The branch main has been updated by imp:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=df9d6403caa6426e92f5e100602f4d2be474bbae

commit df9d6403caa6426e92f5e100602f4d2be474bbae
Author:     Warner Losh <[email protected]>
AuthorDate: 2026-07-11 20:46:55 +0000
Commit:     Warner Losh <[email protected]>
CommitDate: 2026-07-12 03:53:29 +0000

    loader: Add forgotten xz.c and zstdfs.c
    
    These were overlooked when I added compression support.
    
    Fixes: 86d719ae68aa ("loader: Add xzfs, like gzipfs but with xz.")
    Fixes: c61ee49cd06a ("loader: zstd based filesystem, zstdfs like gzipfs")
    Sponsored by:           Netflix
---
 stand/libsa/xz.c     |  21 ++++
 stand/libsa/zstdfs.c | 308 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 329 insertions(+)

diff --git a/stand/libsa/xz.c b/stand/libsa/xz.c
new file mode 100644
index 000000000000..ef9b4be1451e
--- /dev/null
+++ b/stand/libsa/xz.c
@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2026 Netflix, Inc. Written by Warner Losh
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "stand.h"
+#include "xz.h"
+#include "xz_malloc.h"
+
+void *
+xz_malloc(unsigned long size)
+{
+       return (malloc(size));
+}
+
+void
+xz_free(void *addr)
+{
+       free(addr);
+}
diff --git a/stand/libsa/zstdfs.c b/stand/libsa/zstdfs.c
new file mode 100644
index 000000000000..f845ddc70361
--- /dev/null
+++ b/stand/libsa/zstdfs.c
@@ -0,0 +1,308 @@
+/*
+ * Copyright (c) 1998 Michael Smith.
+ * Copyright (c) 2026 Netflix, Inc.
+ * 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 AUTHOR 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 AUTHOR 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.
+ */
+
+/*
+ * Stacked filesystem for .zst compressed files, structured like gzipfs.c and
+ * bzipfs.c above it. Only built when the zstd decompressor is already being
+ * pulled into libsa for ZFS (see libsa/Makefile), since that's the only
+ * source of the ZSTD_* symbols in this environment.
+ */
+
+#include "stand.h"
+
+#include <sys/stat.h>
+#include <string.h>
+#include <zstd.h>
+
+#define ZSTD_BUFSIZE 2048      /* XXX larger? */
+
+struct zstd_file
+{
+    int                        zstdf_rawfd;
+    ZSTD_DStream       *zstdf_strm;
+    ZSTD_inBuffer      zstdf_in;
+    unsigned char      zstdf_inbuf[ZSTD_BUFSIZE];
+    int                        zstdf_endseen;
+    off_t              zstdf_total_out;
+};
+
+static int     zstdf_fill(struct zstd_file *zstdf);
+static int     zstdf_open(const char *path, struct open_file *f);
+static int     zstdf_close(struct open_file *f);
+static int     zstdf_read(struct open_file *f, void *buf, size_t size, size_t 
*resid);
+static off_t   zstdf_seek(struct open_file *f, off_t offset, int where);
+static int     zstdf_stat(struct open_file *f, struct stat *sb);
+
+struct fs_ops zstdfs_fsops = {
+       .fs_name = "zstd",
+       .fs_flags = 0,
+       .fo_open = zstdf_open,
+       .fo_close = zstdf_close,
+       .fo_read = zstdf_read,
+       .fo_write = null_write,
+       .fo_seek = zstdf_seek,
+       .fo_stat = zstdf_stat,
+       .fo_readdir = null_readdir,
+};
+
+static int
+zstdf_fill(struct zstd_file *zstdf)
+{
+    int                result;
+    int                avail_in;
+    int                req;
+
+    avail_in = zstdf->zstdf_in.size - zstdf->zstdf_in.pos;
+    req = ZSTD_BUFSIZE - avail_in;
+    result = 0;
+
+    /* If we need more */
+    if (req > 0) {
+       /* move old data to bottom of buffer */
+       if (avail_in > 0)
+           bcopy(zstdf->zstdf_inbuf + zstdf->zstdf_in.pos, zstdf->zstdf_inbuf, 
avail_in);
+
+       /* read to fill buffer and update availibility data */
+       result = read(zstdf->zstdf_rawfd, zstdf->zstdf_inbuf + avail_in, req);
+       zstdf->zstdf_in.src = zstdf->zstdf_inbuf;
+       zstdf->zstdf_in.pos = 0;
+       zstdf->zstdf_in.size = avail_in + (result >= 0 ? result : 0);
+    }
+    return (result);
+}
+
+static const unsigned char zstd_magic[4] = {0x28, 0xb5, 0x2f, 0xfd};
+
+/*
+ * Peek at the fixed-size zstd frame magic without consuming it, so the
+ * header remains for ZSTD_decompressStream() to parse normally on the
+ * first read.
+ *
+ * Returns 0 if the header is OK, nonzero if not.
+ */
+static int
+check_header(struct zstd_file *zstdf)
+{
+    if (zstdf->zstdf_in.size - zstdf->zstdf_in.pos < sizeof(zstd_magic) &&
+       zstdf_fill(zstdf) == -1)
+       return (1);
+    if (zstdf->zstdf_in.size - zstdf->zstdf_in.pos < sizeof(zstd_magic))
+       return (1);
+    return (memcmp((const unsigned char *)zstdf->zstdf_in.src + 
zstdf->zstdf_in.pos,
+       zstd_magic, sizeof(zstd_magic)) != 0);
+}
+
+static int
+zstdf_open(const char *fname, struct open_file *f)
+{
+    static char                *zstdfname;
+    int                        rawfd;
+    struct zstd_file   *zstdf;
+    char               *cp;
+    struct stat                sb;
+
+    /* Have to be in "just read it" mode */
+    if (f->f_flags != F_READ)
+       return(EPERM);
+
+    /* If the name already ends in a known compressed suffix, ignore it */
+    if ((cp = strrchr(fname, '.')) && (!strcmp(cp, ".gz")
+           || !strcmp(cp, ".bz2") || !strcmp(cp, ".xz")
+           || !strcmp(cp, ".zst") || !strcmp(cp, ".split")))
+       return(ENOENT);
+
+    /* Construct new name */
+    zstdfname = malloc(strlen(fname) + 5);
+    if (zstdfname == NULL)
+        return(ENOMEM);
+    sprintf(zstdfname, "%s.zst", fname);
+
+    /* Try to open the compressed datafile */
+    rawfd = open(zstdfname, O_RDONLY);
+    free(zstdfname);
+    if (rawfd == -1)
+       return(ENOENT);
+
+    if (fstat(rawfd, &sb) < 0) {
+       printf("zstdf_open: stat failed\n");
+       close(rawfd);
+       return(ENOENT);
+    }
+    if (!S_ISREG(sb.st_mode)) {
+       printf("zstdf_open: not a file\n");
+       close(rawfd);
+       return(EISDIR);                 /* best guess */
+    }
+
+    /* Allocate a zstd_file structure, populate it */
+    zstdf = malloc(sizeof(struct zstd_file));
+    if (zstdf == NULL) {
+       close(rawfd);
+        return(ENOMEM);
+    }
+    bzero(zstdf, sizeof(struct zstd_file));
+    zstdf->zstdf_rawfd = rawfd;
+    zstdf->zstdf_in.src = zstdf->zstdf_inbuf;
+
+    /* Verify that the file is zstd compressed */
+    if (check_header(zstdf)) {
+       close(zstdf->zstdf_rawfd);
+       free(zstdf);
+       return(EFTYPE);
+    }
+
+    /* Initialise the inflation engine */
+    zstdf->zstdf_strm = ZSTD_createDStream();
+    if (zstdf->zstdf_strm == NULL) {
+       close(zstdf->zstdf_rawfd);
+       free(zstdf);
+       return(ENOMEM);
+    }
+    if (ZSTD_isError(ZSTD_initDStream(zstdf->zstdf_strm))) {
+       ZSTD_freeDStream(zstdf->zstdf_strm);
+       close(zstdf->zstdf_rawfd);
+       free(zstdf);
+       return(EIO);
+    }
+
+    /* Looks OK, we'll take it */
+    f->f_fsdata = zstdf;
+    return(0);
+}
+
+static int
+zstdf_close(struct open_file *f)
+{
+    struct zstd_file   *zstdf = (struct zstd_file *)f->f_fsdata;
+
+    ZSTD_freeDStream(zstdf->zstdf_strm);
+    close(zstdf->zstdf_rawfd);
+    free(zstdf);
+    return(0);
+}
+
+static int
+zstdf_read(struct open_file *f, void *buf, size_t size, size_t *resid)
+{
+    struct zstd_file   *zstdf = (struct zstd_file *)f->f_fsdata;
+    ZSTD_outBuffer     out = { buf, size, 0 };
+    size_t             ret;
+
+    while (out.pos < out.size && zstdf->zstdf_endseen == 0) {
+       if ((zstdf->zstdf_in.pos == zstdf->zstdf_in.size) && (zstdf_fill(zstdf) 
== -1)) {
+           printf("zstdf_read: fill error\n");
+           return(EIO);
+       }
+       if (zstdf->zstdf_in.pos == zstdf->zstdf_in.size) {      /* oops, 
unexpected EOF */
+           printf("zstdf_read: unexpected EOF\n");
+           if (out.pos == 0)
+               return(EIO);
+           break;
+       }
+
+       ret = ZSTD_decompressStream(zstdf->zstdf_strm, &out, &zstdf->zstdf_in);
+       if (ZSTD_isError(ret)) {                        /* argh, decompression 
error */
+           printf("zstdf_read: %s\n", ZSTD_getErrorName(ret));
+           return(EIO);
+       }
+       if (ret == 0) {                         /* EOF, all done */
+           zstdf->zstdf_endseen = 1;
+           break;
+       }
+    }
+    zstdf->zstdf_total_out += out.pos;
+    if (resid != NULL)
+       *resid = out.size - out.pos;
+    return(0);
+}
+
+static int
+zstdf_rewind(struct open_file *f)
+{
+    struct zstd_file   *zstdf = (struct zstd_file *)f->f_fsdata;
+
+    if (lseek(zstdf->zstdf_rawfd, 0, SEEK_SET) == -1)
+       return(-1);
+    zstdf->zstdf_in.src = zstdf->zstdf_inbuf;
+    zstdf->zstdf_in.pos = 0;
+    zstdf->zstdf_in.size = 0;
+    zstdf->zstdf_endseen = 0;
+    zstdf->zstdf_total_out = 0;
+    if (ZSTD_isError(ZSTD_initDStream(zstdf->zstdf_strm)))
+       return(-1);
+
+    return(0);
+}
+
+static off_t
+zstdf_seek(struct open_file *f, off_t offset, int where)
+{
+    struct zstd_file   *zstdf = (struct zstd_file *)f->f_fsdata;
+    off_t              target;
+    char               discard[16];
+
+    switch (where) {
+    case SEEK_SET:
+       target = offset;
+       break;
+    case SEEK_CUR:
+       target = offset + zstdf->zstdf_total_out;
+       break;
+    default:
+       errno = EINVAL;
+       return(-1);
+    }
+
+    /* rewind if required */
+    if (target < zstdf->zstdf_total_out && zstdf_rewind(f) != 0)
+       return(-1);
+
+    /* skip forwards if required */
+    while (target > zstdf->zstdf_total_out) {
+       errno = zstdf_read(f, discard, min(sizeof(discard),
+           target - zstdf->zstdf_total_out), NULL);
+       if (errno)
+           return(-1);
+       /* Break out of loop if end of file has been reached. */
+       if (zstdf->zstdf_endseen)
+           break;
+    }
+    /* This is where we are (be honest if we overshot) */
+    return(zstdf->zstdf_total_out);
+}
+
+static int
+zstdf_stat(struct open_file *f, struct stat *sb)
+{
+    struct zstd_file   *zstdf = (struct zstd_file *)f->f_fsdata;
+    int                        result;
+
+    /* stat as normal, but indicate that size is unknown */
+    if ((result = fstat(zstdf->zstdf_rawfd, sb)) == 0)
+       sb->st_size = -1;
+    return(result);
+}

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