diff options
Diffstat (limited to 'extlinux')
| -rw-r--r-- | extlinux/btrfs.h | 22 | ||||
| -rw-r--r-- | extlinux/main.c | 264 |
2 files changed, 230 insertions, 56 deletions
diff --git a/extlinux/btrfs.h b/extlinux/btrfs.h new file mode 100644 index 00000000..39a861a5 --- /dev/null +++ b/extlinux/btrfs.h @@ -0,0 +1,22 @@ +#ifndef _BTRFS_H_ +#define _BTRFS_H_ + +#define BTRFS_SUPER_MAGIC 0x9123683E +#define BTRFS_SUPER_INFO_OFFSET (64 * 1024) +#define BTRFS_SUPER_INFO_SIZE 4096 +#define BTRFS_MAGIC "_BHRfS_M" +#define BTRFS_CSUM_SIZE 32 +#define BTRFS_FSID_SIZE 16 + +struct btrfs_super_block { + unsigned char csum[BTRFS_CSUM_SIZE]; + /* the first 3 fields must match struct btrfs_header */ + unsigned char fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */ + u64 bytenr; /* this block number */ + u64 flags; + + /* allowed to be different from the btrfs_header from here own down */ + u64 magic; +} __attribute__ ((__packed__)); + +#endif diff --git a/extlinux/main.c b/extlinux/main.c index 79ead181..7eb59dae 100644 --- a/extlinux/main.c +++ b/extlinux/main.c @@ -14,7 +14,7 @@ /* * extlinux.c * - * Install the extlinux boot block on an ext2/3/4 filesystem + * Install the extlinux boot block on an ext2/3/4 and btrfs filesystem */ #define _GNU_SOURCE /* Enable everything */ @@ -29,6 +29,7 @@ typedef uint64_t u64; #ifndef __KLIBC__ #include <mntent.h> #endif +#include <stdbool.h> #include <stdlib.h> #include <string.h> #include <getopt.h> @@ -46,6 +47,7 @@ typedef uint64_t u64; #undef statfs #include "ext2_fs.h" +#include "btrfs.h" #include "../version.h" #include "syslxint.h" @@ -56,6 +58,10 @@ typedef uint64_t u64; #endif /* Global option handling */ +/* Global fs_type for handling ext2/3/4 vs btrfs */ +#define EXT2 1 +#define BTRFS 2 +int fs_type; const char *program; @@ -130,6 +136,9 @@ static const char short_options[] = "iUuzS:H:rvho:O"; #define EXT2_SUPER_OFFSET 1024 #endif +/* the btrfs partition first 64K blank area is used to store boot sector and + boot image, the boot sector is from 0~512, the boot image starts at 2K */ +#define BTRFS_EXTLINUX_OFFSET (2*1024) /* * Boot block */ @@ -359,10 +368,11 @@ int patch_file_and_bootblock(int fd, int dirfd, int devfd) uint32_t csum; int secptroffset; - if (fstat(dirfd, &dirst)) { - perror("fstat dirfd"); - exit(255); /* This should never happen */ - } + if (fs_type == EXT2) + if (fstat(dirfd, &dirst)) { + perror("fstat dirfd"); + exit(255); /* This should never happen */ + } totalbytes = get_size(devfd); get_geometry(devfd, totalbytes, &geo); @@ -406,14 +416,20 @@ int patch_file_and_bootblock(int fd, int dirfd, int devfd) nsect = (boot_image_len + SECTOR_SIZE - 1) >> SECTOR_SHIFT; nsect += 2; /* Two sectors for the ADV */ sectp = alloca(sizeof(uint32_t) * nsect); - if (sectmap(fd, sectp, nsect)) { - perror("bmap"); - exit(1); + if (fs_type == EXT2) { + if (sectmap(fd, sectp, nsect)) { + perror("bmap"); + exit(1); + } + } else if (fs_type == BTRFS) { + int i; + + for (i = 0; i < nsect; i++) + *(sectp + i) = BTRFS_EXTLINUX_OFFSET/SECTOR_SIZE + i; } /* First sector need pointer in boot sector */ set_32(&bs->NextSector, *sectp++); - /* Stupid mode? */ if (opt.stupid_mode) set_16(&bs->MaxTransfer, 1); @@ -455,13 +471,21 @@ int patch_file_and_bootblock(int fd, int dirfd, int devfd) * Returns -1 on fatal errors, 0 if ADV is okay, and 1 if no valid * ADV was found. */ -int read_adv(const char *path) +int read_adv(const char *path, int devfd) { char *file; int fd = -1; struct stat st; int err = 0; + if (fs_type == BTRFS) { /* btrfs "extlinux.sys" is in 64k blank area */ + if (xpread(devfd, syslinux_adv, 2 * ADV_SIZE, + BTRFS_EXTLINUX_OFFSET + boot_image_len) != 2 * ADV_SIZE) { + perror("writing adv"); + return 1; + } + return 0; + } asprintf(&file, "%s%sextlinux.sys", path, path[0] && path[strlen(path) - 1] == '/' ? "" : "/"); @@ -505,7 +529,7 @@ int read_adv(const char *path) /* * Update the ADV in an existing installation. */ -int write_adv(const char *path) +int write_adv(const char *path, int devfd) { unsigned char advtmp[2 * ADV_SIZE]; char *file; @@ -514,6 +538,14 @@ int write_adv(const char *path) int err = 0; int flags, nflags; + if (fs_type == BTRFS) { /* btrfs "extlinux.sys" is in 64k blank area */ + if (xpwrite(devfd, syslinux_adv, 2 * ADV_SIZE, + BTRFS_EXTLINUX_OFFSET + boot_image_len) != 2 * ADV_SIZE) { + perror("writing adv"); + return 1; + } + return 0; + } asprintf(&file, "%s%sextlinux.sys", path, path[0] && path[strlen(path) - 1] == '/' ? "" : "/"); @@ -611,17 +643,30 @@ int modify_adv(void) int install_bootblock(int fd, const char *device) { struct ext2_super_block sb; + struct btrfs_super_block sb2; + bool ok = false; - if (xpread(fd, &sb, sizeof sb, EXT2_SUPER_OFFSET) != sizeof sb) { - perror("reading superblock"); - return 1; + if (fs_type == EXT2) { + if (xpread(fd, &sb, sizeof sb, EXT2_SUPER_OFFSET) != sizeof sb) { + perror("reading superblock"); + return 1; + } + if (sb.s_magic == EXT2_SUPER_MAGIC) + ok = true; + } else if (fs_type == BTRFS) { + if (xpread(fd, &sb2, sizeof sb2, BTRFS_SUPER_INFO_OFFSET) + != sizeof sb2) { + perror("reading superblock"); + return 1; + } + if (sb2.magic == *(u64 *)BTRFS_MAGIC) + ok = true; } - - if (sb.s_magic != EXT2_SUPER_MAGIC) { - fprintf(stderr, "no ext2/3/4 superblock found on %s\n", device); + if (!ok) { + fprintf(stderr, "no ext2/3/4 or btrfs superblock found on %s\n", + device); return 1; } - if (xpwrite(fd, boot_block, boot_block_len, 0) != boot_block_len) { perror("writing bootblock"); return 1; @@ -630,7 +675,7 @@ int install_bootblock(int fd, const char *device) return 0; } -int install_file(const char *path, int devfd, struct stat *rst) +int ext2_install_file(const char *path, int devfd, struct stat *rst) { char *file; int fd = -1, dirfd = -1, flags; @@ -721,6 +766,40 @@ bail: return 1; } +/* btrfs has to install the extlinux.sys in the first 64K blank area, which + is not managered by btrfs tree, so actually this is not installed as files. + since the cow feature of btrfs will move the extlinux.sys every where */ +int btrfs_install_file(const char *path, int devfd, struct stat *rst) +{ + patch_file_and_bootblock(-1, -1, devfd); + if (xpwrite(devfd, boot_image, boot_image_len, BTRFS_EXTLINUX_OFFSET) + != boot_image_len) { + perror("writing bootblock"); + return 1; + } + printf("write boot_image to 0x%x\n", BTRFS_EXTLINUX_OFFSET); + if (xpwrite(devfd, syslinux_adv, 2 * ADV_SIZE, + BTRFS_EXTLINUX_OFFSET + boot_image_len) != 2 * ADV_SIZE) { + perror("writing adv"); + return 1; + } + printf("write adv to 0x%x\n", BTRFS_EXTLINUX_OFFSET + boot_image_len); + if (stat(path, rst)) { + perror(path); + return 1; + } + return 0; +} + +int install_file(const char *path, int devfd, struct stat *rst) +{ + if (fs_type == EXT2) + return ext2_install_file(path, devfd, rst); + else if (fs_type == BTRFS) + return btrfs_install_file(path, devfd, rst); + return 1; +} + /* EXTLINUX installs the string 'EXTLINUX' at offset 3 in the boot sector; this is consistent with FAT filesystems. */ int already_installed(int devfd) @@ -745,10 +824,13 @@ static void device_cleanup(void) static int validate_device(const char *path, int devfd) { struct stat pst, dst; + struct statfs sfs; - if (stat(path, &pst) || fstat(devfd, &dst)) + if (stat(path, &pst) || fstat(devfd, &dst) || statfs(path, &sfs)) return -1; - + /* btrfs st_dev is not matched with mnt st_rdev, it is a known issue */ + if (fs_type == BTRFS && sfs.f_type == BTRFS_SUPER_MAGIC) + return 0; return (pst.st_dev == dst.st_rdev) ? 0 : -1; } @@ -759,18 +841,35 @@ static const char *find_device(const char *mtab_file, dev_t dev) struct stat dst; FILE *mtab; const char *devname = NULL; + bool done; mtab = setmntent(mtab_file, "r"); if (!mtab) return NULL; + done = false; while ((mnt = getmntent(mtab))) { - if ((!strcmp(mnt->mnt_type, "ext2") || - !strcmp(mnt->mnt_type, "ext3") || - !strcmp(mnt->mnt_type, "ext4")) && - !stat(mnt->mnt_fsname, &dst) && dst.st_rdev == dev) { - devname = strdup(mnt->mnt_fsname); - break; + /* btrfs st_dev is not matched with mnt st_rdev, it is a known issue */ + switch (fs_type) { + case BTRFS: + if (!strcmp(mnt->mnt_type, "btrfs") && + !stat(mnt->mnt_dir, &dst) && + dst.st_dev == dev) + done = true; + break; + case EXT2: + if ((!strcmp(mnt->mnt_type, "ext2") || + !strcmp(mnt->mnt_type, "ext3") || + !strcmp(mnt->mnt_type, "ext4")) && + !stat(mnt->mnt_fsname, &dst) && + dst.st_rdev == dev) { + done = true; + break; + } + } + if (done) { + devname = strdup(mnt->mnt_fsname); + break; } } endmntent(mtab); @@ -779,30 +878,20 @@ static const char *find_device(const char *mtab_file, dev_t dev) } #endif -int install_loader(const char *path, int update_only) +static const char *get_devname(const char *path) { - struct stat st, fst; - int devfd, rv; const char *devname = NULL; + struct stat st; struct statfs sfs; if (stat(path, &st) || !S_ISDIR(st.st_mode)) { fprintf(stderr, "%s: Not a directory: %s\n", program, path); - return 1; + return devname; } - if (statfs(path, &sfs)) { fprintf(stderr, "%s: statfs %s: %s\n", program, path, strerror(errno)); - return 1; - } - - if (sfs.f_type != EXT2_SUPER_MAGIC) { - fprintf(stderr, "%s: not an ext2/3/4 filesystem: %s\n", program, path); - return 1; + return devname; } - - devfd = -1; - #ifdef __KLIBC__ /* klibc doesn't have getmntent and friends; instead, just create @@ -812,7 +901,7 @@ int install_loader(const char *path, int update_only) if (mknod(devname_buf, S_IFBLK | 0600, st.st_dev)) { fprintf(stderr, "%s: cannot create device %s\n", program, devname); - return 1; + return devname; } atexit(device_cleanup); /* unlink the device node on exit */ @@ -827,46 +916,99 @@ int install_loader(const char *path, int update_only) } if (!devname) { fprintf(stderr, "%s: cannot find device for path %s\n", program, path); - return 1; + return devname; } fprintf(stderr, "%s is device %s\n", path, devname); #endif + return devname; +} + +static int open_device(const char *path, struct stat *st, const char **_devname) +{ + int devfd; + const char *devname = NULL; + struct statfs sfs; + + if (st) + if (stat(path, st) || !S_ISDIR(st->st_mode)) { + fprintf(stderr, "%s: Not a directory: %s\n", program, path); + return -1; + } + + if (statfs(path, &sfs)) { + fprintf(stderr, "%s: statfs %s: %s\n", program, path, strerror(errno)); + return -1; + } + if (sfs.f_type == EXT2_SUPER_MAGIC) + fs_type = EXT2; + else if (sfs.f_type == BTRFS_SUPER_MAGIC) + fs_type = BTRFS; + + if (!fs_type) { + fprintf(stderr, "%s: not an ext2/3/4 or btrfs filesystem: %s\n", + program, path); + return -1; + } + + devfd = -1; + devname = get_devname(path); + if (_devname) + *_devname = devname; if ((devfd = open(devname, O_RDWR | O_SYNC)) < 0) { fprintf(stderr, "%s: cannot open device %s\n", program, devname); - return 1; + return -1; } /* Verify that the device we opened is the device intended */ if (validate_device(path, devfd)) { fprintf(stderr, "%s: path %s doesn't match device %s\n", program, path, devname); - return 1; + close(devfd); + return -1; } + return devfd; +} + +int install_loader(const char *path, int update_only) +{ + struct stat st, fst; + int devfd, rv; + const char *devname; + + devfd = open_device(path, &st, &devname); + if (devfd < 0) + return 1; if (update_only && !already_installed(devfd)) { fprintf(stderr, "%s: no previous extlinux boot sector found\n", program); + close(devfd); return 1; } /* Read a pre-existing ADV, if already installed */ if (opt.reset_adv) syslinux_reset_adv(syslinux_adv); - else if (read_adv(path) < 0) + else if (read_adv(path, devfd) < 0) { + close(devfd); return 1; - - if (modify_adv() < 0) + } + if (modify_adv() < 0) { + close(devfd); return 1; + } /* Install extlinux.sys */ - if (install_file(path, devfd, &fst)) + if (install_file(path, devfd, &fst)) { + close(devfd); return 1; - + } if (fst.st_dev != st.st_dev) { fprintf(stderr, "%s: file system changed under us - aborting!\n", program); + close(devfd); return 1; } @@ -883,17 +1025,27 @@ int install_loader(const char *path, int update_only) */ int modify_existing_adv(const char *path) { + int devfd; + + devfd = open_device(path, NULL, NULL); + if (devfd < 0) + return 1; + if (opt.reset_adv) syslinux_reset_adv(syslinux_adv); - else if (read_adv(path) < 0) + else if (read_adv(path, devfd) < 0) { + close(devfd); return 1; - - if (modify_adv() < 0) + } + if (modify_adv() < 0) { + close(devfd); return 1; - - if (write_adv(path) < 0) + } + if (write_adv(path, devfd) < 0) { + close(devfd); return 1; - + } + close(devfd); return 0; } |