xfs_attr.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 2,474 行 · 第 1/5 页

	int blkcnt, valuelen, nmap, error, tmp, committed;

	dp = args->dp;
	mp = dp->i_mount;
	src = args->value;

	/*
	 * Find a "hole" in the attribute address space large enough for
	 * us to drop the new attribute's value into.
	 */
	blkcnt = XFS_B_TO_FSB(mp, args->valuelen);
	lfileoff = 0;
	error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff,
						   XFS_ATTR_FORK);
	if (error) {
		return(error);
	}
	args->rmtblkno = lblkno = (xfs_dablk_t)lfileoff;
	args->rmtblkcnt = blkcnt;

	/*
	 * Roll through the "value", allocating blocks on disk as required.
	 */
	while (blkcnt > 0) {
		/*
		 * Allocate a single extent, up to the size of the value.
		 */
		XFS_BMAP_INIT(args->flist, args->firstblock);
		nmap = 1;
		error = xfs_bmapi(args->trans, dp, (xfs_fileoff_t)lblkno,
				  blkcnt,
				  XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA |
							XFS_BMAPI_WRITE,
				  args->firstblock, args->total, &map, &nmap,
				  args->flist);
		if (!error) {
			error = xfs_bmap_finish(&args->trans, args->flist,
						*args->firstblock, &committed);
		}
		if (error) {
			ASSERT(committed);
			args->trans = NULL;
			xfs_bmap_cancel(args->flist);
			return(error);
		}

		/*
		 * bmap_finish() may have committed the last trans and started
		 * a new one.  We need the inode to be in all transactions.
		 */
		if (committed) {
			xfs_trans_ijoin(args->trans, dp, XFS_ILOCK_EXCL);
			xfs_trans_ihold(args->trans, dp);
		}

		ASSERT(nmap == 1);
		ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
		       (map.br_startblock != HOLESTARTBLOCK));
		lblkno += map.br_blockcount;
		blkcnt -= map.br_blockcount;

		/*
		 * Start the next trans in the chain.
		 */
		if ((error = xfs_attr_rolltrans(&args->trans, dp)))
			return (error);
	}

	/*
	 * Roll through the "value", copying the attribute value to the
	 * already-allocated blocks.  Blocks are written synchronously
	 * so that we can know they are all on disk before we turn off
	 * the INCOMPLETE flag.
	 */
	lblkno = args->rmtblkno;
	valuelen = args->valuelen;
	while (valuelen > 0) {
		/*
		 * Try to remember where we decided to put the value.
		 */
		XFS_BMAP_INIT(args->flist, args->firstblock);
		nmap = 1;
		error = xfs_bmapi(NULL, dp, (xfs_fileoff_t)lblkno,
				  args->rmtblkcnt,
				  XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
				  args->firstblock, 0, &map, &nmap, NULL);
		if (error) {
			return(error);
		}
		ASSERT(nmap == 1);
		ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
		       (map.br_startblock != HOLESTARTBLOCK));

		dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
		blkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);

		bp = xfs_buf_get_flags(mp->m_ddev_targp, dblkno,
							blkcnt, XFS_BUF_LOCK);
		ASSERT(bp);
		ASSERT(!XFS_BUF_GETERROR(bp));

		tmp = (valuelen < XFS_BUF_SIZE(bp)) ? valuelen :
							XFS_BUF_SIZE(bp);
		xfs_biomove(bp, 0, tmp, src, XFS_B_WRITE);
		if (tmp < XFS_BUF_SIZE(bp))
			xfs_biozero(bp, tmp, XFS_BUF_SIZE(bp) - tmp);
		if ((error = xfs_bwrite(mp, bp))) {/* GROT: NOTE: synchronous write */
			return (error);
		}
		src += tmp;
		valuelen -= tmp;

		lblkno += map.br_blockcount;
	}
	ASSERT(valuelen == 0);
	return(0);
}

/*
 * Remove the value associated with an attribute by deleting the
 * out-of-line buffer that it is stored on.
 */
STATIC int
xfs_attr_rmtval_remove(xfs_da_args_t *args)
{
	xfs_mount_t *mp;
	xfs_bmbt_irec_t map;
	xfs_buf_t *bp;
	xfs_daddr_t dblkno;
	xfs_dablk_t lblkno;
	int valuelen, blkcnt, nmap, error, done, committed;

	mp = args->dp->i_mount;

	/*
	 * Roll through the "value", invalidating the attribute value's
	 * blocks.
	 */
	lblkno = args->rmtblkno;
	valuelen = args->rmtblkcnt;
	while (valuelen > 0) {
		/*
		 * Try to remember where we decided to put the value.
		 */
		XFS_BMAP_INIT(args->flist, args->firstblock);
		nmap = 1;
		error = xfs_bmapi(NULL, args->dp, (xfs_fileoff_t)lblkno,
					args->rmtblkcnt,
					XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
					args->firstblock, 0, &map, &nmap,
					args->flist);
		if (error) {
			return(error);
		}
		ASSERT(nmap == 1);
		ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
		       (map.br_startblock != HOLESTARTBLOCK));

		dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
		blkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);

		/*
		 * If the "remote" value is in the cache, remove it.
		 */
		bp = xfs_incore(mp->m_ddev_targp, dblkno, blkcnt,
				XFS_INCORE_TRYLOCK);
		if (bp) {
			XFS_BUF_STALE(bp);
			XFS_BUF_UNDELAYWRITE(bp);
			xfs_buf_relse(bp);
			bp = NULL;
		}

		valuelen -= map.br_blockcount;

		lblkno += map.br_blockcount;
	}

	/*
	 * Keep de-allocating extents until the remote-value region is gone.
	 */
	lblkno = args->rmtblkno;
	blkcnt = args->rmtblkcnt;
	done = 0;
	while (!done) {
		XFS_BMAP_INIT(args->flist, args->firstblock);
		error = xfs_bunmapi(args->trans, args->dp, lblkno, blkcnt,
				    XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
				    1, args->firstblock, args->flist, &done);
		if (!error) {
			error = xfs_bmap_finish(&args->trans, args->flist,
						*args->firstblock, &committed);
		}
		if (error) {
			ASSERT(committed);
			args->trans = NULL;
			xfs_bmap_cancel(args->flist);
			return(error);
		}

		/*
		 * bmap_finish() may have committed the last trans and started
		 * a new one.  We need the inode to be in all transactions.
		 */
		if (committed) {
			xfs_trans_ijoin(args->trans, args->dp, XFS_ILOCK_EXCL);
			xfs_trans_ihold(args->trans, args->dp);
		}

		/*
		 * Close out trans and start the next one in the chain.
		 */
		if ((error = xfs_attr_rolltrans(&args->trans, args->dp)))
			return (error);
	}
	return(0);
}

#if defined(XFS_ATTR_TRACE)
/*
 * Add a trace buffer entry for an attr_list context structure.
 */
void
xfs_attr_trace_l_c(char *where, struct xfs_attr_list_context *context)
{
	xfs_attr_trace_enter(XFS_ATTR_KTRACE_L_C, where,
		(__psunsigned_t)context->dp,
		(__psunsigned_t)context->cursor->hashval,
		(__psunsigned_t)context->cursor->blkno,
		(__psunsigned_t)context->cursor->offset,
		(__psunsigned_t)context->alist,
		(__psunsigned_t)context->bufsize,
		(__psunsigned_t)context->count,
		(__psunsigned_t)context->firstu,
		(__psunsigned_t)
			((context->count > 0) &&
			!(context->flags & (ATTR_KERNAMELS|ATTR_KERNOVAL)))
				? (ATTR_ENTRY(context->alist,
					      context->count-1)->a_valuelen)
				: 0,
		(__psunsigned_t)context->dupcnt,
		(__psunsigned_t)context->flags,
		(__psunsigned_t)NULL,
		(__psunsigned_t)NULL,
		(__psunsigned_t)NULL);
}

/*
 * Add a trace buffer entry for a context structure and a Btree node.
 */
void
xfs_attr_trace_l_cn(char *where, struct xfs_attr_list_context *context,
			 struct xfs_da_intnode *node)
{
	xfs_attr_trace_enter(XFS_ATTR_KTRACE_L_CN, where,
		(__psunsigned_t)context->dp,
		(__psunsigned_t)context->cursor->hashval,
		(__psunsigned_t)context->cursor->blkno,
		(__psunsigned_t)context->cursor->offset,
		(__psunsigned_t)context->alist,
		(__psunsigned_t)context->bufsize,
		(__psunsigned_t)context->count,
		(__psunsigned_t)context->firstu,
		(__psunsigned_t)
			((context->count > 0) &&
			!(context->flags & (ATTR_KERNAMELS|ATTR_KERNOVAL)))
				? (ATTR_ENTRY(context->alist,
					      context->count-1)->a_valuelen)
				: 0,
		(__psunsigned_t)context->dupcnt,
		(__psunsigned_t)context->flags,
		(__psunsigned_t)INT_GET(node->hdr.count, ARCH_CONVERT),
		(__psunsigned_t)INT_GET(node->btree[0].hashval, ARCH_CONVERT),
		(__psunsigned_t)INT_GET(node->btree[INT_GET(node->hdr.count, ARCH_CONVERT)-1].hashval, ARCH_CONVERT));
}

/*
 * Add a trace buffer entry for a context structure and a Btree element.
 */
void
xfs_attr_trace_l_cb(char *where, struct xfs_attr_list_context *context,
			  struct xfs_da_node_entry *btree)
{
	xfs_attr_trace_enter(XFS_ATTR_KTRACE_L_CB, where,
		(__psunsigned_t)context->dp,
		(__psunsigned_t)context->cursor->hashval,
		(__psunsigned_t)context->cursor->blkno,
		(__psunsigned_t)context->cursor->offset,
		(__psunsigned_t)context->alist,
		(__psunsigned_t)context->bufsize,
		(__psunsigned_t)context->count,
		(__psunsigned_t)context->firstu,
		(__psunsigned_t)
			((context->count > 0) &&
			!(context->flags & (ATTR_KERNAMELS|ATTR_KERNOVAL)))
				? (ATTR_ENTRY(context->alist,
					      context->count-1)->a_valuelen)
				: 0,
		(__psunsigned_t)context->dupcnt,
		(__psunsigned_t)context->flags,
		(__psunsigned_t)INT_GET(btree->hashval, ARCH_CONVERT),
		(__psunsigned_t)INT_GET(btree->before, ARCH_CONVERT),
		(__psunsigned_t)NULL);
}

/*
 * Add a trace buffer entry for a context structure and a leaf block.
 */
void
xfs_attr_trace_l_cl(char *where, struct xfs_attr_list_context *context,
			      struct xfs_attr_leafblock *leaf)
{
	xfs_attr_trace_enter(XFS_ATTR_KTRACE_L_CL, where,
		(__psunsigned_t)context->dp,
		(__psunsigned_t)context->cursor->hashval,
		(__psunsigned_t)context->cursor->blkno,
		(__psunsigned_t)context->cursor->offset,
		(__psunsigned_t)context->alist,
		(__psunsigned_t)context->bufsize,
		(__psunsigned_t)context->count,
		(__psunsigned_t)context->firstu,
		(__psunsigned_t)
			((context->count > 0) &&
			!(context->flags & (ATTR_KERNAMELS|ATTR_KERNOVAL)))
				? (ATTR_ENTRY(context->alist,
					      context->count-1)->a_valuelen)
				: 0,
		(__psunsigned_t)context->dupcnt,
		(__psunsigned_t)context->flags,
		(__psunsigned_t)INT_GET(leaf->hdr.count, ARCH_CONVERT),
		(__psunsigned_t)INT_GET(leaf->entries[0].hashval, ARCH_CONVERT),
		(__psunsigned_t)INT_GET(leaf->entries[INT_GET(leaf->hdr.count, ARCH_CONVERT)-1].hashval, ARCH_CONVERT));
}

/*
 * Add a trace buffer entry for the arguments given to the routine,
 * generic form.
 */
void
xfs_attr_trace_enter(int type, char *where,
			 __psunsigned_t a2, __psunsigned_t a3,
			 __psunsigned_t a4, __psunsigned_t a5,
			 __psunsigned_t a6, __psunsigned_t a7,
			 __psunsigned_t a8, __psunsigned_t a9,
			 __psunsigned_t a10, __psunsigned_t a11,
			 __psunsigned_t a12, __psunsigned_t a13,
			 __psunsigned_t a14, __psunsigned_t a15)
{
	ASSERT(xfs_attr_trace_buf);
	ktrace_enter(xfs_attr_trace_buf, (void *)((__psunsigned_t)type),
					 (void *)where,
					 (void *)a2,  (void *)a3,  (void *)a4,
					 (void *)a5,  (void *)a6,  (void *)a7,
					 (void *)a8,  (void *)a9,  (void *)a10,
					 (void *)a11, (void *)a12, (void *)a13,
					 (void *)a14, (void *)a15);
}
#endif	/* XFS_ATTR_TRACE */


/*========================================================================
 * System (pseudo) namespace attribute interface routines.
 *========================================================================*/

STATIC int
posix_acl_access_set(
	vnode_t	*vp, char *name, void *data, size_t size, int xflags)
{
	return xfs_acl_vset(vp, data, size, _ACL_TYPE_ACCESS);
}

STATIC int
posix_acl_access_remove(
	struct vnode *vp, char *name, int xflags)
{
	return xfs_acl_vremove(vp, _ACL_TYPE_ACCESS);
}

STATIC int
posix_acl_access_get(
	vnode_t *vp, char *name, void *data, size_t size, int xflags)
{
	return xfs_acl_vget(vp, data, size, _ACL_TYPE_ACCESS);
}

STATIC int
posix_acl_access_exists(
	vnode_t *vp)
{
	return xfs_acl_vhasacl_access(vp);
}

STATIC int
posix_acl_default_set(
	vnode_t	*vp, char *name, void *data, size_t size, int xflags)
{
	return xfs_acl_vset(vp, data, size, _ACL_TYPE_DEFAULT);
}

STATIC int
posix_acl_default_get(
	vnode_t *vp, char *name, void *data, size_t size, int xflags)
{
	return xfs_acl_vget(vp, data, size, _ACL_TYPE_DEFAULT);
}

STATIC int
posix_acl_default_remove(
	struct vnode *vp, char *name, int xflags)
{
	return xfs_acl_vremove(vp, _ACL_TYPE_DEFAULT);
}

STATIC int
posix_acl_default_exists(
	vnode_t *vp)
{
	return xfs_acl_vhasacl_default(vp);
}

struct attrnames posix_acl_access = {
	.attr_name	= "posix_acl_access",
	.attr_namelen	= sizeof("posix_acl_access") - 1,
	.attr_get	= posix_acl_access_get,
	.attr_set	= posix_acl_access_set,
	.attr_remove	= posix_acl_access_remove,
	.attr_exists	= posix_acl_access_exists,
};

struct attrnames posix_acl_default = {
	.attr_name	= "posix_acl_default",
	.attr_namelen	= sizeof("posix_acl_default") - 1,
	.attr_get	= posix_acl_default_get,
	.attr_set	= posix_acl_default_set,
	.attr_remove	= posix_acl_default_remove,
	.attr_exists	= posix_acl_default_exists,
};

struct attrnames *attr_system_names[] =
	{ &posix_acl_access, &posix_acl_default };


/*========================================================================
 * Namespace-prefix-style attribute name interface routines.
 *========================================================================*/

STATIC int
attr_generic_set(
	struct vnode *vp, char *name, void *data, size_t size, int xflags)
{
	int 	error;

	VOP_ATTR_SET(vp, name, data, size, xflags, NULL, error);
	return -error;
}

STATIC int
attr_generic_get(
	struct vnode *vp, char *name, void *data, size_t size, int xflags)
{
	int	error, asize = size;

	VOP_ATTR_GET(vp, name, data, &asize, xflags, NULL, error);
	if (!error)
		return asize;
	return -error;
}

STATIC int
attr_generic_remove(
	struct vnode *vp, char *name, int xflags)
{
	int	error;

	VOP_ATTR_REMOVE(vp, name, xflags, NULL, error);
	return -error;
}

STATIC int
attr_generic_listadd(
	attrnames_t		*prefix,
	attrnames_t		*namesp,
	void			*data,
	size_t			size,
	ssize_t			*result)
{
	char			*p = data + *result;

	*result += prefix->attr_namelen;
	*result += namesp->attr_namelen + 1;
	if (!size)
		return 0;
	if (*result > size)
		return