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-rw-r--r--fs/logfs/readwrite.c2298
1 files changed, 0 insertions, 2298 deletions
diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c
deleted file mode 100644
index bf19bf4a243f..000000000000
--- a/fs/logfs/readwrite.c
+++ /dev/null
@@ -1,2298 +0,0 @@
-/*
- * 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);
- put_page(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)) {
- put_page(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);
- put_page(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);
- put_page(page);
- set_page_private(page, 0);
- }
- __free_block(sb, block);
-}
-
-
-static const struct logfs_block_ops inode_block_ops = {
- .write_block = inode_write_block,
- .free_block = inode_free_block,
- .write_alias = inode_write_alias,
-};
-
-const 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);
- get_page(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_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(inode);
-
- 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(inode);
-
- 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_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);
- put_page(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);
- get_page(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);
- put_page(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);
-}