[GFS2] Update copyright date to 2006

[mirror_ubuntu-zesty-kernel.git] / fs / gfs2 / ops_file.c

/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 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 v.2.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/pagemap.h>
#include <linux/uio.h>
#include <linux/blkdev.h>
#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/fs.h>
#include <linux/gfs2_ondisk.h>
#include <linux/ext2_fs.h>
#include <linux/crc32.h>
#include <linux/iflags.h>
#include <asm/uaccess.h>

#include "gfs2.h"
#include "lm_interface.h"
#include "incore.h"
#include "bmap.h"
#include "dir.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "lm.h"
#include "log.h"
#include "meta_io.h"
#include "ops_file.h"
#include "ops_vm.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"
#include "eaops.h"

/* "bad" is for NFS support */
struct filldir_bad_entry {
        char *fbe_name;
        unsigned int fbe_length;
        uint64_t fbe_offset;
        struct gfs2_inum fbe_inum;
        unsigned int fbe_type;
};

struct filldir_bad {
        struct gfs2_sbd *fdb_sbd;

        struct filldir_bad_entry *fdb_entry;
        unsigned int fdb_entry_num;
        unsigned int fdb_entry_off;

        char *fdb_name;
        unsigned int fdb_name_size;
        unsigned int fdb_name_off;
};

/* For regular, non-NFS */
struct filldir_reg {
        struct gfs2_sbd *fdr_sbd;
        int fdr_prefetch;

        filldir_t fdr_filldir;
        void *fdr_opaque;
};

/*
 * Most fields left uninitialised to catch anybody who tries to
 * use them. f_flags set to prevent file_accessed() from touching
 * any other part of this. Its use is purely as a flag so that we
 * know (in readpage()) whether or not do to locking.
 */
struct file gfs2_internal_file_sentinal = {
        .f_flags = O_NOATIME|O_RDONLY,
};

static int gfs2_read_actor(read_descriptor_t *desc, struct page *page,
                           unsigned long offset, unsigned long size)
{
        char *kaddr;
        unsigned long count = desc->count;

        if (size > count)
                size = count;

        kaddr = kmap(page);
        memcpy(desc->arg.buf, kaddr + offset, size);
        kunmap(page);

        desc->count = count - size;
        desc->written += size;
        desc->arg.buf += size;
        return size;
}

int gfs2_internal_read(struct gfs2_inode *ip, struct file_ra_state *ra_state,
                       char *buf, loff_t *pos, unsigned size)
{
        struct inode *inode = ip->i_vnode;
        read_descriptor_t desc;
        desc.written = 0;
        desc.arg.buf = buf;
        desc.count = size;
        desc.error = 0;
        do_generic_mapping_read(inode->i_mapping, ra_state,
                                &gfs2_internal_file_sentinal, pos, &desc,
                                gfs2_read_actor);
        return desc.written ? desc.written : desc.error;
}

/**
 * gfs2_llseek - seek to a location in a file
 * @file: the file
 * @offset: the offset
 * @origin: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
 *
 * SEEK_END requires the glock for the file because it references the
 * file's size.
 *
 * Returns: The new offset, or errno
 */

static loff_t gfs2_llseek(struct file *file, loff_t offset, int origin)
{
        struct gfs2_inode *ip = file->f_mapping->host->u.generic_ip;
        struct gfs2_holder i_gh;
        loff_t error;

        if (origin == 2) {
                error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
                                           &i_gh);
                if (!error) {
                        error = remote_llseek(file, offset, origin);
                        gfs2_glock_dq_uninit(&i_gh);
                }
        } else
                error = remote_llseek(file, offset, origin);

        return error;
}


static ssize_t gfs2_direct_IO_read(struct kiocb *iocb, const struct iovec *iov,
                                   loff_t offset, unsigned long nr_segs)
{
        struct file *file = iocb->ki_filp;
        struct address_space *mapping = file->f_mapping;
        ssize_t retval;

        retval = filemap_write_and_wait(mapping);
        if (retval == 0) {
                retval = mapping->a_ops->direct_IO(READ, iocb, iov, offset,
                                                   nr_segs);
        }
        return retval;
}

/**
 * __gfs2_file_aio_read - The main GFS2 read function
 * 
 * N.B. This is almost, but not quite the same as __generic_file_aio_read()
 * the important subtle different being that inode->i_size isn't valid
 * unless we are holding a lock, and we do this _only_ on the O_DIRECT
 * path since otherwise locking is done entirely at the page cache
 * layer.
 */
static ssize_t __gfs2_file_aio_read(struct kiocb *iocb,
                                    const struct iovec *iov,
                                    unsigned long nr_segs, loff_t *ppos)
{
        struct file *filp = iocb->ki_filp;
        struct gfs2_inode *ip = filp->f_mapping->host->u.generic_ip;
        struct gfs2_holder gh;
        ssize_t retval;
        unsigned long seg;
        size_t count;

        count = 0;
        for (seg = 0; seg < nr_segs; seg++) {
                const struct iovec *iv = &iov[seg];

                /*
                 * If any segment has a negative length, or the cumulative
                 * length ever wraps negative then return -EINVAL.
                 */
                count += iv->iov_len;
                if (unlikely((ssize_t)(count|iv->iov_len) < 0))
                        return -EINVAL;
                if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
                        continue;
                if (seg == 0)
                        return -EFAULT;
                nr_segs = seg;
                count -= iv->iov_len;   /* This segment is no good */
                break;
        }

        /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
        if (filp->f_flags & O_DIRECT) {
                loff_t pos = *ppos, size;
                struct address_space *mapping;
                struct inode *inode;

                mapping = filp->f_mapping;
                inode = mapping->host;
                retval = 0;
                if (!count)
                        goto out; /* skip atime */

                gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
                retval = gfs2_glock_nq_m_atime(1, &gh);
                if (retval)
                        goto out;
                if (gfs2_is_stuffed(ip)) {
                        gfs2_glock_dq_m(1, &gh);
                        gfs2_holder_uninit(&gh);
                        goto fallback_to_normal;
                }
                size = i_size_read(inode);
                if (pos < size) {
                        retval = gfs2_direct_IO_read(iocb, iov, pos, nr_segs);
                        if (retval > 0 && !is_sync_kiocb(iocb))
                                retval = -EIOCBQUEUED;
                        if (retval > 0)
                                *ppos = pos + retval;
                }
                file_accessed(filp);
                gfs2_glock_dq_m(1, &gh);
                gfs2_holder_uninit(&gh);
                goto out;
        }

fallback_to_normal:
        retval = 0;
        if (count) {
                for (seg = 0; seg < nr_segs; seg++) {
                        read_descriptor_t desc;

                        desc.written = 0;
                        desc.arg.buf = iov[seg].iov_base;
                        desc.count = iov[seg].iov_len;
                        if (desc.count == 0)
                                continue;
                        desc.error = 0;
                        do_generic_file_read(filp,ppos,&desc,file_read_actor);
                        retval += desc.written;
                        if (desc.error) {
                                retval = retval ?: desc.error;
                                 break;
                        }
                }
        }
out:
        return retval;
}

/**
 * gfs2_read - Read bytes from a file
 * @file: The file to read from
 * @buf: The buffer to copy into
 * @size: The amount of data requested
 * @offset: The current file offset
 *
 * Outputs: Offset - updated according to number of bytes read
 *
 * Returns: The number of bytes read, errno on failure
 */

static ssize_t gfs2_read(struct file *filp, char __user *buf, size_t size,
                         loff_t *offset)
{
        struct iovec local_iov = { .iov_base = buf, .iov_len = size };
        struct kiocb kiocb;
        ssize_t ret;

        init_sync_kiocb(&kiocb, filp);
        ret = __gfs2_file_aio_read(&kiocb, &local_iov, 1, offset);
        if (-EIOCBQUEUED == ret)
                ret = wait_on_sync_kiocb(&kiocb);
        return ret;
}

static ssize_t gfs2_file_readv(struct file *filp, const struct iovec *iov,
                               unsigned long nr_segs, loff_t *ppos)
{
        struct kiocb kiocb;
        ssize_t ret;

        init_sync_kiocb(&kiocb, filp);
        ret = __gfs2_file_aio_read(&kiocb, iov, nr_segs, ppos);
        if (-EIOCBQUEUED == ret)
                ret = wait_on_sync_kiocb(&kiocb);
        return ret;
}

static ssize_t gfs2_file_aio_read(struct kiocb *iocb, char __user *buf,
                                  size_t count, loff_t pos)
{
        struct iovec local_iov = { .iov_base = buf, .iov_len = count };

        BUG_ON(iocb->ki_pos != pos);
        return __gfs2_file_aio_read(iocb, &local_iov, 1, &iocb->ki_pos);
}


/**
 * filldir_reg_func - Report a directory entry to the caller of gfs2_dir_read()
 * @opaque: opaque data used by the function
 * @name: the name of the directory entry
 * @length: the length of the name
 * @offset: the entry's offset in the directory
 * @inum: the inode number the entry points to
 * @type: the type of inode the entry points to
 *
 * Returns: 0 on success, 1 if buffer full
 */

static int filldir_reg_func(void *opaque, const char *name, unsigned int length,
                            uint64_t offset, struct gfs2_inum *inum,
                            unsigned int type)
{
        struct filldir_reg *fdr = (struct filldir_reg *)opaque;
        struct gfs2_sbd *sdp = fdr->fdr_sbd;
        int error;

        error = fdr->fdr_filldir(fdr->fdr_opaque, name, length, offset,
                                 inum->no_formal_ino, type);
        if (error)
                return 1;

        if (fdr->fdr_prefetch && !(length == 1 && *name == '.')) {
                gfs2_glock_prefetch_num(sdp,
                                       inum->no_addr, &gfs2_inode_glops,
                                       LM_ST_SHARED, LM_FLAG_TRY | LM_FLAG_ANY);
                gfs2_glock_prefetch_num(sdp,
                                       inum->no_addr, &gfs2_iopen_glops,
                                       LM_ST_SHARED, LM_FLAG_TRY);
        }

        return 0;
}

/**
 * readdir_reg - Read directory entries from a directory
 * @file: The directory to read from
 * @dirent: Buffer for dirents
 * @filldir: Function used to do the copying
 *
 * Returns: errno
 */

static int readdir_reg(struct file *file, void *dirent, filldir_t filldir)
{
        struct inode *dir = file->f_mapping->host;
        struct gfs2_inode *dip = dir->u.generic_ip;
        struct filldir_reg fdr;
        struct gfs2_holder d_gh;
        uint64_t offset = file->f_pos;
        int error;

        fdr.fdr_sbd = dip->i_sbd;
        fdr.fdr_prefetch = 1;
        fdr.fdr_filldir = filldir;
        fdr.fdr_opaque = dirent;

        gfs2_holder_init(dip->i_gl, LM_ST_SHARED, GL_ATIME, &d_gh);
        error = gfs2_glock_nq_atime(&d_gh);
        if (error) {
                gfs2_holder_uninit(&d_gh);
                return error;
        }

        error = gfs2_dir_read(dir, &offset, &fdr, filldir_reg_func);

        gfs2_glock_dq_uninit(&d_gh);

        file->f_pos = offset;

        return error;
}

/**
 * filldir_bad_func - Report a directory entry to the caller of gfs2_dir_read()
 * @opaque: opaque data used by the function
 * @name: the name of the directory entry
 * @length: the length of the name
 * @offset: the entry's offset in the directory
 * @inum: the inode number the entry points to
 * @type: the type of inode the entry points to
 *
 * For supporting NFS.
 *
 * Returns: 0 on success, 1 if buffer full
 */

static int filldir_bad_func(void *opaque, const char *name, unsigned int length,
                            uint64_t offset, struct gfs2_inum *inum,
                            unsigned int type)
{
        struct filldir_bad *fdb = (struct filldir_bad *)opaque;
        struct gfs2_sbd *sdp = fdb->fdb_sbd;
        struct filldir_bad_entry *fbe;

        if (fdb->fdb_entry_off == fdb->fdb_entry_num ||
            fdb->fdb_name_off + length > fdb->fdb_name_size)
                return 1;

        fbe = &fdb->fdb_entry[fdb->fdb_entry_off];
        fbe->fbe_name = fdb->fdb_name + fdb->fdb_name_off;
        memcpy(fbe->fbe_name, name, length);
        fbe->fbe_length = length;
        fbe->fbe_offset = offset;
        fbe->fbe_inum = *inum;
        fbe->fbe_type = type;

        fdb->fdb_entry_off++;
        fdb->fdb_name_off += length;

        if (!(length == 1 && *name == '.')) {
                gfs2_glock_prefetch_num(sdp,
                                       inum->no_addr, &gfs2_inode_glops,
                                       LM_ST_SHARED, LM_FLAG_TRY | LM_FLAG_ANY);
                gfs2_glock_prefetch_num(sdp,
                                       inum->no_addr, &gfs2_iopen_glops,
                                       LM_ST_SHARED, LM_FLAG_TRY);
        }

        return 0;
}

/**
 * readdir_bad - Read directory entries from a directory
 * @file: The directory to read from
 * @dirent: Buffer for dirents
 * @filldir: Function used to do the copying
 *
 * For supporting NFS.
 *
 * Returns: errno
 */

static int readdir_bad(struct file *file, void *dirent, filldir_t filldir)
{
        struct inode *dir = file->f_mapping->host;
        struct gfs2_inode *dip = dir->u.generic_ip;
        struct gfs2_sbd *sdp = dip->i_sbd;
        struct filldir_reg fdr;
        unsigned int entries, size;
        struct filldir_bad *fdb;
        struct gfs2_holder d_gh;
        uint64_t offset = file->f_pos;
        unsigned int x;
        struct filldir_bad_entry *fbe;
        int error;

        entries = gfs2_tune_get(sdp, gt_entries_per_readdir);
        size = sizeof(struct filldir_bad) +
            entries * (sizeof(struct filldir_bad_entry) + GFS2_FAST_NAME_SIZE);

        fdb = kzalloc(size, GFP_KERNEL);
        if (!fdb)
                return -ENOMEM;

        fdb->fdb_sbd = sdp;
        fdb->fdb_entry = (struct filldir_bad_entry *)(fdb + 1);
        fdb->fdb_entry_num = entries;
        fdb->fdb_name = ((char *)fdb) + sizeof(struct filldir_bad) +
                entries * sizeof(struct filldir_bad_entry);
        fdb->fdb_name_size = entries * GFS2_FAST_NAME_SIZE;

        gfs2_holder_init(dip->i_gl, LM_ST_SHARED, GL_ATIME, &d_gh);
        error = gfs2_glock_nq_atime(&d_gh);
        if (error) {
                gfs2_holder_uninit(&d_gh);
                goto out;
        }

        error = gfs2_dir_read(dir, &offset, fdb, filldir_bad_func);

        gfs2_glock_dq_uninit(&d_gh);

        fdr.fdr_sbd = sdp;
        fdr.fdr_prefetch = 0;
        fdr.fdr_filldir = filldir;
        fdr.fdr_opaque = dirent;

        for (x = 0; x < fdb->fdb_entry_off; x++) {
                fbe = &fdb->fdb_entry[x];

                error = filldir_reg_func(&fdr,
                                         fbe->fbe_name, fbe->fbe_length,
                                         fbe->fbe_offset,
                                         &fbe->fbe_inum, fbe->fbe_type);
                if (error) {
                        file->f_pos = fbe->fbe_offset;
                        error = 0;
                        goto out;
                }
        }

        file->f_pos = offset;

 out:
        kfree(fdb);

        return error;
}

/**
 * gfs2_readdir - Read directory entries from a directory
 * @file: The directory to read from
 * @dirent: Buffer for dirents
 * @filldir: Function used to do the copying
 *
 * Returns: errno
 */

static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
{
        int error;

        if (strcmp(current->comm, "nfsd") != 0)
                error = readdir_reg(file, dirent, filldir);
        else
                error = readdir_bad(file, dirent, filldir);

        return error;
}

static const u32 iflags_to_gfs2[32] = {
        [iflag_Sync] = GFS2_DIF_SYNC,
        [iflag_Immutable] = GFS2_DIF_IMMUTABLE,
        [iflag_Append] = GFS2_DIF_APPENDONLY,
        [iflag_NoAtime] = GFS2_DIF_NOATIME,
        [iflag_Index] = GFS2_DIF_EXHASH,
        [iflag_JournalData] = GFS2_DIF_JDATA,
        [iflag_DirectIO] = GFS2_DIF_DIRECTIO,
};

static const u32 gfs2_to_iflags[32] = {
        [gfs2fl_Sync] = IFLAG_SYNC,
        [gfs2fl_Immutable] = IFLAG_IMMUTABLE,
        [gfs2fl_AppendOnly] = IFLAG_APPEND,
        [gfs2fl_NoAtime] = IFLAG_NOATIME,
        [gfs2fl_ExHash] = IFLAG_INDEX,
        [gfs2fl_Jdata] = IFLAG_JOURNAL_DATA,
        [gfs2fl_Directio] = IFLAG_DIRECTIO,
        [gfs2fl_InheritDirectio] = IFLAG_DIRECTIO,
        [gfs2fl_InheritJdata] = IFLAG_JOURNAL_DATA,
};

static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
{
        struct inode *inode = filp->f_dentry->d_inode;
        struct gfs2_inode *ip = inode->u.generic_ip;
        struct gfs2_holder gh;
        int error;
        u32 iflags;

        gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
        error = gfs2_glock_nq_m_atime(1, &gh);
        if (error)
                return error;
        
        iflags = iflags_cvt(gfs2_to_iflags, ip->i_di.di_flags);
        if (put_user(iflags, ptr))
                error = -EFAULT;

        gfs2_glock_dq_m(1, &gh);
        gfs2_holder_uninit(&gh);
        return error;
}

/* Flags that can be set by user space */
#define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA|                    \
                             GFS2_DIF_DIRECTIO|                 \
                             GFS2_DIF_IMMUTABLE|                \
                             GFS2_DIF_APPENDONLY|               \
                             GFS2_DIF_NOATIME|                  \
                             GFS2_DIF_SYNC|                     \
                             GFS2_DIF_SYSTEM|                   \
                             GFS2_DIF_INHERIT_DIRECTIO|         \
                             GFS2_DIF_INHERIT_JDATA)

/**
 * gfs2_set_flags - set flags on an inode
 * @inode: The inode
 * @flags: The flags to set
 * @mask: Indicates which flags are valid
 *
 */
static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
{
        struct inode *inode = filp->f_dentry->d_inode;
        struct gfs2_inode *ip = inode->u.generic_ip;
        struct gfs2_sbd *sdp = ip->i_sbd;
        struct buffer_head *bh;
        struct gfs2_holder gh;
        int error;
        u32 new_flags, flags;

        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
        if (error) {
                gfs2_holder_uninit(&gh);
                return error;
        }

        flags = ip->i_di.di_flags;
        new_flags = (flags & ~mask) | (reqflags & mask);
        if ((new_flags ^ flags) == 0)
                goto out;

        if (S_ISDIR(inode->i_mode)) {
                if ((new_flags ^ flags) & GFS2_DIF_JDATA)
                        new_flags ^= (GFS2_DIF_JDATA|GFS2_DIF_INHERIT_JDATA);
                if ((new_flags ^ flags) & GFS2_DIF_DIRECTIO)
                        new_flags ^= (GFS2_DIF_DIRECTIO|GFS2_DIF_INHERIT_DIRECTIO);
        }

        error = -EINVAL;
        if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET)
                goto out;

        error = -EPERM;
        if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
                goto out;
        if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
                goto out;
        if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) && 
            !capable(CAP_LINUX_IMMUTABLE))
                goto out;
        if (!IS_IMMUTABLE(inode)) {
                error = gfs2_repermission(inode, MAY_WRITE, NULL);
                if (error)
                        goto out;
        }

        error = gfs2_trans_begin(sdp, RES_DINODE, 0);
        if (error)
                goto out;
        error = gfs2_meta_inode_buffer(ip, &bh);
        if (error)
                goto out_trans_end;
        gfs2_trans_add_bh(ip->i_gl, bh, 1);
        ip->i_di.di_flags = new_flags;
        gfs2_dinode_out(&ip->i_di, bh->b_data);
        brelse(bh);
out_trans_end:
        gfs2_trans_end(sdp);
out:
        gfs2_glock_dq_uninit(&gh);
        return error;
}

static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
{
        u32 iflags, gfsflags;
        if (get_user(iflags, ptr))
                return -EFAULT;
        gfsflags = iflags_cvt(iflags_to_gfs2, iflags);
        return do_gfs2_set_flags(filp, gfsflags, ~0);
}

static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
        switch(cmd) {
        case IFLAGS_GET_IOC:
                return gfs2_get_flags(filp, (u32 __user *)arg);
        case IFLAGS_SET_IOC:
                return gfs2_set_flags(filp, (u32 __user *)arg);
        }
        return -ENOTTY;
}


/**
 * gfs2_mmap -
 * @file: The file to map
 * @vma: The VMA which described the mapping
 *
 * Returns: 0 or error code
 */

static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
{
        struct gfs2_inode *ip = file->f_mapping->host->u.generic_ip;
        struct gfs2_holder i_gh;
        int error;

        gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &i_gh);
        error = gfs2_glock_nq_atime(&i_gh);
        if (error) {
                gfs2_holder_uninit(&i_gh);
                return error;
        }

        /* This is VM_MAYWRITE instead of VM_WRITE because a call
           to mprotect() can turn on VM_WRITE later. */

        if ((vma->vm_flags & (VM_MAYSHARE | VM_MAYWRITE)) ==
            (VM_MAYSHARE | VM_MAYWRITE))
                vma->vm_ops = &gfs2_vm_ops_sharewrite;
        else
                vma->vm_ops = &gfs2_vm_ops_private;

        gfs2_glock_dq_uninit(&i_gh);

        return error;
}

/**
 * gfs2_open - open a file
 * @inode: the inode to open
 * @file: the struct file for this opening
 *
 * Returns: errno
 */

static int gfs2_open(struct inode *inode, struct file *file)
{
        struct gfs2_inode *ip = inode->u.generic_ip;
        struct gfs2_holder i_gh;
        struct gfs2_file *fp;
        int error;

        fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL);
        if (!fp)
                return -ENOMEM;

        mutex_init(&fp->f_fl_mutex);

        gfs2_assert_warn(ip->i_sbd, !file->private_data);
        file->private_data = fp;

        if (S_ISREG(ip->i_di.di_mode)) {
                error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
                                           &i_gh);
                if (error)
                        goto fail;

                if (!(file->f_flags & O_LARGEFILE) &&
                    ip->i_di.di_size > MAX_NON_LFS) {
                        error = -EFBIG;
                        goto fail_gunlock;
                }

                /* Listen to the Direct I/O flag */

                if (ip->i_di.di_flags & GFS2_DIF_DIRECTIO)
                        file->f_flags |= O_DIRECT;

                gfs2_glock_dq_uninit(&i_gh);
        }

        return 0;

 fail_gunlock:
        gfs2_glock_dq_uninit(&i_gh);

 fail:
        file->private_data = NULL;
        kfree(fp);

        return error;
}

/**
 * gfs2_close - called to close a struct file
 * @inode: the inode the struct file belongs to
 * @file: the struct file being closed
 *
 * Returns: errno
 */

static int gfs2_close(struct inode *inode, struct file *file)
{
        struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
        struct gfs2_file *fp;

        fp = file->private_data;
        file->private_data = NULL;

        if (gfs2_assert_warn(sdp, fp))
                return -EIO;

        kfree(fp);

        return 0;
}

/**
 * gfs2_fsync - sync the dirty data for a file (across the cluster)
 * @file: the file that points to the dentry (we ignore this)
 * @dentry: the dentry that points to the inode to sync
 *
 * Returns: errno
 */

static int gfs2_fsync(struct file *file, struct dentry *dentry, int datasync)
{
        struct gfs2_inode *ip = dentry->d_inode->u.generic_ip;

        gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);

        return 0;
}

/**
 * gfs2_lock - acquire/release a posix lock on a file
 * @file: the file pointer
 * @cmd: either modify or retrieve lock state, possibly wait
 * @fl: type and range of lock
 *
 * Returns: errno
 */

static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
{
        struct gfs2_inode *ip = file->f_mapping->host->u.generic_ip;
        struct gfs2_sbd *sdp = ip->i_sbd;
        struct lm_lockname name =
                { .ln_number = ip->i_num.no_addr,
                  .ln_type = LM_TYPE_PLOCK };

        if (!(fl->fl_flags & FL_POSIX))
                return -ENOLCK;
        if ((ip->i_di.di_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
                return -ENOLCK;

        if (sdp->sd_args.ar_localflocks) {
                if (IS_GETLK(cmd)) {
                        struct file_lock tmp;
                        int ret;
                        ret = posix_test_lock(file, fl, &tmp);
                        fl->fl_type = F_UNLCK;
                        if (ret)
                                memcpy(fl, &tmp, sizeof(struct file_lock));
                        return 0;
                } else {
                        return posix_lock_file_wait(file, fl);
                }
        }

        if (IS_GETLK(cmd))
                return gfs2_lm_plock_get(sdp, &name, file, fl);
        else if (fl->fl_type == F_UNLCK)
                return gfs2_lm_punlock(sdp, &name, file, fl);
        else
                return gfs2_lm_plock(sdp, &name, file, cmd, fl);
}

/**
 * gfs2_sendfile - Send bytes to a file or socket
 * @in_file: The file to read from
 * @out_file: The file to write to
 * @count: The amount of data
 * @offset: The beginning file offset
 *
 * Outputs: offset - updated according to number of bytes read
 *
 * Returns: The number of bytes sent, errno on failure
 */

static ssize_t gfs2_sendfile(struct file *in_file, loff_t *offset, size_t count,
                             read_actor_t actor, void *target)
{
        return generic_file_sendfile(in_file, offset, count, actor, target);
}

static int do_flock(struct file *file, int cmd, struct file_lock *fl)
{
        struct gfs2_file *fp = file->private_data;
        struct gfs2_holder *fl_gh = &fp->f_fl_gh;
        struct gfs2_inode *ip = file->f_dentry->d_inode->u.generic_ip;
        struct gfs2_glock *gl;
        unsigned int state;
        int flags;
        int error = 0;

        state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
        flags = ((IS_SETLKW(cmd)) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE;

        mutex_lock(&fp->f_fl_mutex);

        gl = fl_gh->gh_gl;
        if (gl) {
                if (fl_gh->gh_state == state)
                        goto out;
                gfs2_glock_hold(gl);
                flock_lock_file_wait(file,
                                     &(struct file_lock){.fl_type = F_UNLCK});          
                gfs2_glock_dq_uninit(fl_gh);
        } else {
                error = gfs2_glock_get(ip->i_sbd,
                                      ip->i_num.no_addr, &gfs2_flock_glops,
                                      CREATE, &gl);
                if (error)
                        goto out;
        }

        gfs2_holder_init(gl, state, flags, fl_gh);
        gfs2_glock_put(gl);

        error = gfs2_glock_nq(fl_gh);
        if (error) {
                gfs2_holder_uninit(fl_gh);
                if (error == GLR_TRYFAILED)
                        error = -EAGAIN;
        } else {
                error = flock_lock_file_wait(file, fl);
                gfs2_assert_warn(ip->i_sbd, !error);
        }

 out:
        mutex_unlock(&fp->f_fl_mutex);

        return error;
}

static void do_unflock(struct file *file, struct file_lock *fl)
{
        struct gfs2_file *fp = file->private_data;
        struct gfs2_holder *fl_gh = &fp->f_fl_gh;

        mutex_lock(&fp->f_fl_mutex);
        flock_lock_file_wait(file, fl);
        if (fl_gh->gh_gl)
                gfs2_glock_dq_uninit(fl_gh);
        mutex_unlock(&fp->f_fl_mutex);
}

/**
 * gfs2_flock - acquire/release a flock lock on a file
 * @file: the file pointer
 * @cmd: either modify or retrieve lock state, possibly wait
 * @fl: type and range of lock
 *
 * Returns: errno
 */

static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
{
        struct gfs2_inode *ip = file->f_mapping->host->u.generic_ip;
        struct gfs2_sbd *sdp = ip->i_sbd;

        if (!(fl->fl_flags & FL_FLOCK))
                return -ENOLCK;
        if ((ip->i_di.di_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
                return -ENOLCK;

        if (sdp->sd_args.ar_localflocks)
                return flock_lock_file_wait(file, fl);

        if (fl->fl_type == F_UNLCK) {
                do_unflock(file, fl);
                return 0;
        } else
                return do_flock(file, cmd, fl);
}

struct file_operations gfs2_file_fops = {
        .llseek = gfs2_llseek,
        .read = gfs2_read,
        .readv = gfs2_file_readv,
        .aio_read = gfs2_file_aio_read,
        .write = generic_file_write,
        .writev = generic_file_writev,
        .aio_write = generic_file_aio_write,
        .unlocked_ioctl = gfs2_ioctl,
        .mmap = gfs2_mmap,
        .open = gfs2_open,
        .release = gfs2_close,
        .fsync = gfs2_fsync,
        .lock = gfs2_lock,
        .sendfile = gfs2_sendfile,
        .flock = gfs2_flock,
        .splice_read = generic_file_splice_read,
        .splice_write = generic_file_splice_write,
};

struct file_operations gfs2_dir_fops = {
        .readdir = gfs2_readdir,
        .unlocked_ioctl = gfs2_ioctl,
        .open = gfs2_open,
        .release = gfs2_close,
        .fsync = gfs2_fsync,
        .lock = gfs2_lock,
        .flock = gfs2_flock,
};