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. - */ |