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-rw-r--r--fs/xfs/xfs_attr_remote.c541
1 files changed, 541 insertions, 0 deletions
diff --git a/fs/xfs/xfs_attr_remote.c b/fs/xfs/xfs_attr_remote.c
new file mode 100644
index 000000000000..dee84466dcc9
--- /dev/null
+++ b/fs/xfs/xfs_attr_remote.c
@@ -0,0 +1,541 @@
+/*
+ * 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_types.h"
+#include "xfs_bit.h"
+#include "xfs_log.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_mount.h"
+#include "xfs_error.h"
+#include "xfs_da_btree.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_dinode.h"
+#include "xfs_inode.h"
+#include "xfs_alloc.h"
+#include "xfs_inode_item.h"
+#include "xfs_bmap.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"
+
+#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.
+ */
+static int
+xfs_attr3_rmt_blocks(
+ struct xfs_mount *mp,
+ int attrlen)
+{
+ int buflen = XFS_ATTR3_RMT_BUF_SPACE(mp,
+ mp->m_sb.sb_blocksize);
+ return (attrlen + buflen - 1) / buflen;
+}
+
+static bool
+xfs_attr3_rmt_verify(
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = bp->b_target->bt_mount;
+ struct xfs_attr3_rmt_hdr *rmt = bp->b_addr;
+
+ 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 (bp->b_bn != be64_to_cpu(rmt->rm_blkno))
+ 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;
+
+ /* no verification of non-crc buffers */
+ if (!xfs_sb_version_hascrc(&mp->m_sb))
+ return;
+
+ if (!xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
+ XFS_ATTR3_RMT_CRC_OFF) ||
+ !xfs_attr3_rmt_verify(bp)) {
+ XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+ xfs_buf_ioerror(bp, EFSCORRUPTED);
+ }
+}
+
+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;
+
+ /* no verification of non-crc buffers */
+ if (!xfs_sb_version_hascrc(&mp->m_sb))
+ return;
+
+ if (!xfs_attr3_rmt_verify(bp)) {
+ XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+ xfs_buf_ioerror(bp, EFSCORRUPTED);
+ return;
+ }
+
+ if (bip) {
+ struct xfs_attr3_rmt_hdr *rmt = bp->b_addr;
+ rmt->rm_lsn = cpu_to_be64(bip->bli_item.li_lsn);
+ }
+ xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
+ XFS_ATTR3_RMT_CRC_OFF);
+}
+
+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,
+ xfs_ino_t ino,
+ uint32_t offset,
+ uint32_t size,
+ struct xfs_buf *bp)
+{
+ struct xfs_attr3_rmt_hdr *rmt = bp->b_addr;
+
+ 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(bp->b_bn);
+ bp->b_ops = &xfs_attr3_rmt_buf_ops;
+
+ return sizeof(struct xfs_attr3_rmt_hdr);
+}
+
+/*
+ * 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(
+ struct xfs_mount *mp,
+ xfs_ino_t ino,
+ uint32_t offset,
+ uint32_t size,
+ struct xfs_buf *bp)
+{
+ struct xfs_attr3_rmt_hdr *rmt = bp->b_addr;
+
+ 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;
+}
+
+/*
+ * 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_daddr_t dblkno;
+ xfs_dablk_t lblkno = args->rmtblkno;
+ void *dst = args->value;
+ int valuelen = args->valuelen;
+ int nmap;
+ int error;
+ int blkcnt;
+ int i;
+ int offset = 0;
+
+ trace_xfs_attr_rmtval_get(args);
+
+ ASSERT(!(args->flags & ATTR_KERNOVAL));
+
+ while (valuelen > 0) {
+ nmap = ATTR_RMTVALUE_MAPSIZE;
+ error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
+ args->rmtblkcnt, map, &nmap,
+ XFS_BMAPI_ATTRFORK);
+ if (error)
+ return error;
+ ASSERT(nmap >= 1);
+
+ for (i = 0; (i < nmap) && (valuelen > 0); i++) {
+ int byte_cnt;
+ char *src;
+
+ ASSERT((map[i].br_startblock != DELAYSTARTBLOCK) &&
+ (map[i].br_startblock != HOLESTARTBLOCK));
+ dblkno = XFS_FSB_TO_DADDR(mp, map[i].br_startblock);
+ blkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount);
+ error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
+ dblkno, blkcnt, 0, &bp,
+ &xfs_attr3_rmt_buf_ops);
+ if (error)
+ return error;
+
+ byte_cnt = min_t(int, valuelen, BBTOB(bp->b_length));
+ byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, byte_cnt);
+
+ src = bp->b_addr;
+ if (xfs_sb_version_hascrc(&mp->m_sb)) {
+ if (!xfs_attr3_rmt_hdr_ok(mp, args->dp->i_ino,
+ offset, byte_cnt, bp)) {
+ xfs_alert(mp,
+"remote attribute header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
+ offset, byte_cnt, args->dp->i_ino);
+ xfs_buf_relse(bp);
+ return EFSCORRUPTED;
+
+ }
+
+ src += sizeof(struct xfs_attr3_rmt_hdr);
+ }
+
+ memcpy(dst, src, byte_cnt);
+ xfs_buf_relse(bp);
+
+ offset += byte_cnt;
+ dst += byte_cnt;
+ valuelen -= byte_cnt;
+
+ lblkno += 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;
+ struct xfs_buf *bp;
+ xfs_daddr_t dblkno;
+ xfs_dablk_t lblkno;
+ xfs_fileoff_t lfileoff = 0;
+ void *src = args->value;
+ int blkcnt;
+ int valuelen;
+ int nmap;
+ int error;
+ int hdrcnt = 0;
+ bool crcs = xfs_sb_version_hascrc(&mp->m_sb);
+ 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. We calculate the worst case block count in this case
+ * and we may not need that many, so we have to handle this when
+ * allocating the blocks below.
+ */
+ if (!crcs)
+ blkcnt = XFS_B_TO_FSB(mp, args->valuelen);
+ else
+ blkcnt = xfs_attr3_rmt_blocks(mp, args->valuelen);
+
+ error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff,
+ XFS_ATTR_FORK);
+ if (error)
+ return error;
+
+ /* Start with the attribute data. We'll allocate the rest afterwards. */
+ if (crcs)
+ blkcnt = XFS_B_TO_FSB(mp, args->valuelen);
+
+ 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;
+ hdrcnt++;
+
+ /*
+ * If we have enough blocks for the attribute data, calculate
+ * how many extra blocks we need for headers. We might run
+ * through this multiple times in the case that the additional
+ * headers in the blocks needed for the data fragments spills
+ * into requiring more blocks. e.g. for 512 byte blocks, we'll
+ * spill for another block every 9 headers we require in this
+ * loop.
+ */
+ if (crcs && blkcnt == 0) {
+ int total_len;
+
+ total_len = args->valuelen +
+ hdrcnt * sizeof(struct xfs_attr3_rmt_hdr);
+ blkcnt = XFS_B_TO_FSB(mp, total_len);
+ blkcnt -= args->rmtblkcnt;
+ args->rmtblkcnt += blkcnt;
+ }
+
+ /*
+ * 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;
+ valuelen = args->valuelen;
+ while (valuelen > 0) {
+ int byte_cnt;
+ char *buf;
+
+ /*
+ * Try to remember where we decided to put the value.
+ */
+ xfs_bmap_init(args->flist, args->firstblock);
+ nmap = 1;
+ error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno,
+ args->rmtblkcnt, &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),
+ blkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
+
+ bp = xfs_buf_get(mp->m_ddev_targp, dblkno, blkcnt, 0);
+ if (!bp)
+ return ENOMEM;
+ bp->b_ops = &xfs_attr3_rmt_buf_ops;
+
+ byte_cnt = BBTOB(bp->b_length);
+ byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, byte_cnt);
+ if (valuelen < byte_cnt)
+ byte_cnt = valuelen;
+
+ buf = bp->b_addr;
+ buf += xfs_attr3_rmt_hdr_set(mp, dp->i_ino, offset,
+ byte_cnt, bp);
+ memcpy(buf, src, byte_cnt);
+
+ if (byte_cnt < BBTOB(bp->b_length))
+ xfs_buf_zero(bp, byte_cnt,
+ BBTOB(bp->b_length) - byte_cnt);
+
+ error = xfs_bwrite(bp); /* GROT: NOTE: synchronous write */
+ xfs_buf_relse(bp);
+ if (error)
+ return error;
+
+ src += byte_cnt;
+ valuelen -= byte_cnt;
+ offset += byte_cnt;
+ hdrcnt--;
+
+ lblkno += map.br_blockcount;
+ }
+ ASSERT(valuelen == 0);
+ ASSERT(hdrcnt == 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(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;
+
+ trace_xfs_attr_rmtval_remove(args);
+
+ 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.
+ */
+ nmap = 1;
+ error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
+ args->rmtblkcnt, &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),
+ 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, XBF_TRYLOCK);
+ if (bp) {
+ xfs_buf_stale(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,
+ &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);
+}
+