2 files changed, 292 insertions, 51 deletions

diff --git a/fs/xfs/xfs_attr_remote.c b/fs/xfs/xfs_attr_remote.c
index d0d67e935262..53da46b46c2f 100644
--- a/fs/xfs/xfs_attr_remote.c
+++ b/fs/xfs/xfs_attr_remote.c
@@ -1,5 +1,6 @@
 /*
  * 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
@@ -37,63 +38,232 @@
 #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             fsblocks = 0;
+        int             len = attrlen;
+
+        do {
+                fsblocks++;
+                len -= XFS_ATTR3_RMT_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
+        } while (len > 0);
+
+        return fsblocks;
+}
+
+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) >= MAXPATHLEN)
+                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(xfs_da_args_t *args)
+xfs_attr_rmtval_get(
+        struct xfs_da_args      *args)
 {
-        xfs_bmbt_irec_t map[ATTR_RMTVALUE_MAPSIZE];
-        xfs_mount_t *mp;
-        xfs_daddr_t dblkno;
-        void *dst;
-        xfs_buf_t *bp;
-        int nmap, error, tmp, valuelen, blkcnt, i;
-        xfs_dablk_t lblkno;
+        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));
 
-        mp = args->dp->i_mount;
-        dst = args->value;
-        valuelen = args->valuelen;
-        lblkno = args->rmtblkno;
         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);
+                        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, NULL);
+                                                   dblkno, blkcnt, 0, &bp,
+                                                   &xfs_attr3_rmt_buf_ops);
                         if (error)
-                                return(error);
+                                return error;
+
+                        byte_cnt = min_t(int, valuelen, BBTOB(bp->b_length));
+                        byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, byte_cnt);
 
-                        tmp = min_t(int, valuelen, BBTOB(bp->b_length));
-                        xfs_buf_iomove(bp, 0, tmp, dst, XBRW_READ);
+                        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);
-                        dst += tmp;
-                        valuelen -= tmp;
+
+                        offset += byte_cnt;
+                        dst += byte_cnt;
+                        valuelen -= byte_cnt;
 
                         lblkno += map[i].br_blockcount;
                 }
         }
         ASSERT(valuelen == 0);
-        return(0);
+        return 0;
 }
 
 /*
@@ -101,35 +271,49 @@ xfs_attr_rmtval_get(xfs_da_args_t *args)
  * that we have defined for it.
  */
 int
-xfs_attr_rmtval_set(xfs_da_args_t *args)
+xfs_attr_rmtval_set(
+        struct xfs_da_args      *args)
 {
-        xfs_mount_t *mp;
-        xfs_fileoff_t lfileoff;
-        xfs_inode_t *dp;
-        xfs_bmbt_irec_t map;
-        xfs_daddr_t dblkno;
-        void *src;
-        xfs_buf_t *bp;
-        xfs_dablk_t lblkno;
-        int blkcnt, valuelen, nmap, error, tmp, committed;
+        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);
 
-        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.
+         * 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. 
          */
-        blkcnt = XFS_B_TO_FSB(mp, args->valuelen);
-        lfileoff = 0;
+        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);
-        }
+        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;
 
@@ -137,6 +321,8 @@ xfs_attr_rmtval_set(xfs_da_args_t *args)
          * 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.
                  */
@@ -170,6 +356,27 @@ xfs_attr_rmtval_set(xfs_da_args_t *args)
                        (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.
@@ -188,7 +395,8 @@ xfs_attr_rmtval_set(xfs_da_args_t *args)
         lblkno = args->rmtblkno;
         valuelen = args->valuelen;
         while (valuelen > 0) {
-                int buflen;
+                int     byte_cnt;
+                char    *buf;
 
                 /*
                  * Try to remember where we decided to put the value.
@@ -210,24 +418,38 @@ xfs_attr_rmtval_set(xfs_da_args_t *args)
                 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);
 
-                buflen = BBTOB(bp->b_length);
-                tmp = min_t(int, valuelen, buflen);
-                xfs_buf_iomove(bp, 0, tmp, src, XBRW_WRITE);
-                if (tmp < buflen)
-                        xfs_buf_zero(bp, tmp, buflen - tmp);
+                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 += tmp;
-                valuelen -= tmp;
+
+                src += byte_cnt;
+                valuelen -= byte_cnt;
+                offset += byte_cnt;
+                hdrcnt--;
 
                 lblkno += map.br_blockcount;
         }
         ASSERT(valuelen == 0);
-        return(0);
+        ASSERT(hdrcnt == 0);
+        return 0;
 }
 
 /*
@@ -306,7 +528,7 @@ xfs_attr_rmtval_remove(xfs_da_args_t *args)
                         ASSERT(committed);
                         args->trans = NULL;
                         xfs_bmap_cancel(args->flist);
-                        return(error);
+                        return error;
                 }
 
                 /*
diff --git a/fs/xfs/xfs_attr_remote.h b/fs/xfs/xfs_attr_remote.h
index 2a34b9a0813e..0ca8d9a1fa03 100644
--- a/fs/xfs/xfs_attr_remote.h
+++ b/fs/xfs/xfs_attr_remote.h
@@ -18,6 +18,25 @@
 #ifndef __XFS_ATTR_REMOTE_H__
 #define __XFS_ATTR_REMOTE_H__
 
+#define XFS_ATTR3_RMT_MAGIC     0x5841524d      /* XARM */
+
+struct xfs_attr3_rmt_hdr {
+        __be32  rm_magic;
+        __be32  rm_offset;
+        __be32  rm_bytes;
+        __be32  rm_crc;
+        uuid_t  rm_uuid;
+        __be64  rm_owner;
+        __be64  rm_blkno;
+        __be64  rm_lsn;
+};
+
+#define XFS_ATTR3_RMT_CRC_OFF   offsetof(struct xfs_attr3_rmt_hdr, rm_crc)
+
+#define XFS_ATTR3_RMT_BUF_SPACE(mp, bufsize)    \
+        ((bufsize) - (xfs_sb_version_hascrc(&(mp)->m_sb) ? \
+                        sizeof(struct xfs_attr3_rmt_hdr) : 0))
+
 int xfs_attr_rmtval_get(struct xfs_da_args *args);
 int xfs_attr_rmtval_set(struct xfs_da_args *args);
 int xfs_attr_rmtval_remove(struct xfs_da_args *args);