From de881df97768d07b342cbd1f8359b832afccace9 Mon Sep 17 00:00:00 2001 From: Aravind Ramesh Date: Thu, 16 Jul 2020 18:26:56 +0530 Subject: f2fs: support zone capacity less than zone size NVMe Zoned Namespace devices can have zone-capacity less than zone-size. Zone-capacity indicates the maximum number of sectors that are usable in a zone beginning from the first sector of the zone. This makes the sectors sectors after the zone-capacity till zone-size to be unusable. This patch set tracks zone-size and zone-capacity in zoned devices and calculate the usable blocks per segment and usable segments per section. If zone-capacity is less than zone-size mark only those segments which start before zone-capacity as free segments. All segments at and beyond zone-capacity are treated as permanently used segments. In cases where zone-capacity does not align with segment size the last segment will start before zone-capacity and end beyond the zone-capacity of the zone. For such spanning segments only sectors within the zone-capacity are used. During writes and GC manage the usable segments in a section and usable blocks per segment. Segments which are beyond zone-capacity are never allocated, and do not need to be garbage collected, only the segments which are before zone-capacity needs to garbage collected. For spanning segments based on the number of usable blocks in that segment, write to blocks only up to zone-capacity. Zone-capacity is device specific and cannot be configured by the user. Since NVMe ZNS device zones are sequentially write only, a block device with conventional zones or any normal block device is needed along with the ZNS device for the metadata operations of F2fs. A typical nvme-cli output of a zoned device shows zone start and capacity and write pointer as below: SLBA: 0x0 WP: 0x0 Cap: 0x18800 State: EMPTY Type: SEQWRITE_REQ SLBA: 0x20000 WP: 0x20000 Cap: 0x18800 State: EMPTY Type: SEQWRITE_REQ SLBA: 0x40000 WP: 0x40000 Cap: 0x18800 State: EMPTY Type: SEQWRITE_REQ Here zone size is 64MB, capacity is 49MB, WP is at zone start as the zones are in EMPTY state. For each zone, only zone start + 49MB is usable area, any lba/sector after 49MB cannot be read or written to, the drive will fail any attempts to read/write. So, the second zone starts at 64MB and is usable till 113MB (64 + 49) and the range between 113 and 128MB is again unusable. The next zone starts at 128MB, and so on. Signed-off-by: Aravind Ramesh Signed-off-by: Damien Le Moal Signed-off-by: Niklas Cassel Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/gc.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) (limited to 'fs/f2fs/gc.c') diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 11b4adde9baf..2232bcf344b6 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -266,13 +266,14 @@ static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno) unsigned char age = 0; unsigned char u; unsigned int i; + unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi, segno); - for (i = 0; i < sbi->segs_per_sec; i++) + for (i = 0; i < usable_segs_per_sec; i++) mtime += get_seg_entry(sbi, start + i)->mtime; vblocks = get_valid_blocks(sbi, segno, true); - mtime = div_u64(mtime, sbi->segs_per_sec); - vblocks = div_u64(vblocks, sbi->segs_per_sec); + mtime = div_u64(mtime, usable_segs_per_sec); + vblocks = div_u64(vblocks, usable_segs_per_sec); u = (vblocks * 100) >> sbi->log_blocks_per_seg; @@ -536,6 +537,7 @@ static int gc_node_segment(struct f2fs_sb_info *sbi, int phase = 0; bool fggc = (gc_type == FG_GC); int submitted = 0; + unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno); start_addr = START_BLOCK(sbi, segno); @@ -545,7 +547,7 @@ next_step: if (fggc && phase == 2) atomic_inc(&sbi->wb_sync_req[NODE]); - for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { + for (off = 0; off < usable_blks_in_seg; off++, entry++) { nid_t nid = le32_to_cpu(entry->nid); struct page *node_page; struct node_info ni; @@ -1033,13 +1035,14 @@ static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, int off; int phase = 0; int submitted = 0; + unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno); start_addr = START_BLOCK(sbi, segno); next_step: entry = sum; - for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { + for (off = 0; off < usable_blks_in_seg; off++, entry++) { struct page *data_page; struct inode *inode; struct node_info dni; /* dnode info for the data */ @@ -1204,6 +1207,15 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi, if (__is_large_section(sbi)) end_segno = rounddown(end_segno, sbi->segs_per_sec); + /* + * zone-capacity can be less than zone-size in zoned devices, + * resulting in less than expected usable segments in the zone, + * calculate the end segno in the zone which can be garbage collected + */ + if (f2fs_sb_has_blkzoned(sbi)) + end_segno -= sbi->segs_per_sec - + f2fs_usable_segs_in_sec(sbi, segno); + /* readahead multi ssa blocks those have contiguous address */ if (__is_large_section(sbi)) f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), @@ -1356,7 +1368,8 @@ gc_more: goto stop; seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type); - if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec) + if (gc_type == FG_GC && + seg_freed == f2fs_usable_segs_in_sec(sbi, segno)) sec_freed++; total_freed += seg_freed; -- cgit v1.2.3