/* * 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" #include <linux/slab.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) return logfs_buf_recover(area, ofs, a + 1, super->s_writesize); else return logfs_buf_recover(area, ofs, NULL, 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: err = 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 = 0; 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; union { struct logfs_segment_header sh; unsigned char c[ALIGN(sizeof(struct logfs_segment_header), 16)]; } u; u64 ofs; int err; err = logfs_erase_segment(sb, area->a_segno, 1); if (err) return err; memset(&u, 0, sizeof(u)); u.sh.pad = 0; u.sh.type = SEG_JOURNAL; u.sh.level = 0; u.sh.segno = cpu_to_be32(area->a_segno); u.sh.ec = cpu_to_be32(area->a_erase_count); u.sh.gec = cpu_to_be64(logfs_super(sb)->s_gec); u.sh.crc = logfs_crc32(&u.sh, sizeof(u.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 = sizeof(u); logfs_buf_write(area, ofs, &u, sizeof(u)); 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_datalen = cpu_to_be16(datalen); jh->h_compr = compr; jh->h_pad[0] = 'H'; jh->h_pad[1] = 'E'; jh->h_pad[2] = 'A'; jh->h_pad[3] = 'D'; jh->h_pad[4] = 'R'; 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); btree_grim_visitor32(&tree->segment_map, 0, NULL); tree->no_shadowed_segments = 0; 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); BUG_ON(len > sb->s_blocksize); compr_len = logfs_compress(buf, data, len, sb->s_blocksize); if (compr_len < 0 || type == JE_ANCHOR) { 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); BUG_ON(super->s_no_je >= MAX_JOURNAL_ENTRIES); 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 super_block *sb) { struct logfs_super *super = logfs_super(sb); struct logfs_area *area = super->s_journal_area; int i, err; if (!(super->s_flags & LOGFS_SB_FLAG_DIRTY)) return; super->s_flags &= ~LOGFS_SB_FLAG_DIRTY; BUG_ON(super->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; struct btree_head32 *head = &super->s_reserved_segments; 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]) { btree_remove32(head, 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); err = btree_insert32(head, segno, (void *)1, GFP_KERNEL); BUG_ON(err); /* mempool should prevent this */ err = logfs_erase_segment(sb, segno, 1); BUG_ON(err); /* FIXME: remount-ro would be nicer */ } /* Manually move journal_area */ freeseg(sb, area->a_segno); area->a_segno = super->s_journal_seg[0]; area->a_is_open = 0; area->a_used_bytes = 0; /* Write journal */ logfs_write_anchor(sb); /* 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); }