/*

   * Copyright (c) 2000-2006 Silicon Graphics, Inc.

   * All Rights Reserved.

   *

   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License as

   * published by the Free Software Foundation.
   *

   * This program is distributed in the hope that it would be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.

   *

   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write the Free Software Foundation,
   * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

   */

  #include "xfs.h"

  #include "xfs_shared.h"

  #include "xfs_format.h"

  #include "xfs_log_format.h"
  #include "xfs_trans_resv.h"

  #include "xfs_inum.h"

  #include "xfs_sb.h"

  #include "xfs_ag.h"

  #include "xfs_mount.h"

  #include "xfs_da_format.h"

  #include "xfs_inode.h"

  #include "xfs_btree.h"

  #include "xfs_bmap.h"

  #include "xfs_alloc.h"

  #include "xfs_error.h"

  #include "xfs_fsops.h"

  #include "xfs_trans.h"

  #include "xfs_buf_item.h"

  #include "xfs_log.h"

  #include "xfs_log_priv.h"

  #include "xfs_da_btree.h"

  #include "xfs_dir2.h"

  #include "xfs_extfree_item.h"
  #include "xfs_mru_cache.h"
  #include "xfs_inode_item.h"

  #include "xfs_icache.h"

  #include "xfs_trace.h"

  #include "xfs_icreate_item.h"

  #include "xfs_dinode.h"
  #include "xfs_filestream.h"
  #include "xfs_quota.h"

  
  #include <linux/namei.h>
  #include <linux/init.h>

  #include <linux/slab.h>

  #include <linux/mount.h>

  #include <linux/mempool.h>

  #include <linux/writeback.h>

  #include <linux/kthread.h>

  #include <linux/freezer.h>

  #include <linux/parser.h>

  static const struct super_operations xfs_super_operations;

  static kmem_zone_t *xfs_ioend_zone;

  mempool_t *xfs_ioend_pool;

  #define MNTOPT_LOGBUFS	"logbufs"	/* number of XFS log buffers */
  #define MNTOPT_LOGBSIZE	"logbsize"	/* size of XFS log buffers */
  #define MNTOPT_LOGDEV	"logdev"	/* log device */
  #define MNTOPT_RTDEV	"rtdev"		/* realtime I/O device */
  #define MNTOPT_BIOSIZE	"biosize"	/* log2 of preferred buffered io size */
  #define MNTOPT_WSYNC	"wsync"		/* safe-mode nfs compatible mount */

  #define MNTOPT_NOALIGN	"noalign"	/* turn off stripe alignment */
  #define MNTOPT_SWALLOC	"swalloc"	/* turn on stripe width allocation */
  #define MNTOPT_SUNIT	"sunit"		/* data volume stripe unit */
  #define MNTOPT_SWIDTH	"swidth"	/* data volume stripe width */
  #define MNTOPT_NOUUID	"nouuid"	/* ignore filesystem UUID */
  #define MNTOPT_MTPT	"mtpt"		/* filesystem mount point */
  #define MNTOPT_GRPID	"grpid"		/* group-ID from parent directory */
  #define MNTOPT_NOGRPID	"nogrpid"	/* group-ID from current process */
  #define MNTOPT_BSDGROUPS    "bsdgroups"    /* group-ID from parent directory */
  #define MNTOPT_SYSVGROUPS   "sysvgroups"   /* group-ID from current process */
  #define MNTOPT_ALLOCSIZE    "allocsize"    /* preferred allocation size */
  #define MNTOPT_NORECOVERY   "norecovery"   /* don't run XFS recovery */
  #define MNTOPT_BARRIER	"barrier"	/* use writer barriers for log write and
  					 * unwritten extent conversion */
  #define MNTOPT_NOBARRIER "nobarrier"	/* .. disable */

  #define MNTOPT_64BITINODE   "inode64"	/* inodes can be allocated anywhere */

  #define MNTOPT_32BITINODE   "inode32"	/* inode allocation limited to
  					 * XFS_MAXINUMBER_32 */

  #define MNTOPT_IKEEP	"ikeep"		/* do not free empty inode clusters */
  #define MNTOPT_NOIKEEP	"noikeep"	/* free empty inode clusters */
  #define MNTOPT_LARGEIO	   "largeio"	/* report large I/O sizes in stat() */
  #define MNTOPT_NOLARGEIO   "nolargeio"	/* do not report large I/O sizes
  					 * in stat(). */
  #define MNTOPT_ATTR2	"attr2"		/* do use attr2 attribute format */
  #define MNTOPT_NOATTR2	"noattr2"	/* do not use attr2 attribute format */
  #define MNTOPT_FILESTREAM  "filestreams" /* use filestreams allocator */
  #define MNTOPT_QUOTA	"quota"		/* disk quotas (user) */
  #define MNTOPT_NOQUOTA	"noquota"	/* no quotas */
  #define MNTOPT_USRQUOTA	"usrquota"	/* user quota enabled */
  #define MNTOPT_GRPQUOTA	"grpquota"	/* group quota enabled */
  #define MNTOPT_PRJQUOTA	"prjquota"	/* project quota enabled */
  #define MNTOPT_UQUOTA	"uquota"	/* user quota (IRIX variant) */
  #define MNTOPT_GQUOTA	"gquota"	/* group quota (IRIX variant) */
  #define MNTOPT_PQUOTA	"pquota"	/* project quota (IRIX variant) */
  #define MNTOPT_UQUOTANOENF "uqnoenforce"/* user quota limit enforcement */
  #define MNTOPT_GQUOTANOENF "gqnoenforce"/* group quota limit enforcement */
  #define MNTOPT_PQUOTANOENF "pqnoenforce"/* project quota limit enforcement */
  #define MNTOPT_QUOTANOENF  "qnoenforce"	/* same as uqnoenforce */

  #define MNTOPT_DELAYLOG    "delaylog"	/* Delayed logging enabled */
  #define MNTOPT_NODELAYLOG  "nodelaylog"	/* Delayed logging disabled */
  #define MNTOPT_DISCARD	   "discard"	/* Discard unused blocks */
  #define MNTOPT_NODISCARD   "nodiscard"	/* Do not discard unused blocks */

  /*
   * Table driven mount option parser.
   *
   * Currently only used for remount, but it will be used for mount
   * in the future, too.
   */
  enum {

  	Opt_barrier,
  	Opt_nobarrier,
  	Opt_inode64,
  	Opt_inode32,
  	Opt_err

  };

  static const match_table_t tokens = {

  	{Opt_barrier, "barrier"},
  	{Opt_nobarrier, "nobarrier"},

  	{Opt_inode64, "inode64"},

  	{Opt_inode32, "inode32"},

  	{Opt_err, NULL}
  };

  STATIC unsigned long

  suffix_kstrtoint(char *s, unsigned int base, int *res)

  {

  	int	last, shift_left_factor = 0, _res;

  	char	*value = s;
  
  	last = strlen(value) - 1;
  	if (value[last] == 'K' || value[last] == 'k') {
  		shift_left_factor = 10;
  		value[last] = '\0';
  	}
  	if (value[last] == 'M' || value[last] == 'm') {
  		shift_left_factor = 20;
  		value[last] = '\0';
  	}
  	if (value[last] == 'G' || value[last] == 'g') {
  		shift_left_factor = 30;
  		value[last] = '\0';
  	}

  	if (kstrtoint(s, base, &_res))
  		return -EINVAL;
  	*res = _res << shift_left_factor;
  	return 0;

  }

  /*
   * This function fills in xfs_mount_t fields based on mount args.
   * Note: the superblock has _not_ yet been read in.
   *
   * Note that this function leaks the various device name allocations on
   * failure.  The caller takes care of them.
   */

  STATIC int
  xfs_parseargs(
  	struct xfs_mount	*mp,

  	char			*options)

  {

  	struct super_block	*sb = mp->m_super;

  	char			*this_char, *value;

  	int			dsunit = 0;
  	int			dswidth = 0;
  	int			iosize = 0;

  	__uint8_t		iosizelog = 0;

  
  	/*

  	 * set up the mount name first so all the errors will refer to the
  	 * correct device.
  	 */
  	mp->m_fsname = kstrndup(sb->s_id, MAXNAMELEN, GFP_KERNEL);
  	if (!mp->m_fsname)
  		return ENOMEM;
  	mp->m_fsname_len = strlen(mp->m_fsname) + 1;
  
  	/*

  	 * Copy binary VFS mount flags we are interested in.
  	 */
  	if (sb->s_flags & MS_RDONLY)
  		mp->m_flags |= XFS_MOUNT_RDONLY;
  	if (sb->s_flags & MS_DIRSYNC)
  		mp->m_flags |= XFS_MOUNT_DIRSYNC;
  	if (sb->s_flags & MS_SYNCHRONOUS)
  		mp->m_flags |= XFS_MOUNT_WSYNC;
  
  	/*
  	 * Set some default flags that could be cleared by the mount option
  	 * parsing.
  	 */
  	mp->m_flags |= XFS_MOUNT_BARRIER;
  	mp->m_flags |= XFS_MOUNT_COMPAT_IOSIZE;

  #if !XFS_BIG_INUMS

  	mp->m_flags |= XFS_MOUNT_SMALL_INUMS;

  #endif

  	/*
  	 * These can be overridden by the mount option parsing.
  	 */
  	mp->m_logbufs = -1;
  	mp->m_logbsize = -1;

  
  	if (!options)
  		goto done;

  	while ((this_char = strsep(&options, ",")) != NULL) {
  		if (!*this_char)
  			continue;
  		if ((value = strchr(this_char, '=')) != NULL)
  			*value++ = 0;
  
  		if (!strcmp(this_char, MNTOPT_LOGBUFS)) {
  			if (!value || !*value) {

  				xfs_warn(mp, "%s option requires an argument",

  					this_char);
  				return EINVAL;
  			}

  			if (kstrtoint(value, 10, &mp->m_logbufs))
  				return EINVAL;

  		} else if (!strcmp(this_char, MNTOPT_LOGBSIZE)) {
  			if (!value || !*value) {

  				xfs_warn(mp, "%s option requires an argument",

  					this_char);
  				return EINVAL;
  			}

  			if (suffix_kstrtoint(value, 10, &mp->m_logbsize))
  				return EINVAL;

  		} else if (!strcmp(this_char, MNTOPT_LOGDEV)) {
  			if (!value || !*value) {

  				xfs_warn(mp, "%s option requires an argument",

  					this_char);
  				return EINVAL;
  			}

  			mp->m_logname = kstrndup(value, MAXNAMELEN, GFP_KERNEL);
  			if (!mp->m_logname)
  				return ENOMEM;

  		} else if (!strcmp(this_char, MNTOPT_MTPT)) {

  			xfs_warn(mp, "%s option not allowed on this system",

  				this_char);
  			return EINVAL;

  		} else if (!strcmp(this_char, MNTOPT_RTDEV)) {
  			if (!value || !*value) {

  				xfs_warn(mp, "%s option requires an argument",

  					this_char);
  				return EINVAL;
  			}

  			mp->m_rtname = kstrndup(value, MAXNAMELEN, GFP_KERNEL);
  			if (!mp->m_rtname)
  				return ENOMEM;

  		} else if (!strcmp(this_char, MNTOPT_BIOSIZE)) {
  			if (!value || !*value) {

  				xfs_warn(mp, "%s option requires an argument",

  					this_char);
  				return EINVAL;
  			}

  			if (kstrtoint(value, 10, &iosize))
  				return EINVAL;

  			iosizelog = ffs(iosize) - 1;

  		} else if (!strcmp(this_char, MNTOPT_ALLOCSIZE)) {
  			if (!value || !*value) {

  				xfs_warn(mp, "%s option requires an argument",

  					this_char);
  				return EINVAL;
  			}

  			if (suffix_kstrtoint(value, 10, &iosize))
  				return EINVAL;

  			iosizelog = ffs(iosize) - 1;

  		} else if (!strcmp(this_char, MNTOPT_GRPID) ||
  			   !strcmp(this_char, MNTOPT_BSDGROUPS)) {
  			mp->m_flags |= XFS_MOUNT_GRPID;
  		} else if (!strcmp(this_char, MNTOPT_NOGRPID) ||
  			   !strcmp(this_char, MNTOPT_SYSVGROUPS)) {
  			mp->m_flags &= ~XFS_MOUNT_GRPID;
  		} else if (!strcmp(this_char, MNTOPT_WSYNC)) {

  			mp->m_flags |= XFS_MOUNT_WSYNC;

  		} else if (!strcmp(this_char, MNTOPT_NORECOVERY)) {

  			mp->m_flags |= XFS_MOUNT_NORECOVERY;

  		} else if (!strcmp(this_char, MNTOPT_NOALIGN)) {

  			mp->m_flags |= XFS_MOUNT_NOALIGN;

  		} else if (!strcmp(this_char, MNTOPT_SWALLOC)) {

  			mp->m_flags |= XFS_MOUNT_SWALLOC;

  		} else if (!strcmp(this_char, MNTOPT_SUNIT)) {
  			if (!value || !*value) {

  				xfs_warn(mp, "%s option requires an argument",

  					this_char);
  				return EINVAL;
  			}

  			if (kstrtoint(value, 10, &dsunit))
  				return EINVAL;

  		} else if (!strcmp(this_char, MNTOPT_SWIDTH)) {
  			if (!value || !*value) {

  				xfs_warn(mp, "%s option requires an argument",

  					this_char);
  				return EINVAL;
  			}

  			if (kstrtoint(value, 10, &dswidth))
  				return EINVAL;

  		} else if (!strcmp(this_char, MNTOPT_32BITINODE)) {
  			mp->m_flags |= XFS_MOUNT_SMALL_INUMS;

  		} else if (!strcmp(this_char, MNTOPT_64BITINODE)) {

  			mp->m_flags &= ~XFS_MOUNT_SMALL_INUMS;

  #if !XFS_BIG_INUMS

  			xfs_warn(mp, "%s option not allowed on this system",

  				this_char);
  			return EINVAL;
  #endif
  		} else if (!strcmp(this_char, MNTOPT_NOUUID)) {

  			mp->m_flags |= XFS_MOUNT_NOUUID;

  		} else if (!strcmp(this_char, MNTOPT_BARRIER)) {

  			mp->m_flags |= XFS_MOUNT_BARRIER;

  		} else if (!strcmp(this_char, MNTOPT_NOBARRIER)) {

  			mp->m_flags &= ~XFS_MOUNT_BARRIER;

  		} else if (!strcmp(this_char, MNTOPT_IKEEP)) {

  			mp->m_flags |= XFS_MOUNT_IKEEP;

  		} else if (!strcmp(this_char, MNTOPT_NOIKEEP)) {

  			mp->m_flags &= ~XFS_MOUNT_IKEEP;

  		} else if (!strcmp(this_char, MNTOPT_LARGEIO)) {

  			mp->m_flags &= ~XFS_MOUNT_COMPAT_IOSIZE;

  		} else if (!strcmp(this_char, MNTOPT_NOLARGEIO)) {

  			mp->m_flags |= XFS_MOUNT_COMPAT_IOSIZE;

  		} else if (!strcmp(this_char, MNTOPT_ATTR2)) {

  			mp->m_flags |= XFS_MOUNT_ATTR2;

  		} else if (!strcmp(this_char, MNTOPT_NOATTR2)) {

  			mp->m_flags &= ~XFS_MOUNT_ATTR2;
  			mp->m_flags |= XFS_MOUNT_NOATTR2;

  		} else if (!strcmp(this_char, MNTOPT_FILESTREAM)) {

  			mp->m_flags |= XFS_MOUNT_FILESTREAMS;

  		} else if (!strcmp(this_char, MNTOPT_NOQUOTA)) {

  			mp->m_qflags &= ~XFS_ALL_QUOTA_ACCT;
  			mp->m_qflags &= ~XFS_ALL_QUOTA_ENFD;
  			mp->m_qflags &= ~XFS_ALL_QUOTA_ACTIVE;

  		} else if (!strcmp(this_char, MNTOPT_QUOTA) ||
  			   !strcmp(this_char, MNTOPT_UQUOTA) ||
  			   !strcmp(this_char, MNTOPT_USRQUOTA)) {

  			mp->m_qflags |= (XFS_UQUOTA_ACCT | XFS_UQUOTA_ACTIVE |
  					 XFS_UQUOTA_ENFD);

  		} else if (!strcmp(this_char, MNTOPT_QUOTANOENF) ||
  			   !strcmp(this_char, MNTOPT_UQUOTANOENF)) {

  			mp->m_qflags |= (XFS_UQUOTA_ACCT | XFS_UQUOTA_ACTIVE);
  			mp->m_qflags &= ~XFS_UQUOTA_ENFD;

  		} else if (!strcmp(this_char, MNTOPT_PQUOTA) ||
  			   !strcmp(this_char, MNTOPT_PRJQUOTA)) {

  			mp->m_qflags |= (XFS_PQUOTA_ACCT | XFS_PQUOTA_ACTIVE |

  					 XFS_PQUOTA_ENFD);

  		} else if (!strcmp(this_char, MNTOPT_PQUOTANOENF)) {

  			mp->m_qflags |= (XFS_PQUOTA_ACCT | XFS_PQUOTA_ACTIVE);

  			mp->m_qflags &= ~XFS_PQUOTA_ENFD;

  		} else if (!strcmp(this_char, MNTOPT_GQUOTA) ||
  			   !strcmp(this_char, MNTOPT_GRPQUOTA)) {

  			mp->m_qflags |= (XFS_GQUOTA_ACCT | XFS_GQUOTA_ACTIVE |

  					 XFS_GQUOTA_ENFD);

  		} else if (!strcmp(this_char, MNTOPT_GQUOTANOENF)) {

  			mp->m_qflags |= (XFS_GQUOTA_ACCT | XFS_GQUOTA_ACTIVE);

  			mp->m_qflags &= ~XFS_GQUOTA_ENFD;

  		} else if (!strcmp(this_char, MNTOPT_DELAYLOG)) {

  			xfs_warn(mp,
  	"delaylog is the default now, option is deprecated.");

  		} else if (!strcmp(this_char, MNTOPT_NODELAYLOG)) {

  			xfs_warn(mp,

  	"nodelaylog support has been removed, option is deprecated.");

  		} else if (!strcmp(this_char, MNTOPT_DISCARD)) {
  			mp->m_flags |= XFS_MOUNT_DISCARD;
  		} else if (!strcmp(this_char, MNTOPT_NODISCARD)) {
  			mp->m_flags &= ~XFS_MOUNT_DISCARD;

  		} else if (!strcmp(this_char, "ihashsize")) {

  			xfs_warn(mp,
  	"ihashsize no longer used, option is deprecated.");

  		} else if (!strcmp(this_char, "osyncisdsync")) {

  			xfs_warn(mp,
  	"osyncisdsync has no effect, option is deprecated.");

  		} else if (!strcmp(this_char, "osyncisosync")) {

  			xfs_warn(mp,
  	"osyncisosync has no effect, option is deprecated.");

  		} else if (!strcmp(this_char, "irixsgid")) {

  			xfs_warn(mp,
  	"irixsgid is now a sysctl(2) variable, option is deprecated.");

  		} else {

  			xfs_warn(mp, "unknown mount option [%s].", this_char);

  			return EINVAL;
  		}
  	}

  	/*
  	 * no recovery flag requires a read-only mount
  	 */
  	if ((mp->m_flags & XFS_MOUNT_NORECOVERY) &&
  	    !(mp->m_flags & XFS_MOUNT_RDONLY)) {

  		xfs_warn(mp, "no-recovery mounts must be read-only.");

  		return EINVAL;

  	}

  	if ((mp->m_flags & XFS_MOUNT_NOALIGN) && (dsunit || dswidth)) {

  		xfs_warn(mp,
  	"sunit and swidth options incompatible with the noalign option");

  		return EINVAL;
  	}

  #ifndef CONFIG_XFS_QUOTA
  	if (XFS_IS_QUOTA_RUNNING(mp)) {

  		xfs_warn(mp, "quota support not available in this kernel.");

  		return EINVAL;
  	}
  #endif

  	if ((dsunit && !dswidth) || (!dsunit && dswidth)) {

  		xfs_warn(mp, "sunit and swidth must be specified together");

  		return EINVAL;
  	}
  
  	if (dsunit && (dswidth % dsunit != 0)) {

  		xfs_warn(mp,
  	"stripe width (%d) must be a multiple of the stripe unit (%d)",

  			dswidth, dsunit);
  		return EINVAL;
  	}

  done:

  	if (dsunit && !(mp->m_flags & XFS_MOUNT_NOALIGN)) {

  		/*
  		 * At this point the superblock has not been read
  		 * in, therefore we do not know the block size.
  		 * Before the mount call ends we will convert
  		 * these to FSBs.
  		 */

  		mp->m_dalign = dsunit;
  		mp->m_swidth = dswidth;

  	}
  
  	if (mp->m_logbufs != -1 &&
  	    mp->m_logbufs != 0 &&
  	    (mp->m_logbufs < XLOG_MIN_ICLOGS ||
  	     mp->m_logbufs > XLOG_MAX_ICLOGS)) {

  		xfs_warn(mp, "invalid logbufs value: %d [not %d-%d]",

  			mp->m_logbufs, XLOG_MIN_ICLOGS, XLOG_MAX_ICLOGS);
  		return XFS_ERROR(EINVAL);
  	}
  	if (mp->m_logbsize != -1 &&
  	    mp->m_logbsize !=  0 &&
  	    (mp->m_logbsize < XLOG_MIN_RECORD_BSIZE ||
  	     mp->m_logbsize > XLOG_MAX_RECORD_BSIZE ||
  	     !is_power_of_2(mp->m_logbsize))) {

  		xfs_warn(mp,
  			"invalid logbufsize: %d [not 16k,32k,64k,128k or 256k]",

  			mp->m_logbsize);
  		return XFS_ERROR(EINVAL);
  	}

  	if (iosizelog) {
  		if (iosizelog > XFS_MAX_IO_LOG ||
  		    iosizelog < XFS_MIN_IO_LOG) {

  			xfs_warn(mp, "invalid log iosize: %d [not %d-%d]",

  				iosizelog, XFS_MIN_IO_LOG,
  				XFS_MAX_IO_LOG);
  			return XFS_ERROR(EINVAL);
  		}
  
  		mp->m_flags |= XFS_MOUNT_DFLT_IOSIZE;
  		mp->m_readio_log = iosizelog;
  		mp->m_writeio_log = iosizelog;

  	}

  	return 0;
  }
  
  struct proc_xfs_info {
  	int	flag;
  	char	*str;
  };
  
  STATIC int
  xfs_showargs(
  	struct xfs_mount	*mp,
  	struct seq_file		*m)
  {
  	static struct proc_xfs_info xfs_info_set[] = {
  		/* the few simple ones we can get from the mount struct */

  		{ XFS_MOUNT_IKEEP,		"," MNTOPT_IKEEP },

  		{ XFS_MOUNT_WSYNC,		"," MNTOPT_WSYNC },

  		{ XFS_MOUNT_NOALIGN,		"," MNTOPT_NOALIGN },
  		{ XFS_MOUNT_SWALLOC,		"," MNTOPT_SWALLOC },
  		{ XFS_MOUNT_NOUUID,		"," MNTOPT_NOUUID },
  		{ XFS_MOUNT_NORECOVERY,		"," MNTOPT_NORECOVERY },

  		{ XFS_MOUNT_ATTR2,		"," MNTOPT_ATTR2 },
  		{ XFS_MOUNT_FILESTREAMS,	"," MNTOPT_FILESTREAM },

  		{ XFS_MOUNT_GRPID,		"," MNTOPT_GRPID },

  		{ XFS_MOUNT_DISCARD,		"," MNTOPT_DISCARD },

  		{ XFS_MOUNT_SMALL_INUMS,	"," MNTOPT_32BITINODE },

  		{ 0, NULL }
  	};
  	static struct proc_xfs_info xfs_info_unset[] = {
  		/* the few simple ones we can get from the mount struct */

  		{ XFS_MOUNT_COMPAT_IOSIZE,	"," MNTOPT_LARGEIO },
  		{ XFS_MOUNT_BARRIER,		"," MNTOPT_NOBARRIER },
  		{ XFS_MOUNT_SMALL_INUMS,	"," MNTOPT_64BITINODE },
  		{ 0, NULL }
  	};
  	struct proc_xfs_info	*xfs_infop;
  
  	for (xfs_infop = xfs_info_set; xfs_infop->flag; xfs_infop++) {
  		if (mp->m_flags & xfs_infop->flag)
  			seq_puts(m, xfs_infop->str);
  	}
  	for (xfs_infop = xfs_info_unset; xfs_infop->flag; xfs_infop++) {
  		if (!(mp->m_flags & xfs_infop->flag))
  			seq_puts(m, xfs_infop->str);
  	}
  
  	if (mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)
  		seq_printf(m, "," MNTOPT_ALLOCSIZE "=%dk",
  				(int)(1 << mp->m_writeio_log) >> 10);
  
  	if (mp->m_logbufs > 0)
  		seq_printf(m, "," MNTOPT_LOGBUFS "=%d", mp->m_logbufs);
  	if (mp->m_logbsize > 0)
  		seq_printf(m, "," MNTOPT_LOGBSIZE "=%dk", mp->m_logbsize >> 10);
  
  	if (mp->m_logname)
  		seq_printf(m, "," MNTOPT_LOGDEV "=%s", mp->m_logname);
  	if (mp->m_rtname)
  		seq_printf(m, "," MNTOPT_RTDEV "=%s", mp->m_rtname);
  
  	if (mp->m_dalign > 0)
  		seq_printf(m, "," MNTOPT_SUNIT "=%d",
  				(int)XFS_FSB_TO_BB(mp, mp->m_dalign));
  	if (mp->m_swidth > 0)
  		seq_printf(m, "," MNTOPT_SWIDTH "=%d",
  				(int)XFS_FSB_TO_BB(mp, mp->m_swidth));
  
  	if (mp->m_qflags & (XFS_UQUOTA_ACCT|XFS_UQUOTA_ENFD))
  		seq_puts(m, "," MNTOPT_USRQUOTA);
  	else if (mp->m_qflags & XFS_UQUOTA_ACCT)
  		seq_puts(m, "," MNTOPT_UQUOTANOENF);

  	if (mp->m_qflags & XFS_PQUOTA_ACCT) {

  		if (mp->m_qflags & XFS_PQUOTA_ENFD)

  			seq_puts(m, "," MNTOPT_PRJQUOTA);
  		else
  			seq_puts(m, "," MNTOPT_PQUOTANOENF);

  	}
  	if (mp->m_qflags & XFS_GQUOTA_ACCT) {

  		if (mp->m_qflags & XFS_GQUOTA_ENFD)

  			seq_puts(m, "," MNTOPT_GRPQUOTA);
  		else
  			seq_puts(m, "," MNTOPT_GQUOTANOENF);
  	}

  
  	if (!(mp->m_qflags & XFS_ALL_QUOTA_ACCT))
  		seq_puts(m, "," MNTOPT_NOQUOTA);
  
  	return 0;
  }

  __uint64_t
  xfs_max_file_offset(
  	unsigned int		blockshift)
  {
  	unsigned int		pagefactor = 1;
  	unsigned int		bitshift = BITS_PER_LONG - 1;
  
  	/* Figure out maximum filesize, on Linux this can depend on
  	 * the filesystem blocksize (on 32 bit platforms).

  	 * __block_write_begin does this in an [unsigned] long...

  	 *      page->index << (PAGE_CACHE_SHIFT - bbits)
  	 * So, for page sized blocks (4K on 32 bit platforms),
  	 * this wraps at around 8Tb (hence MAX_LFS_FILESIZE which is
  	 *      (((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1)
  	 * but for smaller blocksizes it is less (bbits = log2 bsize).
  	 * Note1: get_block_t takes a long (implicit cast from above)
  	 * Note2: The Large Block Device (LBD and HAVE_SECTOR_T) patch
  	 * can optionally convert the [unsigned] long from above into
  	 * an [unsigned] long long.
  	 */
  
  #if BITS_PER_LONG == 32

  # if defined(CONFIG_LBDAF)

  	ASSERT(sizeof(sector_t) == 8);
  	pagefactor = PAGE_CACHE_SIZE;
  	bitshift = BITS_PER_LONG;
  # else
  	pagefactor = PAGE_CACHE_SIZE >> (PAGE_CACHE_SHIFT - blockshift);
  # endif
  #endif
  
  	return (((__uint64_t)pagefactor) << bitshift) - 1;
  }

  xfs_agnumber_t
  xfs_set_inode32(struct xfs_mount *mp)
  {
  	xfs_agnumber_t	index = 0;

  	xfs_agnumber_t	maxagi = 0;

  	xfs_sb_t	*sbp = &mp->m_sb;
  	xfs_agnumber_t	max_metadata;
  	xfs_agino_t	agino =	XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks -1, 0);
  	xfs_ino_t	ino = XFS_AGINO_TO_INO(mp, sbp->sb_agcount -1, agino);
  	xfs_perag_t	*pag;
  
  	/* Calculate how much should be reserved for inodes to meet
  	 * the max inode percentage.
  	 */
  	if (mp->m_maxicount) {
  		__uint64_t	icount;
  
  		icount = sbp->sb_dblocks * sbp->sb_imax_pct;
  		do_div(icount, 100);
  		icount += sbp->sb_agblocks - 1;
  		do_div(icount, sbp->sb_agblocks);
  		max_metadata = icount;
  	} else {
  		max_metadata = sbp->sb_agcount;
  	}
  
  	for (index = 0; index < sbp->sb_agcount; index++) {
  		ino = XFS_AGINO_TO_INO(mp, index, agino);

  		if (ino > XFS_MAXINUMBER_32) {

  			pag = xfs_perag_get(mp, index);
  			pag->pagi_inodeok = 0;
  			pag->pagf_metadata = 0;
  			xfs_perag_put(pag);
  			continue;

  		}
  
  		pag = xfs_perag_get(mp, index);
  		pag->pagi_inodeok = 1;

  		maxagi++;

  		if (index < max_metadata)
  			pag->pagf_metadata = 1;
  		xfs_perag_put(pag);
  	}

  	mp->m_flags |= (XFS_MOUNT_32BITINODES |
  			XFS_MOUNT_SMALL_INUMS);
  
  	return maxagi;

  }
  
  xfs_agnumber_t
  xfs_set_inode64(struct xfs_mount *mp)
  {
  	xfs_agnumber_t index = 0;
  
  	for (index = 0; index < mp->m_sb.sb_agcount; index++) {
  		struct xfs_perag	*pag;
  
  		pag = xfs_perag_get(mp, index);
  		pag->pagi_inodeok = 1;
  		pag->pagf_metadata = 0;
  		xfs_perag_put(pag);
  	}
  
  	/* There is no need for lock protection on m_flags,
  	 * the rw_semaphore of the VFS superblock is locked
  	 * during mount/umount/remount operations, so this is
  	 * enough to avoid concurency on the m_flags field
  	 */
  	mp->m_flags &= ~(XFS_MOUNT_32BITINODES |
  			 XFS_MOUNT_SMALL_INUMS);
  	return index;
  }

  STATIC int

  xfs_blkdev_get(
  	xfs_mount_t		*mp,
  	const char		*name,
  	struct block_device	**bdevp)
  {
  	int			error = 0;

  	*bdevp = blkdev_get_by_path(name, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
  				    mp);

  	if (IS_ERR(*bdevp)) {
  		error = PTR_ERR(*bdevp);

  		xfs_warn(mp, "Invalid device [%s], error=%d
  ", name, error);

  	}
  
  	return -error;
  }

  STATIC void

  xfs_blkdev_put(
  	struct block_device	*bdev)
  {
  	if (bdev)

  		blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);

  }

  void
  xfs_blkdev_issue_flush(
  	xfs_buftarg_t		*buftarg)
  {

  	blkdev_issue_flush(buftarg->bt_bdev, GFP_NOFS, NULL);

  }

  STATIC void
  xfs_close_devices(
  	struct xfs_mount	*mp)
  {
  	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {

  		struct block_device *logdev = mp->m_logdev_targp->bt_bdev;

  		xfs_free_buftarg(mp, mp->m_logdev_targp);

  		xfs_blkdev_put(logdev);

  	}
  	if (mp->m_rtdev_targp) {

  		struct block_device *rtdev = mp->m_rtdev_targp->bt_bdev;

  		xfs_free_buftarg(mp, mp->m_rtdev_targp);

  		xfs_blkdev_put(rtdev);

  	}

  	xfs_free_buftarg(mp, mp->m_ddev_targp);

  }
  
  /*
   * The file system configurations are:
   *	(1) device (partition) with data and internal log
   *	(2) logical volume with data and log subvolumes.
   *	(3) logical volume with data, log, and realtime subvolumes.
   *
   * We only have to handle opening the log and realtime volumes here if
   * they are present.  The data subvolume has already been opened by
   * get_sb_bdev() and is stored in sb->s_bdev.
   */
  STATIC int
  xfs_open_devices(

  	struct xfs_mount	*mp)

  {
  	struct block_device	*ddev = mp->m_super->s_bdev;
  	struct block_device	*logdev = NULL, *rtdev = NULL;
  	int			error;
  
  	/*
  	 * Open real time and log devices - order is important.
  	 */

  	if (mp->m_logname) {
  		error = xfs_blkdev_get(mp, mp->m_logname, &logdev);

  		if (error)
  			goto out;
  	}

  	if (mp->m_rtname) {
  		error = xfs_blkdev_get(mp, mp->m_rtname, &rtdev);

  		if (error)
  			goto out_close_logdev;
  
  		if (rtdev == ddev || rtdev == logdev) {

  			xfs_warn(mp,
  	"Cannot mount filesystem with identical rtdev and ddev/logdev.");

  			error = EINVAL;
  			goto out_close_rtdev;
  		}
  	}
  
  	/*
  	 * Setup xfs_mount buffer target pointers
  	 */
  	error = ENOMEM;

  	mp->m_ddev_targp = xfs_alloc_buftarg(mp, ddev, 0, mp->m_fsname);

  	if (!mp->m_ddev_targp)
  		goto out_close_rtdev;
  
  	if (rtdev) {

  		mp->m_rtdev_targp = xfs_alloc_buftarg(mp, rtdev, 1,
  							mp->m_fsname);

  		if (!mp->m_rtdev_targp)
  			goto out_free_ddev_targ;
  	}
  
  	if (logdev && logdev != ddev) {

  		mp->m_logdev_targp = xfs_alloc_buftarg(mp, logdev, 1,
  							mp->m_fsname);

  		if (!mp->m_logdev_targp)
  			goto out_free_rtdev_targ;
  	} else {
  		mp->m_logdev_targp = mp->m_ddev_targp;
  	}
  
  	return 0;
  
   out_free_rtdev_targ:
  	if (mp->m_rtdev_targp)

  		xfs_free_buftarg(mp, mp->m_rtdev_targp);

   out_free_ddev_targ:

  	xfs_free_buftarg(mp, mp->m_ddev_targp);

   out_close_rtdev:
  	if (rtdev)
  		xfs_blkdev_put(rtdev);
   out_close_logdev:
  	if (logdev && logdev != ddev)
  		xfs_blkdev_put(logdev);
   out:
  	return error;
  }

  /*
   * Setup xfs_mount buffer target pointers based on superblock
   */
  STATIC int
  xfs_setup_devices(
  	struct xfs_mount	*mp)
  {
  	int			error;

  	error = xfs_setsize_buftarg(mp->m_ddev_targp, mp->m_sb.sb_blocksize,
  				    mp->m_sb.sb_sectsize);
  	if (error)
  		return error;
  
  	if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) {
  		unsigned int	log_sector_size = BBSIZE;
  
  		if (xfs_sb_version_hassector(&mp->m_sb))
  			log_sector_size = mp->m_sb.sb_logsectsize;
  		error = xfs_setsize_buftarg(mp->m_logdev_targp,
  					    mp->m_sb.sb_blocksize,
  					    log_sector_size);
  		if (error)
  			return error;
  	}
  	if (mp->m_rtdev_targp) {
  		error = xfs_setsize_buftarg(mp->m_rtdev_targp,
  					    mp->m_sb.sb_blocksize,
  					    mp->m_sb.sb_sectsize);
  		if (error)
  			return error;
  	}
  
  	return 0;
  }

  STATIC int
  xfs_init_mount_workqueues(
  	struct xfs_mount	*mp)
  {
  	mp->m_data_workqueue = alloc_workqueue("xfs-data/%s",
  			WQ_MEM_RECLAIM, 0, mp->m_fsname);
  	if (!mp->m_data_workqueue)
  		goto out;
  
  	mp->m_unwritten_workqueue = alloc_workqueue("xfs-conv/%s",
  			WQ_MEM_RECLAIM, 0, mp->m_fsname);
  	if (!mp->m_unwritten_workqueue)
  		goto out_destroy_data_iodone_queue;

  	mp->m_cil_workqueue = alloc_workqueue("xfs-cil/%s",
  			WQ_MEM_RECLAIM, 0, mp->m_fsname);
  	if (!mp->m_cil_workqueue)
  		goto out_destroy_unwritten;

  
  	mp->m_reclaim_workqueue = alloc_workqueue("xfs-reclaim/%s",

  			0, 0, mp->m_fsname);

  	if (!mp->m_reclaim_workqueue)
  		goto out_destroy_cil;
  
  	mp->m_log_workqueue = alloc_workqueue("xfs-log/%s",

  			0, 0, mp->m_fsname);

  	if (!mp->m_log_workqueue)
  		goto out_destroy_reclaim;

  	mp->m_eofblocks_workqueue = alloc_workqueue("xfs-eofblocks/%s",

  			0, 0, mp->m_fsname);

  	if (!mp->m_eofblocks_workqueue)
  		goto out_destroy_log;

  	return 0;

  out_destroy_log:
  	destroy_workqueue(mp->m_log_workqueue);

  out_destroy_reclaim:
  	destroy_workqueue(mp->m_reclaim_workqueue);
  out_destroy_cil:
  	destroy_workqueue(mp->m_cil_workqueue);

  out_destroy_unwritten:
  	destroy_workqueue(mp->m_unwritten_workqueue);

  out_destroy_data_iodone_queue:
  	destroy_workqueue(mp->m_data_workqueue);
  out:
  	return -ENOMEM;
  }
  
  STATIC void
  xfs_destroy_mount_workqueues(
  	struct xfs_mount	*mp)
  {

  	destroy_workqueue(mp->m_eofblocks_workqueue);

  	destroy_workqueue(mp->m_log_workqueue);
  	destroy_workqueue(mp->m_reclaim_workqueue);

  	destroy_workqueue(mp->m_cil_workqueue);

  	destroy_workqueue(mp->m_data_workqueue);
  	destroy_workqueue(mp->m_unwritten_workqueue);
  }

  /*
   * Flush all dirty data to disk. Must not be called while holding an XFS_ILOCK
   * or a page lock. We use sync_inodes_sb() here to ensure we block while waiting
   * for IO to complete so that we effectively throttle multiple callers to the
   * rate at which IO is completing.
   */
  void
  xfs_flush_inodes(
  	struct xfs_mount	*mp)
  {
  	struct super_block	*sb = mp->m_super;
  
  	if (down_read_trylock(&sb->s_umount)) {

  		sync_inodes_sb(sb);

  		up_read(&sb->s_umount);
  	}
  }

  /* Catch misguided souls that try to use this interface on XFS */

  STATIC struct inode *

  xfs_fs_alloc_inode(

  	struct super_block	*sb)
  {

  	BUG();

  	return NULL;

  }

  /*

   * Now that the generic code is guaranteed not to be accessing
   * the linux inode, we can reclaim the inode.

   */

  STATIC void

  xfs_fs_destroy_inode(

  	struct inode		*inode)

  {

  	struct xfs_inode	*ip = XFS_I(inode);

  	trace_xfs_destroy_inode(ip);

  
  	XFS_STATS_INC(vn_reclaim);

  	ASSERT(XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0);
  
  	/*
  	 * We should never get here with one of the reclaim flags already set.
  	 */
  	ASSERT_ALWAYS(!xfs_iflags_test(ip, XFS_IRECLAIMABLE));
  	ASSERT_ALWAYS(!xfs_iflags_test(ip, XFS_IRECLAIM));
  
  	/*

  	 * We always use background reclaim here because even if the
  	 * inode is clean, it still may be under IO and hence we have
  	 * to take the flush lock. The background reclaim path handles
  	 * this more efficiently than we can here, so simply let background
  	 * reclaim tear down all inodes.

  	 */

  	xfs_inode_set_reclaim_tag(ip);

  }

  /*
   * Slab object creation initialisation for the XFS inode.
   * This covers only the idempotent fields in the XFS inode;
   * all other fields need to be initialised on allocation

   * from the slab. This avoids the need to repeatedly initialise

   * fields in the xfs inode that left in the initialise state
   * when freeing the inode.
   */

  STATIC void
  xfs_fs_inode_init_once(

  	void			*inode)
  {
  	struct xfs_inode	*ip = inode;
  
  	memset(ip, 0, sizeof(struct xfs_inode));

  
  	/* vfs inode */
  	inode_init_once(VFS_I(ip));
  
  	/* xfs inode */

  	atomic_set(&ip->i_pincount, 0);
  	spin_lock_init(&ip->i_flags_lock);

  
  	mrlock_init(&ip->i_lock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER,
  		     "xfsino", ip->i_ino);

  }

  STATIC void

  xfs_fs_evict_inode(

  	struct inode		*inode)
  {

  	xfs_inode_t		*ip = XFS_I(inode);

  	ASSERT(!rwsem_is_locked(&ip->i_iolock.mr_lock));

  	trace_xfs_evict_inode(ip);

  	truncate_inode_pages_final(&inode->i_data);

  	clear_inode(inode);

  	XFS_STATS_INC(vn_rele);
  	XFS_STATS_INC(vn_remove);
  	XFS_STATS_DEC(vn_active);
  
  	xfs_inactive(ip);

  }

  /*
   * We do an unlocked check for XFS_IDONTCACHE here because we are already
   * serialised against cache hits here via the inode->i_lock and igrab() in
   * xfs_iget_cache_hit(). Hence a lookup that might clear this flag will not be
   * racing with us, and it avoids needing to grab a spinlock here for every inode
   * we drop the final reference on.
   */
  STATIC int
  xfs_fs_drop_inode(
  	struct inode		*inode)
  {
  	struct xfs_inode	*ip = XFS_I(inode);
  
  	return generic_drop_inode(inode) || (ip->i_flags & XFS_IDONTCACHE);
  }

  STATIC void

  xfs_free_fsname(
  	struct xfs_mount	*mp)
  {
  	kfree(mp->m_fsname);
  	kfree(mp->m_rtname);
  	kfree(mp->m_logname);
  }
  
  STATIC void

  xfs_fs_put_super(

  	struct super_block	*sb)
  {

  	struct xfs_mount	*mp = XFS_M(sb);

  	xfs_filestream_unmount(mp);
  	xfs_unmountfs(mp);

  	xfs_freesb(mp);

  	xfs_icsb_destroy_counters(mp);

  	xfs_destroy_mount_workqueues(mp);

  	xfs_close_devices(mp);

  	xfs_free_fsname(mp);

  	kfree(mp);

  }

  STATIC int

  xfs_fs_sync_fs(

  	struct super_block	*sb,
  	int			wait)
  {

  	struct xfs_mount	*mp = XFS_M(sb);

  	/*

  	 * Doing anything during the async pass would be counterproductive.

  	 */

  	if (!wait)

  		return 0;

  	xfs_log_force(mp, XFS_LOG_SYNC);

  	if (laptop_mode) {

  		/*
  		 * The disk must be active because we're syncing.

  		 * We schedule log work now (now that the disk is

  		 * active) instead of later (when it might not be).
  		 */

  		flush_delayed_work(&mp->m_log->l_work);

  	}

  	return 0;

  }
  
  STATIC int

  xfs_fs_statfs(

  	struct dentry		*dentry,

  	struct kstatfs		*statp)
  {

  	struct xfs_mount	*mp = XFS_M(dentry->d_sb);
  	xfs_sb_t		*sbp = &mp->m_sb;

  	struct xfs_inode	*ip = XFS_I(dentry->d_inode);

  	__uint64_t		fakeinos, id;
  	xfs_extlen_t		lsize;

  	__int64_t		ffree;

  
  	statp->f_type = XFS_SB_MAGIC;
  	statp->f_namelen = MAXNAMELEN - 1;
  
  	id = huge_encode_dev(mp->m_ddev_targp->bt_dev);
  	statp->f_fsid.val[0] = (u32)id;
  	statp->f_fsid.val[1] = (u32)(id >> 32);

  	xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT);

  
  	spin_lock(&mp->m_sb_lock);
  	statp->f_bsize = sbp->sb_blocksize;
  	lsize = sbp->sb_logstart ? sbp->sb_logblocks : 0;
  	statp->f_blocks = sbp->sb_dblocks - lsize;
  	statp->f_bfree = statp->f_bavail =
  				sbp->sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
  	fakeinos = statp->f_bfree << sbp->sb_inopblog;

  	statp->f_files =
  	    MIN(sbp->sb_icount + fakeinos, (__uint64_t)XFS_MAXINUMBER);
  	if (mp->m_maxicount)

  		statp->f_files = min_t(typeof(statp->f_files),
  					statp->f_files,
  					mp->m_maxicount);

  
  	/* make sure statp->f_ffree does not underflow */
  	ffree = statp->f_files - (sbp->sb_icount - sbp->sb_ifree);
  	statp->f_ffree = max_t(__int64_t, ffree, 0);

  	spin_unlock(&mp->m_sb_lock);

  	if ((ip->i_d.di_flags & XFS_DIFLAG_PROJINHERIT) &&

  	    ((mp->m_qflags & (XFS_PQUOTA_ACCT|XFS_PQUOTA_ENFD))) ==
  			      (XFS_PQUOTA_ACCT|XFS_PQUOTA_ENFD))

  		xfs_qm_statvfs(ip, statp);

  	return 0;

  }

  STATIC void
  xfs_save_resvblks(struct xfs_mount *mp)
  {
  	__uint64_t resblks = 0;
  
  	mp->m_resblks_save = mp->m_resblks;
  	xfs_reserve_blocks(mp, &resblks, NULL);
  }
  
  STATIC void
  xfs_restore_resvblks(struct xfs_mount *mp)
  {
  	__uint64_t resblks;
  
  	if (mp->m_resblks_save) {
  		resblks = mp->m_resblks_save;
  		mp->m_resblks_save = 0;
  	} else
  		resblks = xfs_default_resblks(mp);
  
  	xfs_reserve_blocks(mp, &resblks, NULL);
  }

  /*
   * Trigger writeback of all the dirty metadata in the file system.
   *
   * This ensures that the metadata is written to their location on disk rather
   * than just existing in transactions in the log. This means after a quiesce

   * there is no log replay required to write the inodes to disk - this is the
   * primary difference between a sync and a quiesce.

   *

   * Note: xfs_log_quiesce() stops background log work - the callers must ensure
   * it is started again when appropriate.

   */

  static void

  xfs_quiesce_attr(
  	struct xfs_mount	*mp)
  {
  	int	error = 0;
  
  	/* wait for all modifications to complete */
  	while (atomic_read(&mp->m_active_trans) > 0)
  		delay(100);
  
  	/* force the log to unpin objects from the now complete transactions */
  	xfs_log_force(mp, XFS_LOG_SYNC);
  
  	/* reclaim inodes to do any IO before the freeze completes */
  	xfs_reclaim_inodes(mp, 0);
  	xfs_reclaim_inodes(mp, SYNC_WAIT);

  	/* Push the superblock and write an unmount record */
  	error = xfs_log_sbcount(mp);
  	if (error)
  		xfs_warn(mp, "xfs_attr_quiesce: failed to log sb changes. "
  				"Frozen image may not be consistent.");

  	/*

  	 * Just warn here till VFS can correctly support
  	 * read-only remount without racing.

  	 */

  	WARN_ON(atomic_read(&mp->m_active_trans) != 0);

  	xfs_log_quiesce(mp);

  }

  STATIC int

  xfs_fs_remount(

  	struct super_block	*sb,
  	int			*flags,
  	char			*options)
  {

  	struct xfs_mount	*mp = XFS_M(sb);

  	substring_t		args[MAX_OPT_ARGS];
  	char			*p;

  	int			error;

  	sync_filesystem(sb);

  	while ((p = strsep(&options, ",")) != NULL) {
  		int token;

  		if (!*p)
  			continue;

  		token = match_token(p, tokens, args);
  		switch (token) {
  		case Opt_barrier:

  			mp->m_flags |= XFS_MOUNT_BARRIER;

  			break;
  		case Opt_nobarrier:

  			mp->m_flags &= ~XFS_MOUNT_BARRIER;

  			break;

  		case Opt_inode64:

  			mp->m_maxagi = xfs_set_inode64(mp);

  			break;

  		case Opt_inode32:
  			mp->m_maxagi = xfs_set_inode32(mp);
  			break;

  		default:

  			/*
  			 * Logically we would return an error here to prevent
  			 * users from believing they might have changed
  			 * mount options using remount which can't be changed.
  			 *
  			 * But unfortunately mount(8) adds all options from
  			 * mtab and fstab to the mount arguments in some cases
  			 * so we can't blindly reject options, but have to
  			 * check for each specified option if it actually
  			 * differs from the currently set option and only
  			 * reject it if that's the case.
  			 *
  			 * Until that is implemented we return success for
  			 * every remount request, and silently ignore all
  			 * options that we can't actually change.
  			 */
  #if 0

  			xfs_info(mp,

  		"mount option \"%s\" not supported for remount", p);

  			return -EINVAL;

  #else

  			break;

  #endif

  		}

  	}

  	/* ro -> rw */

  	if ((mp->m_flags & XFS_MOUNT_RDONLY) && !(*flags & MS_RDONLY)) {
  		mp->m_flags &= ~XFS_MOUNT_RDONLY;

  
  		/*
  		 * If this is the first remount to writeable state we
  		 * might have some superblock changes to update.
  		 */
  		if (mp->m_update_flags) {
  			error = xfs_mount_log_sb(mp, mp->m_update_flags);
  			if (error) {

  				xfs_warn(mp, "failed to write sb changes");

  				return error;
  			}
  			mp->m_update_flags = 0;
  		}

  
  		/*
  		 * Fill out the reserve pool if it is empty. Use the stashed
  		 * value if it is non-zero, otherwise go with the default.
  		 */

  		xfs_restore_resvblks(mp);

  		xfs_log_work_queue(mp);

  	}
  
  	/* rw -> ro */
  	if (!(mp->m_flags & XFS_MOUNT_RDONLY) && (*flags & MS_RDONLY)) {

  		/*

  		 * Before we sync the metadata, we need to free up the reserve
  		 * block pool so that the used block count in the superblock on
  		 * disk is correct at the end of the remount. Stash the current
  		 * reserve pool size so that if we get remounted rw, we can
  		 * return it to the same size.

  		 */

  		xfs_save_resvblks(mp);

  		xfs_quiesce_attr(mp);

  		mp->m_flags |= XFS_MOUNT_RDONLY;
  	}

  	return 0;

  }

  /*
   * Second stage of a freeze. The data is already frozen so we only

   * need to take care of the metadata. Once that's done write a dummy

   * record to dirty the log in case of a crash while frozen.
   */

  STATIC int
  xfs_fs_freeze(

  	struct super_block	*sb)
  {

  	struct xfs_mount	*mp = XFS_M(sb);

  	xfs_save_resvblks(mp);

  	xfs_quiesce_attr(mp);

  	return -xfs_fs_log_dummy(mp);

  }
  
  STATIC int

  xfs_fs_unfreeze(
  	struct super_block	*sb)
  {
  	struct xfs_mount	*mp = XFS_M(sb);
  
  	xfs_restore_resvblks(mp);

  	xfs_log_work_queue(mp);

  	return 0;
  }
  
  STATIC int

  xfs_fs_show_options(

  	struct seq_file		*m,

  	struct dentry		*root)

  {

  	return -xfs_showargs(XFS_M(root->d_sb), m);

  }

  /*
   * This function fills in xfs_mount_t fields based on mount args.

   * Note: the superblock _has_ now been read in.
   */
  STATIC int
  xfs_finish_flags(

  	struct xfs_mount	*mp)
  {
  	int			ronly = (mp->m_flags & XFS_MOUNT_RDONLY);

  	/* Fail a mount where the logbuf is smaller than the log stripe */

  	if (xfs_sb_version_haslogv2(&mp->m_sb)) {

  		if (mp->m_logbsize <= 0 &&
  		    mp->m_sb.sb_logsunit > XLOG_BIG_RECORD_BSIZE) {

  			mp->m_logbsize = mp->m_sb.sb_logsunit;

  		} else if (mp->m_logbsize > 0 &&
  			   mp->m_logbsize < mp->m_sb.sb_logsunit) {

  			xfs_warn(mp,
  		"logbuf size must be greater than or equal to log stripe size");

  			return XFS_ERROR(EINVAL);
  		}
  	} else {
  		/* Fail a mount if the logbuf is larger than 32K */

  		if (mp->m_logbsize > XLOG_BIG_RECORD_BSIZE) {

  			xfs_warn(mp,
  		"logbuf size for version 1 logs must be 16K or 32K");

  			return XFS_ERROR(EINVAL);
  		}
  	}
  
  	/*

  	 * V5 filesystems always use attr2 format for attributes.
  	 */
  	if (xfs_sb_version_hascrc(&mp->m_sb) &&
  	    (mp->m_flags & XFS_MOUNT_NOATTR2)) {
  		xfs_warn(mp,
  "Cannot mount a V5 filesystem as %s. %s is always enabled for V5 filesystems.",
  			MNTOPT_NOATTR2, MNTOPT_ATTR2);
  		return XFS_ERROR(EINVAL);
  	}
  
  	/*

  	 * mkfs'ed attr2 will turn on attr2 mount unless explicitly
  	 * told by noattr2 to turn it off
  	 */
  	if (xfs_sb_version_hasattr2(&mp->m_sb) &&

  	    !(mp->m_flags & XFS_MOUNT_NOATTR2))

  		mp->m_flags |= XFS_MOUNT_ATTR2;
  
  	/*
  	 * prohibit r/w mounts of read-only filesystems
  	 */
  	if ((mp->m_sb.sb_flags & XFS_SBF_READONLY) && !ronly) {

  		xfs_warn(mp,
  			"cannot mount a read-only filesystem as read-write");

  		return XFS_ERROR(EROFS);
  	}

  	if ((mp->m_qflags & (XFS_GQUOTA_ACCT | XFS_GQUOTA_ACTIVE)) &&
  	    (mp->m_qflags & (XFS_PQUOTA_ACCT | XFS_PQUOTA_ACTIVE)) &&
  	    !xfs_sb_version_has_pquotino(&mp->m_sb)) {
  		xfs_warn(mp,
  		  "Super block does not support project and group quota together");
  		return XFS_ERROR(EINVAL);
  	}

  	return 0;
  }

  STATIC int

  xfs_fs_fill_super(

  	struct super_block	*sb,
  	void			*data,
  	int			silent)
  {

  	struct inode		*root;

  	struct xfs_mount	*mp = NULL;

  	int			flags = 0, error = ENOMEM;

  	mp = kzalloc(sizeof(struct xfs_mount), GFP_KERNEL);
  	if (!mp)

  		goto out;

  	spin_lock_init(&mp->m_sb_lock);

  	mutex_init(&mp->m_growlock);
  	atomic_set(&mp->m_active_trans, 0);

  	INIT_DELAYED_WORK(&mp->m_reclaim_work, xfs_reclaim_worker);

  	INIT_DELAYED_WORK(&mp->m_eofblocks_work, xfs_eofblocks_worker);

  	mp->m_super = sb;
  	sb->s_fs_info = mp;

  	error = xfs_parseargs(mp, (char *)data);

  	if (error)

  		goto out_free_fsname;

  
  	sb_min_blocksize(sb, BBSIZE);

  	sb->s_xattr = xfs_xattr_handlers;

  	sb->s_export_op = &xfs_export_operations;

  #ifdef CONFIG_XFS_QUOTA

  	sb->s_qcop = &xfs_quotactl_operations;

  #endif

  	sb->s_op = &xfs_super_operations;

  	if (silent)

  		flags |= XFS_MFSI_QUIET;

  	error = xfs_open_devices(mp);

  	if (error)

  		goto out_free_fsname;

  	error = xfs_init_mount_workqueues(mp);

  	if (error)
  		goto out_close_devices;

  	error = xfs_icsb_init_counters(mp);
  	if (error)
  		goto out_destroy_workqueues;

  	error = xfs_readsb(mp, flags);
  	if (error)

  		goto out_destroy_counters;
  
  	error = xfs_finish_flags(mp);

  	if (error)

  		goto out_free_sb;

  	error = xfs_setup_devices(mp);

  	if (error)

  		goto out_free_sb;

  	error = xfs_filestream_mount(mp);
  	if (error)

  		goto out_free_sb;

  	/*
  	 * we must configure the block size in the superblock before we run the
  	 * full mount process as the mount process can lookup and cache inodes.

  	 */

  	sb->s_magic = XFS_SB_MAGIC;
  	sb->s_blocksize = mp->m_sb.sb_blocksize;
  	sb->s_blocksize_bits = ffs(sb->s_blocksize) - 1;

  	sb->s_maxbytes = xfs_max_file_offset(sb->s_blocksize_bits);

  	sb->s_max_links = XFS_MAXLINK;

  	sb->s_time_gran = 1;
  	set_posix_acl_flag(sb);

  	/* version 5 superblocks support inode version counters. */
  	if (XFS_SB_VERSION_NUM(&mp->m_sb) == XFS_SB_VERSION_5)
  		sb->s_flags |= MS_I_VERSION;

  	error = xfs_mountfs(mp);

  	if (error)

  		goto out_filestream_unmount;

  	root = igrab(VFS_I(mp->m_rootip));

  	if (!root) {

  		error = ENOENT;

  		goto out_unmount;

  	}

  	sb->s_root = d_make_root(root);

  	if (!sb->s_root) {
  		error = ENOMEM;

  		goto out_unmount;

  	}

  	return 0;

   out_filestream_unmount:

  	xfs_filestream_unmount(mp);

   out_free_sb:
  	xfs_freesb(mp);

   out_destroy_counters:

  	xfs_icsb_destroy_counters(mp);

  out_destroy_workqueues:
  	xfs_destroy_mount_workqueues(mp);

   out_close_devices:

  	xfs_close_devices(mp);

   out_free_fsname:
  	xfs_free_fsname(mp);

  	kfree(mp);

   out:

  	return -error;

   out_unmount:

  	xfs_filestream_unmount(mp);

  	xfs_unmountfs(mp);

  	goto out_free_sb;

  }

  STATIC struct dentry *
  xfs_fs_mount(

  	struct file_system_type	*fs_type,
  	int			flags,
  	const char		*dev_name,

  	void			*data)

  {

  	return mount_bdev(fs_type, flags, dev_name, data, xfs_fs_fill_super);

  }

  static long

  xfs_fs_nr_cached_objects(

  	struct super_block	*sb,
  	int			nid)

  {
  	return xfs_reclaim_inodes_count(XFS_M(sb));
  }

  static long

  xfs_fs_free_cached_objects(
  	struct super_block	*sb,

  	long			nr_to_scan,
  	int			nid)

  {

  	return xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan);

  }

  static const struct super_operations xfs_super_operations = {

  	.alloc_inode		= xfs_fs_alloc_inode,
  	.destroy_inode		= xfs_fs_destroy_inode,

  	.evict_inode		= xfs_fs_evict_inode,

  	.drop_inode		= xfs_fs_drop_inode,

  	.put_super		= xfs_fs_put_super,

  	.sync_fs		= xfs_fs_sync_fs,

  	.freeze_fs		= xfs_fs_freeze,

  	.unfreeze_fs		= xfs_fs_unfreeze,

  	.statfs			= xfs_fs_statfs,
  	.remount_fs		= xfs_fs_remount,
  	.show_options		= xfs_fs_show_options,

  	.nr_cached_objects	= xfs_fs_nr_cached_objects,
  	.free_cached_objects	= xfs_fs_free_cached_objects,

  };

  static struct file_system_type xfs_fs_type = {

  	.owner			= THIS_MODULE,
  	.name			= "xfs",

  	.mount			= xfs_fs_mount,

  	.kill_sb		= kill_block_super,
  	.fs_flags		= FS_REQUIRES_DEV,
  };

  MODULE_ALIAS_FS("xfs");

  STATIC int __init

  xfs_init_zones(void)
  {

  
  	xfs_ioend_zone = kmem_zone_init(sizeof(xfs_ioend_t), "xfs_ioend");
  	if (!xfs_ioend_zone)

  		goto out;

  
  	xfs_ioend_pool = mempool_create_slab_pool(4 * MAX_BUF_PER_PAGE,
  						  xfs_ioend_zone);
  	if (!xfs_ioend_pool)
  		goto out_destroy_ioend_zone;
  
  	xfs_log_ticket_zone = kmem_zone_init(sizeof(xlog_ticket_t),
  						"xfs_log_ticket");
  	if (!xfs_log_ticket_zone)
  		goto out_destroy_ioend_pool;
  
  	xfs_bmap_free_item_zone = kmem_zone_init(sizeof(xfs_bmap_free_item_t),
  						"xfs_bmap_free_item");
  	if (!xfs_bmap_free_item_zone)
  		goto out_destroy_log_ticket_zone;

  	xfs_btree_cur_zone = kmem_zone_init(sizeof(xfs_btree_cur_t),
  						"xfs_btree_cur");
  	if (!xfs_btree_cur_zone)
  		goto out_destroy_bmap_free_item_zone;
  
  	xfs_da_state_zone = kmem_zone_init(sizeof(xfs_da_state_t),
  						"xfs_da_state");
  	if (!xfs_da_state_zone)
  		goto out_destroy_btree_cur_zone;

  	xfs_ifork_zone = kmem_zone_init(sizeof(xfs_ifork_t), "xfs_ifork");
  	if (!xfs_ifork_zone)

  		goto out_destroy_da_state_zone;

  
  	xfs_trans_zone = kmem_zone_init(sizeof(xfs_trans_t), "xfs_trans");
  	if (!xfs_trans_zone)
  		goto out_destroy_ifork_zone;

  	xfs_log_item_desc_zone =
  		kmem_zone_init(sizeof(struct xfs_log_item_desc),
  			       "xfs_log_item_desc");
  	if (!xfs_log_item_desc_zone)
  		goto out_destroy_trans_zone;

  	/*
  	 * The size of the zone allocated buf log item is the maximum
  	 * size possible under XFS.  This wastes a little bit of memory,
  	 * but it is much faster.
  	 */