| Message ID | 20161219065642.25078-3-quwenruo@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Dec 19, 2016 at 02:56:38PM +0800, Qu Wenruo wrote: > Introduce basic set operations: is_subset() and is_intersection(). > > This is quite useful to check if a range [start, start + len) subset or > intersection of another range. > So we don't need to use open code to do it, which I sometimes do it > wrong. > > Also use these new facilities in btrfs-convert, to check if a range is a > subset or intersects with btrfs convert reserved ranges. I see the range helpers used only inside convert so I don't think we need to export them into utils. Then you could introduce a helper structure with start and len members and use that instead of 2 arrays > --- a/disk-io.h > +++ b/disk-io.h > @@ -97,11 +97,16 @@ enum btrfs_read_sb_flags { > SBREAD_PARTIAL = (1 << 1), > }; > > +/* > + * Use macro to define mirror super block position > + * So we can use it in static array initializtion > + */ > +#define BTRFS_SB_MIRROR_OFFSET(mirror) ((u64)(16 * 1024) << \ > + (BTRFS_SUPER_MIRROR_SHIFT * (mirror))) This is unrelated change and should go separately. > static inline u64 btrfs_sb_offset(int mirror) > { > - u64 start = 16 * 1024; > if (mirror) > - return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror); > + return BTRFS_SB_MIRROR_OFFSET(mirror); > return BTRFS_SUPER_INFO_OFFSET; > } > -- 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 Mon, Dec 19, 2016 at 02:56:38PM +0800, Qu Wenruo wrote: > +static u64 reserved_range_starts[3] = { 0, BTRFS_SB_MIRROR_OFFSET(1), > + BTRFS_SB_MIRROR_OFFSET(2) }; > +static u64 reserved_range_lens[3] = { 1024 * 1024, 64 * 1024, 64 * 1024 }; Also anywhere in the relevant code, the 3 should be better a named constant and not either 3 or the ARRAY_SIZE, or 2 in some backward going for loop I've seen. -- 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
At 01/24/2017 01:28 AM, David Sterba wrote: > On Mon, Dec 19, 2016 at 02:56:38PM +0800, Qu Wenruo wrote: >> Introduce basic set operations: is_subset() and is_intersection(). >> >> This is quite useful to check if a range [start, start + len) subset or >> intersection of another range. >> So we don't need to use open code to do it, which I sometimes do it >> wrong. >> >> Also use these new facilities in btrfs-convert, to check if a range is a >> subset or intersects with btrfs convert reserved ranges. > > I see the range helpers used only inside convert so I don't think we > need to export them into utils. Then you could introduce a helper > structure with start and len members and use that instead of 2 arrays Right, I could move it convert. > >> --- a/disk-io.h >> +++ b/disk-io.h >> @@ -97,11 +97,16 @@ enum btrfs_read_sb_flags { >> SBREAD_PARTIAL = (1 << 1), >> }; >> >> +/* >> + * Use macro to define mirror super block position >> + * So we can use it in static array initializtion >> + */ >> +#define BTRFS_SB_MIRROR_OFFSET(mirror) ((u64)(16 * 1024) << \ >> + (BTRFS_SUPER_MIRROR_SHIFT * (mirror))) > > This is unrelated change and should go separately. OK, I can send out a patch first. Thanks for reviewing, Qu > >> static inline u64 btrfs_sb_offset(int mirror) >> { >> - u64 start = 16 * 1024; >> if (mirror) >> - return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror); >> + return BTRFS_SB_MIRROR_OFFSET(mirror); >> return BTRFS_SUPER_INFO_OFFSET; >> } >> > > -- 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/convert/main.c b/convert/main.c index 15f14af..db6d371 100644 --- a/convert/main.c +++ b/convert/main.c @@ -61,6 +61,15 @@ #define CONV_IMAGE_SUBVOL_OBJECTID BTRFS_FIRST_FREE_OBJECTID +/* + * Btrfs reserved ranges. + * In these ranges, btrfs record superblocks, so old fs data in these + * range can be relocated to other physical location + */ +static u64 reserved_range_starts[3] = { 0, BTRFS_SB_MIRROR_OFFSET(1), + BTRFS_SB_MIRROR_OFFSET(2) }; +static u64 reserved_range_lens[3] = { 1024 * 1024, 64 * 1024, 64 * 1024 }; + struct task_ctx { uint32_t max_copy_inodes; uint32_t cur_copy_inodes; @@ -2672,6 +2681,48 @@ fail: return -1; } +/* + * Check if [start, start + len) is a subset of btrfs reserved ranges + */ +static int is_range_subset_of_reserved_ranges(u64 start, u64 len) +{ + int i; + int ret = 0; + + for (i = 0; i < ARRAY_SIZE(reserved_range_starts); i++) { + if (is_range_subset(start, len, reserved_range_starts[i], + reserved_range_lens[i])) { + ret = 1; + break; + } + } + return ret; +} + +/* + * Check if [start, start + len) intersects with btrfs reserved ranges + * if intersects, record the first range it intersects with to @ret_index + */ +static int is_range_intersection_of_reserved_ranges(u64 start, u64 len, + int *ret_index) +{ + int nr = -1; + int i; + + for (i = 0; i < ARRAY_SIZE(reserved_range_starts); i++) { + if (is_range_intersect(start, len, reserved_range_starts[i], + reserved_range_lens[i])) { + nr = i; + break; + } + } + if (nr == -1) + return 0; + if (ret_index) + *ret_index = nr; + return 1; +} + static int do_rollback(const char *devname) { int fd = -1; diff --git a/disk-io.h b/disk-io.h index 1c8387e..af6fcfd 100644 --- a/disk-io.h +++ b/disk-io.h @@ -97,11 +97,16 @@ enum btrfs_read_sb_flags { SBREAD_PARTIAL = (1 << 1), }; +/* + * Use macro to define mirror super block position + * So we can use it in static array initializtion + */ +#define BTRFS_SB_MIRROR_OFFSET(mirror) ((u64)(16 * 1024) << \ + (BTRFS_SUPER_MIRROR_SHIFT * (mirror))) static inline u64 btrfs_sb_offset(int mirror) { - u64 start = 16 * 1024; if (mirror) - return start << (BTRFS_SUPER_MIRROR_SHIFT * mirror); + return BTRFS_SB_MIRROR_OFFSET(mirror); return BTRFS_SUPER_INFO_OFFSET; } diff --git a/utils.h b/utils.h index 366ca29..39ca970 100644 --- a/utils.h +++ b/utils.h @@ -457,4 +457,23 @@ unsigned int rand_range(unsigned int upper); /* Also allow setting the seed manually */ void init_rand_seed(u64 seed); +/* + * Basic set operations + * Mainly used for ranges subset/intersect + */ +/* Check if [start1, start1 + len1) is subset of [start2, start2 + len2) */ +static inline int is_range_subset(u64 start1, u64 len1, u64 start2, u64 len2) +{ + if (start1 >= start2 && start1 + len1 <= start2 + len2) + return 1; + return 0; +} + +/* Check if [start1, start1 + len1) intersects with [start2, start2 + len2) */ +static inline int is_range_intersect(u64 start1, u64 len1, u64 start2, u64 len2) +{ + if (start1 >= start2 + len2 || start1 + len1 <= start2) + return 0; + return 1; +} #endif
Introduce basic set operations: is_subset() and is_intersection(). This is quite useful to check if a range [start, start + len) subset or intersection of another range. So we don't need to use open code to do it, which I sometimes do it wrong. Also use these new facilities in btrfs-convert, to check if a range is a subset or intersects with btrfs convert reserved ranges. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> --- convert/main.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ disk-io.h | 9 +++++++-- utils.h | 19 +++++++++++++++++++ 3 files changed, 77 insertions(+), 2 deletions(-)