/*
   *   Copyright (C) International Business Machines  Corp., 2000-2004
   *   Copyright (C) Christoph Hellwig, 2002
   *
   *   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; either version 2 of the License, or

   *   (at your option) any later version.

   *

   *   This program is distributed in the hope that it will 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 to the Free Software

   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */

  #include <linux/capability.h>

  #include <linux/fs.h>
  #include <linux/xattr.h>

  #include <linux/posix_acl_xattr.h>

  #include <linux/slab.h>

  #include <linux/quotaops.h>

  #include <linux/security.h>

  #include "jfs_incore.h"
  #include "jfs_superblock.h"
  #include "jfs_dmap.h"
  #include "jfs_debug.h"
  #include "jfs_dinode.h"
  #include "jfs_extent.h"
  #include "jfs_metapage.h"
  #include "jfs_xattr.h"
  #include "jfs_acl.h"
  
  /*
   *	jfs_xattr.c: extended attribute service
   *
   * Overall design --
   *
   * Format:
   *
   *   Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit
   *   value) and a variable (0 or more) number of extended attribute
   *   entries.  Each extended attribute entry (jfs_ea) is a <name,value> double
   *   where <name> is constructed from a null-terminated ascii string
   *   (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data
   *   (1 ... 65535 bytes).  The in-memory format is
   *
   *   0       1        2        4                4 + namelen + 1
   *   +-------+--------+--------+----------------+-------------------+
   *   | Flags | Name   | Value  | Name String \0 | Data . . . .      |
   *   |       | Length | Length |                |                   |
   *   +-------+--------+--------+----------------+-------------------+
   *
   *   A jfs_ea_list then is structured as
   *
   *   0            4                   4 + EA_SIZE(ea1)
   *   +------------+-------------------+--------------------+-----

   *   | Overall EA | First FEA Element | Second FEA Element | .....

   *   | List Size  |                   |                    |
   *   +------------+-------------------+--------------------+-----
   *
   *   On-disk:
   *

   *	FEALISTs are stored on disk using blocks allocated by dbAlloc() and
   *	written directly. An EA list may be in-lined in the inode if there is
   *	sufficient room available.

   */
  
  struct ea_buffer {
  	int flag;		/* Indicates what storage xattr points to */
  	int max_size;		/* largest xattr that fits in current buffer */
  	dxd_t new_ea;		/* dxd to replace ea when modifying xattr */
  	struct metapage *mp;	/* metapage containing ea list */
  	struct jfs_ea_list *xattr;	/* buffer containing ea list */
  };
  
  /*
   * ea_buffer.flag values
   */
  #define EA_INLINE	0x0001
  #define EA_EXTENT	0x0002
  #define EA_NEW		0x0004
  #define EA_MALLOC	0x0008

  /*
   * Mapping of on-disk attribute names: for on-disk attribute names with an
   * unknown prefix (not "system.", "user.", "security.", or "trusted."), the
   * prefix "os2." is prepended.  On the way back to disk, "os2." prefixes are
   * stripped and we make sure that the remaining name does not start with one
   * of the know prefixes.
   */

  static int is_known_namespace(const char *name)
  {
  	if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
  	    strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
  	    strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
  	    strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
  		return false;
  
  	return true;
  }

  static inline int name_size(struct jfs_ea *ea)
  {

  	if (is_known_namespace(ea->name))

  		return ea->namelen;

  	else
  		return ea->namelen + XATTR_OS2_PREFIX_LEN;

  }
  
  static inline int copy_name(char *buffer, struct jfs_ea *ea)
  {
  	int len = ea->namelen;

  	if (!is_known_namespace(ea->name)) {

  		memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
  		buffer += XATTR_OS2_PREFIX_LEN;
  		len += XATTR_OS2_PREFIX_LEN;
  	}
  	memcpy(buffer, ea->name, ea->namelen);
  	buffer[ea->namelen] = 0;
  
  	return len;
  }
  
  /* Forward references */
  static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
  
  /*
   * NAME: ea_write_inline

   *

   * FUNCTION: Attempt to write an EA inline if area is available

   *

   * PRE CONDITIONS:
   *	Already verified that the specified EA is small enough to fit inline
   *
   * PARAMETERS:
   *	ip	- Inode pointer
   *	ealist	- EA list pointer
   *	size	- size of ealist in bytes
   *	ea	- dxd_t structure to be filled in with necessary EA information
   *		  if we successfully copy the EA inline
   *
   * NOTES:
   *	Checks if the inode's inline area is available.  If so, copies EA inline
   *	and sets <ea> fields appropriately.  Otherwise, returns failure, EA will
   *	have to be put into an extent.
   *
   * RETURNS: 0 for successful copy to inline area; -1 if area not available
   */
  static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist,
  			   int size, dxd_t * ea)
  {
  	struct jfs_inode_info *ji = JFS_IP(ip);
  
  	/*
  	 * Make sure we have an EA -- the NULL EA list is valid, but you
  	 * can't copy it!
  	 */
  	if (ealist && size > sizeof (struct jfs_ea_list)) {
  		assert(size <= sizeof (ji->i_inline_ea));
  
  		/*
  		 * See if the space is available or if it is already being
  		 * used for an inline EA.
  		 */
  		if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE))
  			return -EPERM;
  
  		DXDsize(ea, size);
  		DXDlength(ea, 0);
  		DXDaddress(ea, 0);
  		memcpy(ji->i_inline_ea, ealist, size);
  		ea->flag = DXD_INLINE;
  		ji->mode2 &= ~INLINEEA;
  	} else {
  		ea->flag = 0;
  		DXDsize(ea, 0);
  		DXDlength(ea, 0);
  		DXDaddress(ea, 0);
  
  		/* Free up INLINE area */
  		if (ji->ea.flag & DXD_INLINE)
  			ji->mode2 |= INLINEEA;
  	}
  
  	return 0;
  }
  
  /*
   * NAME: ea_write

   *

   * FUNCTION: Write an EA for an inode

   *
   * PRE CONDITIONS: EA has been verified

   *
   * PARAMETERS:
   *	ip	- Inode pointer
   *	ealist	- EA list pointer
   *	size	- size of ealist in bytes
   *	ea	- dxd_t structure to be filled in appropriately with where the
   *		  EA was copied
   *
   * NOTES: Will write EA inline if able to, otherwise allocates blocks for an
   *	extent and synchronously writes it to those blocks.
   *
   * RETURNS: 0 for success; Anything else indicates failure
   */
  static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size,
  		       dxd_t * ea)
  {
  	struct super_block *sb = ip->i_sb;
  	struct jfs_inode_info *ji = JFS_IP(ip);
  	struct jfs_sb_info *sbi = JFS_SBI(sb);
  	int nblocks;
  	s64 blkno;
  	int rc = 0, i;
  	char *cp;
  	s32 nbytes, nb;
  	s32 bytes_to_write;
  	struct metapage *mp;
  
  	/*
  	 * Quick check to see if this is an in-linable EA.  Short EAs
  	 * and empty EAs are all in-linable, provided the space exists.
  	 */
  	if (!ealist || size <= sizeof (ji->i_inline_ea)) {
  		if (!ea_write_inline(ip, ealist, size, ea))
  			return 0;
  	}
  
  	/* figure out how many blocks we need */
  	nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits;
  
  	/* Allocate new blocks to quota. */

  	rc = dquot_alloc_block(ip, nblocks);
  	if (rc)
  		return rc;

  
  	rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno);
  	if (rc) {
  		/*Rollback quota allocation. */

  		dquot_free_block(ip, nblocks);

  		return rc;
  	}
  
  	/*
  	 * Now have nblocks worth of storage to stuff into the FEALIST.
  	 * loop over the FEALIST copying data into the buffer one page at
  	 * a time.
  	 */
  	cp = (char *) ealist;
  	nbytes = size;
  	for (i = 0; i < nblocks; i += sbi->nbperpage) {
  		/*
  		 * Determine how many bytes for this request, and round up to
  		 * the nearest aggregate block size
  		 */
  		nb = min(PSIZE, nbytes);
  		bytes_to_write =
  		    ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
  		    << sb->s_blocksize_bits;
  
  		if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) {
  			rc = -EIO;
  			goto failed;
  		}
  
  		memcpy(mp->data, cp, nb);
  
  		/*
  		 * We really need a way to propagate errors for
  		 * forced writes like this one.  --hch
  		 *
  		 * (__write_metapage => release_metapage => flush_metapage)
  		 */
  #ifdef _JFS_FIXME
  		if ((rc = flush_metapage(mp))) {
  			/*
  			 * the write failed -- this means that the buffer
  			 * is still assigned and the blocks are not being
  			 * used.  this seems like the best error recovery
  			 * we can get ...
  			 */
  			goto failed;
  		}
  #else
  		flush_metapage(mp);
  #endif
  
  		cp += PSIZE;
  		nbytes -= nb;
  	}
  
  	ea->flag = DXD_EXTENT;
  	DXDsize(ea, le32_to_cpu(ealist->size));
  	DXDlength(ea, nblocks);
  	DXDaddress(ea, blkno);
  
  	/* Free up INLINE area */
  	if (ji->ea.flag & DXD_INLINE)
  		ji->mode2 |= INLINEEA;
  
  	return 0;
  
        failed:
  	/* Rollback quota allocation. */

  	dquot_free_block(ip, nblocks);

  
  	dbFree(ip, blkno, nblocks);
  	return rc;
  }
  
  /*
   * NAME: ea_read_inline

   *

   * FUNCTION: Read an inlined EA into user's buffer

   *

   * PARAMETERS:
   *	ip	- Inode pointer
   *	ealist	- Pointer to buffer to fill in with EA
   *
   * RETURNS: 0
   */
  static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist)
  {
  	struct jfs_inode_info *ji = JFS_IP(ip);
  	int ea_size = sizeDXD(&ji->ea);
  
  	if (ea_size == 0) {
  		ealist->size = 0;
  		return 0;
  	}
  
  	/* Sanity Check */
  	if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea)))
  		return -EIO;
  	if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size)
  	    != ea_size)
  		return -EIO;
  
  	memcpy(ealist, ji->i_inline_ea, ea_size);
  	return 0;
  }
  
  /*
   * NAME: ea_read

   *

   * FUNCTION: copy EA data into user's buffer

   *

   * PARAMETERS:
   *	ip	- Inode pointer
   *	ealist	- Pointer to buffer to fill in with EA
   *
   * NOTES:  If EA is inline calls ea_read_inline() to copy EA.
   *
   * RETURNS: 0 for success; other indicates failure
   */
  static int ea_read(struct inode *ip, struct jfs_ea_list *ealist)
  {
  	struct super_block *sb = ip->i_sb;
  	struct jfs_inode_info *ji = JFS_IP(ip);
  	struct jfs_sb_info *sbi = JFS_SBI(sb);
  	int nblocks;
  	s64 blkno;
  	char *cp = (char *) ealist;
  	int i;
  	int nbytes, nb;
  	s32 bytes_to_read;
  	struct metapage *mp;
  
  	/* quick check for in-line EA */
  	if (ji->ea.flag & DXD_INLINE)
  		return ea_read_inline(ip, ealist);
  
  	nbytes = sizeDXD(&ji->ea);
  	if (!nbytes) {

  		jfs_error(sb, "nbytes is 0
  ");

  		return -EIO;
  	}

  	/*

  	 * Figure out how many blocks were allocated when this EA list was
  	 * originally written to disk.
  	 */
  	nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage;
  	blkno = addressDXD(&ji->ea) << sbi->l2nbperpage;
  
  	/*
  	 * I have found the disk blocks which were originally used to store
  	 * the FEALIST.  now i loop over each contiguous block copying the
  	 * data into the buffer.
  	 */
  	for (i = 0; i < nblocks; i += sbi->nbperpage) {
  		/*
  		 * Determine how many bytes for this request, and round up to
  		 * the nearest aggregate block size
  		 */
  		nb = min(PSIZE, nbytes);
  		bytes_to_read =
  		    ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
  		    << sb->s_blocksize_bits;
  
  		if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1)))
  			return -EIO;
  
  		memcpy(cp, mp->data, nb);
  		release_metapage(mp);
  
  		cp += PSIZE;
  		nbytes -= nb;
  	}
  
  	return 0;
  }
  
  /*
   * NAME: ea_get

   *

   * FUNCTION: Returns buffer containing existing extended attributes.
   *	     The size of the buffer will be the larger of the existing
   *	     attributes size, or min_size.
   *
   *	     The buffer, which may be inlined in the inode or in the

   *	     page cache must be release by calling ea_release or ea_put
   *

   * PARAMETERS:
   *	inode	- Inode pointer
   *	ea_buf	- Structure to be populated with ealist and its metadata
   *	min_size- minimum size of buffer to be returned
   *
   * RETURNS: 0 for success; Other indicates failure
   */
  static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
  {
  	struct jfs_inode_info *ji = JFS_IP(inode);
  	struct super_block *sb = inode->i_sb;
  	int size;
  	int ea_size = sizeDXD(&ji->ea);
  	int blocks_needed, current_blocks;
  	s64 blkno;
  	int rc;
  	int quota_allocation = 0;
  
  	/* When fsck.jfs clears a bad ea, it doesn't clear the size */
  	if (ji->ea.flag == 0)
  		ea_size = 0;
  
  	if (ea_size == 0) {
  		if (min_size == 0) {
  			ea_buf->flag = 0;
  			ea_buf->max_size = 0;
  			ea_buf->xattr = NULL;
  			return 0;
  		}
  		if ((min_size <= sizeof (ji->i_inline_ea)) &&
  		    (ji->mode2 & INLINEEA)) {
  			ea_buf->flag = EA_INLINE | EA_NEW;
  			ea_buf->max_size = sizeof (ji->i_inline_ea);
  			ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
  			DXDlength(&ea_buf->new_ea, 0);
  			DXDaddress(&ea_buf->new_ea, 0);
  			ea_buf->new_ea.flag = DXD_INLINE;
  			DXDsize(&ea_buf->new_ea, min_size);
  			return 0;
  		}
  		current_blocks = 0;
  	} else if (ji->ea.flag & DXD_INLINE) {
  		if (min_size <= sizeof (ji->i_inline_ea)) {
  			ea_buf->flag = EA_INLINE;
  			ea_buf->max_size = sizeof (ji->i_inline_ea);
  			ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
  			goto size_check;
  		}
  		current_blocks = 0;
  	} else {
  		if (!(ji->ea.flag & DXD_EXTENT)) {

  			jfs_error(sb, "invalid ea.flag
  ");

  			return -EIO;
  		}
  		current_blocks = (ea_size + sb->s_blocksize - 1) >>
  		    sb->s_blocksize_bits;
  	}
  	size = max(min_size, ea_size);
  
  	if (size > PSIZE) {
  		/*
  		 * To keep the rest of the code simple.  Allocate a
  		 * contiguous buffer to work with
  		 */
  		ea_buf->xattr = kmalloc(size, GFP_KERNEL);
  		if (ea_buf->xattr == NULL)
  			return -ENOMEM;
  
  		ea_buf->flag = EA_MALLOC;
  		ea_buf->max_size = (size + sb->s_blocksize - 1) &
  		    ~(sb->s_blocksize - 1);
  
  		if (ea_size == 0)
  			return 0;
  
  		if ((rc = ea_read(inode, ea_buf->xattr))) {
  			kfree(ea_buf->xattr);
  			ea_buf->xattr = NULL;
  			return rc;
  		}
  		goto size_check;
  	}
  	blocks_needed = (min_size + sb->s_blocksize - 1) >>
  	    sb->s_blocksize_bits;
  
  	if (blocks_needed > current_blocks) {
  		/* Allocate new blocks to quota. */

  		rc = dquot_alloc_block(inode, blocks_needed);
  		if (rc)

  			return -EDQUOT;
  
  		quota_allocation = blocks_needed;
  
  		rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
  			     &blkno);
  		if (rc)
  			goto clean_up;
  
  		DXDlength(&ea_buf->new_ea, blocks_needed);
  		DXDaddress(&ea_buf->new_ea, blkno);
  		ea_buf->new_ea.flag = DXD_EXTENT;
  		DXDsize(&ea_buf->new_ea, min_size);
  
  		ea_buf->flag = EA_EXTENT | EA_NEW;
  
  		ea_buf->mp = get_metapage(inode, blkno,
  					  blocks_needed << sb->s_blocksize_bits,
  					  1);
  		if (ea_buf->mp == NULL) {
  			dbFree(inode, blkno, (s64) blocks_needed);
  			rc = -EIO;
  			goto clean_up;
  		}
  		ea_buf->xattr = ea_buf->mp->data;
  		ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
  		    ~(sb->s_blocksize - 1);
  		if (ea_size == 0)
  			return 0;
  		if ((rc = ea_read(inode, ea_buf->xattr))) {
  			discard_metapage(ea_buf->mp);
  			dbFree(inode, blkno, (s64) blocks_needed);
  			goto clean_up;
  		}
  		goto size_check;
  	}
  	ea_buf->flag = EA_EXTENT;
  	ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
  				   lengthDXD(&ji->ea) << sb->s_blocksize_bits,
  				   1);
  	if (ea_buf->mp == NULL) {
  		rc = -EIO;
  		goto clean_up;
  	}
  	ea_buf->xattr = ea_buf->mp->data;
  	ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
  	    ~(sb->s_blocksize - 1);
  
        size_check:
  	if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
  		printk(KERN_ERR "ea_get: invalid extended attribute
  ");

  		print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,
  				     ea_buf->xattr, ea_size, 1);

  		ea_release(inode, ea_buf);
  		rc = -EIO;
  		goto clean_up;
  	}
  
  	return ea_size;
  
        clean_up:
  	/* Rollback quota allocation */
  	if (quota_allocation)

  		dquot_free_block(inode, quota_allocation);

  
  	return (rc);
  }
  
  static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
  {
  	if (ea_buf->flag & EA_MALLOC)
  		kfree(ea_buf->xattr);
  	else if (ea_buf->flag & EA_EXTENT) {
  		assert(ea_buf->mp);
  		release_metapage(ea_buf->mp);
  
  		if (ea_buf->flag & EA_NEW)
  			dbFree(inode, addressDXD(&ea_buf->new_ea),
  			       lengthDXD(&ea_buf->new_ea));
  	}
  }

  static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
  		  int new_size)

  {
  	struct jfs_inode_info *ji = JFS_IP(inode);
  	unsigned long old_blocks, new_blocks;
  	int rc = 0;

  
  	if (new_size == 0) {
  		ea_release(inode, ea_buf);
  		ea_buf = NULL;
  	} else if (ea_buf->flag & EA_INLINE) {
  		assert(new_size <= sizeof (ji->i_inline_ea));
  		ji->mode2 &= ~INLINEEA;
  		ea_buf->new_ea.flag = DXD_INLINE;
  		DXDsize(&ea_buf->new_ea, new_size);
  		DXDaddress(&ea_buf->new_ea, 0);
  		DXDlength(&ea_buf->new_ea, 0);
  	} else if (ea_buf->flag & EA_MALLOC) {
  		rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
  		kfree(ea_buf->xattr);
  	} else if (ea_buf->flag & EA_NEW) {
  		/* We have already allocated a new dxd */
  		flush_metapage(ea_buf->mp);
  	} else {
  		/* ->xattr must point to original ea's metapage */
  		rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
  		discard_metapage(ea_buf->mp);
  	}
  	if (rc)
  		return rc;

  	old_blocks = new_blocks = 0;
  
  	if (ji->ea.flag & DXD_EXTENT) {
  		invalidate_dxd_metapages(inode, ji->ea);
  		old_blocks = lengthDXD(&ji->ea);
  	}
  
  	if (ea_buf) {
  		txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
  		if (ea_buf->new_ea.flag & DXD_EXTENT) {
  			new_blocks = lengthDXD(&ea_buf->new_ea);
  			if (ji->ea.flag & DXD_INLINE)
  				ji->mode2 |= INLINEEA;
  		}
  		ji->ea = ea_buf->new_ea;
  	} else {
  		txEA(tid, inode, &ji->ea, NULL);
  		if (ji->ea.flag & DXD_INLINE)
  			ji->mode2 |= INLINEEA;
  		ji->ea.flag = 0;
  		ji->ea.size = 0;
  	}
  
  	/* If old blocks exist, they must be removed from quota allocation. */
  	if (old_blocks)

  		dquot_free_block(inode, old_blocks);

  	inode->i_ctime = current_time(inode);

  	return 0;

  }

  int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
  		   const void *value, size_t value_len, int flags)

  {
  	struct jfs_ea_list *ealist;
  	struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
  	struct ea_buffer ea_buf;
  	int old_ea_size = 0;
  	int xattr_size;
  	int new_size;
  	int namelen = strlen(name);

  	int found = 0;
  	int rc;
  	int length;

  	down_write(&JFS_IP(inode)->xattr_sem);
  
  	xattr_size = ea_get(inode, &ea_buf, 0);
  	if (xattr_size < 0) {
  		rc = xattr_size;
  		goto out;
  	}
  
        again:
  	ealist = (struct jfs_ea_list *) ea_buf.xattr;
  	new_size = sizeof (struct jfs_ea_list);
  
  	if (xattr_size) {
  		for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
  		     ea = NEXT_EA(ea)) {
  			if ((namelen == ea->namelen) &&
  			    (memcmp(name, ea->name, namelen) == 0)) {
  				found = 1;
  				if (flags & XATTR_CREATE) {
  					rc = -EEXIST;
  					goto release;
  				}
  				old_ea = ea;
  				old_ea_size = EA_SIZE(ea);
  				next_ea = NEXT_EA(ea);
  			} else
  				new_size += EA_SIZE(ea);
  		}
  	}
  
  	if (!found) {
  		if (flags & XATTR_REPLACE) {
  			rc = -ENODATA;
  			goto release;
  		}
  		if (value == NULL) {
  			rc = 0;
  			goto release;
  		}
  	}
  	if (value)
  		new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
  
  	if (new_size > ea_buf.max_size) {
  		/*
  		 * We need to allocate more space for merged ea list.
  		 * We should only have loop to again: once.
  		 */
  		ea_release(inode, &ea_buf);
  		xattr_size = ea_get(inode, &ea_buf, new_size);
  		if (xattr_size < 0) {
  			rc = xattr_size;
  			goto out;
  		}
  		goto again;
  	}
  
  	/* Remove old ea of the same name */
  	if (found) {
  		/* number of bytes following target EA */
  		length = (char *) END_EALIST(ealist) - (char *) next_ea;
  		if (length > 0)
  			memmove(old_ea, next_ea, length);
  		xattr_size -= old_ea_size;
  	}
  
  	/* Add new entry to the end */
  	if (value) {
  		if (xattr_size == 0)
  			/* Completely new ea list */
  			xattr_size = sizeof (struct jfs_ea_list);

  		/*
  		 * The size of EA value is limitted by on-disk format up to
  		 *  __le16, there would be an overflow if the size is equal
  		 * to XATTR_SIZE_MAX (65536).  In order to avoid this issue,
  		 * we can pre-checkup the value size against USHRT_MAX, and
  		 * return -E2BIG in this case, which is consistent with the
  		 * VFS setxattr interface.
  		 */
  		if (value_len >= USHRT_MAX) {
  			rc = -E2BIG;
  			goto release;
  		}

  		ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
  		ea->flag = 0;
  		ea->namelen = namelen;
  		ea->valuelen = (cpu_to_le16(value_len));
  		memcpy(ea->name, name, namelen);
  		ea->name[namelen] = 0;
  		if (value_len)
  			memcpy(&ea->name[namelen + 1], value, value_len);
  		xattr_size += EA_SIZE(ea);
  	}
  
  	/* DEBUG - If we did this right, these number match */
  	if (xattr_size != new_size) {
  		printk(KERN_ERR

  		       "__jfs_setxattr: xattr_size = %d, new_size = %d
  ",

  		       xattr_size, new_size);
  
  		rc = -EINVAL;
  		goto release;
  	}
  
  	/*
  	 * If we're left with an empty list, there's no ea
  	 */
  	if (new_size == sizeof (struct jfs_ea_list))
  		new_size = 0;
  
  	ealist->size = cpu_to_le32(new_size);

  	rc = ea_put(tid, inode, &ea_buf, new_size);

  
  	goto out;
        release:
  	ea_release(inode, &ea_buf);
        out:
  	up_write(&JFS_IP(inode)->xattr_sem);

  	return rc;
  }

  ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
  		       size_t buf_size)
  {
  	struct jfs_ea_list *ealist;
  	struct jfs_ea *ea;
  	struct ea_buffer ea_buf;
  	int xattr_size;
  	ssize_t size;
  	int namelen = strlen(name);

  	char *value;

  	down_read(&JFS_IP(inode)->xattr_sem);
  
  	xattr_size = ea_get(inode, &ea_buf, 0);
  
  	if (xattr_size < 0) {
  		size = xattr_size;
  		goto out;
  	}
  
  	if (xattr_size == 0)
  		goto not_found;
  
  	ealist = (struct jfs_ea_list *) ea_buf.xattr;
  
  	/* Find the named attribute */
  	for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
  		if ((namelen == ea->namelen) &&
  		    memcmp(name, ea->name, namelen) == 0) {
  			/* Found it */
  			size = le16_to_cpu(ea->valuelen);
  			if (!data)
  				goto release;
  			else if (size > buf_size) {
  				size = -ERANGE;
  				goto release;
  			}
  			value = ((char *) &ea->name) + ea->namelen + 1;
  			memcpy(data, value, size);
  			goto release;
  		}
        not_found:
  	size = -ENODATA;
        release:
  	ea_release(inode, &ea_buf);
        out:
  	up_read(&JFS_IP(inode)->xattr_sem);

  	return size;
  }

  /*
   * No special permissions are needed to list attributes except for trusted.*
   */
  static inline int can_list(struct jfs_ea *ea)
  {
  	return (strncmp(ea->name, XATTR_TRUSTED_PREFIX,
  			    XATTR_TRUSTED_PREFIX_LEN) ||
  		capable(CAP_SYS_ADMIN));
  }
  
  ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
  {

  	struct inode *inode = d_inode(dentry);

  	char *buffer;
  	ssize_t size = 0;
  	int xattr_size;
  	struct jfs_ea_list *ealist;
  	struct jfs_ea *ea;
  	struct ea_buffer ea_buf;
  
  	down_read(&JFS_IP(inode)->xattr_sem);
  
  	xattr_size = ea_get(inode, &ea_buf, 0);
  	if (xattr_size < 0) {
  		size = xattr_size;
  		goto out;
  	}
  
  	if (xattr_size == 0)
  		goto release;
  
  	ealist = (struct jfs_ea_list *) ea_buf.xattr;
  
  	/* compute required size of list */
  	for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {

  		if (can_list(ea))

  			size += name_size(ea) + 1;
  	}
  
  	if (!data)
  		goto release;
  
  	if (size > buf_size) {
  		size = -ERANGE;
  		goto release;
  	}
  
  	/* Copy attribute names to buffer */
  	buffer = data;
  	for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {

  		if (can_list(ea)) {

  			int namelen = copy_name(buffer, ea);
  			buffer += namelen + 1;
  		}
  	}
  
        release:
  	ea_release(inode, &ea_buf);
        out:
  	up_read(&JFS_IP(inode)->xattr_sem);
  	return size;
  }

  static int __jfs_xattr_set(struct inode *inode, const char *name,
  			   const void *value, size_t size, int flags)

  {

  	struct jfs_inode_info *ji = JFS_IP(inode);

  	tid_t tid;

  	int rc;

  	tid = txBegin(inode->i_sb, 0);

  	mutex_lock(&ji->commit_mutex);

  	rc = __jfs_setxattr(tid, inode, name, value, size, flags);

  	if (!rc)
  		rc = txCommit(tid, 1, &inode, 0);
  	txEnd(tid);

  	mutex_unlock(&ji->commit_mutex);

  
  	return rc;

  }

  static int jfs_xattr_get(const struct xattr_handler *handler,
  			 struct dentry *unused, struct inode *inode,
  			 const char *name, void *value, size_t size)
  {
  	name = xattr_full_name(handler, name);
  	return __jfs_getxattr(inode, name, value, size);
  }
  
  static int jfs_xattr_set(const struct xattr_handler *handler,

  			 struct dentry *unused, struct inode *inode,
  			 const char *name, const void *value,
  			 size_t size, int flags)

  {

  	name = xattr_full_name(handler, name);
  	return __jfs_xattr_set(inode, name, value, size, flags);
  }
  
  static int jfs_xattr_get_os2(const struct xattr_handler *handler,
  			     struct dentry *unused, struct inode *inode,
  			     const char *name, void *value, size_t size)
  {
  	if (is_known_namespace(name))
  		return -EOPNOTSUPP;
  	return __jfs_getxattr(inode, name, value, size);
  }
  
  static int jfs_xattr_set_os2(const struct xattr_handler *handler,

  			     struct dentry *unused, struct inode *inode,
  			     const char *name, const void *value,
  			     size_t size, int flags)

  {

  	if (is_known_namespace(name))
  		return -EOPNOTSUPP;
  	return __jfs_xattr_set(inode, name, value, size, flags);
  }
  
  static const struct xattr_handler jfs_user_xattr_handler = {
  	.prefix = XATTR_USER_PREFIX,
  	.get = jfs_xattr_get,
  	.set = jfs_xattr_set,
  };
  
  static const struct xattr_handler jfs_os2_xattr_handler = {
  	.prefix = XATTR_OS2_PREFIX,
  	.get = jfs_xattr_get_os2,
  	.set = jfs_xattr_set_os2,
  };
  
  static const struct xattr_handler jfs_security_xattr_handler = {
  	.prefix = XATTR_SECURITY_PREFIX,
  	.get = jfs_xattr_get,
  	.set = jfs_xattr_set,
  };
  
  static const struct xattr_handler jfs_trusted_xattr_handler = {
  	.prefix = XATTR_TRUSTED_PREFIX,
  	.get = jfs_xattr_get,
  	.set = jfs_xattr_set,
  };

  const struct xattr_handler *jfs_xattr_handlers[] = {

  #ifdef CONFIG_JFS_POSIX_ACL

  	&posix_acl_access_xattr_handler,
  	&posix_acl_default_xattr_handler,
  #endif

  	&jfs_os2_xattr_handler,
  	&jfs_user_xattr_handler,
  	&jfs_security_xattr_handler,
  	&jfs_trusted_xattr_handler,

  	NULL,
  };

  #ifdef CONFIG_JFS_SECURITY

  static int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
  			  void *fs_info)

  {

  	const struct xattr *xattr;
  	tid_t *tid = fs_info;

  	char *name;

  	int err = 0;
  
  	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
  		name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
  			       strlen(xattr->name) + 1, GFP_NOFS);
  		if (!name) {
  			err = -ENOMEM;
  			break;
  		}
  		strcpy(name, XATTR_SECURITY_PREFIX);
  		strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
  
  		err = __jfs_setxattr(*tid, inode, name,
  				     xattr->value, xattr->value_len, 0);
  		kfree(name);
  		if (err < 0)
  			break;

  	}

  	return err;
  }

  int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir,
  		      const struct qstr *qstr)
  {
  	return security_inode_init_security(inode, dir, qstr,
  					    &jfs_initxattrs, &tid);

  }
  #endif