--- /dev/null
+/*
+ * fs/logfs/readwrite.c
+ *
+ * As should be obvious for Linux kernel code, license is GPLv2
+ *
+ * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
+ *
+ *
+ * Actually contains five sets of very similar functions:
+ * read read blocks from a file
+ * seek_hole find next hole
+ * seek_data find next data block
+ * valid check whether a block still belongs to a file
+ * write write blocks to a file
+ * delete delete a block (for directories and ifile)
+ * rewrite move existing blocks of a file to a new location (gc helper)
+ * truncate truncate a file
+ */
+#include "logfs.h"
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+static u64 adjust_bix(u64 bix, level_t level)
+{
+ switch (level) {
+ case 0:
+ return bix;
+ case LEVEL(1):
+ return max_t(u64, bix, I0_BLOCKS);
+ case LEVEL(2):
+ return max_t(u64, bix, I1_BLOCKS);
+ case LEVEL(3):
+ return max_t(u64, bix, I2_BLOCKS);
+ case LEVEL(4):
+ return max_t(u64, bix, I3_BLOCKS);
+ case LEVEL(5):
+ return max_t(u64, bix, I4_BLOCKS);
+ default:
+ WARN_ON(1);
+ return bix;
+ }
+}
+
+static inline u64 maxbix(u8 height)
+{
+ return 1ULL << (LOGFS_BLOCK_BITS * height);
+}
+
+/**
+ * The inode address space is cut in two halves. Lower half belongs to data
+ * pages, upper half to indirect blocks. If the high bit (INDIRECT_BIT) is
+ * set, the actual block index (bix) and level can be derived from the page
+ * index.
+ *
+ * The lowest three bits of the block index are set to 0 after packing and
+ * unpacking. Since the lowest n bits (9 for 4KiB blocksize) are ignored
+ * anyway this is harmless.
+ */
+#define ARCH_SHIFT (BITS_PER_LONG - 32)
+#define INDIRECT_BIT (0x80000000UL << ARCH_SHIFT)
+#define LEVEL_SHIFT (28 + ARCH_SHIFT)
+static inline pgoff_t first_indirect_block(void)
+{
+ return INDIRECT_BIT | (1ULL << LEVEL_SHIFT);
+}
+
+pgoff_t logfs_pack_index(u64 bix, level_t level)
+{
+ pgoff_t index;
+
+ BUG_ON(bix >= INDIRECT_BIT);
+ if (level == 0)
+ return bix;
+
+ index = INDIRECT_BIT;
+ index |= (__force long)level << LEVEL_SHIFT;
+ index |= bix >> ((__force u8)level * LOGFS_BLOCK_BITS);
+ return index;
+}
+
+void logfs_unpack_index(pgoff_t index, u64 *bix, level_t *level)
+{
+ u8 __level;
+
+ if (!(index & INDIRECT_BIT)) {
+ *bix = index;
+ *level = 0;
+ return;
+ }
+
+ __level = (index & ~INDIRECT_BIT) >> LEVEL_SHIFT;
+ *level = LEVEL(__level);
+ *bix = (index << (__level * LOGFS_BLOCK_BITS)) & ~INDIRECT_BIT;
+ *bix = adjust_bix(*bix, *level);
+ return;
+}
+#undef ARCH_SHIFT
+#undef INDIRECT_BIT
+#undef LEVEL_SHIFT
+
+/*
+ * Time is stored as nanoseconds since the epoch.
+ */
+static struct timespec be64_to_timespec(__be64 betime)
+{
+ return ns_to_timespec(be64_to_cpu(betime));
+}
+
+static __be64 timespec_to_be64(struct timespec tsp)
+{
+ return cpu_to_be64((u64)tsp.tv_sec * NSEC_PER_SEC + tsp.tv_nsec);
+}
+
+static void logfs_disk_to_inode(struct logfs_disk_inode *di, struct inode*inode)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ int i;
+
+ inode->i_mode = be16_to_cpu(di->di_mode);
+ li->li_height = di->di_height;
+ li->li_flags = be32_to_cpu(di->di_flags);
+ i_uid_write(inode, be32_to_cpu(di->di_uid));
+ i_gid_write(inode, be32_to_cpu(di->di_gid));
+ inode->i_size = be64_to_cpu(di->di_size);
+ logfs_set_blocks(inode, be64_to_cpu(di->di_used_bytes));
+ inode->i_atime = be64_to_timespec(di->di_atime);
+ inode->i_ctime = be64_to_timespec(di->di_ctime);
+ inode->i_mtime = be64_to_timespec(di->di_mtime);
+ set_nlink(inode, be32_to_cpu(di->di_refcount));
+ inode->i_generation = be32_to_cpu(di->di_generation);
+
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFSOCK: /* fall through */
+ case S_IFBLK: /* fall through */
+ case S_IFCHR: /* fall through */
+ case S_IFIFO:
+ inode->i_rdev = be64_to_cpu(di->di_data[0]);
+ break;
+ case S_IFDIR: /* fall through */
+ case S_IFREG: /* fall through */
+ case S_IFLNK:
+ for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++)
+ li->li_data[i] = be64_to_cpu(di->di_data[i]);
+ break;
+ default:
+ BUG();
+ }
+}
+
+static void logfs_inode_to_disk(struct inode *inode, struct logfs_disk_inode*di)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ int i;
+
+ di->di_mode = cpu_to_be16(inode->i_mode);
+ di->di_height = li->li_height;
+ di->di_pad = 0;
+ di->di_flags = cpu_to_be32(li->li_flags);
+ di->di_uid = cpu_to_be32(i_uid_read(inode));
+ di->di_gid = cpu_to_be32(i_gid_read(inode));
+ di->di_size = cpu_to_be64(i_size_read(inode));
+ di->di_used_bytes = cpu_to_be64(li->li_used_bytes);
+ di->di_atime = timespec_to_be64(inode->i_atime);
+ di->di_ctime = timespec_to_be64(inode->i_ctime);
+ di->di_mtime = timespec_to_be64(inode->i_mtime);
+ di->di_refcount = cpu_to_be32(inode->i_nlink);
+ di->di_generation = cpu_to_be32(inode->i_generation);
+
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFSOCK: /* fall through */
+ case S_IFBLK: /* fall through */
+ case S_IFCHR: /* fall through */
+ case S_IFIFO:
+ di->di_data[0] = cpu_to_be64(inode->i_rdev);
+ break;
+ case S_IFDIR: /* fall through */
+ case S_IFREG: /* fall through */
+ case S_IFLNK:
+ for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++)
+ di->di_data[i] = cpu_to_be64(li->li_data[i]);
+ break;
+ default:
+ BUG();
+ }
+}
+
+static void __logfs_set_blocks(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct logfs_inode *li = logfs_inode(inode);
+
+ inode->i_blocks = ULONG_MAX;
+ if (li->li_used_bytes >> sb->s_blocksize_bits < ULONG_MAX)
+ inode->i_blocks = ALIGN(li->li_used_bytes, 512) >> 9;
+}
+
+void logfs_set_blocks(struct inode *inode, u64 bytes)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+
+ li->li_used_bytes = bytes;
+ __logfs_set_blocks(inode);
+}
+
+static void prelock_page(struct super_block *sb, struct page *page, int lock)
+{
+ struct logfs_super *super = logfs_super(sb);
+
+ BUG_ON(!PageLocked(page));
+ if (lock) {
+ BUG_ON(PagePreLocked(page));
+ SetPagePreLocked(page);
+ } else {
+ /* We are in GC path. */
+ if (PagePreLocked(page))
+ super->s_lock_count++;
+ else
+ SetPagePreLocked(page);
+ }
+}
+
+static void preunlock_page(struct super_block *sb, struct page *page, int lock)
+{
+ struct logfs_super *super = logfs_super(sb);
+
+ BUG_ON(!PageLocked(page));
+ if (lock)
+ ClearPagePreLocked(page);
+ else {
+ /* We are in GC path. */
+ BUG_ON(!PagePreLocked(page));
+ if (super->s_lock_count)
+ super->s_lock_count--;
+ else
+ ClearPagePreLocked(page);
+ }
+}
+
+/*
+ * Logfs is prone to an AB-BA deadlock where one task tries to acquire
+ * s_write_mutex with a locked page and GC tries to get that page while holding
+ * s_write_mutex.
+ * To solve this issue logfs will ignore the page lock iff the page in question
+ * is waiting for s_write_mutex. We annotate this fact by setting PG_pre_locked
+ * in addition to PG_locked.
+ */
+void logfs_get_wblocks(struct super_block *sb, struct page *page, int lock)
+{
+ struct logfs_super *super = logfs_super(sb);
+
+ if (page)
+ prelock_page(sb, page, lock);
+
+ if (lock) {
+ mutex_lock(&super->s_write_mutex);
+ logfs_gc_pass(sb);
+ /* FIXME: We also have to check for shadowed space
+ * and mempool fill grade */
+ }
+}
+
+void logfs_put_wblocks(struct super_block *sb, struct page *page, int lock)
+{
+ struct logfs_super *super = logfs_super(sb);
+
+ if (page)
+ preunlock_page(sb, page, lock);
+ /* Order matters - we must clear PG_pre_locked before releasing
+ * s_write_mutex or we could race against another task. */
+ if (lock)
+ mutex_unlock(&super->s_write_mutex);
+}
+
+static struct page *logfs_get_read_page(struct inode *inode, u64 bix,
+ level_t level)
+{
+ return find_or_create_page(inode->i_mapping,
+ logfs_pack_index(bix, level), GFP_NOFS);
+}
+
+static void logfs_put_read_page(struct page *page)
+{
+ unlock_page(page);
+ page_cache_release(page);
+}
+
+static void logfs_lock_write_page(struct page *page)
+{
+ int loop = 0;
+
+ while (unlikely(!trylock_page(page))) {
+ if (loop++ > 0x1000) {
+ /* Has been observed once so far... */
+ printk(KERN_ERR "stack at %p\n", &loop);
+ BUG();
+ }
+ if (PagePreLocked(page)) {
+ /* Holder of page lock is waiting for us, it
+ * is safe to use this page. */
+ break;
+ }
+ /* Some other process has this page locked and has
+ * nothing to do with us. Wait for it to finish.
+ */
+ schedule();
+ }
+ BUG_ON(!PageLocked(page));
+}
+
+static struct page *logfs_get_write_page(struct inode *inode, u64 bix,
+ level_t level)
+{
+ struct address_space *mapping = inode->i_mapping;
+ pgoff_t index = logfs_pack_index(bix, level);
+ struct page *page;
+ int err;
+
+repeat:
+ page = find_get_page(mapping, index);
+ if (!page) {
+ page = __page_cache_alloc(GFP_NOFS);
+ if (!page)
+ return NULL;
+ err = add_to_page_cache_lru(page, mapping, index, GFP_NOFS);
+ if (unlikely(err)) {
+ page_cache_release(page);
+ if (err == -EEXIST)
+ goto repeat;
+ return NULL;
+ }
+ } else logfs_lock_write_page(page);
+ BUG_ON(!PageLocked(page));
+ return page;
+}
+
+static void logfs_unlock_write_page(struct page *page)
+{
+ if (!PagePreLocked(page))
+ unlock_page(page);
+}
+
+static void logfs_put_write_page(struct page *page)
+{
+ logfs_unlock_write_page(page);
+ page_cache_release(page);
+}
+
+static struct page *logfs_get_page(struct inode *inode, u64 bix, level_t level,
+ int rw)
+{
+ if (rw == READ)
+ return logfs_get_read_page(inode, bix, level);
+ else
+ return logfs_get_write_page(inode, bix, level);
+}
+
+static void logfs_put_page(struct page *page, int rw)
+{
+ if (rw == READ)
+ logfs_put_read_page(page);
+ else
+ logfs_put_write_page(page);
+}
+
+static unsigned long __get_bits(u64 val, int skip, int no)
+{
+ u64 ret = val;
+
+ ret >>= skip * no;
+ ret <<= 64 - no;
+ ret >>= 64 - no;
+ return ret;
+}
+
+static unsigned long get_bits(u64 val, level_t skip)
+{
+ return __get_bits(val, (__force int)skip, LOGFS_BLOCK_BITS);
+}
+
+static inline void init_shadow_tree(struct super_block *sb,
+ struct shadow_tree *tree)
+{
+ struct logfs_super *super = logfs_super(sb);
+
+ btree_init_mempool64(&tree->new, super->s_btree_pool);
+ btree_init_mempool64(&tree->old, super->s_btree_pool);
+}
+
+static void indirect_write_block(struct logfs_block *block)
+{
+ struct page *page;
+ struct inode *inode;
+ int ret;
+
+ page = block->page;
+ inode = page->mapping->host;
+ logfs_lock_write_page(page);
+ ret = logfs_write_buf(inode, page, 0);
+ logfs_unlock_write_page(page);
+ /*
+ * This needs some rework. Unless you want your filesystem to run
+ * completely synchronously (you don't), the filesystem will always
+ * report writes as 'successful' before the actual work has been
+ * done. The actual work gets done here and this is where any errors
+ * will show up. And there isn't much we can do about it, really.
+ *
+ * Some attempts to fix the errors (move from bad blocks, retry io,...)
+ * have already been done, so anything left should be either a broken
+ * device or a bug somewhere in logfs itself. Being relatively new,
+ * the odds currently favor a bug, so for now the line below isn't
+ * entirely tasteles.
+ */
+ BUG_ON(ret);
+}
+
+static void inode_write_block(struct logfs_block *block)
+{
+ struct inode *inode;
+ int ret;
+
+ inode = block->inode;
+ if (inode->i_ino == LOGFS_INO_MASTER)
+ logfs_write_anchor(inode->i_sb);
+ else {
+ ret = __logfs_write_inode(inode, NULL, 0);
+ /* see indirect_write_block comment */
+ BUG_ON(ret);
+ }
+}
+
+/*
+ * This silences a false, yet annoying gcc warning. I hate it when my editor
+ * jumps into bitops.h each time I recompile this file.
+ * TODO: Complain to gcc folks about this and upgrade compiler.
+ */
+static unsigned long fnb(const unsigned long *addr,
+ unsigned long size, unsigned long offset)
+{
+ return find_next_bit(addr, size, offset);
+}
+
+static __be64 inode_val0(struct inode *inode)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ u64 val;
+
+ /*
+ * Explicit shifting generates good code, but must match the format
+ * of the structure. Add some paranoia just in case.
+ */
+ BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_mode) != 0);
+ BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_height) != 2);
+ BUILD_BUG_ON(offsetof(struct logfs_disk_inode, di_flags) != 4);
+
+ val = (u64)inode->i_mode << 48 |
+ (u64)li->li_height << 40 |
+ (u64)li->li_flags;
+ return cpu_to_be64(val);
+}
+
+static int inode_write_alias(struct super_block *sb,
+ struct logfs_block *block, write_alias_t *write_one_alias)
+{
+ struct inode *inode = block->inode;
+ struct logfs_inode *li = logfs_inode(inode);
+ unsigned long pos;
+ u64 ino , bix;
+ __be64 val;
+ level_t level;
+ int err;
+
+ for (pos = 0; ; pos++) {
+ pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos);
+ if (pos >= LOGFS_EMBEDDED_FIELDS + INODE_POINTER_OFS)
+ return 0;
+
+ switch (pos) {
+ case INODE_HEIGHT_OFS:
+ val = inode_val0(inode);
+ break;
+ case INODE_USED_OFS:
+ val = cpu_to_be64(li->li_used_bytes);
+ break;
+ case INODE_SIZE_OFS:
+ val = cpu_to_be64(i_size_read(inode));
+ break;
+ case INODE_POINTER_OFS ... INODE_POINTER_OFS + LOGFS_EMBEDDED_FIELDS - 1:
+ val = cpu_to_be64(li->li_data[pos - INODE_POINTER_OFS]);
+ break;
+ default:
+ BUG();
+ }
+
+ ino = LOGFS_INO_MASTER;
+ bix = inode->i_ino;
+ level = LEVEL(0);
+ err = write_one_alias(sb, ino, bix, level, pos, val);
+ if (err)
+ return err;
+ }
+}
+
+static int indirect_write_alias(struct super_block *sb,
+ struct logfs_block *block, write_alias_t *write_one_alias)
+{
+ unsigned long pos;
+ struct page *page = block->page;
+ u64 ino , bix;
+ __be64 *child, val;
+ level_t level;
+ int err;
+
+ for (pos = 0; ; pos++) {
+ pos = fnb(block->alias_map, LOGFS_BLOCK_FACTOR, pos);
+ if (pos >= LOGFS_BLOCK_FACTOR)
+ return 0;
+
+ ino = page->mapping->host->i_ino;
+ logfs_unpack_index(page->index, &bix, &level);
+ child = kmap_atomic(page);
+ val = child[pos];
+ kunmap_atomic(child);
+ err = write_one_alias(sb, ino, bix, level, pos, val);
+ if (err)
+ return err;
+ }
+}
+
+int logfs_write_obj_aliases_pagecache(struct super_block *sb)
+{
+ struct logfs_super *super = logfs_super(sb);
+ struct logfs_block *block;
+ int err;
+
+ list_for_each_entry(block, &super->s_object_alias, alias_list) {
+ err = block->ops->write_alias(sb, block, write_alias_journal);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
+void __free_block(struct super_block *sb, struct logfs_block *block)
+{
+ BUG_ON(!list_empty(&block->item_list));
+ list_del(&block->alias_list);
+ mempool_free(block, logfs_super(sb)->s_block_pool);
+}
+
+static void inode_free_block(struct super_block *sb, struct logfs_block *block)
+{
+ struct inode *inode = block->inode;
+
+ logfs_inode(inode)->li_block = NULL;
+ __free_block(sb, block);
+}
+
+static void indirect_free_block(struct super_block *sb,
+ struct logfs_block *block)
+{
+ struct page *page = block->page;
+
+ if (PagePrivate(page)) {
+ ClearPagePrivate(page);
+ page_cache_release(page);
+ set_page_private(page, 0);
+ }
+ __free_block(sb, block);
+}
+
+
+static struct logfs_block_ops inode_block_ops = {
+ .write_block = inode_write_block,
+ .free_block = inode_free_block,
+ .write_alias = inode_write_alias,
+};
+
+struct logfs_block_ops indirect_block_ops = {
+ .write_block = indirect_write_block,
+ .free_block = indirect_free_block,
+ .write_alias = indirect_write_alias,
+};
+
+struct logfs_block *__alloc_block(struct super_block *sb,
+ u64 ino, u64 bix, level_t level)
+{
+ struct logfs_super *super = logfs_super(sb);
+ struct logfs_block *block;
+
+ block = mempool_alloc(super->s_block_pool, GFP_NOFS);
+ memset(block, 0, sizeof(*block));
+ INIT_LIST_HEAD(&block->alias_list);
+ INIT_LIST_HEAD(&block->item_list);
+ block->sb = sb;
+ block->ino = ino;
+ block->bix = bix;
+ block->level = level;
+ return block;
+}
+
+static void alloc_inode_block(struct inode *inode)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ struct logfs_block *block;
+
+ if (li->li_block)
+ return;
+
+ block = __alloc_block(inode->i_sb, LOGFS_INO_MASTER, inode->i_ino, 0);
+ block->inode = inode;
+ li->li_block = block;
+ block->ops = &inode_block_ops;
+}
+
+void initialize_block_counters(struct page *page, struct logfs_block *block,
+ __be64 *array, int page_is_empty)
+{
+ u64 ptr;
+ int i, start;
+
+ block->partial = 0;
+ block->full = 0;
+ start = 0;
+ if (page->index < first_indirect_block()) {
+ /* Counters are pointless on level 0 */
+ return;
+ }
+ if (page->index == first_indirect_block()) {
+ /* Skip unused pointers */
+ start = I0_BLOCKS;
+ block->full = I0_BLOCKS;
+ }
+ if (!page_is_empty) {
+ for (i = start; i < LOGFS_BLOCK_FACTOR; i++) {
+ ptr = be64_to_cpu(array[i]);
+ if (ptr)
+ block->partial++;
+ if (ptr & LOGFS_FULLY_POPULATED)
+ block->full++;
+ }
+ }
+}
+
+static void alloc_data_block(struct inode *inode, struct page *page)
+{
+ struct logfs_block *block;
+ u64 bix;
+ level_t level;
+
+ if (PagePrivate(page))
+ return;
+
+ logfs_unpack_index(page->index, &bix, &level);
+ block = __alloc_block(inode->i_sb, inode->i_ino, bix, level);
+ block->page = page;
+
+ SetPagePrivate(page);
+ page_cache_get(page);
+ set_page_private(page, (unsigned long) block);
+
+ block->ops = &indirect_block_ops;
+}
+
+static void alloc_indirect_block(struct inode *inode, struct page *page,
+ int page_is_empty)
+{
+ struct logfs_block *block;
+ __be64 *array;
+
+ if (PagePrivate(page))
+ return;
+
+ alloc_data_block(inode, page);
+
+ block = logfs_block(page);
+ array = kmap_atomic(page);
+ initialize_block_counters(page, block, array, page_is_empty);
+ kunmap_atomic(array);
+}
+
+static void block_set_pointer(struct page *page, int index, u64 ptr)
+{
+ struct logfs_block *block = logfs_block(page);
+ __be64 *array;
+ u64 oldptr;
+
+ BUG_ON(!block);
+ array = kmap_atomic(page);
+ oldptr = be64_to_cpu(array[index]);
+ array[index] = cpu_to_be64(ptr);
+ kunmap_atomic(array);
+ SetPageUptodate(page);
+
+ block->full += !!(ptr & LOGFS_FULLY_POPULATED)
+ - !!(oldptr & LOGFS_FULLY_POPULATED);
+ block->partial += !!ptr - !!oldptr;
+}
+
+static u64 block_get_pointer(struct page *page, int index)
+{
+ __be64 *block;
+ u64 ptr;
+
+ block = kmap_atomic(page);
+ ptr = be64_to_cpu(block[index]);
+ kunmap_atomic(block);
+ return ptr;
+}
+
+static int logfs_read_empty(struct page *page)
+{
+ zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+ return 0;
+}
+
+static int logfs_read_direct(struct inode *inode, struct page *page)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ pgoff_t index = page->index;
+ u64 block;
+
+ block = li->li_data[index];
+ if (!block)
+ return logfs_read_empty(page);
+
+ return logfs_segment_read(inode, page, block, index, 0);
+}
+
+static int logfs_read_loop(struct inode *inode, struct page *page,
+ int rw_context)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ u64 bix, bofs = li->li_data[INDIRECT_INDEX];
+ level_t level, target_level;
+ int ret;
+ struct page *ipage;
+
+ logfs_unpack_index(page->index, &bix, &target_level);
+ if (!bofs)
+ return logfs_read_empty(page);
+
+ if (bix >= maxbix(li->li_height))
+ return logfs_read_empty(page);
+
+ for (level = LEVEL(li->li_height);
+ (__force u8)level > (__force u8)target_level;
+ level = SUBLEVEL(level)){
+ ipage = logfs_get_page(inode, bix, level, rw_context);
+ if (!ipage)
+ return -ENOMEM;
+
+ ret = logfs_segment_read(inode, ipage, bofs, bix, level);
+ if (ret) {
+ logfs_put_read_page(ipage);
+ return ret;
+ }
+
+ bofs = block_get_pointer(ipage, get_bits(bix, SUBLEVEL(level)));
+ logfs_put_page(ipage, rw_context);
+ if (!bofs)
+ return logfs_read_empty(page);
+ }
+
+ return logfs_segment_read(inode, page, bofs, bix, 0);
+}
+
+static int logfs_read_block(struct inode *inode, struct page *page,
+ int rw_context)
+{
+ pgoff_t index = page->index;
+
+ if (index < I0_BLOCKS)
+ return logfs_read_direct(inode, page);
+ return logfs_read_loop(inode, page, rw_context);
+}
+
+static int logfs_exist_loop(struct inode *inode, u64 bix)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ u64 bofs = li->li_data[INDIRECT_INDEX];
+ level_t level;
+ int ret;
+ struct page *ipage;
+
+ if (!bofs)
+ return 0;
+ if (bix >= maxbix(li->li_height))
+ return 0;
+
+ for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)) {
+ ipage = logfs_get_read_page(inode, bix, level);
+ if (!ipage)
+ return -ENOMEM;
+
+ ret = logfs_segment_read(inode, ipage, bofs, bix, level);
+ if (ret) {
+ logfs_put_read_page(ipage);
+ return ret;
+ }
+
+ bofs = block_get_pointer(ipage, get_bits(bix, SUBLEVEL(level)));
+ logfs_put_read_page(ipage);
+ if (!bofs)
+ return 0;
+ }
+
+ return 1;
+}
+
+int logfs_exist_block(struct inode *inode, u64 bix)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+
+ if (bix < I0_BLOCKS)
+ return !!li->li_data[bix];
+ return logfs_exist_loop(inode, bix);
+}
+
+static u64 seek_holedata_direct(struct inode *inode, u64 bix, int data)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+
+ for (; bix < I0_BLOCKS; bix++)
+ if (data ^ (li->li_data[bix] == 0))
+ return bix;
+ return I0_BLOCKS;
+}
+
+static u64 seek_holedata_loop(struct inode *inode, u64 bix, int data)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ __be64 *rblock;
+ u64 increment, bofs = li->li_data[INDIRECT_INDEX];
+ level_t level;
+ int ret, slot;
+ struct page *page;
+
+ BUG_ON(!bofs);
+
+ for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)) {
+ increment = 1 << (LOGFS_BLOCK_BITS * ((__force u8)level-1));
+ page = logfs_get_read_page(inode, bix, level);
+ if (!page)
+ return bix;
+
+ ret = logfs_segment_read(inode, page, bofs, bix, level);
+ if (ret) {
+ logfs_put_read_page(page);
+ return bix;
+ }
+
+ slot = get_bits(bix, SUBLEVEL(level));
+ rblock = kmap_atomic(page);
+ while (slot < LOGFS_BLOCK_FACTOR) {
+ if (data && (rblock[slot] != 0))
+ break;
+ if (!data && !(be64_to_cpu(rblock[slot]) & LOGFS_FULLY_POPULATED))
+ break;
+ slot++;
+ bix += increment;
+ bix &= ~(increment - 1);
+ }
+ if (slot >= LOGFS_BLOCK_FACTOR) {
+ kunmap_atomic(rblock);
+ logfs_put_read_page(page);
+ return bix;
+ }
+ bofs = be64_to_cpu(rblock[slot]);
+ kunmap_atomic(rblock);
+ logfs_put_read_page(page);
+ if (!bofs) {
+ BUG_ON(data);
+ return bix;
+ }
+ }
+ return bix;
+}
+
+/**
+ * logfs_seek_hole - find next hole starting at a given block index
+ * @inode: inode to search in
+ * @bix: block index to start searching
+ *
+ * Returns next hole. If the file doesn't contain any further holes, the
+ * block address next to eof is returned instead.
+ */
+u64 logfs_seek_hole(struct inode *inode, u64 bix)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+
+ if (bix < I0_BLOCKS) {
+ bix = seek_holedata_direct(inode, bix, 0);
+ if (bix < I0_BLOCKS)
+ return bix;
+ }
+
+ if (!li->li_data[INDIRECT_INDEX])
+ return bix;
+ else if (li->li_data[INDIRECT_INDEX] & LOGFS_FULLY_POPULATED)
+ bix = maxbix(li->li_height);
+ else if (bix >= maxbix(li->li_height))
+ return bix;
+ else {
+ bix = seek_holedata_loop(inode, bix, 0);
+ if (bix < maxbix(li->li_height))
+ return bix;
+ /* Should not happen anymore. But if some port writes semi-
+ * corrupt images (as this one used to) we might run into it.
+ */
+ WARN_ON_ONCE(bix == maxbix(li->li_height));
+ }
+
+ return bix;
+}
+
+static u64 __logfs_seek_data(struct inode *inode, u64 bix)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+
+ if (bix < I0_BLOCKS) {
+ bix = seek_holedata_direct(inode, bix, 1);
+ if (bix < I0_BLOCKS)
+ return bix;
+ }
+
+ if (bix < maxbix(li->li_height)) {
+ if (!li->li_data[INDIRECT_INDEX])
+ bix = maxbix(li->li_height);
+ else
+ return seek_holedata_loop(inode, bix, 1);
+ }
+
+ return bix;
+}
+
+/**
+ * logfs_seek_data - find next data block after a given block index
+ * @inode: inode to search in
+ * @bix: block index to start searching
+ *
+ * Returns next data block. If the file doesn't contain any further data
+ * blocks, the last block in the file is returned instead.
+ */
+u64 logfs_seek_data(struct inode *inode, u64 bix)
+{
+ struct super_block *sb = inode->i_sb;
+ u64 ret, end;
+
+ ret = __logfs_seek_data(inode, bix);
+ end = i_size_read(inode) >> sb->s_blocksize_bits;
+ if (ret >= end)
+ ret = max(bix, end);
+ return ret;
+}
+
+static int logfs_is_valid_direct(struct logfs_inode *li, u64 bix, u64 ofs)
+{
+ return pure_ofs(li->li_data[bix]) == ofs;
+}
+
+static int __logfs_is_valid_loop(struct inode *inode, u64 bix,
+ u64 ofs, u64 bofs)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ level_t level;
+ int ret;
+ struct page *page;
+
+ for (level = LEVEL(li->li_height); level != 0; level = SUBLEVEL(level)){
+ page = logfs_get_write_page(inode, bix, level);
+ BUG_ON(!page);
+
+ ret = logfs_segment_read(inode, page, bofs, bix, level);
+ if (ret) {
+ logfs_put_write_page(page);
+ return 0;
+ }
+
+ bofs = block_get_pointer(page, get_bits(bix, SUBLEVEL(level)));
+ logfs_put_write_page(page);
+ if (!bofs)
+ return 0;
+
+ if (pure_ofs(bofs) == ofs)
+ return 1;
+ }
+ return 0;
+}
+
+static int logfs_is_valid_loop(struct inode *inode, u64 bix, u64 ofs)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ u64 bofs = li->li_data[INDIRECT_INDEX];
+
+ if (!bofs)
+ return 0;
+
+ if (bix >= maxbix(li->li_height))
+ return 0;
+
+ if (pure_ofs(bofs) == ofs)
+ return 1;
+
+ return __logfs_is_valid_loop(inode, bix, ofs, bofs);
+}
+
+static int __logfs_is_valid_block(struct inode *inode, u64 bix, u64 ofs)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+
+ if ((inode->i_nlink == 0) && atomic_read(&inode->i_count) == 1)
+ return 0;
+
+ if (bix < I0_BLOCKS)
+ return logfs_is_valid_direct(li, bix, ofs);
+ return logfs_is_valid_loop(inode, bix, ofs);
+}
+
+/**
+ * logfs_is_valid_block - check whether this block is still valid
+ *
+ * @sb: superblock
+ * @ofs: block physical offset
+ * @ino: block inode number
+ * @bix: block index
+ * @gc_level: block level
+ *
+ * Returns 0 if the block is invalid, 1 if it is valid and 2 if it will
+ * become invalid once the journal is written.
+ */
+int logfs_is_valid_block(struct super_block *sb, u64 ofs, u64 ino, u64 bix,
+ gc_level_t gc_level)
+{
+ struct logfs_super *super = logfs_super(sb);
+ struct inode *inode;
+ int ret, cookie;
+
+ /* Umount closes a segment with free blocks remaining. Those
+ * blocks are by definition invalid. */
+ if (ino == -1)
+ return 0;
+
+ LOGFS_BUG_ON((u64)(u_long)ino != ino, sb);
+
+ inode = logfs_safe_iget(sb, ino, &cookie);
+ if (IS_ERR(inode))
+ goto invalid;
+
+ ret = __logfs_is_valid_block(inode, bix, ofs);
+ logfs_safe_iput(inode, cookie);
+ if (ret)
+ return ret;
+
+invalid:
+ /* Block is nominally invalid, but may still sit in the shadow tree,
+ * waiting for a journal commit.
+ */
+ if (btree_lookup64(&super->s_shadow_tree.old, ofs))
+ return 2;
+ return 0;
+}
+
+int logfs_readpage_nolock(struct page *page)
+{
+ struct inode *inode = page->mapping->host;
+ int ret = -EIO;
+
+ ret = logfs_read_block(inode, page, READ);
+
+ if (ret) {
+ ClearPageUptodate(page);
+ SetPageError(page);
+ } else {
+ SetPageUptodate(page);
+ ClearPageError(page);
+ }
+ flush_dcache_page(page);
+
+ return ret;
+}
+
+static int logfs_reserve_bytes(struct inode *inode, int bytes)
+{
+ struct logfs_super *super = logfs_super(inode->i_sb);
+ u64 available = super->s_free_bytes + super->s_dirty_free_bytes
+ - super->s_dirty_used_bytes - super->s_dirty_pages;
+
+ if (!bytes)
+ return 0;
+
+ if (available < bytes)
+ return -ENOSPC;
+
+ if (available < bytes + super->s_root_reserve &&
+ !capable(CAP_SYS_RESOURCE))
+ return -ENOSPC;
+
+ return 0;
+}
+
+int get_page_reserve(struct inode *inode, struct page *page)
+{
+ struct logfs_super *super = logfs_super(inode->i_sb);
+ struct logfs_block *block = logfs_block(page);
+ int ret;
+
+ if (block && block->reserved_bytes)
+ return 0;
+
+ logfs_get_wblocks(inode->i_sb, page, WF_LOCK);
+ while ((ret = logfs_reserve_bytes(inode, 6 * LOGFS_MAX_OBJECTSIZE)) &&
+ !list_empty(&super->s_writeback_list)) {
+ block = list_entry(super->s_writeback_list.next,
+ struct logfs_block, alias_list);
+ block->ops->write_block(block);
+ }
+ if (!ret) {
+ alloc_data_block(inode, page);
+ block = logfs_block(page);
+ block->reserved_bytes += 6 * LOGFS_MAX_OBJECTSIZE;
+ super->s_dirty_pages += 6 * LOGFS_MAX_OBJECTSIZE;
+ list_move_tail(&block->alias_list, &super->s_writeback_list);
+ }
+ logfs_put_wblocks(inode->i_sb, page, WF_LOCK);
+ return ret;
+}
+
+/*
+ * We are protected by write lock. Push victims up to superblock level
+ * and release transaction when appropriate.
+ */
+/* FIXME: This is currently called from the wrong spots. */
+static void logfs_handle_transaction(struct inode *inode,
+ struct logfs_transaction *ta)
+{
+ struct logfs_super *super = logfs_super(inode->i_sb);
+
+ if (!ta)
+ return;
+ logfs_inode(inode)->li_block->ta = NULL;
+
+ if (inode->i_ino != LOGFS_INO_MASTER) {
+ BUG(); /* FIXME: Yes, this needs more thought */
+ /* just remember the transaction until inode is written */
+ //BUG_ON(logfs_inode(inode)->li_transaction);
+ //logfs_inode(inode)->li_transaction = ta;
+ return;
+ }
+
+ switch (ta->state) {
+ case CREATE_1: /* fall through */
+ case UNLINK_1:
+ BUG_ON(super->s_victim_ino);
+ super->s_victim_ino = ta->ino;
+ break;
+ case CREATE_2: /* fall through */
+ case UNLINK_2:
+ BUG_ON(super->s_victim_ino != ta->ino);
+ super->s_victim_ino = 0;
+ /* transaction ends here - free it */
+ kfree(ta);
+ break;
+ case CROSS_RENAME_1:
+ BUG_ON(super->s_rename_dir);
+ BUG_ON(super->s_rename_pos);
+ super->s_rename_dir = ta->dir;
+ super->s_rename_pos = ta->pos;
+ break;
+ case CROSS_RENAME_2:
+ BUG_ON(super->s_rename_dir != ta->dir);
+ BUG_ON(super->s_rename_pos != ta->pos);
+ super->s_rename_dir = 0;
+ super->s_rename_pos = 0;
+ kfree(ta);
+ break;
+ case TARGET_RENAME_1:
+ BUG_ON(super->s_rename_dir);
+ BUG_ON(super->s_rename_pos);
+ BUG_ON(super->s_victim_ino);
+ super->s_rename_dir = ta->dir;
+ super->s_rename_pos = ta->pos;
+ super->s_victim_ino = ta->ino;
+ break;
+ case TARGET_RENAME_2:
+ BUG_ON(super->s_rename_dir != ta->dir);
+ BUG_ON(super->s_rename_pos != ta->pos);
+ BUG_ON(super->s_victim_ino != ta->ino);
+ super->s_rename_dir = 0;
+ super->s_rename_pos = 0;
+ break;
+ case TARGET_RENAME_3:
+ BUG_ON(super->s_rename_dir);
+ BUG_ON(super->s_rename_pos);
+ BUG_ON(super->s_victim_ino != ta->ino);
+ super->s_victim_ino = 0;
+ kfree(ta);
+ break;
+ default:
+ BUG();
+ }
+}
+
+/*
+ * Not strictly a reservation, but rather a check that we still have enough
+ * space to satisfy the write.
+ */
+static int logfs_reserve_blocks(struct inode *inode, int blocks)
+{
+ return logfs_reserve_bytes(inode, blocks * LOGFS_MAX_OBJECTSIZE);
+}
+
+struct write_control {
+ u64 ofs;
+ long flags;
+};
+
+static struct logfs_shadow *alloc_shadow(struct inode *inode, u64 bix,
+ level_t level, u64 old_ofs)
+{
+ struct logfs_super *super = logfs_super(inode->i_sb);
+ struct logfs_shadow *shadow;
+
+ shadow = mempool_alloc(super->s_shadow_pool, GFP_NOFS);
+ memset(shadow, 0, sizeof(*shadow));
+ shadow->ino = inode->i_ino;
+ shadow->bix = bix;
+ shadow->gc_level = expand_level(inode->i_ino, level);
+ shadow->old_ofs = old_ofs & ~LOGFS_FULLY_POPULATED;
+ return shadow;
+}
+
+static void free_shadow(struct inode *inode, struct logfs_shadow *shadow)
+{
+ struct logfs_super *super = logfs_super(inode->i_sb);
+
+ mempool_free(shadow, super->s_shadow_pool);
+}
+
+static void mark_segment(struct shadow_tree *tree, u32 segno)
+{
+ int err;
+
+ if (!btree_lookup32(&tree->segment_map, segno)) {
+ err = btree_insert32(&tree->segment_map, segno, (void *)1,
+ GFP_NOFS);
+ BUG_ON(err);
+ tree->no_shadowed_segments++;
+ }
+}
+
+/**
+ * fill_shadow_tree - Propagate shadow tree changes due to a write
+ * @inode: Inode owning the page
+ * @page: Struct page that was written
+ * @shadow: Shadow for the current write
+ *
+ * Writes in logfs can result in two semi-valid objects. The old object
+ * is still valid as long as it can be reached by following pointers on
+ * the medium. Only when writes propagate all the way up to the journal
+ * has the new object safely replaced the old one.
+ *
+ * To handle this problem, a struct logfs_shadow is used to represent
+ * every single write. It is attached to the indirect block, which is
+ * marked dirty. When the indirect block is written, its shadows are
+ * handed up to the next indirect block (or inode). Untimately they
+ * will reach the master inode and be freed upon journal commit.
+ *
+ * This function handles a single step in the propagation. It adds the
+ * shadow for the current write to the tree, along with any shadows in
+ * the page's tree, in case it was an indirect block. If a page is
+ * written, the inode parameter is left NULL, if an inode is written,
+ * the page parameter is left NULL.
+ */
+static void fill_shadow_tree(struct inode *inode, struct page *page,
+ struct logfs_shadow *shadow)
+{
+ struct logfs_super *super = logfs_super(inode->i_sb);
+ struct logfs_block *block = logfs_block(page);
+ struct shadow_tree *tree = &super->s_shadow_tree;
+
+ if (PagePrivate(page)) {
+ if (block->alias_map)
+ super->s_no_object_aliases -= bitmap_weight(
+ block->alias_map, LOGFS_BLOCK_FACTOR);
+ logfs_handle_transaction(inode, block->ta);
+ block->ops->free_block(inode->i_sb, block);
+ }
+ if (shadow) {
+ if (shadow->old_ofs)
+ btree_insert64(&tree->old, shadow->old_ofs, shadow,
+ GFP_NOFS);
+ else
+ btree_insert64(&tree->new, shadow->new_ofs, shadow,
+ GFP_NOFS);
+
+ super->s_dirty_used_bytes += shadow->new_len;
+ super->s_dirty_free_bytes += shadow->old_len;
+ mark_segment(tree, shadow->old_ofs >> super->s_segshift);
+ mark_segment(tree, shadow->new_ofs >> super->s_segshift);
+ }
+}
+
+static void logfs_set_alias(struct super_block *sb, struct logfs_block *block,
+ long child_no)
+{
+ struct logfs_super *super = logfs_super(sb);
+
+ if (block->inode && block->inode->i_ino == LOGFS_INO_MASTER) {
+ /* Aliases in the master inode are pointless. */
+ return;
+ }
+
+ if (!test_bit(child_no, block->alias_map)) {
+ set_bit(child_no, block->alias_map);
+ super->s_no_object_aliases++;
+ }
+ list_move_tail(&block->alias_list, &super->s_object_alias);
+}
+
+/*
+ * Object aliases can and often do change the size and occupied space of a
+ * file. So not only do we have to change the pointers, we also have to
+ * change inode->i_size and li->li_used_bytes. Which is done by setting
+ * another two object aliases for the inode itself.
+ */
+static void set_iused(struct inode *inode, struct logfs_shadow *shadow)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+
+ if (shadow->new_len == shadow->old_len)
+ return;
+
+ alloc_inode_block(inode);
+ li->li_used_bytes += shadow->new_len - shadow->old_len;
+ __logfs_set_blocks(inode);
+ logfs_set_alias(inode->i_sb, li->li_block, INODE_USED_OFS);
+ logfs_set_alias(inode->i_sb, li->li_block, INODE_SIZE_OFS);
+}
+
+static int logfs_write_i0(struct inode *inode, struct page *page,
+ struct write_control *wc)
+{
+ struct logfs_shadow *shadow;
+ u64 bix;
+ level_t level;
+ int full, err = 0;
+
+ logfs_unpack_index(page->index, &bix, &level);
+ if (wc->ofs == 0)
+ if (logfs_reserve_blocks(inode, 1))
+ return -ENOSPC;
+
+ shadow = alloc_shadow(inode, bix, level, wc->ofs);
+ if (wc->flags & WF_WRITE)
+ err = logfs_segment_write(inode, page, shadow);
+ if (wc->flags & WF_DELETE)
+ logfs_segment_delete(inode, shadow);
+ if (err) {
+ free_shadow(inode, shadow);
+ return err;
+ }
+
+ set_iused(inode, shadow);
+ full = 1;
+ if (level != 0) {
+ alloc_indirect_block(inode, page, 0);
+ full = logfs_block(page)->full == LOGFS_BLOCK_FACTOR;
+ }
+ fill_shadow_tree(inode, page, shadow);
+ wc->ofs = shadow->new_ofs;
+ if (wc->ofs && full)
+ wc->ofs |= LOGFS_FULLY_POPULATED;
+ return 0;
+}
+
+static int logfs_write_direct(struct inode *inode, struct page *page,
+ long flags)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ struct write_control wc = {
+ .ofs = li->li_data[page->index],
+ .flags = flags,
+ };
+ int err;
+
+ alloc_inode_block(inode);
+
+ err = logfs_write_i0(inode, page, &wc);
+ if (err)
+ return err;
+
+ li->li_data[page->index] = wc.ofs;
+ logfs_set_alias(inode->i_sb, li->li_block,
+ page->index + INODE_POINTER_OFS);
+ return 0;
+}
+
+static int ptr_change(u64 ofs, struct page *page)
+{
+ struct logfs_block *block = logfs_block(page);
+ int empty0, empty1, full0, full1;
+
+ empty0 = ofs == 0;
+ empty1 = block->partial == 0;
+ if (empty0 != empty1)
+ return 1;
+
+ /* The !! is necessary to shrink result to int */
+ full0 = !!(ofs & LOGFS_FULLY_POPULATED);
+ full1 = block->full == LOGFS_BLOCK_FACTOR;
+ if (full0 != full1)
+ return 1;
+ return 0;
+}
+
+static int __logfs_write_rec(struct inode *inode, struct page *page,
+ struct write_control *this_wc,
+ pgoff_t bix, level_t target_level, level_t level)
+{
+ int ret, page_empty = 0;
+ int child_no = get_bits(bix, SUBLEVEL(level));
+ struct page *ipage;
+ struct write_control child_wc = {
+ .flags = this_wc->flags,
+ };
+
+ ipage = logfs_get_write_page(inode, bix, level);
+ if (!ipage)
+ return -ENOMEM;
+
+ if (this_wc->ofs) {
+ ret = logfs_segment_read(inode, ipage, this_wc->ofs, bix, level);
+ if (ret)
+ goto out;
+ } else if (!PageUptodate(ipage)) {
+ page_empty = 1;
+ logfs_read_empty(ipage);
+ }
+
+ child_wc.ofs = block_get_pointer(ipage, child_no);
+
+ if ((__force u8)level-1 > (__force u8)target_level)
+ ret = __logfs_write_rec(inode, page, &child_wc, bix,
+ target_level, SUBLEVEL(level));
+ else
+ ret = logfs_write_i0(inode, page, &child_wc);
+
+ if (ret)
+ goto out;
+
+ alloc_indirect_block(inode, ipage, page_empty);
+ block_set_pointer(ipage, child_no, child_wc.ofs);
+ /* FIXME: first condition seems superfluous */
+ if (child_wc.ofs || logfs_block(ipage)->partial)
+ this_wc->flags |= WF_WRITE;
+ /* the condition on this_wc->ofs ensures that we won't consume extra
+ * space for indirect blocks in the future, which we cannot reserve */
+ if (!this_wc->ofs || ptr_change(this_wc->ofs, ipage))
+ ret = logfs_write_i0(inode, ipage, this_wc);
+ else
+ logfs_set_alias(inode->i_sb, logfs_block(ipage), child_no);
+out:
+ logfs_put_write_page(ipage);
+ return ret;
+}
+
+static int logfs_write_rec(struct inode *inode, struct page *page,
+ pgoff_t bix, level_t target_level, long flags)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ struct write_control wc = {
+ .ofs = li->li_data[INDIRECT_INDEX],
+ .flags = flags,
+ };
+ int ret;
+
+ alloc_inode_block(inode);
+
+ if (li->li_height > (__force u8)target_level)
+ ret = __logfs_write_rec(inode, page, &wc, bix, target_level,
+ LEVEL(li->li_height));
+ else
+ ret = logfs_write_i0(inode, page, &wc);
+ if (ret)
+ return ret;
+
+ if (li->li_data[INDIRECT_INDEX] != wc.ofs) {
+ li->li_data[INDIRECT_INDEX] = wc.ofs;
+ logfs_set_alias(inode->i_sb, li->li_block,
+ INDIRECT_INDEX + INODE_POINTER_OFS);
+ }
+ return ret;
+}
+
+void logfs_add_transaction(struct inode *inode, struct logfs_transaction *ta)
+{
+ alloc_inode_block(inode);
+ logfs_inode(inode)->li_block->ta = ta;
+}
+
+void logfs_del_transaction(struct inode *inode, struct logfs_transaction *ta)
+{
+ struct logfs_block *block = logfs_inode(inode)->li_block;
+
+ if (block && block->ta)
+ block->ta = NULL;
+}
+
+static int grow_inode(struct inode *inode, u64 bix, level_t level)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ u8 height = (__force u8)level;
+ struct page *page;
+ struct write_control wc = {
+ .flags = WF_WRITE,
+ };
+ int err;
+
+ BUG_ON(height > 5 || li->li_height > 5);
+ while (height > li->li_height || bix >= maxbix(li->li_height)) {
+ page = logfs_get_write_page(inode, I0_BLOCKS + 1,
+ LEVEL(li->li_height + 1));
+ if (!page)
+ return -ENOMEM;
+ logfs_read_empty(page);
+ alloc_indirect_block(inode, page, 1);
+ block_set_pointer(page, 0, li->li_data[INDIRECT_INDEX]);
+ err = logfs_write_i0(inode, page, &wc);
+ logfs_put_write_page(page);
+ if (err)
+ return err;
+ li->li_data[INDIRECT_INDEX] = wc.ofs;
+ wc.ofs = 0;
+ li->li_height++;
+ logfs_set_alias(inode->i_sb, li->li_block, INODE_HEIGHT_OFS);
+ }
+ return 0;
+}
+
+static int __logfs_write_buf(struct inode *inode, struct page *page, long flags)
+{
+ struct logfs_super *super = logfs_super(inode->i_sb);
+ pgoff_t index = page->index;
+ u64 bix;
+ level_t level;
+ int err;
+
+ flags |= WF_WRITE | WF_DELETE;
+ inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+
+ logfs_unpack_index(index, &bix, &level);
+ if (logfs_block(page) && logfs_block(page)->reserved_bytes)
+ super->s_dirty_pages -= logfs_block(page)->reserved_bytes;
+
+ if (index < I0_BLOCKS)
+ return logfs_write_direct(inode, page, flags);
+
+ bix = adjust_bix(bix, level);
+ err = grow_inode(inode, bix, level);
+ if (err)
+ return err;
+ return logfs_write_rec(inode, page, bix, level, flags);
+}
+
+int logfs_write_buf(struct inode *inode, struct page *page, long flags)
+{
+ struct super_block *sb = inode->i_sb;
+ int ret;
+
+ logfs_get_wblocks(sb, page, flags & WF_LOCK);
+ ret = __logfs_write_buf(inode, page, flags);
+ logfs_put_wblocks(sb, page, flags & WF_LOCK);
+ return ret;
+}
+
+static int __logfs_delete(struct inode *inode, struct page *page)
+{
+ long flags = WF_DELETE;
+ int err;
+
+ inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+
+ if (page->index < I0_BLOCKS)
+ return logfs_write_direct(inode, page, flags);
+ err = grow_inode(inode, page->index, 0);
+ if (err)
+ return err;
+ return logfs_write_rec(inode, page, page->index, 0, flags);
+}
+
+int logfs_delete(struct inode *inode, pgoff_t index,
+ struct shadow_tree *shadow_tree)
+{
+ struct super_block *sb = inode->i_sb;
+ struct page *page;
+ int ret;
+
+ page = logfs_get_read_page(inode, index, 0);
+ if (!page)
+ return -ENOMEM;
+
+ logfs_get_wblocks(sb, page, 1);
+ ret = __logfs_delete(inode, page);
+ logfs_put_wblocks(sb, page, 1);
+
+ logfs_put_read_page(page);
+
+ return ret;
+}
+
+int logfs_rewrite_block(struct inode *inode, u64 bix, u64 ofs,
+ gc_level_t gc_level, long flags)
+{
+ level_t level = shrink_level(gc_level);
+ struct page *page;
+ int err;
+
+ page = logfs_get_write_page(inode, bix, level);
+ if (!page)
+ return -ENOMEM;
+
+ err = logfs_segment_read(inode, page, ofs, bix, level);
+ if (!err) {
+ if (level != 0)
+ alloc_indirect_block(inode, page, 0);
+ err = logfs_write_buf(inode, page, flags);
+ if (!err && shrink_level(gc_level) == 0) {
+ /* Rewrite cannot mark the inode dirty but has to
+ * write it immediately.
+ * Q: Can't we just create an alias for the inode
+ * instead? And if not, why not?
+ */
+ if (inode->i_ino == LOGFS_INO_MASTER)
+ logfs_write_anchor(inode->i_sb);
+ else {
+ err = __logfs_write_inode(inode, page, flags);
+ }
+ }
+ }
+ logfs_put_write_page(page);
+ return err;
+}
+
+static int truncate_data_block(struct inode *inode, struct page *page,
+ u64 ofs, struct logfs_shadow *shadow, u64 size)
+{
+ loff_t pageofs = page->index << inode->i_sb->s_blocksize_bits;
+ u64 bix;
+ level_t level;
+ int err;
+
+ /* Does truncation happen within this page? */
+ if (size <= pageofs || size - pageofs >= PAGE_SIZE)
+ return 0;
+
+ logfs_unpack_index(page->index, &bix, &level);
+ BUG_ON(level != 0);
+
+ err = logfs_segment_read(inode, page, ofs, bix, level);
+ if (err)
+ return err;
+
+ zero_user_segment(page, size - pageofs, PAGE_CACHE_SIZE);
+ return logfs_segment_write(inode, page, shadow);
+}
+
+static int logfs_truncate_i0(struct inode *inode, struct page *page,
+ struct write_control *wc, u64 size)
+{
+ struct logfs_shadow *shadow;
+ u64 bix;
+ level_t level;
+ int err = 0;
+
+ logfs_unpack_index(page->index, &bix, &level);
+ BUG_ON(level != 0);
+ shadow = alloc_shadow(inode, bix, level, wc->ofs);
+
+ err = truncate_data_block(inode, page, wc->ofs, shadow, size);
+ if (err) {
+ free_shadow(inode, shadow);
+ return err;
+ }
+
+ logfs_segment_delete(inode, shadow);
+ set_iused(inode, shadow);
+ fill_shadow_tree(inode, page, shadow);
+ wc->ofs = shadow->new_ofs;
+ return 0;
+}
+
+static int logfs_truncate_direct(struct inode *inode, u64 size)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ struct write_control wc;
+ struct page *page;
+ int e;
+ int err;
+
+ alloc_inode_block(inode);
+
+ for (e = I0_BLOCKS - 1; e >= 0; e--) {
+ if (size > (e+1) * LOGFS_BLOCKSIZE)
+ break;
+
+ wc.ofs = li->li_data[e];
+ if (!wc.ofs)
+ continue;
+
+ page = logfs_get_write_page(inode, e, 0);
+ if (!page)
+ return -ENOMEM;
+ err = logfs_segment_read(inode, page, wc.ofs, e, 0);
+ if (err) {
+ logfs_put_write_page(page);
+ return err;
+ }
+ err = logfs_truncate_i0(inode, page, &wc, size);
+ logfs_put_write_page(page);
+ if (err)
+ return err;
+
+ li->li_data[e] = wc.ofs;
+ }
+ return 0;
+}
+
+/* FIXME: these need to become per-sb once we support different blocksizes */
+static u64 __logfs_step[] = {
+ 1,
+ I1_BLOCKS,
+ I2_BLOCKS,
+ I3_BLOCKS,
+};
+
+static u64 __logfs_start_index[] = {
+ I0_BLOCKS,
+ I1_BLOCKS,
+ I2_BLOCKS,
+ I3_BLOCKS
+};
+
+static inline u64 logfs_step(level_t level)
+{
+ return __logfs_step[(__force u8)level];
+}
+
+static inline u64 logfs_factor(u8 level)
+{
+ return __logfs_step[level] * LOGFS_BLOCKSIZE;
+}
+
+static inline u64 logfs_start_index(level_t level)
+{
+ return __logfs_start_index[(__force u8)level];
+}
+
+static void logfs_unpack_raw_index(pgoff_t index, u64 *bix, level_t *level)
+{
+ logfs_unpack_index(index, bix, level);
+ if (*bix <= logfs_start_index(SUBLEVEL(*level)))
+ *bix = 0;
+}
+
+static int __logfs_truncate_rec(struct inode *inode, struct page *ipage,
+ struct write_control *this_wc, u64 size)
+{
+ int truncate_happened = 0;
+ int e, err = 0;
+ u64 bix, child_bix, next_bix;
+ level_t level;
+ struct page *page;
+ struct write_control child_wc = { /* FIXME: flags */ };
+
+ logfs_unpack_raw_index(ipage->index, &bix, &level);
+ err = logfs_segment_read(inode, ipage, this_wc->ofs, bix, level);
+ if (err)
+ return err;
+
+ for (e = LOGFS_BLOCK_FACTOR - 1; e >= 0; e--) {
+ child_bix = bix + e * logfs_step(SUBLEVEL(level));
+ next_bix = child_bix + logfs_step(SUBLEVEL(level));
+ if (size > next_bix * LOGFS_BLOCKSIZE)
+ break;
+
+ child_wc.ofs = pure_ofs(block_get_pointer(ipage, e));
+ if (!child_wc.ofs)
+ continue;
+
+ page = logfs_get_write_page(inode, child_bix, SUBLEVEL(level));
+ if (!page)
+ return -ENOMEM;
+
+ if ((__force u8)level > 1)
+ err = __logfs_truncate_rec(inode, page, &child_wc, size);
+ else
+ err = logfs_truncate_i0(inode, page, &child_wc, size);
+ logfs_put_write_page(page);
+ if (err)
+ return err;
+
+ truncate_happened = 1;
+ alloc_indirect_block(inode, ipage, 0);
+ block_set_pointer(ipage, e, child_wc.ofs);
+ }
+
+ if (!truncate_happened) {
+ printk("ineffectual truncate (%lx, %lx, %llx)\n", inode->i_ino, ipage->index, size);
+ return 0;
+ }
+
+ this_wc->flags = WF_DELETE;
+ if (logfs_block(ipage)->partial)
+ this_wc->flags |= WF_WRITE;
+
+ return logfs_write_i0(inode, ipage, this_wc);
+}
+
+static int logfs_truncate_rec(struct inode *inode, u64 size)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ struct write_control wc = {
+ .ofs = li->li_data[INDIRECT_INDEX],
+ };
+ struct page *page;
+ int err;
+
+ alloc_inode_block(inode);
+
+ if (!wc.ofs)
+ return 0;
+
+ page = logfs_get_write_page(inode, 0, LEVEL(li->li_height));
+ if (!page)
+ return -ENOMEM;
+
+ err = __logfs_truncate_rec(inode, page, &wc, size);
+ logfs_put_write_page(page);
+ if (err)
+ return err;
+
+ if (li->li_data[INDIRECT_INDEX] != wc.ofs)
+ li->li_data[INDIRECT_INDEX] = wc.ofs;
+ return 0;
+}
+
+static int __logfs_truncate(struct inode *inode, u64 size)
+{
+ int ret;
+
+ if (size >= logfs_factor(logfs_inode(inode)->li_height))
+ return 0;
+
+ ret = logfs_truncate_rec(inode, size);
+ if (ret)
+ return ret;
+
+ return logfs_truncate_direct(inode, size);
+}
+
+/*
+ * Truncate, by changing the segment file, can consume a fair amount
+ * of resources. So back off from time to time and do some GC.
+ * 8 or 2048 blocks should be well within safety limits even if
+ * every single block resided in a different segment.
+ */
+#define TRUNCATE_STEP (8 * 1024 * 1024)
+int logfs_truncate(struct inode *inode, u64 target)
+{
+ struct super_block *sb = inode->i_sb;
+ u64 size = i_size_read(inode);
+ int err = 0;
+
+ size = ALIGN(size, TRUNCATE_STEP);
+ while (size > target) {
+ if (size > TRUNCATE_STEP)
+ size -= TRUNCATE_STEP;
+ else
+ size = 0;
+ if (size < target)
+ size = target;
+
+ logfs_get_wblocks(sb, NULL, 1);
+ err = __logfs_truncate(inode, size);
+ if (!err)
+ err = __logfs_write_inode(inode, NULL, 0);
+ logfs_put_wblocks(sb, NULL, 1);
+ }
+
+ if (!err) {
+ err = inode_newsize_ok(inode, target);
+ if (err)
+ goto out;
+
+ truncate_setsize(inode, target);
+ }
+
+ out:
+ /* I don't trust error recovery yet. */
+ WARN_ON(err);
+ return err;
+}
+
+static void move_page_to_inode(struct inode *inode, struct page *page)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ struct logfs_block *block = logfs_block(page);
+
+ if (!block)
+ return;
+
+ log_blockmove("move_page_to_inode(%llx, %llx, %x)\n",
+ block->ino, block->bix, block->level);
+ BUG_ON(li->li_block);
+ block->ops = &inode_block_ops;
+ block->inode = inode;
+ li->li_block = block;
+
+ block->page = NULL;
+ if (PagePrivate(page)) {
+ ClearPagePrivate(page);
+ page_cache_release(page);
+ set_page_private(page, 0);
+ }
+}
+
+static void move_inode_to_page(struct page *page, struct inode *inode)
+{
+ struct logfs_inode *li = logfs_inode(inode);
+ struct logfs_block *block = li->li_block;
+
+ if (!block)
+ return;
+
+ log_blockmove("move_inode_to_page(%llx, %llx, %x)\n",
+ block->ino, block->bix, block->level);
+ BUG_ON(PagePrivate(page));
+ block->ops = &indirect_block_ops;
+ block->page = page;
+
+ if (!PagePrivate(page)) {
+ SetPagePrivate(page);
+ page_cache_get(page);
+ set_page_private(page, (unsigned long) block);
+ }
+
+ block->inode = NULL;
+ li->li_block = NULL;
+}
+
+int logfs_read_inode(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct logfs_super *super = logfs_super(sb);
+ struct inode *master_inode = super->s_master_inode;
+ struct page *page;
+ struct logfs_disk_inode *di;
+ u64 ino = inode->i_ino;
+
+ if (ino << sb->s_blocksize_bits > i_size_read(master_inode))
+ return -ENODATA;
+ if (!logfs_exist_block(master_inode, ino))
+ return -ENODATA;
+
+ page = read_cache_page(master_inode->i_mapping, ino,
+ (filler_t *)logfs_readpage, NULL);
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ di = kmap_atomic(page);
+ logfs_disk_to_inode(di, inode);
+ kunmap_atomic(di);
+ move_page_to_inode(inode, page);
+ page_cache_release(page);
+ return 0;
+}
+
+/* Caller must logfs_put_write_page(page); */
+static struct page *inode_to_page(struct inode *inode)
+{
+ struct inode *master_inode = logfs_super(inode->i_sb)->s_master_inode;
+ struct logfs_disk_inode *di;
+ struct page *page;
+
+ BUG_ON(inode->i_ino == LOGFS_INO_MASTER);
+
+ page = logfs_get_write_page(master_inode, inode->i_ino, 0);
+ if (!page)
+ return NULL;
+
+ di = kmap_atomic(page);
+ logfs_inode_to_disk(inode, di);
+ kunmap_atomic(di);
+ move_inode_to_page(page, inode);
+ return page;
+}
+
+static int do_write_inode(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct inode *master_inode = logfs_super(sb)->s_master_inode;
+ loff_t size = (inode->i_ino + 1) << inode->i_sb->s_blocksize_bits;
+ struct page *page;
+ int err;
+
+ BUG_ON(inode->i_ino == LOGFS_INO_MASTER);
+ /* FIXME: lock inode */
+
+ if (i_size_read(master_inode) < size)
+ i_size_write(master_inode, size);
+
+ /* TODO: Tell vfs this inode is clean now */
+
+ page = inode_to_page(inode);
+ if (!page)
+ return -ENOMEM;
+
+ /* FIXME: transaction is part of logfs_block now. Is that enough? */
+ err = logfs_write_buf(master_inode, page, 0);
+ if (err)
+ move_page_to_inode(inode, page);
+
+ logfs_put_write_page(page);
+ return err;
+}
+
+static void logfs_mod_segment_entry(struct super_block *sb, u32 segno,
+ int write,
+ void (*change_se)(struct logfs_segment_entry *, long),
+ long arg)
+{
+ struct logfs_super *super = logfs_super(sb);
+ struct inode *inode;
+ struct page *page;
+ struct logfs_segment_entry *se;
+ pgoff_t page_no;
+ int child_no;
+
+ page_no = segno >> (sb->s_blocksize_bits - 3);
+ child_no = segno & ((sb->s_blocksize >> 3) - 1);
+
+ inode = super->s_segfile_inode;
+ page = logfs_get_write_page(inode, page_no, 0);
+ BUG_ON(!page); /* FIXME: We need some reserve page for this case */
+ if (!PageUptodate(page))
+ logfs_read_block(inode, page, WRITE);
+
+ if (write)
+ alloc_indirect_block(inode, page, 0);
+ se = kmap_atomic(page);
+ change_se(se + child_no, arg);
+ if (write) {
+ logfs_set_alias(sb, logfs_block(page), child_no);
+ BUG_ON((int)be32_to_cpu(se[child_no].valid) > super->s_segsize);
+ }
+ kunmap_atomic(se);
+
+ logfs_put_write_page(page);
+}
+
+static void __get_segment_entry(struct logfs_segment_entry *se, long _target)
+{
+ struct logfs_segment_entry *target = (void *)_target;
+
+ *target = *se;
+}
+
+void logfs_get_segment_entry(struct super_block *sb, u32 segno,
+ struct logfs_segment_entry *se)
+{
+ logfs_mod_segment_entry(sb, segno, 0, __get_segment_entry, (long)se);
+}
+
+static void __set_segment_used(struct logfs_segment_entry *se, long increment)
+{
+ u32 valid;
+
+ valid = be32_to_cpu(se->valid);
+ valid += increment;
+ se->valid = cpu_to_be32(valid);
+}
+
+void logfs_set_segment_used(struct super_block *sb, u64 ofs, int increment)
+{
+ struct logfs_super *super = logfs_super(sb);
+ u32 segno = ofs >> super->s_segshift;
+
+ if (!increment)
+ return;
+
+ logfs_mod_segment_entry(sb, segno, 1, __set_segment_used, increment);
+}
+
+static void __set_segment_erased(struct logfs_segment_entry *se, long ec_level)
+{
+ se->ec_level = cpu_to_be32(ec_level);
+}
+
+void logfs_set_segment_erased(struct super_block *sb, u32 segno, u32 ec,
+ gc_level_t gc_level)
+{
+ u32 ec_level = ec << 4 | (__force u8)gc_level;
+
+ logfs_mod_segment_entry(sb, segno, 1, __set_segment_erased, ec_level);
+}
+
+static void __set_segment_reserved(struct logfs_segment_entry *se, long ignore)
+{
+ se->valid = cpu_to_be32(RESERVED);
+}
+
+void logfs_set_segment_reserved(struct super_block *sb, u32 segno)
+{
+ logfs_mod_segment_entry(sb, segno, 1, __set_segment_reserved, 0);
+}
+
+static void __set_segment_unreserved(struct logfs_segment_entry *se,
+ long ec_level)
+{
+ se->valid = 0;
+ se->ec_level = cpu_to_be32(ec_level);
+}
+
+void logfs_set_segment_unreserved(struct super_block *sb, u32 segno, u32 ec)
+{
+ u32 ec_level = ec << 4;
+
+ logfs_mod_segment_entry(sb, segno, 1, __set_segment_unreserved,
+ ec_level);
+}
+
+int __logfs_write_inode(struct inode *inode, struct page *page, long flags)
+{
+ struct super_block *sb = inode->i_sb;
+ int ret;
+
+ logfs_get_wblocks(sb, page, flags & WF_LOCK);
+ ret = do_write_inode(inode);
+ logfs_put_wblocks(sb, page, flags & WF_LOCK);
+ return ret;
+}
+
+static int do_delete_inode(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct inode *master_inode = logfs_super(sb)->s_master_inode;
+ struct page *page;
+ int ret;
+
+ page = logfs_get_write_page(master_inode, inode->i_ino, 0);
+ if (!page)
+ return -ENOMEM;
+
+ move_inode_to_page(page, inode);
+
+ logfs_get_wblocks(sb, page, 1);
+ ret = __logfs_delete(master_inode, page);
+ logfs_put_wblocks(sb, page, 1);
+
+ logfs_put_write_page(page);
+ return ret;
+}
+
+/*
+ * ZOMBIE inodes have already been deleted before and should remain dead,
+ * if it weren't for valid checking. No need to kill them again here.
+ */
+void logfs_evict_inode(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct logfs_inode *li = logfs_inode(inode);
+ struct logfs_block *block = li->li_block;
+ struct page *page;
+
+ if (!inode->i_nlink) {
+ if (!(li->li_flags & LOGFS_IF_ZOMBIE)) {
+ li->li_flags |= LOGFS_IF_ZOMBIE;
+ if (i_size_read(inode) > 0)
+ logfs_truncate(inode, 0);
+ do_delete_inode(inode);
+ }
+ }
+ truncate_inode_pages_final(&inode->i_data);
+ clear_inode(inode);
+
+ /* Cheaper version of write_inode. All changes are concealed in
+ * aliases, which are moved back. No write to the medium happens.
+ */
+ /* Only deleted files may be dirty at this point */
+ BUG_ON(inode->i_state & I_DIRTY && inode->i_nlink);
+ if (!block)
+ return;
+ if ((logfs_super(sb)->s_flags & LOGFS_SB_FLAG_SHUTDOWN)) {
+ block->ops->free_block(inode->i_sb, block);
+ return;
+ }
+
+ page = inode_to_page(inode);
+ BUG_ON(!page); /* FIXME: Use emergency page */
+ logfs_put_write_page(page);
+}
+
+void btree_write_block(struct logfs_block *block)
+{
+ struct inode *inode;
+ struct page *page;
+ int err, cookie;
+
+ inode = logfs_safe_iget(block->sb, block->ino, &cookie);
+ page = logfs_get_write_page(inode, block->bix, block->level);
+
+ err = logfs_readpage_nolock(page);
+ BUG_ON(err);
+ BUG_ON(!PagePrivate(page));
+ BUG_ON(logfs_block(page) != block);
+ err = __logfs_write_buf(inode, page, 0);
+ BUG_ON(err);
+ BUG_ON(PagePrivate(page) || page->private);
+
+ logfs_put_write_page(page);
+ logfs_safe_iput(inode, cookie);
+}
+
+/**
+ * logfs_inode_write - write inode or dentry objects
+ *
+ * @inode: parent inode (ifile or directory)
+ * @buf: object to write (inode or dentry)
+ * @count: object size
+ * @bix: block index
+ * @flags: write flags
+ * @shadow_tree: shadow below this inode
+ *
+ * FIXME: All caller of this put a 200-300 byte variable on the stack,
+ * only to call here and do a memcpy from that stack variable. A good
+ * example of wasted performance and stack space.
+ */
+int logfs_inode_write(struct inode *inode, const void *buf, size_t count,
+ loff_t bix, long flags, struct shadow_tree *shadow_tree)
+{
+ loff_t pos = bix << inode->i_sb->s_blocksize_bits;
+ int err;
+ struct page *page;
+ void *pagebuf;
+
+ BUG_ON(pos & (LOGFS_BLOCKSIZE-1));
+ BUG_ON(count > LOGFS_BLOCKSIZE);
+ page = logfs_get_write_page(inode, bix, 0);
+ if (!page)
+ return -ENOMEM;
+
+ pagebuf = kmap_atomic(page);
+ memcpy(pagebuf, buf, count);
+ flush_dcache_page(page);
+ kunmap_atomic(pagebuf);
+
+ if (i_size_read(inode) < pos + LOGFS_BLOCKSIZE)
+ i_size_write(inode, pos + LOGFS_BLOCKSIZE);
+
+ err = logfs_write_buf(inode, page, flags);
+ logfs_put_write_page(page);
+ return err;
+}
+
+int logfs_open_segfile(struct super_block *sb)
+{
+ struct logfs_super *super = logfs_super(sb);
+ struct inode *inode;
+
+ inode = logfs_read_meta_inode(sb, LOGFS_INO_SEGFILE);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+ super->s_segfile_inode = inode;
+ return 0;
+}
+
+int logfs_init_rw(struct super_block *sb)
+{
+ struct logfs_super *super = logfs_super(sb);
+ int min_fill = 3 * super->s_no_blocks;
+
+ INIT_LIST_HEAD(&super->s_object_alias);
+ INIT_LIST_HEAD(&super->s_writeback_list);
+ mutex_init(&super->s_write_mutex);
+ super->s_block_pool = mempool_create_kmalloc_pool(min_fill,
+ sizeof(struct logfs_block));
+ super->s_shadow_pool = mempool_create_kmalloc_pool(min_fill,
+ sizeof(struct logfs_shadow));
+ return 0;
+}
+
+void logfs_cleanup_rw(struct super_block *sb)
+{
+ struct logfs_super *super = logfs_super(sb);
+
+ logfs_mempool_destroy(super->s_block_pool);
+ logfs_mempool_destroy(super->s_shadow_pool);
+}
Code Review / kvmfornfv.git / blobdiff