Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * 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 version 2.

 */

#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/fs.h>

#include <linux/gfs2_ondisk.h>

#include <linux/ext2_fs.h>

#include <linux/crc32.h>

#include <linux/lm_interface.h>

#include <linux/writeback.h>

#include <asm/uaccess.h>

#include "gfs2.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"

/*

 * 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_sentinel = {

        .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.data, 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_inode;

        read_descriptor_t desc;

        desc.written = 0;

        desc.arg.data = buf;

        desc.count = size;

        desc.error = 0;

        do_generic_mapping_read(inode->i_mapping, ra_state,

                                &gfs2_internal_file_sentinel, 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 = GFS2_I(file->f_mapping->host);

        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;

}

/**

 * 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)

{

        struct inode *dir = file->f_mapping->host;

        struct gfs2_inode *dip = GFS2_I(dir);

        struct gfs2_holder d_gh;

        u64 offset = file->f_pos;

        int error;

        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, dirent, filldir);

        gfs2_glock_dq_uninit(&d_gh);

        file->f_pos = offset;

        return error;

}

/**

 * fsflags_cvt

 * @table: A table of 32 u32 flags

 * @val: a 32 bit value to convert

 *

 * This function can be used to convert between fsflags values and

 * GFS2's own flags values.

 *

 * Returns: the converted flags

 */

static u32 fsflags_cvt(const u32 *table, u32 val)

{

        u32 res = 0;

        while(val) {

                if (val & 1)

                        res |= *table;

                table++;

                val >>= 1;

        }

        return res;

}

static const u32 fsflags_to_gfs2[32] = {

        [3] = GFS2_DIF_SYNC,

        [4] = GFS2_DIF_IMMUTABLE,

        [5] = GFS2_DIF_APPENDONLY,

        [7] = GFS2_DIF_NOATIME,

        [12] = GFS2_DIF_EXHASH,

        [14] = GFS2_DIF_INHERIT_JDATA,

        [20] = GFS2_DIF_INHERIT_DIRECTIO,

};

static const u32 gfs2_to_fsflags[32] = {

        [gfs2fl_Sync] = FS_SYNC_FL,

        [gfs2fl_Immutable] = FS_IMMUTABLE_FL,

        [gfs2fl_AppendOnly] = FS_APPEND_FL,

        [gfs2fl_NoAtime] = FS_NOATIME_FL,

        [gfs2fl_ExHash] = FS_INDEX_FL,

        [gfs2fl_InheritDirectio] = FS_DIRECTIO_FL,

        [gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL,

};

static int gfs2_get_flags(struct file *filp, u32 __user *ptr)

{

        struct inode *inode = filp->f_path.dentry->d_inode;

        struct gfs2_inode *ip = GFS2_I(inode);

        struct gfs2_holder gh;

        int error;

        u32 fsflags;

        gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);

        error = gfs2_glock_nq_atime(&gh);

        if (error)

                return error;

        fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_di.di_flags);

        if (!S_ISDIR(inode->i_mode)) {

                if (ip->i_di.di_flags & GFS2_DIF_JDATA)

                        fsflags |= FS_JOURNAL_DATA_FL;

                if (ip->i_di.di_flags & GFS2_DIF_DIRECTIO)

                        fsflags |= FS_DIRECTIO_FL;

        }

        if (put_user(fsflags, ptr))

                error = -EFAULT;

        gfs2_glock_dq_m(1, &gh);

        gfs2_holder_uninit(&gh);

        return error;

}

void gfs2_set_inode_flags(struct inode *inode)

{

        struct gfs2_inode *ip = GFS2_I(inode);

        struct gfs2_dinode_host *di = &ip->i_di;

        unsigned int flags = inode->i_flags;

        flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);

        if (di->di_flags & GFS2_DIF_IMMUTABLE)

                flags |= S_IMMUTABLE;

        if (di->di_flags & GFS2_DIF_APPENDONLY)

                flags |= S_APPEND;

        if (di->di_flags & GFS2_DIF_NOATIME)

                flags |= S_NOATIME;

        if (di->di_flags & GFS2_DIF_SYNC)

                flags |= S_SYNC;

        inode->i_flags = flags;

}

/* 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_path.dentry->d_inode;

        struct gfs2_inode *ip = GFS2_I(inode);

        struct gfs2_sbd *sdp = GFS2_SB(inode);

        struct buffer_head *bh;

        struct gfs2_holder gh;

        int error;

        u32 new_flags, flags;

        error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);

        if (error)

                return error;

        flags = ip->i_di.di_flags;

        new_flags = (flags & ~mask) | (reqflags & mask);

        if ((new_flags ^ flags) == 0)

                goto out;

        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 = permission(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, bh->b_data);

        brelse(bh);

        gfs2_set_inode_flags(inode);

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)

{

        struct inode *inode = filp->f_path.dentry->d_inode;

        u32 fsflags, gfsflags;

        if (get_user(fsflags, ptr))

                return -EFAULT;

        gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags);

        if (!S_ISDIR(inode->i_mode)) {

                if (gfsflags & GFS2_DIF_INHERIT_JDATA)

                        gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA);

                if (gfsflags & GFS2_DIF_INHERIT_DIRECTIO)

                        gfsflags ^= (GFS2_DIF_DIRECTIO | GFS2_DIF_INHERIT_DIRECTIO);

                return do_gfs2_set_flags(filp, gfsflags, ~0);

        }

        return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_JDATA);

}

static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)

{

        switch(cmd) {

        case FS_IOC_GETFLAGS:

                return gfs2_get_flags(filp, (u32 __user *)arg);

        case FS_IOC_SETFLAGS:

                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 = GFS2_I(file->f_mapping->host);

        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 = GFS2_I(inode);

        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(GFS2_SB(inode), !file->private_data);

        file->private_data = fp;

        if (S_ISREG(ip->i_inode.i_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 = -EOVERFLOW;

                        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

 *

 * The VFS will flush "normal" data for us. We only need to worry

 * about metadata here. For journaled data, we just do a log flush

 * as we can't avoid it. Otherwise we can just bale out if datasync

 * is set. For stuffed inodes we must flush the log in order to

 * ensure that all data is on disk.

 *

 * The call to write_inode_now() is there to write back metadata and

 * the inode itself. It does also try and write the data, but thats

 * (hopefully) a no-op due to the VFS having already called filemap_fdatawrite()

 * for us.

 *

 * Returns: errno

 */

static int gfs2_fsync(struct file *file, struct dentry *dentry, int datasync)

{

        struct inode *inode = dentry->d_inode;

        int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);

        int ret = 0;

        if (gfs2_is_jdata(GFS2_I(inode))) {

                gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);

                return 0;

        }

        if (sync_state != 0) {

                if (!datasync)

                        ret = write_inode_now(inode, 0);

                if (gfs2_is_stuffed(GFS2_I(inode)))

                        gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);

        }

        return ret;

}

/**

 * gfs2_setlease - acquire/release a file lease

 * @file: the file pointer

 * @arg: lease type

 * @fl: file lock

 *

 * Returns: errno

 */

static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl)

{

        struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);

        /*

         * We don't currently have a way to enforce a lease across the whole

         * cluster; until we do, disable leases (by just returning -EINVAL),

         * unless the administrator has requested purely local locking.

         */

        if (!sdp->sd_args.ar_localflocks)

                return -EINVAL;

        return generic_setlease(file, arg, fl);

}

/**

 * 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 = GFS2_I(file->f_mapping->host);

        struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);

        struct lm_lockname name =

                { .ln_number = ip->i_no_addr,

                  .ln_type = LM_TYPE_PLOCK };

        if (!(fl->fl_flags & FL_POSIX))

                return -ENOLCK;

        if (__mandatory_lock(&ip->i_inode))

                return -ENOLCK;

        if (sdp->sd_args.ar_localflocks) {

                if (IS_GETLK(cmd)) {

                        posix_test_lock(file, fl);

                        return 0;

                } else {

                        return posix_lock_file_wait(file, fl);

                }

        }

        if (cmd == F_CANCELLK) {

                /* Hack: */

                cmd = F_SETLK;

                fl->fl_type = F_UNLCK;

        }

        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);

}

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 = GFS2_I(file->f_path.dentry->d_inode);

        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

                | GL_FLOCK;

        mutex_lock(&fp->f_fl_mutex);

        gl = fl_gh->gh_gl;

        if (gl) {

                if (fl_gh->gh_state == state)

                        goto out;

                flock_lock_file_wait(file,

                                     &(struct file_lock){.fl_type = F_UNLCK});

                gfs2_glock_dq_wait(fl_gh);

                gfs2_holder_reinit(state, flags, fl_gh);

        } else {

                error = gfs2_glock_get(GFS2_SB(&ip->i_inode),

                                      ip->i_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(GFS2_SB(&ip->i_inode), !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 = GFS2_I(file->f_mapping->host);

        struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);

        if (!(fl->fl_flags & FL_FLOCK))

                return -ENOLCK;

        if (__mandatory_lock(&ip->i_inode))

                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);

        }

}

const struct file_operations gfs2_file_fops = {

        .llseek         = gfs2_llseek,

        .read           = do_sync_read,

        .aio_read       = generic_file_aio_read,

        .write          = do_sync_write,

        .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,

        .flock          = gfs2_flock,

        .splice_read    = generic_file_splice_read,

        .splice_write   = generic_file_splice_write,

        .setlease       = gfs2_setlease,

};

const 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,

};