtime = di->di_ctime = cpu_to_be64(tv.tv_sec);
        di->di_major = cpu_to_be32(MAJOR(dev));
        di->di_minor = cpu_to_be32(MINOR(dev));
        di->di_goal_meta = di->di_goal_data = cpu_to_be64(inum->no_addr);
        di->di_generation = cpu_to_be64(*generation);
        di->di_flags = 0;
        di->__pad1 = 0;
        di->di_payload_format = cpu_to_be32(S_ISDIR(mode) ? GFS2_FORMAT_DE : 0);
        di->di_height = 0;
        di->__pad2 = 0;
        di->__pad3 = 0;
        di->di_depth = 0;
        di->di_entries = 0;
        memset(&di->__pad4, 0, sizeof(di->__pad4));
        di->di_eattr = 0;
        di->di_atime_nsec = cpu_to_be32(tv.tv_nsec);
        di->di_mtime_nsec = cpu_to_be32(tv.tv_nsec);
        di->di_ctime_nsec = cpu_to_be32(tv.tv_nsec);
        memset(&di->di_reserved, 0, sizeof(di->di_reserved));

        switch(mode & S_IFMT) { 
        case S_IFREG:
                if ((dip->i_diskflags & GFS2_DIF_INHERIT_JDATA) ||
                    gfs2_tune_get(sdp, gt_new_files_jdata))
                        di->di_flags |= cpu_to_be32(GFS2_DIF_JDATA);
                break;
        case S_IFDIR:
                di->di_flags |= cpu_to_be32(dip->i_diskflags &
                                            GFS2_DIF_INHERIT_JDATA);
                di->di_flags |= cpu_to_be32(GFS2_DIF_JDATA);
                di->di_size = cpu_to_be64(sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode));
                di->di_entries = cpu_to_be32(2);
                gfs2_init_dir(dibh, dip);
                break;
        case S_IFLNK:
                memcpy(dibh->b_data + sizeof(struct gfs2_dinode), symname, size);
                break;
        }

        set_buffer_uptodate(dibh);

        *bhp = dibh;
}

static int make_dinode(struct gfs2_inode *dip, struct gfs2_glock *gl,
                       umode_t mode, const struct gfs2_inum_host *inum,
                       const u64 *generation, dev_t dev, const char *symname,
                       unsigned int size, struct buffer_head **bhp)
{
        struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
        unsigned int uid, gid;
        int error;

        munge_mode_uid_gid(dip, &mode, &uid, &gid);
        error = gfs2_rindex_update(sdp);
        if (error)
                return error;

        error = gfs2_quota_lock(dip, uid, gid);
        if (error)
                return error;

        error = gfs2_quota_check(dip, uid, gid);
        if (error)
                goto out_quota;

        error = gfs2_trans_begin(sdp, RES_DINODE + RES_QUOTA, 0);
        if (error)
                goto out_quota;

        init_dinode(dip, gl, inum, mode, uid, gid, generation, dev, symname, size, bhp);
        gfs2_quota_change(dip, +1, uid, gid);
        gfs2_trans_end(sdp);

out_quota:
        gfs2_quota_unlock(dip);
        return error;
}

static int link_dinode(struct gfs2_inode *dip, const struct qstr *name,
                       struct gfs2_inode *ip)
{
        struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
        int alloc_required;
        struct buffer_head *dibh;
        int error;

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

        error = gfs2_quota_lock(dip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
        if (error)
                goto fail;

        error = alloc_required = gfs2_diradd_alloc_required(&dip->i_inode, name);
        if (alloc_required < 0)
                goto fail_quota_locks;
        if (alloc_required) {
                error = gfs2_quota_check(dip, dip->i_inode.i_uid, dip->i_inode.i_gid);
                if (error)
                        goto fail_quota_locks;

                error = gfs2_inplace_reserve(dip, sdp->sd_max_dirres);
                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;

        error = gfs2_meta_inode_buffer(ip, &dibh);
        if (error)
                goto fail_end_trans;
        set_nlink(&ip->i_inode, S_ISDIR(ip->i_inode.i_mode) ? 2 : 1);
        gfs2_trans_add_bh(ip->i_gl, dibh, 1);
        gfs2_dinode_out(ip, dibh->b_data);
        brelse(dibh);
        return 0;

fail_end_trans:
        gfs2_trans_end(sdp);

fail_ipreserv:
        if (alloc_required)
                gfs2_inplace_release(dip);

fail_quota_locks:
        gfs2_quota_unlock(dip);

fail:
        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
 * @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,
                             umode_t mode, dev_t dev, const char *symname,
                             unsigned int size, int excl)
{
        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_inum_host inum = { .no_addr = 0, .no_formal_ino = 0 };
        int error;
        u64 generation;
        struct buffer_head *bh = NULL;

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

        /* We need a reservation to allocate the new dinode block. The
           directory ip temporarily points to the reservation, but this is
           being done to get a set of contiguous blocks for the new dinode.
           Since this is a create, we don't have a sizehint yet, so it will
           have to use the minimum reservation size. */
        error = gfs2_rs_alloc(dip);
        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 == -EEXIST) && S_ISREG(mode) && !excl) {
                inode = gfs2_lookupi(dir, &dentry->d_name, 0);
                gfs2_glock_dq_uninit(ghs);
                d_instantiate(dentry, inode);
                return IS_ERR(inode) ? PTR_ERR(inode) : 0;
        }
        if (error)
                goto fail_gunlock;

        error = alloc_dinode(dip, &inum.no_addr, &generation);
        if (error)
                goto fail_gunlock;
        inum.no_formal_ino = generation;

        error = gfs2_glock_nq_num(sdp, inum.no_addr, &gfs2_inode_glops,
                                  LM_ST_EXCLUSIVE, GL_SKIP, ghs + 1);
        if (error)
                goto fail_gunlock;

        error = make_dinode(dip, ghs[1].gh_gl, mode, &inum, &generation, dev, symname, size, &bh);
        if (error)
                goto fail_gunlock2;

        inode = gfs2_inode_lookup(dir->i_sb, IF2DT(mode), inum.no_addr,
                                  inum.no_formal_ino, 0);
        if (IS_ERR(inode))
                goto fail_gunlock2;

        ip = GFS2_I(inode);
        error = gfs2_inode_refresh(ip);
        if (error)
                goto fail_gunlock2;

        /* The newly created inode needs a reservation so it can allocate
           xattrs. At the same time, we want new blocks allocated to the new
           dinode to be as contiguous as possible. Since we allocated the
           dinode block under the directory's reservation, we transfer
           ownership of that reservation to the new inode. The directory
           doesn't need a reservation unless it needs a new allocation. */
        ip->i_res = dip->i_res;
        dip->i_res = NULL;

        error = gfs2_acl_create(dip, inode);
        if (error)
                goto fail_gunlock2;

        error = gfs2_security_init(dip, ip, name);
        if (error)
                goto fail_gunlock2;

        error = link_dinode(dip, name, ip);
        if (error)
                goto fail_gunlock2;

        if (bh)
                brelse(bh);

        gfs2_trans_end(sdp);
        /* Check if we reserved space in the rgrp. Function link_dinode may
           not, depending on whether alloc is required. */
        if (gfs2_mb_reserved(dip))
                gfs2_inplace_release(dip);
        gfs2_quota_unlock(dip);
        mark_inode_dirty(inode);
        gfs2_glock_dq_uninit_m(2, ghs);
        d_instantiate(dentry, inode);
        return 0;

fail_gunlock2:
        gfs2_glock_dq_uninit(ghs + 1);
fail_gunlock:
        gfs2_glock_dq_uninit(ghs);
        if (inode && !IS_ERR(inode)) {
                set_bit(GIF_ALLOC_FAILED, &GFS2_I(inode)->i_flags);
                iput(inode);
        }
fail:
        gfs2_rs_delete(dip);
        if (bh)
                brelse(bh);
        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, struct nameidata *nd)
{
        int excl = 0;
        if (nd && (nd->flags & LOOKUP_EXCL))
                excl = 1;
        return gfs2_create_inode(dir, dentry, S_IFREG | mode, 0, NULL, 0, excl);
}

/**
 * gfs2_lookup - Look up a filename in a directory and return its inode
 * @dir: The directory inode
 * @dentry: The dentry of the new inode
 * @nd: passed from Linux VFS, ignored by us
 *
 * Called by the VFS layer. Lock dir and call gfs2_lookupi()
 *
 * Returns: errno
 */

static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry,
                                  struct nameidata *nd)
{
        struct inode *inode = gfs2_lookupi(dir, &dentry->d_name, 0);
        if (inode && !IS_ERR(inode)) {
                struct gfs2_glock *gl = GFS2_I(inode)->i_gl;
                struct gfs2_holder gh;
                int error;
                error = gfs2_glock_nq_init(gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
                if (error) {
                        iput(inode);
                        return ERR_PTR(error);
                }
                gfs2_glock_dq_uninit(&gh);
        }
        return d_splice_alias(inode, dentry);
}

/**
 * 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_rs_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) {
                error = gfs2_quota_lock_check(dip);
                if (error)
                        goto out_gunlock;

                error = gfs2_inplace_reserve(dip, sdp->sd_max_dirres);
                if (error)
                        goto out_gunlock_q;

                error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
                                         gfs2_rg_blocks(dip) +
                                         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_bh(ip->i_gl, dibh, 1);
        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) &&
            dip->i_inode.i_uid != current_fsuid() &&
            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
 * @bh: The inode buffer for the inode to be removed
 * @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 buffer_head *bh)
{
        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 buffer_head *bh;
        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_gunlock;

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

        error = gfs2_unlink_inode(dip, dentry, bh);
        brelse(bh);

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, S_IFLNK | S_IRWXUGO, 0, symname, size, 0);
}

/**
 * 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)
{
        return gfs2_create_inode(dir, dentry, S_IFDIR | mode, 0, NULL, 0, 0);
}

/**
 * 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, mode, dev, NULL, 0, 0);
}

/*
 * 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 (IS_ERR(tmp)) {
                        error = PTR_ERR(tmp);
                        break;
                }

                iput(dir);
                dir = tmp;
        }

        iput(dir);

        return error;
}

/**
 * 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 = { .gh_gl = NULL, };
        struct gfs2_rgrpd *nrgd;
        unsigned int num_gh;
        int dir_rename = 0;
        int alloc_required = 0;
        unsigned int x;
        int error;

        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_rs_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 dirctory into it's 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) {
                error = gfs2_quota_lock_check(ndip);
                if (error)
                        goto out_gunlock;

                error = gfs2_inplace_reserve(ndip, sdp->sd_max_dirres);
                if (error)
                        goto out_gunlock_q;

                error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +
                                         gfs2_rg_blocks(ndip) +
                                         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) {
                struct buffer_head *bh;
                error = gfs2_meta_inode_buffer(nip, &bh);
                if (error)
                        goto out_end_trans;
                error = gfs2_unlink_inode(ndip, ndentry, bh);
                brelse(bh);
        }

        if (dir_rename) {
                error = gfs2_dir_mvino(ip, &gfs2_qdotdot, ndip, DT_DIR);
                if (error)
                        goto out_end_trans;
        } else {
                struct buffer_head *dibh;
                error = gfs2_meta_inode_buffer(ip, &dibh);
                if (error)
                        goto out_end_trans;
                ip->i_inode.i_ctime = CURRENT_TIME;
                gfs2_trans_add_bh(ip->i_gl, dibh, 1);
                gfs2_dinode_out(ip, dibh->b_data);
                brelse(dibh);
        }

        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 (r_gh.gh_gl)
                gfs2_glock_dq_uninit(&r_gh);
out:
        return error;
}

/**
 * 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;
}

static void gfs2_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
{
        char *s = nd_get_link(nd);
        if (!IS_ERR(s))
                kfree(s);
}

/**
 * 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;
        int unlock = 0;


        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;
                unlock = 1;
        }

        if ((mask & MAY_WRITE) && IS_IMMUTABLE(inode))
                error = -EACCES;
        else
                error = generic_permission(inode, mask);
        if (unlock)
                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);
        u32 ouid, ogid, nuid, ngid;
        int error;

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

        if (!(attr->ia_valid & ATTR_UID) || ouid == nuid)
                ouid = nuid = NO_QUOTA_CHANGE;
        if (!(attr->ia_valid & ATTR_GID) || ogid == ngid)
                ogid = ngid = NO_QUOTA_CHANGE;

        error = gfs2_quota_lock(ip, nuid, ngid);
        if (error)
                return error;

        if (ouid != NO_QUOTA_CHANGE || ogid != NO_QUOTA_CHANGE) {
                error = gfs2_quota_check(ip, nuid, ngid);
                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 (ouid != NO_QUOTA_CHANGE || ogid != NO_QUOTA_CHANGE) {
                u64 blocks = gfs2_get_inode_blocks(&ip->i_inode);
                gfs2_quota_change(ip, -blocks, ouid, ogid);
                gfs2_quota_change(ip, blocks, nuid, ngid);
        }

out_end_trans:
        gfs2_trans_end(sdp);
out_gunlock_q:
        gfs2_quota_unlock(ip);
        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_rs_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;
        int unlock = 0;

        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;
                unlock = 1;
        }

        generic_fillattr(inode, stat);
        if (unlock)
                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 = 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;

        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 = 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 gfs2_dir_iops = {
        .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,
};

const struct inode_operations gfs2_symlink_iops = {
        .readlink = generic_readlink,
        .follow_link = gfs2_follow_link,
        .put_link = gfs2_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,
};