fs/bootfs/bootfs_construct.c

	bootfs_construct.c revision 76ca3cb000306bc4052fe820a7e4a6998dbcf932
/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright (c) 2015 Joyent, Inc.  All rights reserved.
 */

/*
 * This file takes care of reading the boot time modules and constructing them
 * into the appropriate series of vnodes.
 */

#include <sys/conf.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/vfs.h>
#include <sys/sysmacros.h>
#include <sys/stat.h>

#include <sys/fs/bootfs_impl.h>

kmem_cache_t *bootfs_node_cache;

static const vattr_t bootfs_vattr_dir = {
    AT_ALL,                 /* va_mask */
    VDIR,                   /* va_type */
    S_IFDIR | 0555,             /* va_mode */
    0,                  /* va_uid */
    0,                  /* va_gid */
    0,                  /* va_fsid */
    0,                  /* va_nodeid */
    1,                  /* va_nlink */
    0,                  /* va_size */
    0,                  /* va_atime */
    0,                  /* va_mtime */
    0,                  /* va_ctime */
    0,                  /* va_rdev */
    0,                  /* va_blksize */
    0,                  /* va_nblocks */
    0                   /* va_seq */
};

static const vattr_t bootfs_vattr_reg = {
    AT_ALL,                 /* va_mask */
    VREG,                   /* va_type */
    S_IFREG | 0555,             /* va_mode */
    0,                  /* va_uid */
    0,                  /* va_gid */
    0,                  /* va_fsid */
    0,                  /* va_nodeid */
    1,                  /* va_nlink */
    0,                  /* va_size */
    0,                  /* va_atime */
    0,                  /* va_mtime */
    0,                  /* va_ctime */
    0,                  /* va_rdev */
    0,                  /* va_blksize */
    0,                  /* va_nblocks */
    0                   /* va_seq */
};

/*ARGSUSED*/
int
bootfs_node_constructor(void *buf, void *arg, int kmflags)
{
    bootfs_node_t *bnp = buf;

    bnp->bvn_vnp = vn_alloc(kmflags);
    if (bnp->bvn_vnp == NULL)
        return (-1);

    return (0);
}

/*ARGSUSED*/
void
bootfs_node_destructor(void *buf, void *arg)
{
    bootfs_node_t *bnp = buf;

    vn_free(bnp->bvn_vnp);
}

static int
bootfs_comparator(const void *a, const void *b)
{
    const bootfs_node_t *lfs, *rfs;
    int ret;

    lfs = a;
    rfs = b;

    ret = strcmp(lfs->bvn_name, rfs->bvn_name);
    if (ret > 0)
        ret = 1;
    if (ret < 0)
        ret = -1;
    return (ret);
}

static void
bootfs_node_init(bootfs_t *bfs, bootfs_node_t *bnp, const struct vattr *vap,
    const char *name, size_t namelen)
{
    timestruc_t now;

    vn_reinit(bnp->bvn_vnp);

    bnp->bvn_vnp->v_flag |= VNOSWAP;
    bnp->bvn_vnp->v_type = vap->va_type;
    bnp->bvn_vnp->v_vfsp = bfs->bfs_vfsp;
    bnp->bvn_vnp->v_rdev = 0;
    bnp->bvn_vnp->v_data = (caddr_t)bnp;
    vn_setops(bnp->bvn_vnp, bootfs_vnodeops);

    bnp->bvn_name = kmem_alloc(namelen + 1, KM_SLEEP);
    bcopy(name, bnp->bvn_name, namelen);
    bnp->bvn_name[namelen] = '\0';
    if (vap->va_type == VDIR) {
        avl_create(&bnp->bvn_dir, bootfs_comparator,
            sizeof (bootfs_node_t),
            offsetof(bootfs_node_t, bvn_link));
    }
    bzero(&bnp->bvn_link, sizeof (avl_node_t));
    bcopy(vap, &bnp->bvn_attr, sizeof (vattr_t));

    gethrestime(&now);
    bnp->bvn_attr.va_atime = now;
    bnp->bvn_attr.va_ctime = now;
    bnp->bvn_attr.va_mtime = now;
    bnp->bvn_attr.va_fsid = makedevice(bootfs_major, bfs->bfs_minor);
    bnp->bvn_attr.va_nodeid = bfs->bfs_ninode;
    bnp->bvn_attr.va_blksize = PAGESIZE;
    bfs->bfs_ninode++;
    list_insert_tail(&bfs->bfs_nodes, bnp);
}

static void
bootfs_mkroot(bootfs_t *bfs)
{
    bootfs_node_t *bnp;

    bnp = kmem_cache_alloc(bootfs_node_cache, KM_SLEEP);
    bootfs_node_init(bfs, bnp, &bootfs_vattr_dir, "/", 1);
    bnp->bvn_vnp->v_flag |= VROOT;
    bnp->bvn_parent = bnp;
    bfs->bfs_rootvn = bnp;
    bfs->bfs_stat.bfss_ndirs.value.ui32++;
    vn_exists(bnp->bvn_vnp);
}

static int
bootfs_mknode(bootfs_t *bfs, bootfs_node_t *parent, bootfs_node_t **outp,
    const char *name, size_t namelen, const vattr_t *vap, uintptr_t addr,
    uint64_t size)
{
    bootfs_node_t *bnp;
    bootfs_node_t sn;
    avl_index_t where;
    char *buf;

    ASSERT(parent->bvn_attr.va_type == VDIR);
    buf = kmem_alloc(namelen + 1, KM_SLEEP);
    bcopy(name, buf, namelen);
    buf[namelen] = '\0';
    sn.bvn_name = buf;
    if ((bnp = avl_find(&parent->bvn_dir, &sn, &where)) != NULL) {
        kmem_free(buf, namelen + 1);
        /* Directories can collide, files cannot */
        if (vap->va_type == VDIR) {
            *outp = bnp;
            return (0);
        }
        return (EEXIST);
    }
    kmem_free(buf, namelen + 1);

    bnp = kmem_cache_alloc(bootfs_node_cache, KM_SLEEP);
    bootfs_node_init(bfs, bnp, vap, name, namelen);
    bnp->bvn_parent = parent;
    avl_add(&parent->bvn_dir, bnp);
    *outp = bnp;

    if (vap->va_type == VDIR) {
        parent->bvn_attr.va_size++;
        parent->bvn_attr.va_nlink++;
        bfs->bfs_stat.bfss_ndirs.value.ui32++;
    } else {
        bnp->bvn_addr = addr;
        bnp->bvn_size = size;
        bfs->bfs_stat.bfss_nfiles.value.ui32++;
        bfs->bfs_stat.bfss_nbytes.value.ui64 += size;
        bnp->bvn_attr.va_nblocks = P2ROUNDUP(size, 512) >> 9;
        bnp->bvn_attr.va_size = size;
    }

    vn_exists(bnp->bvn_vnp);

    return (0);
}

/*
 * Given the address, size, and path a boot-time module would like, go through
 * and create all of the directory entries that are required and then the file
 * itself. If someone has passed in a module that has the same name as another
 * one, we honor the first one.
 */
static int
bootfs_construct_entry(bootfs_t *bfs, uintptr_t addr, uint64_t size,
    const char *mname)
{
    char *sp;
    size_t nlen;
    int ret;
    bootfs_node_t *nbnp;

    const char *p = mname;
    bootfs_node_t *bnp = bfs->bfs_rootvn;

    if (*p == '\0')
        return (EINVAL);

    for (;;) {
        /* First eliminate all leading / characters. */
        while (*p == '/')
            p++;

        /* A name with all slashes or ending in a / */
        if (*p == '\0')
            return (EINVAL);

        sp = strchr(p, '/');
        if (sp == NULL)
            break;
        nlen = (ptrdiff_t)sp - (ptrdiff_t)p;
        if (strncmp(p, ".", nlen) == 0) {
            p = sp + 1;
            continue;
        }

        if (strncmp(p, "..", nlen) == 0) {
            bnp = bnp->bvn_parent;
            p = sp + 1;
            continue;
        }

        VERIFY(bootfs_mknode(bfs, bnp, &nbnp, p, nlen,
            &bootfs_vattr_dir, addr, size) == 0);
        p = sp + 1;
        bnp = nbnp;
    }

    nlen = strlen(p);
    ret = bootfs_mknode(bfs, bnp, &nbnp, p, nlen, &bootfs_vattr_reg,
        addr, size);
    if (ret != 0)
        return (ret);

    return (0);
}

/*
 * We're going to go through every boot time module and construct the
 * appropriate vnodes for them now. Because there are very few of these that
 * exist, generally on the order of a handful, we're going to create them all
 * when the file system is initialized and then tear them all down when the
 * module gets unloaded.
 *
 * The information about the modules is contained in properties on the root of
 * the devinfo tree. Specifically there are three properties per module:
 *
 *   - module-size-%d   int64_t size, in bytes, of the boot time module.
 *   - module-addr-%d   The address of the boot time module
 *   - module-name-%d   The string name of the boot time module
 *
 * Note that the module-size and module-addr fields are always 64-bit values
 * regardless of being on a 32-bit or 64-bit kernel. module-name is a string
 * property.
 *
 * There is no property that indicates the total number of such modules. Modules
 * start at 0 and work their way up incrementally. The first time we can't find
 * a module or a property, then we stop.
 */
void
bootfs_construct(bootfs_t *bfs)
{
    uint_t id = 0, ndata;
    char paddr[64], psize[64], pname[64], *mname;
    dev_info_t *root;
    uchar_t *datap;
    uint64_t size = 0, addr = 0;
    int ret;

    bootfs_mkroot(bfs);
    root = ddi_root_node();

    for (;;) {
        if (id == UINT32_MAX)
            break;

        if (snprintf(paddr, sizeof (paddr), "module-addr-%d", id) >
            sizeof (paddr))
            break;

        if (snprintf(psize, sizeof (paddr), "module-size-%d", id) >
            sizeof (paddr))
            break;

        if (snprintf(pname, sizeof (paddr), "module-name-%d", id) >
            sizeof (paddr))
            break;

        if (ddi_prop_lookup_byte_array(DDI_DEV_T_ANY, root,
            DDI_PROP_DONTPASS, paddr, &datap, &ndata) !=
            DDI_PROP_SUCCESS)
            break;

        if (ndata == 8)
            bcopy(datap, &addr, sizeof (uint64_t));
        ddi_prop_free(datap);
        if (ndata != 8)
            break;

        if (ddi_prop_lookup_byte_array(DDI_DEV_T_ANY, root,
            DDI_PROP_DONTPASS, psize, &datap, &ndata) !=
            DDI_PROP_SUCCESS)
            break;
        if (ndata == 8)
            bcopy(datap, &size, sizeof (uint64_t));
        ddi_prop_free(datap);
        if (ndata != 8)
            break;

        if (ddi_prop_lookup_string(DDI_DEV_T_ANY, root,
            DDI_PROP_DONTPASS, pname, &mname) != DDI_PROP_SUCCESS)
            break;

        ret = bootfs_construct_entry(bfs, addr, size, mname);
        if (ret == EINVAL)
            bfs->bfs_stat.bfss_ndiscards.value.ui32++;
        if (ret == EEXIST)
            bfs->bfs_stat.bfss_ndups.value.ui32++;
        ddi_prop_free(mname);

        id++;
    }
}

void
bootfs_destruct(bootfs_t *bfs)
{
    bootfs_node_t *bnp;

    while ((bnp = list_remove_head(&bfs->bfs_nodes)) != NULL) {
        ASSERT(bnp->bvn_vnp->v_count == 1);
        VN_RELE(bnp->bvn_vnp);
        kmem_free(bnp->bvn_name, strlen(bnp->bvn_name) + 1);
        kmem_cache_free(bootfs_node_cache, bnp);
    }
}