diff options
Diffstat (limited to 'fs/logfs/readwrite.c')
| -rw-r--r-- | fs/logfs/readwrite.c | 2298 |
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); -} |