[PATCH 9/17] [LogFS] journal.c

Joern Engel
2009-11-20T20:24:40Z

---
fs/logfs/journal.c | 879 ++++++++++++++

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);
+}