diff options
Diffstat (limited to 'fs/logfs/journal.c')
| -rw-r--r-- | fs/logfs/journal.c | 879 |
1 files changed, 879 insertions, 0 deletions
diff --git a/fs/logfs/journal.c b/fs/logfs/journal.c new file mode 100644 index 0000000..7a023db --- /dev/null +++ b/fs/logfs/journal.c @@ -0,0 +1,879 @@ +/* + * fs/logfs/journal.c - journal handling code + * + * As should be obvious for Linux kernel code, license is GPLv2 + * + * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org> + */ +#include "logfs.h" + +static void logfs_calc_free(struct super_block *sb) +{ + struct logfs_super *super = logfs_super(sb); + u64 reserve, no_segs = super->s_no_segs; + s64 free; + int i; + + /* superblock segments */ + no_segs -= 2; + super->s_no_journal_segs = 0; + /* journal */ + journal_for_each(i) + if (super->s_journal_seg[i]) { + no_segs--; + super->s_no_journal_segs++; + } + + /* open segments plus one extra per level for GC */ + no_segs -= 2 * super->s_total_levels; + + free = no_segs * (super->s_segsize - LOGFS_SEGMENT_RESERVE); + free -= super->s_used_bytes; + /* just a bit extra */ + free -= super->s_total_levels * 4096; + + /* Bad blocks are 'paid' for with speed reserve - the filesystem + * simply gets slower as bad blocks accumulate. Until the bad blocks + * exceed the speed reserve - then the filesystem gets smaller. + */ + reserve = super->s_bad_segments + super->s_bad_seg_reserve; + reserve *= super->s_segsize - LOGFS_SEGMENT_RESERVE; + reserve = max(reserve, super->s_speed_reserve); + free -= reserve; + if (free < 0) + free = 0; + + super->s_free_bytes = free; +} + +static void reserve_sb_and_journal(struct super_block *sb) +{ + struct logfs_super *super = logfs_super(sb); + struct btree_head32 *head = &super->s_reserved_segments; + int i, err; + + err = btree_insert32(head, seg_no(sb, super->s_sb_ofs[0]), (void *)1, + GFP_KERNEL); + BUG_ON(err); + + err = btree_insert32(head, seg_no(sb, super->s_sb_ofs[1]), (void *)1, + GFP_KERNEL); + BUG_ON(err); + + journal_for_each(i) { + if (!super->s_journal_seg[i]) + continue; + err = btree_insert32(head, super->s_journal_seg[i], (void *)1, + GFP_KERNEL); + BUG_ON(err); + } +} + +static void read_dynsb(struct super_block *sb, + struct logfs_je_dynsb *dynsb) +{ + struct logfs_super *super = logfs_super(sb); + + super->s_gec = be64_to_cpu(dynsb->ds_gec); + super->s_sweeper = be64_to_cpu(dynsb->ds_sweeper); + super->s_victim_ino = be64_to_cpu(dynsb->ds_victim_ino); + super->s_rename_dir = be64_to_cpu(dynsb->ds_rename_dir); + super->s_rename_pos = be64_to_cpu(dynsb->ds_rename_pos); + super->s_used_bytes = be64_to_cpu(dynsb->ds_used_bytes); + super->s_generation = be32_to_cpu(dynsb->ds_generation); +} + +static void read_anchor(struct super_block *sb, + struct logfs_je_anchor *da) +{ + struct logfs_super *super = logfs_super(sb); + struct inode *inode = super->s_master_inode; + struct logfs_inode *li = logfs_inode(inode); + int i; + + super->s_last_ino = be64_to_cpu(da->da_last_ino); + li->li_flags = 0; + li->li_height = da->da_height; + i_size_write(inode, be64_to_cpu(da->da_size)); + li->li_used_bytes = be64_to_cpu(da->da_used_bytes); + + for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++) + li->li_data[i] = be64_to_cpu(da->da_data[i]); +} + +static void read_erasecount(struct super_block *sb, + struct logfs_je_journal_ec *ec) +{ + struct logfs_super *super = logfs_super(sb); + int i; + + journal_for_each(i) + super->s_journal_ec[i] = be32_to_cpu(ec->ec[i]); +} + +static int read_area(struct super_block *sb, struct logfs_je_area *a) +{ + struct logfs_super *super = logfs_super(sb); + struct logfs_area *area = super->s_area[a->gc_level]; + u64 ofs; + u32 writemask = ~(super->s_writesize - 1); + + if (a->gc_level >= LOGFS_NO_AREAS) + return -EIO; + if (a->vim != VIM_DEFAULT) + return -EIO; /* TODO: close area and continue */ + + area->a_used_bytes = be32_to_cpu(a->used_bytes); + area->a_written_bytes = area->a_used_bytes & writemask; + area->a_segno = be32_to_cpu(a->segno); + if (area->a_segno) + area->a_is_open = 1; + + ofs = dev_ofs(sb, area->a_segno, area->a_written_bytes); + if (super->s_writesize > 1) + logfs_buf_recover(area, ofs, a + 1, super->s_writesize); + else + logfs_buf_recover(area, ofs, NULL, 0); + return 0; +} + +static void *unpack(void *from, void *to) +{ + struct logfs_journal_header *jh = from; + void *data = from + sizeof(struct logfs_journal_header); + int err; + size_t inlen, outlen; + + inlen = be16_to_cpu(jh->h_len); + outlen = be16_to_cpu(jh->h_datalen); + + if (jh->h_compr == COMPR_NONE) + memcpy(to, data, inlen); + else { + err = logfs_uncompress(data, to, inlen, outlen); + BUG_ON(err); + } + return to; +} + +static int __read_je_header(struct super_block *sb, u64 ofs, + struct logfs_journal_header *jh) +{ + struct logfs_super *super = logfs_super(sb); + size_t bufsize = max_t(size_t, sb->s_blocksize, super->s_writesize) + + MAX_JOURNAL_HEADER; + u16 type, len, datalen; + int err; + + /* read header only */ + err = wbuf_read(sb, ofs, sizeof(*jh), jh); + if (err) + return err; + type = be16_to_cpu(jh->h_type); + len = be16_to_cpu(jh->h_len); + datalen = be16_to_cpu(jh->h_datalen); + if (len > sb->s_blocksize) + return -EIO; + if ((type < JE_FIRST) || (type > JE_LAST)) + return -EIO; + if (datalen > bufsize) + return -EIO; + return 0; +} + +static int __read_je_payload(struct super_block *sb, u64 ofs, + struct logfs_journal_header *jh) +{ + u16 len; + int err; + + len = be16_to_cpu(jh->h_len); + err = wbuf_read(sb, ofs + sizeof(*jh), len, jh + 1); + if (err) + return err; + if (jh->h_crc != logfs_crc32(jh, len + sizeof(*jh), 4)) { + /* Old code was confused. It forgot about the header length + * and stopped calculating the crc 16 bytes before the end + * of data - ick! + * FIXME: Remove this hack once the old code is fixed. + */ + if (jh->h_crc == logfs_crc32(jh, len, 4)) + WARN_ON_ONCE(1); + else + return -EIO; + } + return 0; +} + +/* + * jh needs to be large enough to hold the complete entry, not just the header + */ +static int __read_je(struct super_block *sb, u64 ofs, + struct logfs_journal_header *jh) +{ + int err; + + err = __read_je_header(sb, ofs, jh); + if (err) + return err; + return __read_je_payload(sb, ofs, jh); +} + +static int read_je(struct super_block *sb, u64 ofs) +{ + struct logfs_super *super = logfs_super(sb); + struct logfs_journal_header *jh = super->s_compressed_je; + void *scratch = super->s_je; + u16 type, datalen; + int err; + + err = __read_je(sb, ofs, jh); + if (err) + return err; + type = be16_to_cpu(jh->h_type); + datalen = be16_to_cpu(jh->h_datalen); + + switch (type) { + case JE_DYNSB: + read_dynsb(sb, unpack(jh, scratch)); + break; + case JE_ANCHOR: + read_anchor(sb, unpack(jh, scratch)); + break; + case JE_ERASECOUNT: + read_erasecount(sb, unpack(jh, scratch)); + break; + case JE_AREA: + read_area(sb, unpack(jh, scratch)); + break; + case JE_OBJ_ALIAS: + err = logfs_load_object_aliases(sb, unpack(jh, scratch), + datalen); + break; + default: + WARN_ON_ONCE(1); + return -EIO; + } + return err; +} + +static int logfs_read_segment(struct super_block *sb, u32 segno) +{ + struct logfs_super *super = logfs_super(sb); + struct logfs_journal_header *jh = super->s_compressed_je; + u64 ofs, seg_ofs = dev_ofs(sb, segno, 0); + u32 h_ofs, last_ofs = 0; + u16 len, datalen, last_len; + int i, err; + + /* search for most recent commit */ + for (h_ofs = 0; h_ofs < super->s_segsize; h_ofs += sizeof(*jh)) { + ofs = seg_ofs + h_ofs; + err = __read_je_header(sb, ofs, jh); + if (err) + continue; + if (jh->h_type != cpu_to_be16(JE_COMMIT)) + continue; + err = __read_je_payload(sb, ofs, jh); + if (err) + continue; + len = be16_to_cpu(jh->h_len); + datalen = be16_to_cpu(jh->h_datalen); + if ((datalen > sizeof(super->s_je_array)) || + (datalen % sizeof(__be64))) + continue; + last_ofs = h_ofs; + last_len = datalen; + h_ofs += ALIGN(len, sizeof(*jh)) - sizeof(*jh); + } + /* read commit */ + if (last_ofs == 0) + return -ENOENT; + ofs = seg_ofs + last_ofs; + log_journal("Read commit from %llx\n", ofs); + err = __read_je(sb, ofs, jh); + BUG_ON(err); /* We should have caught it in the scan loop already */ + if (err) + return err; + /* uncompress */ + unpack(jh, super->s_je_array); + super->s_no_je = last_len / sizeof(__be64); + /* iterate over array */ + for (i = 0; i < super->s_no_je; i++) { + err = read_je(sb, be64_to_cpu(super->s_je_array[i])); + if (err) + return err; + } + super->s_journal_area->a_segno = segno; + return 0; +} + +static u64 read_gec(struct super_block *sb, u32 segno) +{ + struct logfs_segment_header sh; + __be32 crc; + int err; + + if (!segno) + return 0; + err = wbuf_read(sb, dev_ofs(sb, segno, 0), sizeof(sh), &sh); + if (err) + return 0; + crc = logfs_crc32(&sh, sizeof(sh), 4); + if (crc != sh.crc) { + WARN_ON(sh.gec != cpu_to_be64(0xffffffffffffffffull)); + /* Most likely it was just erased */ + return 0; + } + return be64_to_cpu(sh.gec); +} + +static int logfs_read_journal(struct super_block *sb) +{ + struct logfs_super *super = logfs_super(sb); + u64 gec[LOGFS_JOURNAL_SEGS], max; + u32 segno; + int i, max_i; + + max = 0; + max_i = -1; + journal_for_each(i) { + segno = super->s_journal_seg[i]; + gec[i] = read_gec(sb, super->s_journal_seg[i]); + if (gec[i] > max) { + max = gec[i]; + max_i = i; + } + } + if (max_i == -1) + return -EIO; + /* FIXME: Try older segments in case of error */ + return logfs_read_segment(sb, super->s_journal_seg[max_i]); +} + +/* + * First search the current segment (outer loop), then pick the next segment + * in the array, skipping any zero entries (inner loop). + */ +static void journal_get_free_segment(struct logfs_area *area) +{ + struct logfs_super *super = logfs_super(area->a_sb); + int i; + + journal_for_each(i) { + if (area->a_segno != super->s_journal_seg[i]) + continue; + + do { + i++; + if (i == LOGFS_JOURNAL_SEGS) + i = 0; + } while (!super->s_journal_seg[i]); + + area->a_segno = super->s_journal_seg[i]; + area->a_erase_count = ++(super->s_journal_ec[i]); + log_journal("Journal now at %x (ec %x)\n", area->a_segno, + area->a_erase_count); + return; + } + BUG(); +} + +static void journal_get_erase_count(struct logfs_area *area) +{ + /* erase count is stored globally and incremented in + * journal_get_free_segment() - nothing to do here */ +} + +static int journal_erase_segment(struct logfs_area *area) +{ + struct super_block *sb = area->a_sb; + struct logfs_segment_header sh; + u64 ofs; + int err; + + err = logfs_erase_segment(sb, area->a_segno); + if (err) + return err; + + sh.pad = 0; + sh.type = SEG_JOURNAL; + sh.level = 0; + sh.segno = cpu_to_be32(area->a_segno); + sh.ec = cpu_to_be32(area->a_erase_count); + sh.gec = cpu_to_be64(logfs_super(sb)->s_gec); + sh.crc = logfs_crc32(&sh, sizeof(sh), 4); + + /* This causes a bug in segment.c. Not yet. */ + //logfs_set_segment_erased(sb, area->a_segno, area->a_erase_count, 0); + + ofs = dev_ofs(sb, area->a_segno, 0); + area->a_used_bytes = ALIGN(sizeof(sh), 16); + logfs_buf_write(area, ofs, &sh, sizeof(sh)); + return 0; +} + +static size_t __logfs_write_header(struct logfs_super *super, + struct logfs_journal_header *jh, size_t len, size_t datalen, + u16 type, u8 compr) +{ + jh->h_len = cpu_to_be16(len); + jh->h_type = cpu_to_be16(type); + jh->h_version = cpu_to_be16(++super->s_last_version); + jh->h_datalen = cpu_to_be16(datalen); + jh->h_compr = compr; + jh->h_pad[0] = 'H'; + jh->h_pad[1] = 'A'; + jh->h_pad[2] = 'T'; + jh->h_crc = logfs_crc32(jh, len + sizeof(*jh), 4); + return ALIGN(len, 16) + sizeof(*jh); +} + +static size_t logfs_write_header(struct logfs_super *super, + struct logfs_journal_header *jh, size_t datalen, u16 type) +{ + size_t len = datalen; + + return __logfs_write_header(super, jh, len, datalen, type, COMPR_NONE); +} + +static inline size_t logfs_journal_erasecount_size(struct logfs_super *super) +{ + return LOGFS_JOURNAL_SEGS * sizeof(__be32); +} + +static void *logfs_write_erasecount(struct super_block *sb, void *_ec, + u16 *type, size_t *len) +{ + struct logfs_super *super = logfs_super(sb); + struct logfs_je_journal_ec *ec = _ec; + int i; + + journal_for_each(i) + ec->ec[i] = cpu_to_be32(super->s_journal_ec[i]); + *type = JE_ERASECOUNT; + *len = logfs_journal_erasecount_size(super); + return ec; +} + +static void account_shadow(void *_shadow, unsigned long _sb, u64 ignore, + size_t ignore2) +{ + struct logfs_shadow *shadow = _shadow; + struct super_block *sb = (void *)_sb; + struct logfs_super *super = logfs_super(sb); + + /* consume new space */ + super->s_free_bytes -= shadow->new_len; + super->s_used_bytes += shadow->new_len; + super->s_dirty_used_bytes -= shadow->new_len; + + /* free up old space */ + super->s_free_bytes += shadow->old_len; + super->s_used_bytes -= shadow->old_len; + super->s_dirty_free_bytes -= shadow->old_len; + + logfs_set_segment_used(sb, shadow->old_ofs, -shadow->old_len); + logfs_set_segment_used(sb, shadow->new_ofs, shadow->new_len); + + log_journal("account_shadow(%llx, %llx, %x) %llx->%llx %x->%x\n", + shadow->ino, shadow->bix, shadow->gc_level, + shadow->old_ofs, shadow->new_ofs, + shadow->old_len, shadow->new_len); + mempool_free(shadow, super->s_shadow_pool); +} + +static void account_shadows(struct super_block *sb) +{ + struct logfs_super *super = logfs_super(sb); + struct inode *inode = super->s_master_inode; + struct logfs_inode *li = logfs_inode(inode); + struct shadow_tree *tree = &super->s_shadow_tree; + + btree_grim_visitor64(&tree->new, (unsigned long)sb, account_shadow); + btree_grim_visitor64(&tree->old, (unsigned long)sb, account_shadow); + + if (li->li_block) { + /* + * We never actually use the structure, when attached to the + * master inode. But it is easier to always free it here than + * to have checks in several places elsewhere when allocating + * it. + */ + li->li_block->ops->free_block(sb, li->li_block); + } + BUG_ON((s64)li->li_used_bytes < 0); +} + +static void *__logfs_write_anchor(struct super_block *sb, void *_da, + u16 *type, size_t *len) +{ + struct logfs_super *super = logfs_super(sb); + struct logfs_je_anchor *da = _da; + struct inode *inode = super->s_master_inode; + struct logfs_inode *li = logfs_inode(inode); + int i; + + da->da_height = li->li_height; + da->da_last_ino = cpu_to_be64(super->s_last_ino); + da->da_size = cpu_to_be64(i_size_read(inode)); + da->da_used_bytes = cpu_to_be64(li->li_used_bytes); + for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++) + da->da_data[i] = cpu_to_be64(li->li_data[i]); + *type = JE_ANCHOR; + *len = sizeof(*da); + return da; +} + +static void *logfs_write_dynsb(struct super_block *sb, void *_dynsb, + u16 *type, size_t *len) +{ + struct logfs_super *super = logfs_super(sb); + struct logfs_je_dynsb *dynsb = _dynsb; + + dynsb->ds_gec = cpu_to_be64(super->s_gec); + dynsb->ds_sweeper = cpu_to_be64(super->s_sweeper); + dynsb->ds_victim_ino = cpu_to_be64(super->s_victim_ino); + dynsb->ds_rename_dir = cpu_to_be64(super->s_rename_dir); + dynsb->ds_rename_pos = cpu_to_be64(super->s_rename_pos); + dynsb->ds_used_bytes = cpu_to_be64(super->s_used_bytes); + dynsb->ds_generation = cpu_to_be32(super->s_generation); + *type = JE_DYNSB; + *len = sizeof(*dynsb); + return dynsb; +} + +static void write_wbuf(struct super_block *sb, struct logfs_area *area, + void *wbuf) +{ + struct logfs_super *super = logfs_super(sb); + struct address_space *mapping = super->s_mapping_inode->i_mapping; + u64 ofs; + pgoff_t index; + int page_ofs; + struct page *page; + + ofs = dev_ofs(sb, area->a_segno, + area->a_used_bytes & ~(super->s_writesize - 1)); + index = ofs >> PAGE_SHIFT; + page_ofs = ofs & (PAGE_SIZE - 1); + + page = find_lock_page(mapping, index); + BUG_ON(!page); + memcpy(wbuf, page_address(page) + page_ofs, super->s_writesize); + unlock_page(page); +} + +static void *logfs_write_area(struct super_block *sb, void *_a, + u16 *type, size_t *len) +{ + struct logfs_super *super = logfs_super(sb); + struct logfs_area *area = super->s_area[super->s_sum_index]; + struct logfs_je_area *a = _a; + + a->vim = VIM_DEFAULT; + a->gc_level = super->s_sum_index; + a->used_bytes = cpu_to_be32(area->a_used_bytes); + a->segno = cpu_to_be32(area->a_segno); + if (super->s_writesize > 1) + write_wbuf(sb, area, a + 1); + + *type = JE_AREA; + *len = sizeof(*a) + super->s_writesize; + return a; +} + +static void *logfs_write_commit(struct super_block *sb, void *h, + u16 *type, size_t *len) +{ + struct logfs_super *super = logfs_super(sb); + + *type = JE_COMMIT; + *len = super->s_no_je * sizeof(__be64); + return super->s_je_array; +} + +static size_t __logfs_write_je(struct super_block *sb, void *buf, u16 type, + size_t len) +{ + struct logfs_super *super = logfs_super(sb); + void *header = super->s_compressed_je; + void *data = header + sizeof(struct logfs_journal_header); + ssize_t compr_len, pad_len; + u8 compr = COMPR_ZLIB; + + if (len == 0) + return logfs_write_header(super, header, 0, type); + + compr_len = logfs_compress(buf, data, len, sb->s_blocksize); + if (compr_len < 0 || type == JE_ANCHOR) { + BUG_ON(len > sb->s_blocksize); + memcpy(data, buf, len); + compr_len = len; + compr = COMPR_NONE; + } + + pad_len = ALIGN(compr_len, 16); + memset(data + compr_len, 0, pad_len - compr_len); + + return __logfs_write_header(super, header, compr_len, len, type, compr); +} + +static s64 logfs_get_free_bytes(struct logfs_area *area, size_t *bytes, + int must_pad) +{ + u32 writesize = logfs_super(area->a_sb)->s_writesize; + s32 ofs; + int ret; + + ret = logfs_open_area(area, *bytes); + if (ret) + return -EAGAIN; + + ofs = area->a_used_bytes; + area->a_used_bytes += *bytes; + + if (must_pad) { + area->a_used_bytes = ALIGN(area->a_used_bytes, writesize); + *bytes = area->a_used_bytes - ofs; + } + + return dev_ofs(area->a_sb, area->a_segno, ofs); +} + +static int logfs_write_je_buf(struct super_block *sb, void *buf, u16 type, + size_t buf_len) +{ + struct logfs_super *super = logfs_super(sb); + struct logfs_area *area = super->s_journal_area; + struct logfs_journal_header *jh = super->s_compressed_je; + size_t len; + int must_pad = 0; + s64 ofs; + + len = __logfs_write_je(sb, buf, type, buf_len); + if (jh->h_type == cpu_to_be16(JE_COMMIT)) + must_pad = 1; + + ofs = logfs_get_free_bytes(area, &len, must_pad); + if (ofs < 0) + return ofs; + logfs_buf_write(area, ofs, super->s_compressed_je, len); + super->s_je_array[super->s_no_je++] = cpu_to_be64(ofs); + return 0; +} + +static int logfs_write_je(struct super_block *sb, + void* (*write)(struct super_block *sb, void *scratch, + u16 *type, size_t *len)) +{ + void *buf; + size_t len; + u16 type; + + buf = write(sb, logfs_super(sb)->s_je, &type, &len); + return logfs_write_je_buf(sb, buf, type, len); +} + +int write_alias_journal(struct super_block *sb, u64 ino, u64 bix, + level_t level, int child_no, __be64 val) +{ + struct logfs_super *super = logfs_super(sb); + struct logfs_obj_alias *oa = super->s_je; + int err = 0, fill = super->s_je_fill; + + log_aliases("logfs_write_obj_aliases #%x(%llx, %llx, %x, %x) %llx\n", + fill, ino, bix, level, child_no, be64_to_cpu(val)); + oa[fill].ino = cpu_to_be64(ino); + oa[fill].bix = cpu_to_be64(bix); + oa[fill].val = val; + oa[fill].level = (__force u8)level; + oa[fill].child_no = cpu_to_be16(child_no); + fill++; + if (fill >= sb->s_blocksize / sizeof(*oa)) { + err = logfs_write_je_buf(sb, oa, JE_OBJ_ALIAS, sb->s_blocksize); + fill = 0; + } + + super->s_je_fill = fill; + return err; +} + +static int logfs_write_obj_aliases(struct super_block *sb) +{ + struct logfs_super *super = logfs_super(sb); + int err; + + log_journal("logfs_write_obj_aliases: %d aliases to write\n", + super->s_no_object_aliases); + super->s_je_fill = 0; + err = logfs_write_obj_aliases_pagecache(sb); + if (err) + return err; + + if (super->s_je_fill) + err = logfs_write_je_buf(sb, super->s_je, JE_OBJ_ALIAS, + super->s_je_fill + * sizeof(struct logfs_obj_alias)); + return err; +} + +/* + * Write all journal entries. The goto logic ensures that all journal entries + * are written whenever a new segment is used. It is ugly and potentially a + * bit wasteful, but robustness is more important. With this we can *always* + * erase all journal segments except the one containing the most recent commit. + */ +void logfs_write_anchor(struct inode *inode) +{ + struct super_block *sb = inode->i_sb; + struct logfs_super *super = logfs_super(sb); + struct logfs_area *area = super->s_journal_area; + int i, err; + + BUG_ON(logfs_super(sb)->s_flags & LOGFS_SB_FLAG_SHUTDOWN); + mutex_lock(&super->s_journal_mutex); + + /* Do this first or suffer corruption */ + logfs_sync_segments(sb); + account_shadows(sb); + +again: + super->s_no_je = 0; + for_each_area(i) { + if (!super->s_area[i]->a_is_open) + continue; + super->s_sum_index = i; + err = logfs_write_je(sb, logfs_write_area); + if (err) + goto again; + } + err = logfs_write_obj_aliases(sb); + if (err) + goto again; + err = logfs_write_je(sb, logfs_write_erasecount); + if (err) + goto again; + err = logfs_write_je(sb, __logfs_write_anchor); + if (err) + goto again; + err = logfs_write_je(sb, logfs_write_dynsb); + if (err) + goto again; + /* + * Order is imperative. First we sync all writes, including the + * non-committed journal writes. Then we write the final commit and + * sync the current journal segment. + * There is a theoretical bug here. Syncing the journal segment will + * write a number of journal entries and the final commit. All these + * are written in a single operation. If the device layer writes the + * data back-to-front, the commit will precede the other journal + * entries, leaving a race window. + * Two fixes are possible. Preferred is to fix the device layer to + * ensure writes happen front-to-back. Alternatively we can insert + * another logfs_sync_area() super->s_devops->sync() combo before + * writing the commit. + */ + /* + * On another subject, super->s_devops->sync is usually not necessary. + * Unless called from sys_sync or friends, a barrier would suffice. + */ + super->s_devops->sync(sb); + err = logfs_write_je(sb, logfs_write_commit); + if (err) + goto again; + log_journal("Write commit to %llx\n", + be64_to_cpu(super->s_je_array[super->s_no_je - 1])); + logfs_sync_area(area); + BUG_ON(area->a_used_bytes != area->a_written_bytes); + super->s_devops->sync(sb); + + mutex_unlock(&super->s_journal_mutex); + return; +} + +void do_logfs_journal_wl_pass(struct super_block *sb) +{ + struct logfs_super *super = logfs_super(sb); + struct logfs_area *area = super->s_journal_area; + u32 segno, ec; + int i, err; + + log_journal("Journal requires wear-leveling.\n"); + /* Drop old segments */ + journal_for_each(i) + if (super->s_journal_seg[i]) { + logfs_set_segment_unreserved(sb, + super->s_journal_seg[i], + super->s_journal_ec[i]); + super->s_journal_seg[i] = 0; + super->s_journal_ec[i] = 0; + } + /* Get new segments */ + for (i = 0; i < super->s_no_journal_segs; i++) { + segno = get_best_cand(sb, &super->s_reserve_list, &ec); + super->s_journal_seg[i] = segno; + super->s_journal_ec[i] = ec; + logfs_set_segment_reserved(sb, segno); + } + /* Manually move journal_area */ + area->a_segno = super->s_journal_seg[0]; + area->a_is_open = 0; + area->a_used_bytes = 0; + /* Write journal */ + logfs_write_anchor(super->s_master_inode); + /* Write superblocks */ + err = logfs_write_sb(sb); + BUG_ON(err); +} + +static const struct logfs_area_ops journal_area_ops = { + .get_free_segment = journal_get_free_segment, + .get_erase_count = journal_get_erase_count, + .erase_segment = journal_erase_segment, +}; + +int logfs_init_journal(struct super_block *sb) +{ + struct logfs_super *super = logfs_super(sb); + size_t bufsize = max_t(size_t, sb->s_blocksize, super->s_writesize) + + MAX_JOURNAL_HEADER; + int ret = -ENOMEM; + + mutex_init(&super->s_journal_mutex); + btree_init_mempool32(&super->s_reserved_segments, super->s_btree_pool); + + super->s_je = kzalloc(bufsize, GFP_KERNEL); + if (!super->s_je) + return ret; + + super->s_compressed_je = kzalloc(bufsize, GFP_KERNEL); + if (!super->s_compressed_je) + return ret; + + super->s_master_inode = logfs_new_meta_inode(sb, LOGFS_INO_MASTER); + if (IS_ERR(super->s_master_inode)) + return PTR_ERR(super->s_master_inode); + + ret = logfs_read_journal(sb); + if (ret) + return -EIO; + + reserve_sb_and_journal(sb); + logfs_calc_free(sb); + + super->s_journal_area->a_ops = &journal_area_ops; + return 0; +} + +void logfs_cleanup_journal(struct super_block *sb) +{ + struct logfs_super *super = logfs_super(sb); + + btree_grim_visitor32(&super->s_reserved_segments, 0, NULL); + destroy_meta_inode(super->s_master_inode); + super->s_master_inode = NULL; + + kfree(super->s_compressed_je); + kfree(super->s_je); +} |
