diff options
Diffstat (limited to 'arch/um/drivers/cow_user.c')
-rw-r--r-- | arch/um/drivers/cow_user.c | 133 |
1 files changed, 65 insertions, 68 deletions
diff --git a/arch/um/drivers/cow_user.c b/arch/um/drivers/cow_user.c index 0ec4052db9c5..93f227a25ba4 100644 --- a/arch/um/drivers/cow_user.c +++ b/arch/um/drivers/cow_user.c @@ -1,17 +1,18 @@ -#include <stddef.h> -#include <string.h> -#include <errno.h> -/* _XOPEN_SOURCE is needed for pread, but we define _GNU_SOURCE, which defines +/* + * Copyright (C) 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com) + * Licensed under the GPL + */ + +/* + * _XOPEN_SOURCE is needed for pread, but we define _GNU_SOURCE, which defines * that. */ #include <unistd.h> #include <byteswap.h> -#include <sys/time.h> -#include <sys/param.h> -#include <sys/user.h> - -#include "os.h" - +#include <errno.h> +#include <string.h> +#include <arpa/inet.h> +#include <asm/types.h> #include "cow.h" #include "cow_sys.h" @@ -28,7 +29,8 @@ struct cow_header_v1 { __s32 sectorsize; } __attribute__((packed)); -/* Define PATH_LEN_V3 as the usual value of MAXPATHLEN, just hard-code it in +/* + * Define PATH_LEN_V3 as the usual value of MAXPATHLEN, just hard-code it in * case other systems have different values for MAXPATHLEN. * * The same must hold for V2 - we want file format compatibility, not anything @@ -46,7 +48,8 @@ struct cow_header_v2 { __s32 sectorsize; } __attribute__((packed)); -/* Changes from V2 - +/* + * Changes from V2 - * PATH_LEN_V3 as described above * Explicitly specify field bit lengths for systems with different * lengths for the usual C types. Not sure whether char or @@ -70,7 +73,8 @@ struct cow_header_v2 { * Fixed (finally!) the rounding bug */ -/* Until Dec2005, __attribute__((packed)) was left out from the below +/* + * Until Dec2005, __attribute__((packed)) was left out from the below * definition, leading on 64-bit systems to 4 bytes of padding after mtime, to * align size to 8-byte alignment. This shifted all fields above (no padding * was present on 32-bit, no other padding was added). @@ -122,7 +126,7 @@ void cow_sizes(int version, __u64 size, int sectorsize, int align, int bitmap_offset, unsigned long *bitmap_len_out, int *data_offset_out) { - if(version < 3){ + if (version < 3) { *bitmap_len_out = (size + sectorsize - 1) / (8 * sectorsize); *data_offset_out = bitmap_offset + *bitmap_len_out; @@ -144,46 +148,46 @@ static int absolutize(char *to, int size, char *from) char save_cwd[256], *slash; int remaining; - if(getcwd(save_cwd, sizeof(save_cwd)) == NULL) { + if (getcwd(save_cwd, sizeof(save_cwd)) == NULL) { cow_printf("absolutize : unable to get cwd - errno = %d\n", errno); - return(-1); + return -1; } slash = strrchr(from, '/'); - if(slash != NULL){ + if (slash != NULL) { *slash = '\0'; - if(chdir(from)){ + if (chdir(from)) { *slash = '/'; cow_printf("absolutize : Can't cd to '%s' - " "errno = %d\n", from, errno); - return(-1); + return -1; } *slash = '/'; - if(getcwd(to, size) == NULL){ + if (getcwd(to, size) == NULL) { cow_printf("absolutize : unable to get cwd of '%s' - " "errno = %d\n", from, errno); - return(-1); + return -1; } remaining = size - strlen(to); - if(strlen(slash) + 1 > remaining){ + if (strlen(slash) + 1 > remaining) { cow_printf("absolutize : unable to fit '%s' into %d " "chars\n", from, size); - return(-1); + return -1; } strcat(to, slash); } else { - if(strlen(save_cwd) + 1 + strlen(from) + 1 > size){ + if (strlen(save_cwd) + 1 + strlen(from) + 1 > size) { cow_printf("absolutize : unable to fit '%s' into %d " "chars\n", from, size); - return(-1); + return -1; } strcpy(to, save_cwd); strcat(to, "/"); strcat(to, from); } chdir(save_cwd); - return(0); + return 0; } int write_cow_header(char *cow_file, int fd, char *backing_file, @@ -194,22 +198,23 @@ int write_cow_header(char *cow_file, int fd, char *backing_file, int err; err = cow_seek_file(fd, 0); - if(err < 0){ + if (err < 0) { cow_printf("write_cow_header - lseek failed, err = %d\n", -err); goto out; } err = -ENOMEM; header = cow_malloc(sizeof(*header)); - if(header == NULL){ - cow_printf("write_cow_header - failed to allocate COW V3 header\n"); + if (header == NULL) { + cow_printf("write_cow_header - failed to allocate COW V3 " + "header\n"); goto out; } header->magic = htonl(COW_MAGIC); header->version = htonl(COW_VERSION); err = -EINVAL; - if(strlen(backing_file) > sizeof(header->backing_file) - 1){ + if (strlen(backing_file) > sizeof(header->backing_file) - 1) { /* Below, %zd is for a size_t value */ cow_printf("Backing file name \"%s\" is too long - names are " "limited to %zd characters\n", backing_file, @@ -217,12 +222,12 @@ int write_cow_header(char *cow_file, int fd, char *backing_file, goto out_free; } - if(absolutize(header->backing_file, sizeof(header->backing_file), + if (absolutize(header->backing_file, sizeof(header->backing_file), backing_file)) goto out_free; err = os_file_modtime(header->backing_file, &modtime); - if(err < 0){ + if (err < 0) { cow_printf("write_cow_header - backing file '%s' mtime " "request failed, err = %d\n", header->backing_file, -err); @@ -230,7 +235,7 @@ int write_cow_header(char *cow_file, int fd, char *backing_file, } err = cow_file_size(header->backing_file, size); - if(err < 0){ + if (err < 0) { cow_printf("write_cow_header - couldn't get size of " "backing file '%s', err = %d\n", header->backing_file, -err); @@ -244,7 +249,7 @@ int write_cow_header(char *cow_file, int fd, char *backing_file, header->cow_format = COW_BITMAP; err = cow_write_file(fd, header, sizeof(*header)); - if(err != sizeof(*header)){ + if (err != sizeof(*header)) { cow_printf("write_cow_header - write of header to " "new COW file '%s' failed, err = %d\n", cow_file, -err); @@ -254,14 +259,14 @@ int write_cow_header(char *cow_file, int fd, char *backing_file, out_free: cow_free(header); out: - return(err); + return err; } int file_reader(__u64 offset, char *buf, int len, void *arg) { int fd = *((int *) arg); - return(pread(fd, buf, len, offset)); + return pread(fd, buf, len, offset); } /* XXX Need to sanity-check the values read from the header */ @@ -278,31 +283,29 @@ int read_cow_header(int (*reader)(__u64, char *, int, void *), void *arg, unsigned long version, magic; header = cow_malloc(sizeof(*header)); - if(header == NULL){ + if (header == NULL) { cow_printf("read_cow_header - Failed to allocate header\n"); - return(-ENOMEM); + return -ENOMEM; } err = -EINVAL; n = (*reader)(0, (char *) header, sizeof(*header), arg); - if(n < offsetof(typeof(header->v1), backing_file)){ + if (n < offsetof(typeof(header->v1), backing_file)) { cow_printf("read_cow_header - short header\n"); goto out; } magic = header->v1.magic; - if(magic == COW_MAGIC) { + if (magic == COW_MAGIC) version = header->v1.version; - } - else if(magic == ntohl(COW_MAGIC)){ + else if (magic == ntohl(COW_MAGIC)) version = ntohl(header->v1.version); - } /* No error printed because the non-COW case comes through here */ else goto out; *version_out = version; - if(version == 1){ - if(n < sizeof(header->v1)){ + if (version == 1) { + if (n < sizeof(header->v1)) { cow_printf("read_cow_header - failed to read V1 " "header\n"); goto out; @@ -314,8 +317,8 @@ int read_cow_header(int (*reader)(__u64, char *, int, void *), void *arg, *align_out = *sectorsize_out; file = header->v1.backing_file; } - else if(version == 2){ - if(n < sizeof(header->v2)){ + else if (version == 2) { + if (n < sizeof(header->v2)) { cow_printf("read_cow_header - failed to read V2 " "header\n"); goto out; @@ -328,8 +331,8 @@ int read_cow_header(int (*reader)(__u64, char *, int, void *), void *arg, file = header->v2.backing_file; } /* This is very subtle - see above at union cow_header definition */ - else if(version == 3 && (*((int*)header->v3.backing_file) != 0)){ - if(n < sizeof(header->v3)){ + else if (version == 3 && (*((int*)header->v3.backing_file) != 0)) { + if (n < sizeof(header->v3)) { cow_printf("read_cow_header - failed to read V3 " "header\n"); goto out; @@ -345,17 +348,18 @@ int read_cow_header(int (*reader)(__u64, char *, int, void *), void *arg, *bitmap_offset_out = ROUND_UP(sizeof(header->v3), *align_out); file = header->v3.backing_file; } - else if(version == 3){ + else if (version == 3) { cow_printf("read_cow_header - broken V3 file with" " 64-bit layout - recovering content.\n"); - if(n < sizeof(header->v3_b)){ + if (n < sizeof(header->v3_b)) { cow_printf("read_cow_header - failed to read V3 " "header\n"); goto out; } - /* this was used until Dec2005 - 64bits are needed to represent + /* + * this was used until Dec2005 - 64bits are needed to represent * 2038+. I.e. we can safely do this truncating cast. * * Additionally, we must use ntohl() instead of ntohll(), since @@ -381,7 +385,7 @@ int read_cow_header(int (*reader)(__u64, char *, int, void *), void *arg, } err = -ENOMEM; *backing_file_out = cow_strdup(file); - if(*backing_file_out == NULL){ + if (*backing_file_out == NULL) { cow_printf("read_cow_header - failed to allocate backing " "file\n"); goto out; @@ -389,7 +393,7 @@ int read_cow_header(int (*reader)(__u64, char *, int, void *), void *arg, err = 0; out: cow_free(header); - return(err); + return err; } int init_cow_file(int fd, char *cow_file, char *backing_file, int sectorsize, @@ -402,7 +406,7 @@ int init_cow_file(int fd, char *cow_file, char *backing_file, int sectorsize, err = write_cow_header(cow_file, fd, backing_file, sectorsize, alignment, &size); - if(err) + if (err) goto out; *bitmap_offset_out = ROUND_UP(sizeof(struct cow_header_v3), alignment); @@ -411,17 +415,18 @@ int init_cow_file(int fd, char *cow_file, char *backing_file, int sectorsize, offset = *data_offset_out + size - sizeof(zero); err = cow_seek_file(fd, offset); - if(err < 0){ + if (err < 0) { cow_printf("cow bitmap lseek failed : err = %d\n", -err); goto out; } - /* does not really matter how much we write it is just to set EOF + /* + * does not really matter how much we write it is just to set EOF * this also sets the entire COW bitmap * to zero without having to allocate it */ err = cow_write_file(fd, &zero, sizeof(zero)); - if(err != sizeof(zero)){ + if (err != sizeof(zero)) { cow_printf("Write of bitmap to new COW file '%s' failed, " "err = %d\n", cow_file, -err); if (err >= 0) @@ -429,15 +434,7 @@ int init_cow_file(int fd, char *cow_file, char *backing_file, int sectorsize, goto out; } - return(0); - + return 0; out: - return(err); + return err; } - -/* - * --------------------------------------------------------------------------- - * Local variables: - * c-file-style: "linux" - * End: - */ |