FreeBSD/Linux Kernel Cross Reference
sys/geom/label/g_label_ufs.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2002, 2003 Gordon Tetlow
      * Copyright (c) 2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/disklabel.h>
    #include <sys/malloc.h>
    #include <sys/vnode.h>
    
    #include <ufs/ufs/dinode.h>
    #include <ufs/ffs/fs.h>
    #include <ufs/ufs/quota.h>
    #include <ufs/ufs/extattr.h>
    #include <ufs/ffs/ffs_extern.h>
    
    #include <geom/geom.h>
    #include <geom/geom_dbg.h>
    #include <geom/label/g_label.h>
    
    #define G_LABEL_UFS_VOLUME      0
    #define G_LABEL_UFS_ID          1
    
    /*
     * G_LABEL_UFS_CMP returns true if difference between provider mediasize
     * and filesystem size is less than G_LABEL_UFS_MAXDIFF sectors
     */
    #define G_LABEL_UFS_CMP(prov, fsys, size)                                  \
            ( abs( ((fsys)->size) - ( (prov)->mediasize / (fsys)->fs_fsize ))  \
                                    < G_LABEL_UFS_MAXDIFF )
    #define G_LABEL_UFS_MAXDIFF     0x100
    
    /*
     * For providers that look like disklabels we need to check if the file system
     * size is almost equal to the provider's size, because sysinstall(8) used to
     * bogusly put the first partition at offset 0 instead of 16, and glabel/ufs
     * would find a file system on the slice instead of the partition.
     *
     * In addition, media size can be a bit bigger than file system size. For
     * instance, mkuzip can append bytes to align data to large sector size (it
     * improves compression rates).
     */
    static bool
    g_label_ufs_ignore_bsdlabel_slice(struct g_consumer *cp,
        struct fs *fs)
    {
            struct g_provider *pp;
            u_char *buf;
            uint32_t magic1, magic2;
            int error;
    
            pp = cp->provider;
    
            /*
             * If the expected provider size for the filesystem matches the
             * real provider size then don't ignore this filesystem.
             */
            if (G_LABEL_UFS_CMP(pp, fs, fs_providersize))
                    return (false);
    
            /*
             * If the filesystem size matches the real provider size then
             * don't ignore this filesystem.
             */
            if (fs->fs_magic == FS_UFS1_MAGIC ?
                G_LABEL_UFS_CMP(pp, fs, fs_old_size) :
                G_LABEL_UFS_CMP(pp, fs, fs_size))
                    return (false);
    
            /*
             * Provider is bigger than expected; probe to see if there's a
            * disklabel. Adapted from g_part_bsd_probe.
            */
   
           /* Check if the superblock overlaps where the disklabel lives. */
           if (fs->fs_sblockloc < pp->sectorsize * 2)
                   return (false);
   
           /* Sanity-check the provider. */
           if (pp->sectorsize < sizeof(struct disklabel) ||
               pp->mediasize < BBSIZE)
                   return (false);
           if (BBSIZE % pp->sectorsize)
                   return (false);
   
           /* Check that there's a disklabel. */
           buf = g_read_data(cp, pp->sectorsize, pp->sectorsize, &error);
           if (buf == NULL)
                   return (false);
           magic1 = le32dec(buf + 0);
           magic2 = le32dec(buf + 132);
           g_free(buf);
           if (magic1 == DISKMAGIC && magic2 == DISKMAGIC)
                   return (true);
   
           return (false);
   }
   
   /*
    * Try to find a superblock on the provider. If successful, look for a volume
    * label and create an appropriate provider based on that.
    */
   static void
   g_label_ufs_taste_common(struct g_consumer *cp, char *label, size_t size, int what)
   {
           struct g_provider *pp;
           struct fs *fs;
   
           g_topology_assert_not();
           pp = cp->provider;
           label[0] = '\0';
   
           fs = NULL;
           KASSERT(pp->sectorsize != 0, ("Tasting a disk with 0 sectorsize"));
           if (SBLOCKSIZE % pp->sectorsize != 0 || ffs_sbget(cp, &fs, UFS_STDSB,
               UFS_NOHASHFAIL | UFS_NOCSUM | UFS_NOMSG, M_GEOM, g_use_g_read_data)
               != 0) {
                   KASSERT(fs == NULL,
                       ("g_label_ufs_taste_common: non-NULL fs %p\n", fs));
                   return;
           }
   
           /* Check for magic. */
           if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_fsize > 0) {
                   /* Valid UFS1. */
           } else if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_fsize > 0) {
                   /* Valid UFS2. */
           } else {
                   goto out;
           }
           /* Check if this should be ignored for compatibility. */
           if (g_label_ufs_ignore_bsdlabel_slice(cp, fs))
                   goto out;
           G_LABEL_DEBUG(1, "%s file system detected on %s.",
               fs->fs_magic == FS_UFS1_MAGIC ? "UFS1" : "UFS2", pp->name);
           switch (what) {
           case G_LABEL_UFS_VOLUME:
                   /* Check for volume label */
                   if (fs->fs_volname[0] != '\0')
                           strlcpy(label, fs->fs_volname, size);
                   break;
           case G_LABEL_UFS_ID:
                   if (fs->fs_id[0] != 0 || fs->fs_id[1] != 0)
                           snprintf(label, size, "%08x%08x", fs->fs_id[0],
                               fs->fs_id[1]);
                   break;
           }
   out:
           g_free(fs);
   }
   
   static void
   g_label_ufs_volume_taste(struct g_consumer *cp, char *label, size_t size)
   {
   
           g_label_ufs_taste_common(cp, label, size, G_LABEL_UFS_VOLUME);
   }
   
   static void
   g_label_ufs_id_taste(struct g_consumer *cp, char *label, size_t size)
   {
   
           g_label_ufs_taste_common(cp, label, size, G_LABEL_UFS_ID);
   }
   
   struct g_label_desc g_label_ufs_volume = {
           .ld_taste = g_label_ufs_volume_taste,
           .ld_dirprefix = "ufs/",
           .ld_enabled = 1
   };
   
   struct g_label_desc g_label_ufs_id = {
           .ld_taste = g_label_ufs_id_taste,
           .ld_dirprefix = "ufsid/",
           .ld_enabled = 1
   };
   
   G_LABEL_INIT(ufsid, g_label_ufs_id, "Create device nodes for UFS file system IDs");
   G_LABEL_INIT(ufs, g_label_ufs_volume, "Create device nodes for UFS volume names");
   
   MODULE_DEPEND(g_label, ufs, 1, 1, 1);

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