1 files changed, 628 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c
new file mode 100644
index 0000000..7510ab8
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_attr_remote.c
@@ -0,0 +1,628 @@
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * Copyright (c) 2013 Red Hat, 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_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_bit.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_mount.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_inode.h"
+#include "xfs_alloc.h"
+#include "xfs_trans.h"
+#include "xfs_inode_item.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_util.h"
+#include "xfs_attr.h"
+#include "xfs_attr_leaf.h"
+#include "xfs_attr_remote.h"
+#include "xfs_trans_space.h"
+#include "xfs_trace.h"
+#include "xfs_cksum.h"
+#include "xfs_buf_item.h"
+#include "xfs_error.h"
+
+#define ATTR_RMTVALUE_MAPSIZE	1	/* # of map entries at once */
+
+/*
+ * Each contiguous block has a header, so it is not just a simple attribute
+ * length to FSB conversion.
+ */
+int
+xfs_attr3_rmt_blocks(
+	struct xfs_mount *mp,
+	int		attrlen)
+{
+	if (xfs_sb_version_hascrc(&mp->m_sb)) {
+		int buflen = XFS_ATTR3_RMT_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
+		return (attrlen + buflen - 1) / buflen;
+	}
+	return XFS_B_TO_FSB(mp, attrlen);
+}
+
+/*
+ * Checking of the remote attribute header is split into two parts. The verifier
+ * does CRC, location and bounds checking, the unpacking function checks the
+ * attribute parameters and owner.
+ */
+static bool
+xfs_attr3_rmt_hdr_ok(
+	void			*ptr,
+	xfs_ino_t		ino,
+	uint32_t		offset,
+	uint32_t		size,
+	xfs_daddr_t		bno)
+{
+	struct xfs_attr3_rmt_hdr *rmt = ptr;
+
+	if (bno != be64_to_cpu(rmt->rm_blkno))
+		return false;
+	if (offset != be32_to_cpu(rmt->rm_offset))
+		return false;
+	if (size != be32_to_cpu(rmt->rm_bytes))
+		return false;
+	if (ino != be64_to_cpu(rmt->rm_owner))
+		return false;
+
+	/* ok */
+	return true;
+}
+
+static bool
+xfs_attr3_rmt_verify(
+	struct xfs_mount	*mp,
+	void			*ptr,
+	int			fsbsize,
+	xfs_daddr_t		bno)
+{
+	struct xfs_attr3_rmt_hdr *rmt = ptr;
+
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return false;
+	if (rmt->rm_magic != cpu_to_be32(XFS_ATTR3_RMT_MAGIC))
+		return false;
+	if (!uuid_equal(&rmt->rm_uuid, &mp->m_sb.sb_uuid))
+		return false;
+	if (be64_to_cpu(rmt->rm_blkno) != bno)
+		return false;
+	if (be32_to_cpu(rmt->rm_bytes) > fsbsize - sizeof(*rmt))
+		return false;
+	if (be32_to_cpu(rmt->rm_offset) +
+				be32_to_cpu(rmt->rm_bytes) > XATTR_SIZE_MAX)
+		return false;
+	if (rmt->rm_owner == 0)
+		return false;
+
+	return true;
+}
+
+static void
+xfs_attr3_rmt_read_verify(
+	struct xfs_buf	*bp)
+{
+	struct xfs_mount *mp = bp->b_target->bt_mount;
+	char		*ptr;
+	int		len;
+	xfs_daddr_t	bno;
+	int		blksize = mp->m_attr_geo->blksize;
+
+	/* no verification of non-crc buffers */
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return;
+
+	ptr = bp->b_addr;
+	bno = bp->b_bn;
+	len = BBTOB(bp->b_length);
+	ASSERT(len >= blksize);
+
+	while (len > 0) {
+		if (!xfs_verify_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF)) {
+			xfs_buf_ioerror(bp, -EFSBADCRC);
+			break;
+		}
+		if (!xfs_attr3_rmt_verify(mp, ptr, blksize, bno)) {
+			xfs_buf_ioerror(bp, -EFSCORRUPTED);
+			break;
+		}
+		len -= blksize;
+		ptr += blksize;
+		bno += BTOBB(blksize);
+	}
+
+	if (bp->b_error)
+		xfs_verifier_error(bp);
+	else
+		ASSERT(len == 0);
+}
+
+static void
+xfs_attr3_rmt_write_verify(
+	struct xfs_buf	*bp)
+{
+	struct xfs_mount *mp = bp->b_target->bt_mount;
+	struct xfs_buf_log_item	*bip = bp->b_fspriv;
+	char		*ptr;
+	int		len;
+	xfs_daddr_t	bno;
+	int		blksize = mp->m_attr_geo->blksize;
+
+	/* no verification of non-crc buffers */
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return;
+
+	ptr = bp->b_addr;
+	bno = bp->b_bn;
+	len = BBTOB(bp->b_length);
+	ASSERT(len >= blksize);
+
+	while (len > 0) {
+		if (!xfs_attr3_rmt_verify(mp, ptr, blksize, bno)) {
+			xfs_buf_ioerror(bp, -EFSCORRUPTED);
+			xfs_verifier_error(bp);
+			return;
+		}
+		if (bip) {
+			struct xfs_attr3_rmt_hdr *rmt;
+
+			rmt = (struct xfs_attr3_rmt_hdr *)ptr;
+			rmt->rm_lsn = cpu_to_be64(bip->bli_item.li_lsn);
+		}
+		xfs_update_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF);
+
+		len -= blksize;
+		ptr += blksize;
+		bno += BTOBB(blksize);
+	}
+	ASSERT(len == 0);
+}
+
+const struct xfs_buf_ops xfs_attr3_rmt_buf_ops = {
+	.verify_read = xfs_attr3_rmt_read_verify,
+	.verify_write = xfs_attr3_rmt_write_verify,
+};
+
+STATIC int
+xfs_attr3_rmt_hdr_set(
+	struct xfs_mount	*mp,
+	void			*ptr,
+	xfs_ino_t		ino,
+	uint32_t		offset,
+	uint32_t		size,
+	xfs_daddr_t		bno)
+{
+	struct xfs_attr3_rmt_hdr *rmt = ptr;
+
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return 0;
+
+	rmt->rm_magic = cpu_to_be32(XFS_ATTR3_RMT_MAGIC);
+	rmt->rm_offset = cpu_to_be32(offset);
+	rmt->rm_bytes = cpu_to_be32(size);
+	uuid_copy(&rmt->rm_uuid, &mp->m_sb.sb_uuid);
+	rmt->rm_owner = cpu_to_be64(ino);
+	rmt->rm_blkno = cpu_to_be64(bno);
+
+	return sizeof(struct xfs_attr3_rmt_hdr);
+}
+
+/*
+ * Helper functions to copy attribute data in and out of the one disk extents
+ */
+STATIC int
+xfs_attr_rmtval_copyout(
+	struct xfs_mount *mp,
+	struct xfs_buf	*bp,
+	xfs_ino_t	ino,
+	int		*offset,
+	int		*valuelen,
+	__uint8_t	**dst)
+{
+	char		*src = bp->b_addr;
+	xfs_daddr_t	bno = bp->b_bn;
+	int		len = BBTOB(bp->b_length);
+	int		blksize = mp->m_attr_geo->blksize;
+
+	ASSERT(len >= blksize);
+
+	while (len > 0 && *valuelen > 0) {
+		int hdr_size = 0;
+		int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, blksize);
+
+		byte_cnt = min(*valuelen, byte_cnt);
+
+		if (xfs_sb_version_hascrc(&mp->m_sb)) {
+			if (!xfs_attr3_rmt_hdr_ok(src, ino, *offset,
+						  byte_cnt, bno)) {
+				xfs_alert(mp,
+"remote attribute header mismatch bno/off/len/owner (0x%llx/0x%x/Ox%x/0x%llx)",
+					bno, *offset, byte_cnt, ino);
+				return -EFSCORRUPTED;
+			}
+			hdr_size = sizeof(struct xfs_attr3_rmt_hdr);
+		}
+
+		memcpy(*dst, src + hdr_size, byte_cnt);
+
+		/* roll buffer forwards */
+		len -= blksize;
+		src += blksize;
+		bno += BTOBB(blksize);
+
+		/* roll attribute data forwards */
+		*valuelen -= byte_cnt;
+		*dst += byte_cnt;
+		*offset += byte_cnt;
+	}
+	return 0;
+}
+
+STATIC void
+xfs_attr_rmtval_copyin(
+	struct xfs_mount *mp,
+	struct xfs_buf	*bp,
+	xfs_ino_t	ino,
+	int		*offset,
+	int		*valuelen,
+	__uint8_t	**src)
+{
+	char		*dst = bp->b_addr;
+	xfs_daddr_t	bno = bp->b_bn;
+	int		len = BBTOB(bp->b_length);
+	int		blksize = mp->m_attr_geo->blksize;
+
+	ASSERT(len >= blksize);
+
+	while (len > 0 && *valuelen > 0) {
+		int hdr_size;
+		int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, blksize);
+
+		byte_cnt = min(*valuelen, byte_cnt);
+		hdr_size = xfs_attr3_rmt_hdr_set(mp, dst, ino, *offset,
+						 byte_cnt, bno);
+
+		memcpy(dst + hdr_size, *src, byte_cnt);
+
+		/*
+		 * If this is the last block, zero the remainder of it.
+		 * Check that we are actually the last block, too.
+		 */
+		if (byte_cnt + hdr_size < blksize) {
+			ASSERT(*valuelen - byte_cnt == 0);
+			ASSERT(len == blksize);
+			memset(dst + hdr_size + byte_cnt, 0,
+					blksize - hdr_size - byte_cnt);
+		}
+
+		/* roll buffer forwards */
+		len -= blksize;
+		dst += blksize;
+		bno += BTOBB(blksize);
+
+		/* roll attribute data forwards */
+		*valuelen -= byte_cnt;
+		*src += byte_cnt;
+		*offset += byte_cnt;
+	}
+}
+
+/*
+ * Read the value associated with an attribute from the out-of-line buffer
+ * that we stored it in.
+ */
+int
+xfs_attr_rmtval_get(
+	struct xfs_da_args	*args)
+{
+	struct xfs_bmbt_irec	map[ATTR_RMTVALUE_MAPSIZE];
+	struct xfs_mount	*mp = args->dp->i_mount;
+	struct xfs_buf		*bp;
+	xfs_dablk_t		lblkno = args->rmtblkno;
+	__uint8_t		*dst = args->value;
+	int			valuelen;
+	int			nmap;
+	int			error;
+	int			blkcnt = args->rmtblkcnt;
+	int			i;
+	int			offset = 0;
+
+	trace_xfs_attr_rmtval_get(args);
+
+	ASSERT(!(args->flags & ATTR_KERNOVAL));
+	ASSERT(args->rmtvaluelen == args->valuelen);
+
+	valuelen = args->rmtvaluelen;
+	while (valuelen > 0) {
+		nmap = ATTR_RMTVALUE_MAPSIZE;
+		error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
+				       blkcnt, map, &nmap,
+				       XFS_BMAPI_ATTRFORK);
+		if (error)
+			return error;
+		ASSERT(nmap >= 1);
+
+		for (i = 0; (i < nmap) && (valuelen > 0); i++) {
+			xfs_daddr_t	dblkno;
+			int		dblkcnt;
+
+			ASSERT((map[i].br_startblock != DELAYSTARTBLOCK) &&
+			       (map[i].br_startblock != HOLESTARTBLOCK));
+			dblkno = XFS_FSB_TO_DADDR(mp, map[i].br_startblock);
+			dblkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount);
+			error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
+						   dblkno, dblkcnt, 0, &bp,
+						   &xfs_attr3_rmt_buf_ops);
+			if (error)
+				return error;
+
+			error = xfs_attr_rmtval_copyout(mp, bp, args->dp->i_ino,
+							&offset, &valuelen,
+							&dst);
+			xfs_buf_relse(bp);
+			if (error)
+				return error;
+
+			/* roll attribute extent map forwards */
+			lblkno += map[i].br_blockcount;
+			blkcnt -= map[i].br_blockcount;
+		}
+	}
+	ASSERT(valuelen == 0);
+	return 0;
+}
+
+/*
+ * Write the value associated with an attribute into the out-of-line buffer
+ * that we have defined for it.
+ */
+int
+xfs_attr_rmtval_set(
+	struct xfs_da_args	*args)
+{
+	struct xfs_inode	*dp = args->dp;
+	struct xfs_mount	*mp = dp->i_mount;
+	struct xfs_bmbt_irec	map;
+	xfs_dablk_t		lblkno;
+	xfs_fileoff_t		lfileoff = 0;
+	__uint8_t		*src = args->value;
+	int			blkcnt;
+	int			valuelen;
+	int			nmap;
+	int			error;
+	int			offset = 0;
+
+	trace_xfs_attr_rmtval_set(args);
+
+	/*
+	 * Find a "hole" in the attribute address space large enough for
+	 * us to drop the new attribute's value into. Because CRC enable
+	 * attributes have headers, we can't just do a straight byte to FSB
+	 * conversion and have to take the header space into account.
+	 */
+	blkcnt = xfs_attr3_rmt_blocks(mp, args->rmtvaluelen);
+	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) {
+		int	committed;
+
+		/*
+		 * Allocate a single extent, up to the size of the value.
+		 */
+		xfs_bmap_init(args->flist, args->firstblock);
+		nmap = 1;
+		error = xfs_bmapi_write(args->trans, dp, (xfs_fileoff_t)lblkno,
+				  blkcnt,
+				  XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
+				  args->firstblock, args->total, &map, &nmap,
+				  args->flist);
+		if (!error) {
+			error = xfs_bmap_finish(&args->trans, args->flist,
+						&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, 0);
+
+		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.
+		 */
+		error = xfs_trans_roll(&args->trans, dp);
+		if (error)
+			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;
+	blkcnt = args->rmtblkcnt;
+	valuelen = args->rmtvaluelen;
+	while (valuelen > 0) {
+		struct xfs_buf	*bp;
+		xfs_daddr_t	dblkno;
+		int		dblkcnt;
+
+		ASSERT(blkcnt > 0);
+
+		xfs_bmap_init(args->flist, args->firstblock);
+		nmap = 1;
+		error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno,
+				       blkcnt, &map, &nmap,
+				       XFS_BMAPI_ATTRFORK);
+		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),
+		dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
+
+		bp = xfs_buf_get(mp->m_ddev_targp, dblkno, dblkcnt, 0);
+		if (!bp)
+			return -ENOMEM;
+		bp->b_ops = &xfs_attr3_rmt_buf_ops;
+
+		xfs_attr_rmtval_copyin(mp, bp, args->dp->i_ino, &offset,
+				       &valuelen, &src);
+
+		error = xfs_bwrite(bp);	/* GROT: NOTE: synchronous write */
+		xfs_buf_relse(bp);
+		if (error)
+			return error;
+
+
+		/* roll attribute extent map forwards */
+		lblkno += map.br_blockcount;
+		blkcnt -= 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.
+ */
+int
+xfs_attr_rmtval_remove(
+	struct xfs_da_args	*args)
+{
+	struct xfs_mount	*mp = args->dp->i_mount;
+	xfs_dablk_t		lblkno;
+	int			blkcnt;
+	int			error;
+	int			done;
+
+	trace_xfs_attr_rmtval_remove(args);
+
+	/*
+	 * Roll through the "value", invalidating the attribute value's blocks.
+	 */
+	lblkno = args->rmtblkno;
+	blkcnt = args->rmtblkcnt;
+	while (blkcnt > 0) {
+		struct xfs_bmbt_irec	map;
+		struct xfs_buf		*bp;
+		xfs_daddr_t		dblkno;
+		int			dblkcnt;
+		int			nmap;
+
+		/*
+		 * Try to remember where we decided to put the value.
+		 */
+		nmap = 1;
+		error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
+				       blkcnt, &map, &nmap, XFS_BMAPI_ATTRFORK);
+		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),
+		dblkcnt = 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, dblkcnt, XBF_TRYLOCK);
+		if (bp) {
+			xfs_buf_stale(bp);
+			xfs_buf_relse(bp);
+			bp = NULL;
+		}
+
+		lblkno += map.br_blockcount;
+		blkcnt -= map.br_blockcount;
+	}
+
+	/*
+	 * Keep de-allocating extents until the remote-value region is gone.
+	 */
+	lblkno = args->rmtblkno;
+	blkcnt = args->rmtblkcnt;
+	done = 0;
+	while (!done) {
+		int committed;
+
+		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,
+						&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, 0);
+
+		/*
+		 * Close out trans and start the next one in the chain.
+		 */
+		error = xfs_trans_roll(&args->trans, args->dp);
+		if (error)
+			return error;
+	}
+	return 0;
+}