| Message ID | 1380296700-7232-1-git-send-email-anand.jain@oracle.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
Following this patch the idea is to use lblkid to scan for the btrfs disks by default which means we don't use BTRFS_SCAN_PROC any more. which implies commands btrfs filesystem show and btrfs device scan will use lblkid to scan disks instead of current /proc/partitions by default. So now the question is, if there is any need to have option to scan using /proc/partitions ? and instead of removing it completely would we need it under a new option '-p' (in filesystem show and device scan) so that user can use /proc/partitions when needed, I really don't know what would be that circumstance though, Any thoughts? Thanks Anand On 09/27/2013 11:45 PM, Anand Jain wrote: > Signed-off-by: Anand Jain <anand.jain@oracle.com> > --- > utils.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > utils.h | 2 ++ > 2 files changed, 56 insertions(+) > > diff --git a/utils.c b/utils.c > index c6022fc..ccb5199 100644 > --- a/utils.c > +++ b/utils.c > @@ -1914,6 +1914,57 @@ int test_dev_for_mkfs(char *file, int force_overwrite, char *estr) > return 0; > } > > +int test_skip_this_disk(char *path) > +{ > + int fd; > + /* this will eliminate disks which are mounted (btrfs) > + * and non-dm disk path when dm is enabled > + */ > + fd = open(path, O_RDWR|O_EXCL); > + if (fd < 0) > + return 1; > + close(fd); > + return 0; > +} > + > +int btrfs_scan_lblkid(int update_kernel) > +{ > + int fd = -1; > + u64 num_devices; > + struct btrfs_fs_devices *tmp_devices; > + blkid_dev_iterate iter = NULL; > + blkid_dev dev = NULL; > + blkid_cache cache = NULL; > + char path[PATH_MAX]; > + > + if (blkid_get_cache(&cache, 0) < 0) { > + printf("ERROR: lblkid cache get failed\n"); > + return 1; > + } > + blkid_probe_all(cache); > + iter = blkid_dev_iterate_begin(cache); > + blkid_dev_set_search(iter, "TYPE", "btrfs"); > + while (blkid_dev_next(iter, &dev) == 0) { > + dev = blkid_verify(cache, dev); > + if (!dev) > + continue; > + /* if we are here its definitly a btrfs disk*/ > + strcpy(path, blkid_dev_devname(dev)); > + if (test_skip_this_disk(path)) > + continue; > + > + fd = open(path, O_RDONLY); > + btrfs_scan_one_device(fd, path, &tmp_devices, > + &num_devices, BTRFS_SUPER_INFO_OFFSET); > + close(fd); > + fd = -1; > + if (update_kernel) > + btrfs_register_one_device(path); > + } > + blkid_dev_iterate_end(iter); > + return 0; > +} > + > /* > * scans devs for the btrfs > */ > @@ -1928,6 +1979,9 @@ int scan_for_btrfs(int where, int update_kernel) > case BTRFS_SCAN_DEV: > ret = btrfs_scan_one_dir("/dev", update_kernel); > break; > + case BTRFS_SCAN_LBLKID: > + ret = btrfs_scan_lblkid(update_kernel); > + break; > } > return ret; > } > diff --git a/utils.h b/utils.h > index e944685..0f31db7 100644 > --- a/utils.h > +++ b/utils.h > @@ -28,6 +28,7 @@ > #define BTRFS_SCAN_PROC (1ULL << 0) > #define BTRFS_SCAN_DEV (1ULL << 1) > #define BTRFS_SCAN_MOUNTED (1ULL << 2) > +#define BTRFS_SCAN_LBLKID (1ULL << 3) > > #define BTRFS_UPDATE_KERNEL 1 > > @@ -89,5 +90,6 @@ int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf, > int verify); > int ask_user(char *question); > int lookup_ino_rootid(int fd, u64 *rootid); > +int btrfs_scan_lblkid(int update_kernel); > > #endif > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Helo Anand, > > > Following this patch the idea is to use lblkid to scan > for the btrfs disks by default which means we don't > use BTRFS_SCAN_PROC any more. Firstly, i would like to know if we will get any different results between scanning /proc/partions and using lbkid. If not, why we can use liblkid totally,since this is more simple. Thanks, Wang > which implies commands btrfs filesystem show and btrfs device scan will > use lblkid to scan disks instead of current /proc/partitions > by default. > > So now the question is, if there is any need to have option to scan > using /proc/partitions ? and instead of removing it completely > would we need it under a new option '-p' (in filesystem show and > device scan) so that user can use /proc/partitions when needed, > I really don't know what would be that circumstance though, > > Any thoughts? > > Thanks Anand > > > > On 09/27/2013 11:45 PM, Anand Jain wrote: >> Signed-off-by: Anand Jain <anand.jain@oracle.com> >> --- >> utils.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ >> utils.h | 2 ++ >> 2 files changed, 56 insertions(+) >> >> diff --git a/utils.c b/utils.c >> index c6022fc..ccb5199 100644 >> --- a/utils.c >> +++ b/utils.c >> @@ -1914,6 +1914,57 @@ int test_dev_for_mkfs(char *file, int force_overwrite, char *estr) >> return 0; >> } >> >> +int test_skip_this_disk(char *path) >> +{ >> + int fd; >> + /* this will eliminate disks which are mounted (btrfs) >> + * and non-dm disk path when dm is enabled >> + */ >> + fd = open(path, O_RDWR|O_EXCL); >> + if (fd < 0) >> + return 1; >> + close(fd); >> + return 0; >> +} >> + >> +int btrfs_scan_lblkid(int update_kernel) >> +{ >> + int fd = -1; >> + u64 num_devices; >> + struct btrfs_fs_devices *tmp_devices; >> + blkid_dev_iterate iter = NULL; >> + blkid_dev dev = NULL; >> + blkid_cache cache = NULL; >> + char path[PATH_MAX]; >> + >> + if (blkid_get_cache(&cache, 0) < 0) { >> + printf("ERROR: lblkid cache get failed\n"); >> + return 1; >> + } >> + blkid_probe_all(cache); >> + iter = blkid_dev_iterate_begin(cache); >> + blkid_dev_set_search(iter, "TYPE", "btrfs"); >> + while (blkid_dev_next(iter, &dev) == 0) { >> + dev = blkid_verify(cache, dev); >> + if (!dev) >> + continue; >> + /* if we are here its definitly a btrfs disk*/ >> + strcpy(path, blkid_dev_devname(dev)); >> + if (test_skip_this_disk(path)) >> + continue; >> + >> + fd = open(path, O_RDONLY); >> + btrfs_scan_one_device(fd, path, &tmp_devices, >> + &num_devices, BTRFS_SUPER_INFO_OFFSET); >> + close(fd); >> + fd = -1; >> + if (update_kernel) >> + btrfs_register_one_device(path); >> + } >> + blkid_dev_iterate_end(iter); >> + return 0; >> +} >> + >> /* >> * scans devs for the btrfs >> */ >> @@ -1928,6 +1979,9 @@ int scan_for_btrfs(int where, int update_kernel) >> case BTRFS_SCAN_DEV: >> ret = btrfs_scan_one_dir("/dev", update_kernel); >> break; >> + case BTRFS_SCAN_LBLKID: >> + ret = btrfs_scan_lblkid(update_kernel); >> + break; >> } >> return ret; >> } >> diff --git a/utils.h b/utils.h >> index e944685..0f31db7 100644 >> --- a/utils.h >> +++ b/utils.h >> @@ -28,6 +28,7 @@ >> #define BTRFS_SCAN_PROC (1ULL << 0) >> #define BTRFS_SCAN_DEV (1ULL << 1) >> #define BTRFS_SCAN_MOUNTED (1ULL << 2) >> +#define BTRFS_SCAN_LBLKID (1ULL << 3) >> >> #define BTRFS_UPDATE_KERNEL 1 >> >> @@ -89,5 +90,6 @@ int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf, >> int verify); >> int ask_user(char *question); >> int lookup_ino_rootid(int fd, u64 *rootid); >> +int btrfs_scan_lblkid(int update_kernel); >> >> #endif >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, Sep 28, 2013 at 12:21:51AM +0800, Wang Shilong wrote: > > Following this patch the idea is to use lblkid to scan > > for the btrfs disks by default which means we don't > > use BTRFS_SCAN_PROC any more. > > Firstly, i would like to know if we will get any different results between scanning > /proc/partions and using lbkid. I take blkid as a more authoritative source, /proc/partitions was a workaround to avoid scanning the whole /dev directory. > If not, why we can use liblkid totally,since this is more simple. Agreed, blkid by default and --all-devices as a last resort fallback. The proc workaround can go away. david -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/utils.c b/utils.c index c6022fc..ccb5199 100644 --- a/utils.c +++ b/utils.c @@ -1914,6 +1914,57 @@ int test_dev_for_mkfs(char *file, int force_overwrite, char *estr) return 0; } +int test_skip_this_disk(char *path) +{ + int fd; + /* this will eliminate disks which are mounted (btrfs) + * and non-dm disk path when dm is enabled + */ + fd = open(path, O_RDWR|O_EXCL); + if (fd < 0) + return 1; + close(fd); + return 0; +} + +int btrfs_scan_lblkid(int update_kernel) +{ + int fd = -1; + u64 num_devices; + struct btrfs_fs_devices *tmp_devices; + blkid_dev_iterate iter = NULL; + blkid_dev dev = NULL; + blkid_cache cache = NULL; + char path[PATH_MAX]; + + if (blkid_get_cache(&cache, 0) < 0) { + printf("ERROR: lblkid cache get failed\n"); + return 1; + } + blkid_probe_all(cache); + iter = blkid_dev_iterate_begin(cache); + blkid_dev_set_search(iter, "TYPE", "btrfs"); + while (blkid_dev_next(iter, &dev) == 0) { + dev = blkid_verify(cache, dev); + if (!dev) + continue; + /* if we are here its definitly a btrfs disk*/ + strcpy(path, blkid_dev_devname(dev)); + if (test_skip_this_disk(path)) + continue; + + fd = open(path, O_RDONLY); + btrfs_scan_one_device(fd, path, &tmp_devices, + &num_devices, BTRFS_SUPER_INFO_OFFSET); + close(fd); + fd = -1; + if (update_kernel) + btrfs_register_one_device(path); + } + blkid_dev_iterate_end(iter); + return 0; +} + /* * scans devs for the btrfs */ @@ -1928,6 +1979,9 @@ int scan_for_btrfs(int where, int update_kernel) case BTRFS_SCAN_DEV: ret = btrfs_scan_one_dir("/dev", update_kernel); break; + case BTRFS_SCAN_LBLKID: + ret = btrfs_scan_lblkid(update_kernel); + break; } return ret; } diff --git a/utils.h b/utils.h index e944685..0f31db7 100644 --- a/utils.h +++ b/utils.h @@ -28,6 +28,7 @@ #define BTRFS_SCAN_PROC (1ULL << 0) #define BTRFS_SCAN_DEV (1ULL << 1) #define BTRFS_SCAN_MOUNTED (1ULL << 2) +#define BTRFS_SCAN_LBLKID (1ULL << 3) #define BTRFS_UPDATE_KERNEL 1 @@ -89,5 +90,6 @@ int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf, int verify); int ask_user(char *question); int lookup_ino_rootid(int fd, u64 *rootid); +int btrfs_scan_lblkid(int update_kernel); #endif
Signed-off-by: Anand Jain <anand.jain@oracle.com> --- utils.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ utils.h | 2 ++ 2 files changed, 56 insertions(+)