[XFS] Improve error handling for the zero-fsblock extent detection code.

SGI-PV: 955302
SGI-Modid: xfs-linux-melb:xfs-kern:26802a

Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

4 files changed, 51 insertions, 68 deletions

diff --git a/fs/xfs/linux-2.6/xfs_globals.c b/fs/xfs/linux-2.6/xfs_globals.c
index 6c162c3dde7e..ed3a5e1b4b67 100644
--- a/fs/xfs/linux-2.6/xfs_globals.c
+++ b/fs/xfs/linux-2.6/xfs_globals.c
@@ -34,7 +34,7 @@ xfs_param_t xfs_params = {
         .restrict_chown = {     0,              1,              1       },
         .sgid_inherit   = {     0,              0,              1       },
         .symlink_mode   = {     0,              0,              1       },
-        .panic_mask     = {     0,              0,              127     },
+        .panic_mask     = {     0,              0,              255     },
         .error_level    = {     0,              3,              11      },
         .syncd_timer    = {     1*100,          30*100,         7200*100},
         .stats_clear    = {     0,              0,              1       },
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index e28146fe046a..5b050c06795f 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -3705,7 +3705,7 @@ STATIC xfs_bmbt_rec_t *                 /* pointer to found extent entry */
 xfs_bmap_search_extents(
         xfs_inode_t     *ip,            /* incore inode pointer */
         xfs_fileoff_t   bno,            /* block number searched for */
-        int             whichfork,      /* data or attr fork */
+        int             fork,           /* data or attr fork */
         int             *eofp,          /* out: end of file found */
         xfs_extnum_t    *lastxp,        /* out: last extent index */
         xfs_bmbt_irec_t *gotp,          /* out: extent entry found */
@@ -3713,25 +3713,28 @@ xfs_bmap_search_extents(
 {
         xfs_ifork_t     *ifp;           /* inode fork pointer */
         xfs_bmbt_rec_t  *ep;            /* extent record pointer */
-        int             rt;             /* realtime flag    */
 
         XFS_STATS_INC(xs_look_exlist);
-        ifp = XFS_IFORK_PTR(ip, whichfork);
+        ifp = XFS_IFORK_PTR(ip, fork);
 
         ep = xfs_bmap_search_multi_extents(ifp, bno, eofp, lastxp, gotp, prevp);
 
-        rt = (whichfork == XFS_DATA_FORK) && XFS_IS_REALTIME_INODE(ip);
-        if (unlikely(!rt && !gotp->br_startblock && (*lastxp != NULLEXTNUM))) {
-                cmn_err(CE_PANIC,"Access to block zero: fs: <%s> inode: %lld "
-                        "start_block : %llx start_off : %llx blkcnt : %llx "
-                        "extent-state : %x \n",
-                        (ip->i_mount)->m_fsname, (long long)ip->i_ino,
+        if (unlikely(!(gotp->br_startblock) && (*lastxp != NULLEXTNUM) &&
+                     !(XFS_IS_REALTIME_INODE(ip) && fork == XFS_DATA_FORK))) {
+                xfs_cmn_err(XFS_PTAG_FSBLOCK_ZERO, CE_ALERT, ip->i_mount,
+                                "Access to block zero in inode %llu "
+                                "start_block: %llx start_off: %llx "
+                                "blkcnt: %llx extent-state: %x lastx: %x\n",
+                        (unsigned long long)ip->i_ino,
                         (unsigned long long)gotp->br_startblock,
                         (unsigned long long)gotp->br_startoff,
                         (unsigned long long)gotp->br_blockcount,
-                        gotp->br_state);
-        }
-        return ep;
+                        gotp->br_state, *lastxp);
+                *lastxp = NULLEXTNUM;
+                *eofp = 1;
+                return NULL;
+        }
+        return ep;
 }
 
 
diff --git a/fs/xfs/xfs_error.h b/fs/xfs/xfs_error.h
index f90fd500b940..0893e16b7d83 100644
--- a/fs/xfs/xfs_error.h
+++ b/fs/xfs/xfs_error.h
@@ -167,6 +167,7 @@ extern int xfs_errortag_clearall_umount(int64_t fsid, char *fsname, int loud);
 #define         XFS_PTAG_SHUTDOWN_CORRUPT       0x00000010
 #define         XFS_PTAG_SHUTDOWN_IOERROR       0x00000020
 #define         XFS_PTAG_SHUTDOWN_LOGERROR      0x00000040
+#define         XFS_PTAG_FSBLOCK_ZERO           0x00000080
 
 struct xfs_mount;
 /* PRINTFLIKE4 */
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index f1949c16df15..19655124da78 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -398,6 +398,23 @@ xfs_flush_space(
         return 1;
 }
 
+STATIC int
+xfs_cmn_err_fsblock_zero(
+        xfs_inode_t     *ip,
+        xfs_bmbt_irec_t *imap)
+{
+        xfs_cmn_err(XFS_PTAG_FSBLOCK_ZERO, CE_ALERT, ip->i_mount,
+                        "Access to block zero in inode %llu "
+                        "start_block: %llx start_off: %llx "
+                        "blkcnt: %llx extent-state: %x\n",
+                (unsigned long long)ip->i_ino,
+                (unsigned long long)imap->br_startblock,
+                (unsigned long long)imap->br_startoff,
+                (unsigned long long)imap->br_blockcount,
+                imap->br_state);
+        return EFSCORRUPTED;
+}
+
 int
 xfs_iomap_write_direct(
         xfs_inode_t     *ip,
@@ -536,23 +553,17 @@ xfs_iomap_write_direct(
          * Copy any maps to caller's array and return any error.
          */
         if (nimaps == 0) {
-                error = (ENOSPC);
+                error = ENOSPC;
+                goto error_out;
+        }
+
+        if (unlikely(!imap.br_startblock && !(io->io_flags & XFS_IOCORE_RT))) {
+                error = xfs_cmn_err_fsblock_zero(ip, &imap);
                 goto error_out;
         }
 
         *ret_imap = imap;
         *nmaps = 1;
-        if ( !(io->io_flags & XFS_IOCORE_RT)  && !ret_imap->br_startblock) {
-                cmn_err(CE_PANIC,"Access to block zero:  fs <%s> inode: %lld "
-                        "start_block : %llx start_off : %llx blkcnt : %llx "
-                        "extent-state : %x \n",
-                        (ip->i_mount)->m_fsname,
-                        (long long)ip->i_ino,
-                        (unsigned long long)ret_imap->br_startblock,
-                        (unsigned long long)ret_imap->br_startoff,
-                        (unsigned long long)ret_imap->br_blockcount,
-                        ret_imap->br_state);
-        }
         return 0;
 
 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
@@ -715,17 +726,8 @@ retry:
                 goto retry;
         }
 
-        if (!(io->io_flags & XFS_IOCORE_RT)  && !ret_imap->br_startblock) {
-                cmn_err(CE_PANIC,"Access to block zero:  fs <%s> inode: %lld "
-                        "start_block : %llx start_off : %llx blkcnt : %llx "
-                        "extent-state : %x \n",
-                        (ip->i_mount)->m_fsname,
-                        (long long)ip->i_ino,
-                        (unsigned long long)ret_imap->br_startblock,
-                        (unsigned long long)ret_imap->br_startoff,
-                        (unsigned long long)ret_imap->br_blockcount,
-                        ret_imap->br_state);
-        }
+        if (unlikely(!imap[0].br_startblock && !(io->io_flags & XFS_IOCORE_RT)))
+                return xfs_cmn_err_fsblock_zero(ip, &imap[0]);
 
         *ret_imap = imap[0];
         *nmaps = 1;
@@ -853,24 +855,10 @@ xfs_iomap_write_allocate(
                  * See if we were able to allocate an extent that
                  * covers at least part of the callers request
                  */
-
                 for (i = 0; i < nimaps; i++) {
-                        if (!(io->io_flags & XFS_IOCORE_RT)  &&
-                            !imap[i].br_startblock) {
-                                cmn_err(CE_PANIC,"Access to block zero:  "
-                                        "fs <%s> inode: %lld "
-                                        "start_block : %llx start_off : %llx "
-                                        "blkcnt : %llx extent-state : %x \n",
-                                        (ip->i_mount)->m_fsname,
-                                        (long long)ip->i_ino,
-                                        (unsigned long long)
-                                                imap[i].br_startblock,
-                                        (unsigned long long)
-                                                imap[i].br_startoff,
-                                        (unsigned long long)
-                                                imap[i].br_blockcount,
-                                        imap[i].br_state);
-                        }
+                        if (unlikely(!imap[i].br_startblock &&
+                                     !(io->io_flags & XFS_IOCORE_RT)))
+                                return xfs_cmn_err_fsblock_zero(ip, &imap[i]);
                         if ((offset_fsb >= imap[i].br_startoff) &&
                             (offset_fsb < (imap[i].br_startoff +
                                            imap[i].br_blockcount))) {
@@ -941,7 +929,7 @@ xfs_iomap_write_unwritten(
                                 XFS_WRITE_LOG_COUNT);
                 if (error) {
                         xfs_trans_cancel(tp, 0);
-                        goto error0;
+                        return XFS_ERROR(error);
                 }
 
                 xfs_ilock(ip, XFS_ILOCK_EXCL);
@@ -967,19 +955,11 @@ xfs_iomap_write_unwritten(
                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
                 if (error)
-                        goto error0;
-
-                if ( !(io->io_flags & XFS_IOCORE_RT)  && !imap.br_startblock) {
-                        cmn_err(CE_PANIC,"Access to block zero:  fs <%s> "
-                                "inode: %lld start_block : %llx start_off : "
-                                "%llx blkcnt : %llx extent-state : %x \n",
-                                (ip->i_mount)->m_fsname,
-                                (long long)ip->i_ino,
-                                (unsigned long long)imap.br_startblock,
-                                (unsigned long long)imap.br_startoff,
-                                (unsigned long long)imap.br_blockcount,
-                                imap.br_state);
-                }
+                        return XFS_ERROR(error);
+
+                if (unlikely(!imap.br_startblock &&
+                             !(io->io_flags & XFS_IOCORE_RT)))
+                        return xfs_cmn_err_fsblock_zero(ip, &imap);
 
                 if ((numblks_fsb = imap.br_blockcount) == 0) {
                         /*
@@ -999,6 +979,5 @@ error_on_bmapi_transaction:
         xfs_bmap_cancel(&free_list);
         xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
         xfs_iunlock(ip, XFS_ILOCK_EXCL);
-error0:
         return XFS_ERROR(error);
 }