Hi,
On Thu, 2013-08-08 at 18:02 +0100, Andrew Price wrote:
> sdp->device_name wasn't getting set in gfs2_grow so is_gfs2() (called
> via check_for_gfs2()) fails to open "" and so we get an ENOENT.
>
> This fixes the open("") by setting sdp->device_name before passing it to
> is_pathname_mounted(), which has been updated to make it more clear
> which args will be modified by it.
>
> is_gfs2() and check_for_gfs2() have also been removed from libgfs2 as
> these were the only places they were being called and they aren't
> needed: superblock checking is done further along via other functions
> calling check_sb().
>
Definitely an improvement over what we had before, but I wonder whether
we can do better still. Is the fd always open before we call
is_pathname_mounted() I wonder? If so we should be able to just pass the
fd to it which reduces the possibility for races I think, and may also
simplify things a bit more,
Steve.
> Signed-off-by: Andrew Price <[email protected]>
> ---
> gfs2/fsck/initialize.c | 2 +-
> gfs2/libgfs2/libgfs2.h | 4 +---
> gfs2/libgfs2/misc.c | 42 ++++++------------------------------------
> gfs2/mkfs/main_grow.c | 10 +++++++---
> gfs2/mkfs/main_jadd.c | 3 ++-
> 5 files changed, 17 insertions(+), 44 deletions(-)
>
> diff --git a/gfs2/fsck/initialize.c b/gfs2/fsck/initialize.c
> index b45ae08..6612fe7 100644
> --- a/gfs2/fsck/initialize.c
> +++ b/gfs2/fsck/initialize.c
> @@ -1491,7 +1491,7 @@ int initialize(struct gfs2_sbd *sdp, int force_check,
> int preen,
> strncpy(sdp->device_name, opts.device,
> sizeof(sdp->device_name));
> sdp->path_name = sdp->device_name; /* This gets overwritten */
> - is_mounted = is_pathname_mounted(sdp, &ro);
> + is_mounted = is_pathname_mounted(sdp->path_name,
> sdp->device_name, &ro);
> /* If the device is busy, but not because it's mounted, fail.
> This protects against cases where the file system is LVM
> and perhaps mounted on a different node. */
> diff --git a/gfs2/libgfs2/libgfs2.h b/gfs2/libgfs2/libgfs2.h
> index fe7129a..e994d3b 100644
> --- a/gfs2/libgfs2/libgfs2.h
> +++ b/gfs2/libgfs2/libgfs2.h
> @@ -716,11 +716,9 @@ extern void decrease_verbosity(void);
> extern int compute_heightsize(struct gfs2_sbd *sdp, uint64_t *heightsize,
> uint32_t *maxheight, uint32_t bsize1, int diptrs, int inptrs);
> extern int compute_constants(struct gfs2_sbd *sdp);
> -extern int is_pathname_mounted(struct gfs2_sbd *sdp, int *ro_mount);
> -extern int is_gfs2(struct gfs2_sbd *sdp);
> +extern int is_pathname_mounted(char *path_name, char *device_name, int
> *ro_mount);
> extern int find_gfs2_meta(struct gfs2_sbd *sdp);
> extern int dir_exists(const char *dir);
> -extern int check_for_gfs2(struct gfs2_sbd *sdp);
> extern int mount_gfs2_meta(struct gfs2_sbd *sdp);
> extern void cleanup_metafs(struct gfs2_sbd *sdp);
> extern int set_sysfs(const char *fsname, const char *filename, const char
> *val);
> diff --git a/gfs2/libgfs2/misc.c b/gfs2/libgfs2/misc.c
> index c05a770..6f2dbdb 100644
> --- a/gfs2/libgfs2/misc.c
> +++ b/gfs2/libgfs2/misc.c
> @@ -99,7 +99,7 @@ int compute_constants(struct gfs2_sbd *sdp)
> return 0;
> }
>
> -int is_pathname_mounted(struct gfs2_sbd *sdp, int *ro_mount)
> +int is_pathname_mounted(char *path_name, char *device_name, int *ro_mount)
> {
> FILE *fp;
> struct mntent *mnt;
> @@ -112,7 +112,7 @@ int is_pathname_mounted(struct gfs2_sbd *sdp, int
> *ro_mount)
> perror("open: /proc/mounts");
> return 0;
> }
> - if (stat(sdp->path_name, &st_buf) == 0) {
> + if (stat(path_name, &st_buf) == 0) {
> if (S_ISBLK(st_buf.st_mode)) {
> #ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */
> file_rdev = st_buf.st_rdev;
> @@ -124,12 +124,12 @@ int is_pathname_mounted(struct gfs2_sbd *sdp, int
> *ro_mount)
> }
> while ((mnt = getmntent (fp)) != NULL) {
> /* Check if they specified the device instead of mnt point */
> - if (strcmp(sdp->device_name, mnt->mnt_fsname) == 0) {
> - strcpy(sdp->path_name, mnt->mnt_dir); /* fix it */
> + if (strcmp(device_name, mnt->mnt_fsname) == 0) {
> + strcpy(path_name, mnt->mnt_dir); /* fix it */
> break;
> }
> - if (strcmp(sdp->path_name, mnt->mnt_dir) == 0) {
> - strcpy(sdp->device_name, mnt->mnt_fsname); /* fix it */
> + if (strcmp(path_name, mnt->mnt_dir) == 0) {
> + strcpy(device_name, mnt->mnt_fsname); /* fix it */
> break;
> }
> if (stat(mnt->mnt_fsname, &st_buf) == 0) {
> @@ -160,36 +160,6 @@ int is_pathname_mounted(struct gfs2_sbd *sdp, int
> *ro_mount)
> return 1; /* mounted */
> }
>
> -int is_gfs2(struct gfs2_sbd *sdp)
> -{
> - int fd, rc;
> - struct gfs2_sb sb;
> -
> - fd = open(sdp->device_name, O_RDWR);
> - if (fd < 0)
> - return 0;
> -
> - rc = 0;
> - if (lseek(fd, GFS2_SB_ADDR * GFS2_BASIC_BLOCK, SEEK_SET) >= 0 &&
> - read(fd, &sb, sizeof(sb)) == sizeof(sb) &&
> - be32_to_cpu(sb.sb_header.mh_magic) == GFS2_MAGIC &&
> - be32_to_cpu(sb.sb_header.mh_type) == GFS2_METATYPE_SB)
> - rc = 1;
> - close(fd);
> - return rc;
> -}
> -
> -int check_for_gfs2(struct gfs2_sbd *sdp)
> -{
> - int ro;
> -
> - if (!is_pathname_mounted(sdp, &ro))
> - return -1;
> - if (!is_gfs2(sdp))
> - return -1;
> - return 0;
> -}
> -
> static int lock_for_admin(struct gfs2_sbd *sdp)
> {
> int error;
> diff --git a/gfs2/mkfs/main_grow.c b/gfs2/mkfs/main_grow.c
> index 73c7f84..d324af9 100644
> --- a/gfs2/mkfs/main_grow.c
> +++ b/gfs2/mkfs/main_grow.c
> @@ -323,6 +323,7 @@ main_grow(int argc, char *argv[])
> int rgcount, rindex_fd;
> char rindex_name[PATH_MAX];
> int error = EXIT_SUCCESS;
> + int ro_mnt = 0;
>
> memset(sdp, 0, sizeof(struct gfs2_sbd));
> sdp->bsize = GFS2_DEFAULT_BSIZE;
> @@ -336,17 +337,20 @@ main_grow(int argc, char *argv[])
> int sane;
> struct rgrp_tree *last_rgrp;
>
> + strncpy(sdp->device_name, argv[optind], PATH_MAX - 1);
> sdp->path_name = argv[optind++];
> - sdp->path_fd = open(sdp->path_name, O_RDONLY | O_CLOEXEC);
> - if (sdp->path_fd < 0){
> +
> + if ((!is_pathname_mounted(sdp->path_name, sdp->device_name,
> &ro_mnt))) {
> perror(sdp->path_name);
> exit(EXIT_FAILURE);
> }
>
> - if (check_for_gfs2(sdp)) {
> + sdp->path_fd = open(sdp->path_name, O_RDONLY | O_CLOEXEC);
> + if (sdp->path_fd < 0){
> perror(sdp->path_name);
> exit(EXIT_FAILURE);
> }
> +
> sdp->device_fd = open(sdp->device_name,
> (test ? O_RDONLY : O_RDWR) | O_CLOEXEC);
> if (sdp->device_fd < 0){
> diff --git a/gfs2/mkfs/main_jadd.c b/gfs2/mkfs/main_jadd.c
> index 58fb046..2646829 100644
> --- a/gfs2/mkfs/main_jadd.c
> +++ b/gfs2/mkfs/main_jadd.c
> @@ -491,6 +491,7 @@ void main_jadd(int argc, char *argv[])
> {
> struct gfs2_sbd sbd, *sdp = &sbd;
> unsigned int total;
> + int ro_mnt = 0;
>
> memset(sdp, 0, sizeof(struct gfs2_sbd));
> sdp->jsize = GFS2_DEFAULT_JSIZE;
> @@ -506,7 +507,7 @@ void main_jadd(int argc, char *argv[])
> exit(EXIT_FAILURE);
> }
>
> - if (check_for_gfs2(sdp)) {
> + if (!is_pathname_mounted(sdp->path_name, sdp->device_name, &ro_mnt)) {
> perror(sdp->path_name);
> exit(EXIT_FAILURE);
> }
