On Thu, Dec 28, 2017 at 1:40 PM, zhangyi (F) <yi.zhang@xxxxxxxxxx> wrote:
> Encapsulate separate underlying directories options to use -o option as
> for mount, see mount(8).
>
> Old Usage:
> fsck.overlay [-l lowerdir] [-u upperdir] [-w workdir]
>
> New Usage:
> fsck.overlay [-o lowerdir=<lowers>,upperdir=<upper>,workdir=<work>]
>
> Example:
> fsck.overlay -o lowerdir=lower,upperdir=upper,workdir=work
> or
> fsck.overlay -o lowerdir=lower -o upperdir=upper -o workdir=work
>
> Signed-off-by: zhangyi (F) <yi.zhang@xxxxxxxxxx>
Looks ok.
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
> README.md | 11 ++--
> check.c | 4 +-
> fsck.c | 78 +++++++++++++--------------
> mount.c | 182 +++++++++++++++++++++++++++++++++++---------------------------
> mount.h | 12 ++++-
> 5 files changed, 157 insertions(+), 130 deletions(-)
>
> diff --git a/README.md b/README.md
> index 458a815..a8d0b1c 100644
> --- a/README.md
> +++ b/README.md
> @@ -44,13 +44,11 @@ Usage
>
> 2. Run fsck.overlay program:
> Usage:
> - fsck.overlay [-l lowerdir] [-u upperdir] [-w workdir] [-pnyvhV]
> + fsck.overlay [-o lowerdir=<lowers>,upperdir=<upper>,workdir=<work>] [-pnyvhV]
>
> Options:
> - -l, --lowerdir=LOWERDIR specify lower directories of overlayfs,
> - multiple lower use ':' as separator.
> - -u, --upperdir=UPPERDIR specify upper directory of overlayfs
> - -w, --workdir=WORKDIR specify work directory of overlayfs
> + -o, specify underlying directories of overlayfs:
> + multiple lower directories use ':' as separator
> -p, automatic repair (no questions)
> -n, make no changes to the filesystem
> -y, assume "yes" to all questions
> @@ -58,6 +56,9 @@ Usage
> -h, --help display this usage of overlayfs
> -V, --version display version information
>
> + Example:
> + fsck.overlay -o lowerdir=lower,upperdir=upper,workdir=work
> +
> 3. Exit value:
> 0 No errors
> 1 Filesystem errors corrected
> diff --git a/check.c b/check.c
> index efa180f..0b5d49b 100644
> --- a/check.c
> +++ b/check.c
> @@ -58,8 +58,8 @@ struct ovl_redirect_entry {
> #define WHITEOUT_MOD 0
>
> extern char **lowerdir;
> -extern char upperdir[];
> -extern char workdir[];
> +extern char *upperdir;
> +extern char *workdir;
> extern int lower_num;
> extern int flags;
> extern int status;
> diff --git a/fsck.c b/fsck.c
> index 44211f7..5d34378 100644
> --- a/fsck.c
> +++ b/fsck.c
> @@ -38,15 +38,16 @@
>
> char *program_name;
>
> +char *lowerdirs = NULL;
> char **lowerdir = NULL;
> -char upperdir[PATH_MAX] = {0};
> -char workdir[PATH_MAX] = {0};
> +char *upperdir = NULL;
> +char *workdir = NULL;
> int lower_num = 0;
> int flags = 0; /* user input option flags */
> int status = 0; /* fsck scan status */
>
> -/* Cleanup lower directories buf */
> -static void ovl_clean_lowerdirs(void)
> +/* Cleanup underlying directories buffer */
> +static void ovl_clean_dirs(void)
> {
> int i;
>
> @@ -57,17 +58,19 @@ static void ovl_clean_lowerdirs(void)
> free(lowerdir);
> lowerdir = NULL;
> lower_num = 0;
> + free(upperdir);
> + upperdir = NULL;
> + free(workdir);
> + workdir = NULL;
> }
>
> static void usage(void)
> {
> - print_info(_("Usage:\n\t%s [-l lowerdir] [-u upperdir] [-w workdir] "
> + print_info(_("Usage:\n\t%s [-o lowerdir=<lowers>,upperdir=<upper>,workdir=<work>] "
> "[-pnyvhV]\n\n"), program_name);
> print_info(_("Options:\n"
> - "-l, --lowerdir=LOWERDIR specify lower directories of overlayfs,\n"
> - " multiple lower use ':' as separator\n"
> - "-u, --upperdir=UPPERDIR specify upper directory of overlayfs\n"
> - "-w, --workdir=WORKDIR specify work directory of overlayfs\n"
> + "-o, specify underlying directories of overlayfs:\n"
> + " multiple lower directories use ':' as separator\n"
> "-p, automatic repair (no questions)\n"
> "-n, make no changes to the filesystem\n"
> "-y, assume \"yes\" to all questions\n"
> @@ -79,46 +82,25 @@ static void usage(void)
>
> static void parse_options(int argc, char *argv[])
> {
> - char *lowertemp;
> + struct ovl_config config = {0};
> + char *ovl_opts = NULL;
> int c;
> int ret = 0;
> - bool show_usage = false;
> bool opt_conflict = false;
>
> struct option long_options[] = {
> - {"lowerdir", required_argument, NULL, 'l'},
> - {"upperdir", required_argument, NULL, 'u'},
> - {"workdir", required_argument, NULL, 'w'},
> {"verbose", no_argument, NULL, 'v'},
> {"version", no_argument, NULL, 'V'},
> {"help", no_argument, NULL, 'h'},
> {NULL, 0, NULL, 0}
> };
>
> - while ((c = getopt_long(argc, argv, "l:u:w:apnyvVh", long_options, NULL)) != -1) {
> + while ((c = getopt_long(argc, argv, "o:apnyvVh", long_options, NULL)) != -1) {
> switch (c) {
> - case 'l':
> - lowertemp = strdup(optarg);
> - ret = ovl_resolve_lowerdirs(lowertemp, &lowerdir, &lower_num);
> - free(lowertemp);
> - break;
> - case 'u':
> - if (realpath(optarg, upperdir)) {
> - print_debug(_("Upperdir:%s\n"), upperdir);
> - flags |= FL_UPPER;
> - } else {
> - print_err(_("Failed to resolve upperdir:%s\n"), optarg);
> - ret = -1;
> - }
> - break;
> - case 'w':
> - if (realpath(optarg, workdir)) {
> - print_debug(_("Workdir:%s\n"), workdir);
> - flags |= FL_WORK;
> - } else {
> - print_err(_("Failed to resolve workdir:%s\n"), optarg);
> - ret = -1;
> - }
> + case 'o':
> + ovl_opts = sstrdup(optarg);
> + ovl_parse_opt(ovl_opts, &config);
> + free(ovl_opts);
> break;
> case 'a':
> case 'p':
> @@ -155,23 +137,35 @@ static void parse_options(int argc, char *argv[])
> goto err_out;
> }
>
> + /* Resolve and get each underlying directory of overlay filesystem */
> + ovl_get_dirs(&config, &lowerdir, &lower_num, &upperdir, &workdir);
> + if (upperdir)
> + flags |= FL_UPPER;
> + if (workdir)
> + flags |= FL_WORK;
> +
> if (!lower_num || (!(flags & FL_UPPER) && lower_num == 1)) {
> print_info(_("Please specify correct lowerdirs and upperdir!\n\n"));
> - show_usage = true;
> + goto err_out;
> + }
> +
> + if ((flags & FL_UPPER) && !(flags & FL_WORK)) {
> + print_info(_("Please specify correct workdir!\n\n"));
> goto err_out;
> }
>
> if (opt_conflict) {
> print_info(_("Only one of the options -p/-a, -n or -y can be specified!\n\n"));
> - show_usage = true;
> goto err_out;
> }
>
> + ovl_free_opt(&config);
> return;
>
> err_out:
> - if (show_usage)
> - usage();
> + ovl_free_opt(&config);
> + ovl_clean_dirs();
> + usage();
> exit(1);
> }
>
> @@ -212,7 +206,7 @@ int main(int argc, char *argv[])
>
> out:
> fsck_status_check(&exit_value);
> - ovl_clean_lowerdirs();
> + ovl_clean_dirs();
>
> if (err)
> exit_value |= FSCK_ERROR;
> diff --git a/mount.c b/mount.c
> index fba51e9..908cee0 100644
> --- a/mount.c
> +++ b/mount.c
> @@ -38,19 +38,18 @@
> #include "mount.h"
>
> struct ovl_mnt_entry {
> - char *lowers;
> char **lowerdir;
> int lowernum;
> - char upperdir[PATH_MAX];
> - char workdir[PATH_MAX];
> + char *upperdir;
> + char *workdir;
> };
>
> /* Mount buf allocate a time */
> #define ALLOC_NUM 16
>
> extern char **lowerdir;
> -extern char upperdir[];
> -extern char workdir[];
> +extern char *upperdir;
> +extern char *workdir;
> extern int lower_num;
>
> /*
> @@ -78,9 +77,10 @@ static unsigned int ovl_split_lowerdirs(char *lower)
> }
>
> /* Resolve each lower directories and check the validity */
> -int ovl_resolve_lowerdirs(char *loweropt, char ***lowerdir,
> - int *lowernum)
> +static int ovl_resolve_lowerdirs(char *loweropt, char ***lowerdir,
> + int *lowernum)
> {
> + char temp[PATH_MAX] = {0};
> int num;
> char **dirs;
> char *p;
> @@ -97,12 +97,12 @@ int ovl_resolve_lowerdirs(char *loweropt, char ***lowerdir,
>
> p = loweropt;
> for (i = 0; i < num; i++) {
> - dirs[i] = smalloc(PATH_MAX);
> - if (!realpath(p, dirs[i])) {
> + if (!realpath(p, temp)) {
> print_err(_("Failed to resolve lowerdir:%s:%s\n"),
> p, strerror(errno));
> goto err;
> }
> + dirs[i] = sstrdup(temp);
> print_debug(_("Lowerdir %u:%s\n"), i, dirs[i]);
> p = strchr(p, '\0') + 1;
> }
> @@ -115,6 +115,7 @@ err:
> for (i--; i >= 0; i--)
> free(dirs[i]);
> free(dirs);
> + *lowerdir = NULL;
> *lowernum = 0;
> return -1;
> }
> @@ -146,79 +147,99 @@ static char *ovl_next_opt(char **s)
> return sbegin;
> }
>
> +static inline char *ovl_match_dump(const char *opt, const char *type)
> +{
> + int len = strlen(opt) - strlen(type) + 1;
> +
> + return sstrndup(opt+strlen(type), len);
> +}
> +
> /*
> - * Split and parse opt to each directories.
> - *
> - * Note: FIXME: We cannot distinguish mounted directories if overlayfs was
> - * mounted use relative path, so there may have misjudgment.
> + * Resolve and get each underlying directory of overlay filesystem
> + */
> +int ovl_get_dirs(struct ovl_config *config, char ***lowerdir,
> + int *lowernum, char **upperdir, char **workdir)
> +{
> + char temp[PATH_MAX] = {0};
> +
> + /* Resolve upperdir */
> + if (!realpath(config->upperdir, temp)) {
> + print_err(_("Faile to resolve upperdir:%s:%s\n"),
> + config->upperdir, strerror(errno));
> + goto err_out;
> + }
> + *upperdir = sstrdup(temp);
> + print_debug(_("Upperdir: %s\n"), *upperdir);
> +
> + /* Resolve workdir */
> + if (!realpath(config->workdir, temp)) {
> + print_err(_("Faile to resolve workdir:%s:%s\n"),
> + config->workdir, strerror(errno));
> + goto err_work;
> + }
> + *workdir = sstrdup(temp);
> + print_debug(_("Workdir: %s\n"), *workdir);
> +
> + /* Resolve lowerdir */
> + if (ovl_resolve_lowerdirs(config->lowerdir, lowerdir, lowernum))
> + goto err_lower;
> +
> + return 0;
> +
> +err_lower:
> + free(*workdir);
> + *workdir = NULL;
> +err_work:
> + free(*upperdir);
> + *upperdir = NULL;
> +err_out:
> + return -1;
> +}
> +
> +void ovl_free_opt(struct ovl_config *config)
> +{
> + free(config->upperdir);
> + config->upperdir = NULL;
> + free(config->lowerdir);
> + config->lowerdir = NULL;
> + free(config->workdir);
> + config->workdir = NULL;
> +}
> +
> +/*
> + * Split and parse opt to each underlying directories.
> */
> -static int ovl_parse_opt(char *opt, struct ovl_mnt_entry *entry)
> +void ovl_parse_opt(char *opt, struct ovl_config *config)
> {
> - char tmp[PATH_MAX] = {0};
> char *p;
> - int len;
> - int ret;
> - int i;
>
> while ((p = ovl_next_opt(&opt)) != NULL) {
> if (!*p)
> continue;
>
> if (!strncmp(p, OPT_UPPERDIR, strlen(OPT_UPPERDIR))) {
> - len = strlen(p) - strlen(OPT_UPPERDIR) + 1;
> - strncpy(tmp, p+strlen(OPT_UPPERDIR), len);
> -
> - if (!realpath(tmp, entry->upperdir)) {
> - print_err(_("Faile to resolve path:%s:%s\n"),
> - tmp, strerror(errno));
> - ret = -1;
> - goto errout;
> - }
> + free(config->upperdir);
> + config->upperdir = ovl_match_dump(p, OPT_UPPERDIR);
> } else if (!strncmp(p, OPT_LOWERDIR, strlen(OPT_LOWERDIR))) {
> - len = strlen(p) - strlen(OPT_LOWERDIR) + 1;
> - entry->lowers = smalloc(len);
> - strncpy(entry->lowers, p+strlen(OPT_LOWERDIR), len);
> -
> - if ((ret = ovl_resolve_lowerdirs(entry->lowers,
> - &entry->lowerdir, &entry->lowernum)))
> - goto errout;
> -
> + free(config->lowerdir);
> + config->lowerdir = ovl_match_dump(p, OPT_LOWERDIR);
> } else if (!strncmp(p, OPT_WORKDIR, strlen(OPT_WORKDIR))) {
> - len = strlen(p) - strlen(OPT_WORKDIR) + 1;
> - strncpy(tmp, p+strlen(OPT_WORKDIR), len);
> -
> - if (!realpath(tmp, entry->workdir)) {
> - print_err(_("Faile to resolve path:%s:%s\n"),
> - tmp, strerror(errno));
> - ret = -1;
> - goto errout;
> - }
> + free(config->workdir);
> + config->workdir = ovl_match_dump(p, OPT_WORKDIR);
> }
> }
> -
> -errout:
> - if (entry->lowernum) {
> - for (i = 0; i < entry->lowernum; i++)
> - free(entry->lowerdir[i]);
> - free(entry->lowerdir);
> - entry->lowerdir = NULL;
> - entry->lowernum = 0;
> - }
> - free(entry->lowers);
> - entry->lowers = NULL;
> -
> - return ret;
> }
>
> /* Scan current mounted overlayfs and get used underlying directories */
> static int ovl_scan_mount_init(struct ovl_mnt_entry **ovl_mnt_entries,
> int *ovl_mnt_count)
> {
> - struct ovl_mnt_entry *mnt_entries;
> - struct mntent *mnt;
> + struct ovl_mnt_entry *entries = NULL;
> + struct mntent *mnt = NULL;
> + struct ovl_config config = {0};
> FILE *fp;
> char *opt;
> - int allocated, num = 0;
> + int allocated, i = 0;
>
> fp = setmntent(MOUNT_TAB, "r");
> if (!fp) {
> @@ -227,32 +248,32 @@ static int ovl_scan_mount_init(struct ovl_mnt_entry **ovl_mnt_entries,
> return -1;
> }
>
> - allocated = ALLOC_NUM;
> - mnt_entries = smalloc(sizeof(struct ovl_mnt_entry) * allocated);
> + allocated = sizeof(struct ovl_mnt_entry) * ALLOC_NUM;
> + entries = smalloc(allocated);
>
> while ((mnt = getmntent(fp))) {
> - if (!strcmp(mnt->mnt_type, OVERLAY_NAME) ||
> - !strcmp(mnt->mnt_type, OVERLAY_NAME_OLD)) {
> + if (strcmp(mnt->mnt_type, OVERLAY_NAME))
> + continue;
>
> - opt = sstrdup(mnt->mnt_opts);
> - if (ovl_parse_opt(opt, &mnt_entries[num])) {
> - free(opt);
> - continue;
> - }
> + opt = sstrdup(mnt->mnt_opts);
> + ovl_parse_opt(opt, &config);
>
> - num++;
> - if (num % ALLOC_NUM == 0) {
> - allocated += ALLOC_NUM;
> - mnt_entries = srealloc(mnt_entries,
> - sizeof(struct ovl_mnt_entry) * allocated);
> + if (!ovl_get_dirs(&config,
> + &entries[i].lowerdir, &entries[i].lowernum,
> + &entries[i].upperdir, &entries[i].workdir)) {
> + i++;
> + if (i % ALLOC_NUM == 0) {
> + allocated += sizeof(struct ovl_mnt_entry) * ALLOC_NUM;
> + entries = srealloc(entries, allocated);
> }
> -
> - free(opt);
> }
> +
> + ovl_free_opt(&config);
> + free(opt);
> }
>
> - *ovl_mnt_entries = mnt_entries;
> - *ovl_mnt_count = num;
> + *ovl_mnt_entries = entries;
> + *ovl_mnt_count = i;
>
> endmntent(fp);
> return 0;
> @@ -267,7 +288,8 @@ static void ovl_scan_mount_exit(struct ovl_mnt_entry *ovl_mnt_entries,
> for (j = 0; j < ovl_mnt_entries[i].lowernum; j++)
> free(ovl_mnt_entries[i].lowerdir[j]);
> free(ovl_mnt_entries[i].lowerdir);
> - free(ovl_mnt_entries[i].lowers);
> + free(ovl_mnt_entries[i].upperdir);
> + free(ovl_mnt_entries[i].workdir);
> }
> free(ovl_mnt_entries);
> }
> @@ -279,6 +301,8 @@ static void ovl_scan_mount_exit(struct ovl_mnt_entry *ovl_mnt_entries,
> *
> * Note: fsck may modify lower layers, so even match only one directory
> * is triggered as mounted.
> + * FIXME: We cannot distinguish mounted directories if overlayfs was
> + * mounted use relative path, so there may have misjudgment.
> */
> int ovl_check_mount(bool *mounted)
> {
> diff --git a/mount.h b/mount.h
> index 7eed0d0..2cf5e6a 100644
> --- a/mount.h
> +++ b/mount.h
> @@ -19,8 +19,16 @@
> #ifndef OVL_MOUNT_H
> #define OVL_MOUNT_H
>
> -int ovl_resolve_lowerdirs(char *loweropt, char ***lowerdir,
> - int *lowernum);
> +struct ovl_config {
> + char *lowerdir;
> + char *upperdir;
> + char *workdir;
> +};
> +
> +void ovl_parse_opt(char *opt, struct ovl_config *config);
> +void ovl_free_opt(struct ovl_config *config);
> +int ovl_get_dirs(struct ovl_config *config, char ***lowerdir,
> + int *lowernum, char **upperdir, char **workdir);
> int ovl_check_mount(bool *mounted);
>
> #endif /* OVL_MOUNT_H */
> --
> 2.9.5
>
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