From c2ea3fde61f1df1dbf062345f23277dcd6f01dfe Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Fri, 10 Oct 2008 09:40:52 -0400 Subject: ext4: Remove old legacy block allocator Signed-off-by: "Theodore Ts'o" --- fs/ext4/balloc.c | 1355 +----------------------------------------------------- 1 file changed, 11 insertions(+), 1344 deletions(-) (limited to 'fs/ext4/balloc.c') diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index cca7fd53ad7..59566c082f1 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -83,6 +83,7 @@ static int ext4_group_used_meta_blocks(struct super_block *sb, } return used_blocks; } + /* Initializes an uninitialized block bitmap if given, and returns the * number of blocks free in the group. */ unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, @@ -345,303 +346,6 @@ ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group) */ return bh; } -/* - * The reservation window structure operations - * -------------------------------------------- - * Operations include: - * dump, find, add, remove, is_empty, find_next_reservable_window, etc. - * - * We use a red-black tree to represent per-filesystem reservation - * windows. - * - */ - -/** - * __rsv_window_dump() -- Dump the filesystem block allocation reservation map - * @rb_root: root of per-filesystem reservation rb tree - * @verbose: verbose mode - * @fn: function which wishes to dump the reservation map - * - * If verbose is turned on, it will print the whole block reservation - * windows(start, end). Otherwise, it will only print out the "bad" windows, - * those windows that overlap with their immediate neighbors. - */ -#if 1 -static void __rsv_window_dump(struct rb_root *root, int verbose, - const char *fn) -{ - struct rb_node *n; - struct ext4_reserve_window_node *rsv, *prev; - int bad; - -restart: - n = rb_first(root); - bad = 0; - prev = NULL; - - printk(KERN_DEBUG "Block Allocation Reservation " - "Windows Map (%s):\n", fn); - while (n) { - rsv = rb_entry(n, struct ext4_reserve_window_node, rsv_node); - if (verbose) - printk(KERN_DEBUG "reservation window 0x%p " - "start: %llu, end: %llu\n", - rsv, rsv->rsv_start, rsv->rsv_end); - if (rsv->rsv_start && rsv->rsv_start >= rsv->rsv_end) { - printk(KERN_DEBUG "Bad reservation %p (start >= end)\n", - rsv); - bad = 1; - } - if (prev && prev->rsv_end >= rsv->rsv_start) { - printk(KERN_DEBUG "Bad reservation %p " - "(prev->end >= start)\n", rsv); - bad = 1; - } - if (bad) { - if (!verbose) { - printk(KERN_DEBUG "Restarting reservation " - "walk in verbose mode\n"); - verbose = 1; - goto restart; - } - } - n = rb_next(n); - prev = rsv; - } - printk(KERN_DEBUG "Window map complete.\n"); - BUG_ON(bad); -} -#define rsv_window_dump(root, verbose) \ - __rsv_window_dump((root), (verbose), __func__) -#else -#define rsv_window_dump(root, verbose) do {} while (0) -#endif - -/** - * goal_in_my_reservation() - * @rsv: inode's reservation window - * @grp_goal: given goal block relative to the allocation block group - * @group: the current allocation block group - * @sb: filesystem super block - * - * Test if the given goal block (group relative) is within the file's - * own block reservation window range. - * - * If the reservation window is outside the goal allocation group, return 0; - * grp_goal (given goal block) could be -1, which means no specific - * goal block. In this case, always return 1. - * If the goal block is within the reservation window, return 1; - * otherwise, return 0; - */ -static int -goal_in_my_reservation(struct ext4_reserve_window *rsv, ext4_grpblk_t grp_goal, - ext4_group_t group, struct super_block *sb) -{ - ext4_fsblk_t group_first_block, group_last_block; - - group_first_block = ext4_group_first_block_no(sb, group); - group_last_block = group_first_block + (EXT4_BLOCKS_PER_GROUP(sb) - 1); - - if ((rsv->_rsv_start > group_last_block) || - (rsv->_rsv_end < group_first_block)) - return 0; - if ((grp_goal >= 0) && ((grp_goal + group_first_block < rsv->_rsv_start) - || (grp_goal + group_first_block > rsv->_rsv_end))) - return 0; - return 1; -} - -/** - * search_reserve_window() - * @rb_root: root of reservation tree - * @goal: target allocation block - * - * Find the reserved window which includes the goal, or the previous one - * if the goal is not in any window. - * Returns NULL if there are no windows or if all windows start after the goal. - */ -static struct ext4_reserve_window_node * -search_reserve_window(struct rb_root *root, ext4_fsblk_t goal) -{ - struct rb_node *n = root->rb_node; - struct ext4_reserve_window_node *rsv; - - if (!n) - return NULL; - - do { - rsv = rb_entry(n, struct ext4_reserve_window_node, rsv_node); - - if (goal < rsv->rsv_start) - n = n->rb_left; - else if (goal > rsv->rsv_end) - n = n->rb_right; - else - return rsv; - } while (n); - /* - * We've fallen off the end of the tree: the goal wasn't inside - * any particular node. OK, the previous node must be to one - * side of the interval containing the goal. If it's the RHS, - * we need to back up one. - */ - if (rsv->rsv_start > goal) { - n = rb_prev(&rsv->rsv_node); - rsv = rb_entry(n, struct ext4_reserve_window_node, rsv_node); - } - return rsv; -} - -/** - * ext4_rsv_window_add() -- Insert a window to the block reservation rb tree. - * @sb: super block - * @rsv: reservation window to add - * - * Must be called with rsv_lock hold. - */ -void ext4_rsv_window_add(struct super_block *sb, - struct ext4_reserve_window_node *rsv) -{ - struct rb_root *root = &EXT4_SB(sb)->s_rsv_window_root; - struct rb_node *node = &rsv->rsv_node; - ext4_fsblk_t start = rsv->rsv_start; - - struct rb_node **p = &root->rb_node; - struct rb_node *parent = NULL; - struct ext4_reserve_window_node *this; - - while (*p) - { - parent = *p; - this = rb_entry(parent, struct ext4_reserve_window_node, rsv_node); - - if (start < this->rsv_start) - p = &(*p)->rb_left; - else if (start > this->rsv_end) - p = &(*p)->rb_right; - else { - rsv_window_dump(root, 1); - BUG(); - } - } - - rb_link_node(node, parent, p); - rb_insert_color(node, root); -} - -/** - * ext4_rsv_window_remove() -- unlink a window from the reservation rb tree - * @sb: super block - * @rsv: reservation window to remove - * - * Mark the block reservation window as not allocated, and unlink it - * from the filesystem reservation window rb tree. Must be called with - * rsv_lock hold. - */ -static void rsv_window_remove(struct super_block *sb, - struct ext4_reserve_window_node *rsv) -{ - rsv->rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED; - rsv->rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED; - rsv->rsv_alloc_hit = 0; - rb_erase(&rsv->rsv_node, &EXT4_SB(sb)->s_rsv_window_root); -} - -/* - * rsv_is_empty() -- Check if the reservation window is allocated. - * @rsv: given reservation window to check - * - * returns 1 if the end block is EXT4_RESERVE_WINDOW_NOT_ALLOCATED. - */ -static inline int rsv_is_empty(struct ext4_reserve_window *rsv) -{ - /* a valid reservation end block could not be 0 */ - return rsv->_rsv_end == EXT4_RESERVE_WINDOW_NOT_ALLOCATED; -} - -/** - * ext4_init_block_alloc_info() - * @inode: file inode structure - * - * Allocate and initialize the reservation window structure, and - * link the window to the ext4 inode structure at last - * - * The reservation window structure is only dynamically allocated - * and linked to ext4 inode the first time the open file - * needs a new block. So, before every ext4_new_block(s) call, for - * regular files, we should check whether the reservation window - * structure exists or not. In the latter case, this function is called. - * Fail to do so will result in block reservation being turned off for that - * open file. - * - * This function is called from ext4_get_blocks_handle(), also called - * when setting the reservation window size through ioctl before the file - * is open for write (needs block allocation). - * - * Needs down_write(i_data_sem) protection prior to call this function. - */ -void ext4_init_block_alloc_info(struct inode *inode) -{ - struct ext4_inode_info *ei = EXT4_I(inode); - struct ext4_block_alloc_info *block_i = ei->i_block_alloc_info; - struct super_block *sb = inode->i_sb; - - block_i = kmalloc(sizeof(*block_i), GFP_NOFS); - if (block_i) { - struct ext4_reserve_window_node *rsv = &block_i->rsv_window_node; - - rsv->rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED; - rsv->rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED; - - /* - * if filesystem is mounted with NORESERVATION, the goal - * reservation window size is set to zero to indicate - * block reservation is off - */ - if (!test_opt(sb, RESERVATION)) - rsv->rsv_goal_size = 0; - else - rsv->rsv_goal_size = EXT4_DEFAULT_RESERVE_BLOCKS; - rsv->rsv_alloc_hit = 0; - block_i->last_alloc_logical_block = 0; - block_i->last_alloc_physical_block = 0; - } - ei->i_block_alloc_info = block_i; -} - -/** - * ext4_discard_reservation() - * @inode: inode - * - * Discard(free) block reservation window on last file close, or truncate - * or at last iput(). - * - * It is being called in three cases: - * ext4_release_file(): last writer close the file - * ext4_clear_inode(): last iput(), when nobody link to this file. - * ext4_truncate(): when the block indirect map is about to change. - * - */ -void ext4_discard_reservation(struct inode *inode) -{ - struct ext4_inode_info *ei = EXT4_I(inode); - struct ext4_block_alloc_info *block_i = ei->i_block_alloc_info; - struct ext4_reserve_window_node *rsv; - spinlock_t *rsv_lock = &EXT4_SB(inode->i_sb)->s_rsv_window_lock; - - ext4_mb_discard_inode_preallocations(inode); - - if (!block_i) - return; - - rsv = &block_i->rsv_window_node; - if (!rsv_is_empty(&rsv->rsv_window)) { - spin_lock(rsv_lock); - if (!rsv_is_empty(&rsv->rsv_window)) - rsv_window_remove(inode->i_sb, rsv); - spin_unlock(rsv_lock); - } -} /** * ext4_free_blocks_sb() -- Free given blocks and update quota @@ -650,6 +354,13 @@ void ext4_discard_reservation(struct inode *inode) * @block: start physcial block to free * @count: number of blocks to free * @pdquot_freed_blocks: pointer to quota + * + * XXX This function is only used by the on-line resizing code, which + * should probably be fixed up to call the mballoc variant. There + * this needs to be cleaned up later; in fact, I'm not convinced this + * is 100% correct in the face of the mballoc code. The online resizing + * code needs to be fixed up to more tightly (and correctly) interlock + * with the mballoc code. */ void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb, ext4_fsblk_t block, unsigned long count, @@ -861,747 +572,13 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode, sb = inode->i_sb; - if (!test_opt(sb, MBALLOC) || !EXT4_SB(sb)->s_group_info) - ext4_free_blocks_sb(handle, sb, block, count, - &dquot_freed_blocks); - else - ext4_mb_free_blocks(handle, inode, block, count, - metadata, &dquot_freed_blocks); + ext4_mb_free_blocks(handle, inode, block, count, + metadata, &dquot_freed_blocks); if (dquot_freed_blocks) DQUOT_FREE_BLOCK(inode, dquot_freed_blocks); return; } -/** - * ext4_test_allocatable() - * @nr: given allocation block group - * @bh: bufferhead contains the bitmap of the given block group - * - * For ext4 allocations, we must not reuse any blocks which are - * allocated in the bitmap buffer's "last committed data" copy. This - * prevents deletes from freeing up the page for reuse until we have - * committed the delete transaction. - * - * If we didn't do this, then deleting something and reallocating it as - * data would allow the old block to be overwritten before the - * transaction committed (because we force data to disk before commit). - * This would lead to corruption if we crashed between overwriting the - * data and committing the delete. - * - * @@@ We may want to make this allocation behaviour conditional on - * data-writes at some point, and disable it for metadata allocations or - * sync-data inodes. - */ -static int ext4_test_allocatable(ext4_grpblk_t nr, struct buffer_head *bh) -{ - int ret; - struct journal_head *jh = bh2jh(bh); - - if (ext4_test_bit(nr, bh->b_data)) - return 0; - - jbd_lock_bh_state(bh); - if (!jh->b_committed_data) - ret = 1; - else - ret = !ext4_test_bit(nr, jh->b_committed_data); - jbd_unlock_bh_state(bh); - return ret; -} - -/** - * bitmap_search_next_usable_block() - * @start: the starting block (group relative) of the search - * @bh: bufferhead contains the block group bitmap - * @maxblocks: the ending block (group relative) of the reservation - * - * The bitmap search --- search forward alternately through the actual - * bitmap on disk and the last-committed copy in journal, until we find a - * bit free in both bitmaps. - */ -static ext4_grpblk_t -bitmap_search_next_usable_block(ext4_grpblk_t start, struct buffer_head *bh, - ext4_grpblk_t maxblocks) -{ - ext4_grpblk_t next; - struct journal_head *jh = bh2jh(bh); - - while (start < maxblocks) { - next = ext4_find_next_zero_bit(bh->b_data, maxblocks, start); - if (next >= maxblocks) - return -1; - if (ext4_test_allocatable(next, bh)) - return next; - jbd_lock_bh_state(bh); - if (jh->b_committed_data) - start = ext4_find_next_zero_bit(jh->b_committed_data, - maxblocks, next); - jbd_unlock_bh_state(bh); - } - return -1; -} - -/** - * find_next_usable_block() - * @start: the starting block (group relative) to find next - * allocatable block in bitmap. - * @bh: bufferhead contains the block group bitmap - * @maxblocks: the ending block (group relative) for the search - * - * Find an allocatable block in a bitmap. We honor both the bitmap and - * its last-committed copy (if that exists), and perform the "most - * appropriate allocation" algorithm of looking for a free block near - * the initial goal; then for a free byte somewhere in the bitmap; then - * for any free bit in the bitmap. - */ -static ext4_grpblk_t -find_next_usable_block(ext4_grpblk_t start, struct buffer_head *bh, - ext4_grpblk_t maxblocks) -{ - ext4_grpblk_t here, next; - char *p, *r; - - if (start > 0) { - /* - * The goal was occupied; search forward for a free - * block within the next XX blocks. - * - * end_goal is more or less random, but it has to be - * less than EXT4_BLOCKS_PER_GROUP. Aligning up to the - * next 64-bit boundary is simple.. - */ - ext4_grpblk_t end_goal = (start + 63) & ~63; - if (end_goal > maxblocks) - end_goal = maxblocks; - here = ext4_find_next_zero_bit(bh->b_data, end_goal, start); - if (here < end_goal && ext4_test_allocatable(here, bh)) - return here; - ext4_debug("Bit not found near goal\n"); - } - - here = start; - if (here < 0) - here = 0; - - p = ((char *)bh->b_data) + (here >> 3); - r = memscan(p, 0, ((maxblocks + 7) >> 3) - (here >> 3)); - next = (r - ((char *)bh->b_data)) << 3; - - if (next < maxblocks && next >= start && ext4_test_allocatable(next, bh)) - return next; - - /* - * The bitmap search --- search forward alternately through the actual - * bitmap and the last-committed copy until we find a bit free in - * both - */ - here = bitmap_search_next_usable_block(here, bh, maxblocks); - return here; -} - -/** - * claim_block() - * @block: the free block (group relative) to allocate - * @bh: the bufferhead containts the block group bitmap - * - * We think we can allocate this block in this bitmap. Try to set the bit. - * If that succeeds then check that nobody has allocated and then freed the - * block since we saw that is was not marked in b_committed_data. If it _was_ - * allocated and freed then clear the bit in the bitmap again and return - * zero (failure). - */ -static inline int -claim_block(spinlock_t *lock, ext4_grpblk_t block, struct buffer_head *bh) -{ - struct journal_head *jh = bh2jh(bh); - int ret; - - if (ext4_set_bit_atomic(lock, block, bh->b_data)) - return 0; - jbd_lock_bh_state(bh); - if (jh->b_committed_data && ext4_test_bit(block, jh->b_committed_data)) { - ext4_clear_bit_atomic(lock, block, bh->b_data); - ret = 0; - } else { - ret = 1; - } - jbd_unlock_bh_state(bh); - return ret; -} - -/** - * ext4_try_to_allocate() - * @sb: superblock - * @handle: handle to this transaction - * @group: given allocation block group - * @bitmap_bh: bufferhead holds the block bitmap - * @grp_goal: given target block within the group - * @count: target number of blocks to allocate - * @my_rsv: reservation window - * - * Attempt to allocate blocks within a give range. Set the range of allocation - * first, then find the first free bit(s) from the bitmap (within the range), - * and at last, allocate the blocks by claiming the found free bit as allocated. - * - * To set the range of this allocation: - * if there is a reservation window, only try to allocate block(s) from the - * file's own reservation window; - * Otherwise, the allocation range starts from the give goal block, ends at - * the block group's last block. - * - * If we failed to allocate the desired block then we may end up crossing to a - * new bitmap. In that case we must release write access to the old one via - * ext4_journal_release_buffer(), else we'll run out of credits. - */ -static ext4_grpblk_t -ext4_try_to_allocate(struct super_block *sb, handle_t *handle, - ext4_group_t group, struct buffer_head *bitmap_bh, - ext4_grpblk_t grp_goal, unsigned long *count, - struct ext4_reserve_window *my_rsv) -{ - ext4_fsblk_t group_first_block; - ext4_grpblk_t start, end; - unsigned long num = 0; - - /* we do allocation within the reservation window if we have a window */ - if (my_rsv) { - group_first_block = ext4_group_first_block_no(sb, group); - if (my_rsv->_rsv_start >= group_first_block) - start = my_rsv->_rsv_start - group_first_block; - else - /* reservation window cross group boundary */ - start = 0; - end = my_rsv->_rsv_end - group_first_block + 1; - if (end > EXT4_BLOCKS_PER_GROUP(sb)) - /* reservation window crosses group boundary */ - end = EXT4_BLOCKS_PER_GROUP(sb); - if ((start <= grp_goal) && (grp_goal < end)) - start = grp_goal; - else - grp_goal = -1; - } else { - if (grp_goal > 0) - start = grp_goal; - else - start = 0; - end = EXT4_BLOCKS_PER_GROUP(sb); - } - - BUG_ON(start > EXT4_BLOCKS_PER_GROUP(sb)); - -repeat: - if (grp_goal < 0 || !ext4_test_allocatable(grp_goal, bitmap_bh)) { - grp_goal = find_next_usable_block(start, bitmap_bh, end); - if (grp_goal < 0) - goto fail_access; - if (!my_rsv) { - int i; - - for (i = 0; i < 7 && grp_goal > start && - ext4_test_allocatable(grp_goal - 1, - bitmap_bh); - i++, grp_goal--) - ; - } - } - start = grp_goal; - - if (!claim_block(sb_bgl_lock(EXT4_SB(sb), group), - grp_goal, bitmap_bh)) { - /* - * The block was allocated by another thread, or it was - * allocated and then freed by another thread - */ - start++; - grp_goal++; - if (start >= end) - goto fail_access; - goto repeat; - } - num++; - grp_goal++; - while (num < *count && grp_goal < end - && ext4_test_allocatable(grp_goal, bitmap_bh) - && claim_block(sb_bgl_lock(EXT4_SB(sb), group), - grp_goal, bitmap_bh)) { - num++; - grp_goal++; - } - *count = num; - return grp_goal - num; -fail_access: - *count = num; - return -1; -} - -/** - * find_next_reservable_window(): - * find a reservable space within the given range. - * It does not allocate the reservation window for now: - * alloc_new_reservation() will do the work later. - * - * @search_head: the head of the searching list; - * This is not necessarily the list head of the whole filesystem - * - * We have both head and start_block to assist the search - * for the reservable space. The list starts from head, - * but we will shift to the place where start_block is, - * then start from there, when looking for a reservable space. - * - * @size: the target new reservation window size - * - * @group_first_block: the first block we consider to start - * the real search from - * - * @last_block: - * the maximum block number that our goal reservable space - * could start from. This is normally the last block in this - * group. The search will end when we found the start of next - * possible reservable space is out of this boundary. - * This could handle the cross boundary reservation window - * request. - * - * basically we search from the given range, rather than the whole - * reservation double linked list, (start_block, last_block) - * to find a free region that is of my size and has not - * been reserved. - * - */ -static int find_next_reservable_window( - struct ext4_reserve_window_node *search_head, - struct ext4_reserve_window_node *my_rsv, - struct super_block *sb, - ext4_fsblk_t start_block, - ext4_fsblk_t last_block) -{ - struct rb_node *next; - struct ext4_reserve_window_node *rsv, *prev; - ext4_fsblk_t cur; - int size = my_rsv->rsv_goal_size; - - /* TODO: make the start of the reservation window byte-aligned */ - /* cur = *start_block & ~7;*/ - cur = start_block; - rsv = search_head; - if (!rsv) - return -1; - - while (1) { - if (cur <= rsv->rsv_end) - cur = rsv->rsv_end + 1; - - /* TODO? - * in the case we could not find a reservable space - * that is what is expected, during the re-search, we could - * remember what's the largest reservable space we could have - * and return that one. - * - * For now it will fail if we could not find the reservable - * space with expected-size (or more)... - */ - if (cur > last_block) - return -1; /* fail */ - - prev = rsv; - next = rb_next(&rsv->rsv_node); - rsv = rb_entry(next, struct ext4_reserve_window_node, rsv_node); - - /* - * Reached the last reservation, we can just append to the - * previous one. - */ - if (!next) - break; - - if (cur + size <= rsv->rsv_start) { - /* - * Found a reserveable space big enough. We could - * have a reservation across the group boundary here - */ - break; - } - } - /* - * we come here either : - * when we reach the end of the whole list, - * and there is empty reservable space after last entry in the list. - * append it to the end of the list. - * - * or we found one reservable space in the middle of the list, - * return the reservation window that we could append to. - * succeed. - */ - - if ((prev != my_rsv) && (!rsv_is_empty(&my_rsv->rsv_window))) - rsv_window_remove(sb, my_rsv); - - /* - * Let's book the whole avaliable window for now. We will check the - * disk bitmap later and then, if there are free blocks then we adjust - * the window size if it's larger than requested. - * Otherwise, we will remove this node from the tree next time - * call find_next_reservable_window. - */ - my_rsv->rsv_start = cur; - my_rsv->rsv_end = cur + size - 1; - my_rsv->rsv_alloc_hit = 0; - - if (prev != my_rsv) - ext4_rsv_window_add(sb, my_rsv); - - return 0; -} - -/** - * alloc_new_reservation()--allocate a new reservation window - * - * To make a new reservation, we search part of the filesystem - * reservation list (the list that inside the group). We try to - * allocate a new reservation window near the allocation goal, - * or the beginning of the group, if there is no goal. - * - * We first find a reservable space after the goal, then from - * there, we check the bitmap for the first free block after - * it. If there is no free block until the end of group, then the - * whole group is full, we failed. Otherwise, check if the free - * block is inside the expected reservable space, if so, we - * succeed. - * If the first free block is outside the reservable space, then - * start from the first free block, we search for next available - * space, and go on. - * - * on succeed, a new reservation will be found and inserted into the list - * It contains at least one free block, and it does not overlap with other - * reservation windows. - * - * failed: we failed to find a reservation window in this group - * - * @rsv: the reservation - * - * @grp_goal: The goal (group-relative). It is where the search for a - * free reservable space should start from. - * if we have a grp_goal(grp_goal >0 ), then start from there, - * no grp_goal(grp_goal = -1), we start from the first block - * of the group. - * - * @sb: the super block - * @group: the group we are trying to allocate in - * @bitmap_bh: the block group block bitmap - * - */ -static int alloc_new_reservation(struct ext4_reserve_window_node *my_rsv, - ext4_grpblk_t grp_goal, struct super_block *sb, - ext4_group_t group, struct buffer_head *bitmap_bh) -{ - struct ext4_reserve_window_node *search_head; - ext4_fsblk_t group_first_block, group_end_block, start_block; - ext4_grpblk_t first_free_block; - struct rb_root *fs_rsv_root = &EXT4_SB(sb)->s_rsv_window_root; - unsigned long size; - int ret; - spinlock_t *rsv_lock = &EXT4_SB(sb)->s_rsv_window_lock; - - group_first_block = ext4_group_first_block_no(sb, group); - group_end_block = group_first_block + (EXT4_BLOCKS_PER_GROUP(sb) - 1); - - if (grp_goal < 0) - start_block = group_first_block; - else - start_block = grp_goal + group_first_block; - - size = my_rsv->rsv_goal_size; - - if (!rsv_is_empty(&my_rsv->rsv_window)) { - /* - * if the old reservation is cross group boundary - * and if the goal is inside the old reservation window, - * we will come here when we just failed to allocate from - * the first part of the window. We still have another part - * that belongs to the next group. In this case, there is no - * point to discard our window and try to allocate a new one - * in this group(which will fail). we should - * keep the reservation window, just simply move on. - * - * Maybe we could shift the start block of the reservation - * window to the first block of next group. - */ - - if ((my_rsv->rsv_start <= group_end_block) && - (my_rsv->rsv_end > group_end_block) && - (start_block >= my_rsv->rsv_start)) - return -1; - - if ((my_rsv->rsv_alloc_hit > - (my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) { - /* - * if the previously allocation hit ratio is - * greater than 1/2, then we double the size of - * the reservation window the next time, - * otherwise we keep the same size window - */ - size = size * 2; - if (size > EXT4_MAX_RESERVE_BLOCKS) - size = EXT4_MAX_RESERVE_BLOCKS; - my_rsv->rsv_goal_size = size; - } - } - - spin_lock(rsv_lock); - /* - * shift the search start to the window near the goal block - */ - search_head = search_reserve_window(fs_rsv_root, start_block); - - /* - * find_next_reservable_window() simply finds a reservable window - * inside the given range(start_block, group_end_block). - * - * To make sure the reservation window has a free bit inside it, we - * need to check the bitmap after we found a reservable window. - */ -retry: - ret = find_next_reservable_window(search_head, my_rsv, sb, - start_block, group_end_block); - - if (ret == -1) { - if (!rsv_is_empty(&my_rsv->rsv_window)) - rsv_window_remove(sb, my_rsv); - spin_unlock(rsv_lock); - return -1; - } - - /* - * On success, find_next_reservable_window() returns the - * reservation window where there is a reservable space after it. - * Before we reserve this reservable space, we need - * to make sure there is at least a free block inside this region. - * - * searching the first free bit on the block bitmap and copy of - * last committed bitmap alternatively, until we found a allocatable - * block. Search start from the start block of the reservable space - * we just found. - */ - spin_unlock(rsv_lock); - first_free_block = bitmap_search_next_usable_block( - my_rsv->rsv_start - group_first_block, - bitmap_bh, group_end_block - group_first_block + 1); - - if (first_free_block < 0) { - /* - * no free block left on the bitmap, no point - * to reserve the space. return failed. - */ - spin_lock(rsv_lock); - if (!rsv_is_empty(&my_rsv->rsv_window)) - rsv_window_remove(sb, my_rsv); - spin_unlock(rsv_lock); - return -1; /* failed */ - } - - start_block = first_free_block + group_first_block; - /* - * check if the first free block is within the - * free space we just reserved - */ - if (start_block >= my_rsv->rsv_start && start_block <= my_rsv->rsv_end) - return 0; /* success */ - /* - * if the first free bit we found is out of the reservable space - * continue search for next reservable space, - * start from where the free block is, - * we also shift the list head to where we stopped last time - */ - search_head = my_rsv; - spin_lock(rsv_lock); - goto retry; -} - -/** - * try_to_extend_reservation() - * @my_rsv: given reservation window - * @sb: super block - * @size: the delta to extend - * - * Attempt to expand the reservation window large enough to have - * required number of free blocks - * - * Since ext4_try_to_allocate() will always allocate blocks within - * the reservation window range, if the window size is too small, - * multiple blocks allocation has to stop at the end of the reservation - * window. To make this more efficient, given the total number of - * blocks needed and the current size of the window, we try to - * expand the reservation window size if necessary on a best-effort - * basis before ext4_new_blocks() tries to allocate blocks, - */ -static void try_to_extend_reservation(struct ext4_reserve_window_node *my_rsv, - struct super_block *sb, int size) -{ - struct ext4_reserve_window_node *next_rsv; - struct rb_node *next; - spinlock_t *rsv_lock = &EXT4_SB(sb)->s_rsv_window_lock; - - if (!spin_trylock(rsv_lock)) - return; - - next = rb_next(&my_rsv->rsv_node); - - if (!next) - my_rsv->rsv_end += size; - else { - next_rsv = rb_entry(next, struct ext4_reserve_window_node, rsv_node); - - if ((next_rsv->rsv_start - my_rsv->rsv_end - 1) >= size) - my_rsv->rsv_end += size; - else - my_rsv->rsv_end = next_rsv->rsv_start - 1; - } - spin_unlock(rsv_lock); -} - -/** - * ext4_try_to_allocate_with_rsv() - * @sb: superblock - * @handle: handle to this transaction - * @group: given allocation block group - * @bitmap_bh: bufferhead holds the block bitmap - * @grp_goal: given target block within the group - * @count: target number of blocks to allocate - * @my_rsv: reservation window - * @errp: pointer to store the error code - * - * This is the main function used to allocate a new block and its reservation - * window. - * - * Each time when a new block allocation is need, first try to allocate from - * its own reservation. If it does not have a reservation window, instead of - * looking for a free bit on bitmap first, then look up the reservation list to - * see if it is inside somebody else's reservation window, we try to allocate a - * reservation window for it starting from the goal first. Then do the block - * allocation within the reservation window. - * - * This will avoid keeping on searching the reservation list again and - * again when somebody is looking for a free block (without - * reservation), and there are lots of free blocks, but they are all - * being reserved. - * - * We use a red-black tree for the per-filesystem reservation list. - * - */ -static ext4_grpblk_t -ext4_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle, - ext4_group_t group, struct buffer_head *bitmap_bh, - ext4_grpblk_t grp_goal, - struct ext4_reserve_window_node *my_rsv, - unsigned long *count, int *errp) -{ - ext4_fsblk_t group_first_block, group_last_block; - ext4_grpblk_t ret = 0; - int fatal; - unsigned long num = *count; - - *errp = 0; - - /* - * Make sure we use undo access for the bitmap, because it is critical - * that we do the frozen_data COW on bitmap buffers in all cases even - * if the buffer is in BJ_Forget state in the committing transaction. - */ - BUFFER_TRACE(bitmap_bh, "get undo access for new block"); - fatal = ext4_journal_get_undo_access(handle, bitmap_bh); - if (fatal) { - *errp = fatal; - return -1; - } - - /* - * we don't deal with reservation when - * filesystem is mounted without reservation - * or the file is not a regular file - * or last attempt to allocate a block with reservation turned on failed - */ - if (my_rsv == NULL) { - ret = ext4_try_to_allocate(sb, handle, group, bitmap_bh, - grp_goal, count, NULL); - goto out; - } - /* - * grp_goal is a group relative block number (if there is a goal) - * 0 <= grp_goal < EXT4_BLOCKS_PER_GROUP(sb) - * first block is a filesystem wide block number - * first block is the block number of the first block in this group - */ - group_first_block = ext4_group_first_block_no(sb, group); - group_last_block = group_first_block + (EXT4_BLOCKS_PER_GROUP(sb) - 1); - - /* - * Basically we will allocate a new block from inode's reservation - * window. - * - * We need to allocate a new reservation window, if: - * a) inode does not have a reservation window; or - * b) last attempt to allocate a block from existing reservation - * failed; or - * c) we come here with a goal and with a reservation window - * - * We do not need to allocate a new reservation window if we come here - * at the beginning with a goal and the goal is inside the window, or - * we don't have a goal but already have a reservation window. - * then we could go to allocate from the reservation window directly. - */ - while (1) { - if (rsv_is_empty(&my_rsv->rsv_window) || (ret < 0) || - !goal_in_my_reservation(&my_rsv->rsv_window, - grp_goal, group, sb)) { - if (my_rsv->rsv_goal_size < *count) - my_rsv->rsv_goal_size = *count; - ret = alloc_new_reservation(my_rsv, grp_goal, sb, - group, bitmap_bh); - if (ret < 0) - break; /* failed */ - - if (!goal_in_my_reservation(&my_rsv->rsv_window, - grp_goal, group, sb)) - grp_goal = -1; - } else if (grp_goal >= 0) { - int curr = my_rsv->rsv_end - - (grp_goal + group_first_block) + 1; - - if (curr < *count) - try_to_extend_reservation(my_rsv, sb, - *count - curr); - } - - if ((my_rsv->rsv_start > group_last_block) || - (my_rsv->rsv_end < group_first_block)) { - rsv_window_dump(&EXT4_SB(sb)->s_rsv_window_root, 1); - BUG(); - } - ret = ext4_try_to_allocate(sb, handle, group, bitmap_bh, - grp_goal, &num, &my_rsv->rsv_window); - if (ret >= 0) { - my_rsv->rsv_alloc_hit += num; - *count = num; - break; /* succeed */ - } - num = *count; - } -out: - if (ret >= 0) { - BUFFER_TRACE(bitmap_bh, "journal_dirty_metadata for " - "bitmap block"); - fatal = ext4_journal_dirty_metadata(handle, bitmap_bh); - if (fatal) { - *errp = fatal; - return -1; - } - return ret; - } - - BUFFER_TRACE(bitmap_bh, "journal_release_buffer"); - ext4_journal_release_buffer(handle, bitmap_bh); - return ret; -} - int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks) { @@ -1702,313 +679,6 @@ int ext4_should_retry_alloc(struct super_block *sb, int *retries) return jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal); } -/** - * ext4_old_new_blocks() -- core block bitmap based block allocation function - * - * @handle: handle to this transaction - * @inode: file inode - * @goal: given target block(filesystem wide) - * @count: target number of blocks to allocate - * @errp: error code - * - * ext4_old_new_blocks uses a goal block to assist allocation and look up - * the block bitmap directly to do block allocation. It tries to - * allocate block(s) from the block group contains the goal block first. If - * that fails, it will try to allocate block(s) from other block groups - * without any specific goal block. - * - * This function is called when -o nomballoc mount option is enabled - * - */ -ext4_fsblk_t ext4_old_new_blocks(handle_t *handle, struct inode *inode, - ext4_fsblk_t goal, unsigned long *count, int *errp) -{ - struct buffer_head *bitmap_bh = NULL; - struct buffer_head *gdp_bh; - ext4_group_t group_no; - ext4_group_t goal_group; - ext4_grpblk_t grp_target_blk; /* blockgroup relative goal block */ - ext4_grpblk_t grp_alloc_blk; /* blockgroup-relative allocated block*/ - ext4_fsblk_t ret_block; /* filesyetem-wide allocated block */ - ext4_group_t bgi; /* blockgroup iteration index */ - int fatal = 0, err; - int performed_allocation = 0; - ext4_grpblk_t free_blocks; /* number of free blocks in a group */ - struct super_block *sb; - struct ext4_group_desc *gdp; - struct ext4_super_block *es; - struct ext4_sb_info *sbi; - struct ext4_reserve_window_node *my_rsv = NULL; - struct ext4_block_alloc_info *block_i; - unsigned short windowsz = 0; - ext4_group_t ngroups; - unsigned long num = *count; - - sb = inode->i_sb; - if (!sb) { - *errp = -ENODEV; - printk(KERN_ERR "ext4_new_block: nonexistent superblock"); - return 0; - } - - sbi = EXT4_SB(sb); - if (!EXT4_I(inode)->i_delalloc_reserved_flag) { - /* - * With delalloc we already reserved the blocks - */ - while (*count && ext4_claim_free_blocks(sbi, *count)) { - /* let others to free the space */ - yield(); - *count = *count >> 1; - } - if (!*count) { - *errp = -ENOSPC; - return 0; /*return with ENOSPC error */ - } - num = *count; - } - /* - * Check quota for allocation of this block. - */ - if (DQUOT_ALLOC_BLOCK(inode, num)) { - *errp = -EDQUOT; - return 0; - } - - sbi = EXT4_SB(sb); - es = EXT4_SB(sb)->s_es; - ext4_debug("goal=%llu.\n", goal); - /* - * Allocate a block from reservation only when - * filesystem is mounted with reservation(default,-o reservation), and - * it's a regular file, and - * the desired window size is greater than 0 (One could use ioctl - * command EXT4_IOC_SETRSVSZ to set the window size to 0 to turn off - * reservation on that particular file) - */ - block_i = EXT4_I(inode)->i_block_alloc_info; - if (block_i && ((windowsz = block_i->rsv_window_node.rsv_goal_size) > 0)) - my_rsv = &block_i->rsv_window_node; - - /* - * First, test whether the goal block is free. - */ - if (goal < le32_to_cpu(es->s_first_data_block) || - goal >= ext4_blocks_count(es)) - goal = le32_to_cpu(es->s_first_data_block); - ext4_get_group_no_and_offset(sb, goal, &group_no, &grp_target_blk); - goal_group = group_no; -retry_alloc: - gdp = ext4_get_group_desc(sb, group_no, &gdp_bh); - if (!gdp) - goto io_error; - - free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); - - if (free_blocks > 0) { - /* - * try to allocate with group target block - * in the goal group. If we have low free_blocks - * count turn off reservation - */ - if (my_rsv && (free_blocks < windowsz) - && (rsv_is_empty(&my_rsv->rsv_window))) - my_rsv = NULL; - - bitmap_bh = ext4_read_block_bitmap(sb, group_no); - if (!bitmap_bh) - goto io_error; - grp_alloc_blk = ext4_try_to_allocate_with_rsv(sb, handle, - group_no, bitmap_bh, grp_target_blk, - my_rsv, &num, &fatal); - if (fatal) - goto out; - if (grp_alloc_blk >= 0) - goto allocated; - } - - ngroups = EXT4_SB(sb)->s_groups_count; - smp_rmb(); - - /* - * Now search the rest of the groups. We assume that - * group_no and gdp correctly point to the last group visited. - */ - for (bgi = 0; bgi < ngroups; bgi++) { - group_no++; - if (group_no >= ngroups) - group_no = 0; - gdp = ext4_get_group_desc(sb, group_no, &gdp_bh); - if (!gdp) - goto io_error; - free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); - /* - * skip this group if the number of - * free blocks is less than half of the reservation - * window size. - */ - if (my_rsv && (free_blocks <= (windowsz/2))) - continue; - - brelse(bitmap_bh); - bitmap_bh = ext4_read_block_bitmap(sb, group_no); - if (!bitmap_bh) - goto io_error; - /* - * try to allocate block(s) from this group, without a goal(-1). - */ - grp_alloc_blk = ext4_try_to_allocate_with_rsv(sb, handle, - group_no, bitmap_bh, -1, my_rsv, - &num, &fatal); - if (fatal) - goto out; - if (grp_alloc_blk >= 0) - goto allocated; - } - /* - * We may end up a bogus ealier ENOSPC error due to - * filesystem is "full" of reservations, but - * there maybe indeed free blocks avaliable on disk - * In this case, we just forget about the reservations - * just do block allocation as without reservations. - */ - if (my_rsv) { - my_rsv = NULL; - windowsz = 0; - group_no = goal_group; - goto retry_alloc; - } - /* No space left on the device */ - *errp = -ENOSPC; - goto out; - -allocated: - - ext4_debug("using block group %lu(%d)\n", - group_no, gdp->bg_free_blocks_count); - - BUFFER_TRACE(gdp_bh, "get_write_access"); - fatal = ext4_journal_get_write_access(handle, gdp_bh); - if (fatal) - goto out; - - ret_block = grp_alloc_blk + ext4_group_first_block_no(sb, group_no); - - if (in_range(ext4_block_bitmap(sb, gdp), ret_block, num) || - in_range(ext4_inode_bitmap(sb, gdp), ret_block, num) || - in_range(ret_block, ext4_inode_table(sb, gdp), - EXT4_SB(sb)->s_itb_per_group) || - in_range(ret_block + num - 1, ext4_inode_table(sb, gdp), - EXT4_SB(sb)->s_itb_per_group)) { - ext4_error(sb, "ext4_new_block", - "Allocating block in system zone - " - "blocks from %llu, length %lu", - ret_block, num); - /* - * claim_block marked the blocks we allocated - * as in use. So we may want to selectively - * mark some of the blocks as free - */ - goto retry_alloc; - } - - performed_allocation = 1; - -#ifdef CONFIG_JBD2_DEBUG - { - struct buffer_head *debug_bh; - - /* Record bitmap buffer state in the newly allocated block */ - debug_bh = sb_find_get_block(sb, ret_block); - if (debug_bh) { - BUFFER_TRACE(debug_bh, "state when allocated"); - BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap state"); - brelse(debug_bh); - } - } - jbd_lock_bh_state(bitmap_bh); - spin_lock(sb_bgl_lock(sbi, group_no)); - if (buffer_jbd(bitmap_bh) && bh2jh(bitmap_bh)->b_committed_data) { - int i; - - for (i = 0; i < num; i++) { - if (ext4_test_bit(grp_alloc_blk+i, - bh2jh(bitmap_bh)->b_committed_data)) { - printk(KERN_ERR "%s: block was unexpectedly " - "set in b_committed_data\n", __func__); - } - } - } - ext4_debug("found bit %d\n", grp_alloc_blk); - spin_unlock(sb_bgl_lock(sbi, group_no)); - jbd_unlock_bh_state(bitmap_bh); -#endif - - if (ret_block + num - 1 >= ext4_blocks_count(es)) { - ext4_error(sb, "ext4_new_block", - "block(%llu) >= blocks count(%llu) - " - "block_group = %lu, es == %p ", ret_block, - ext4_blocks_count(es), group_no, es); - goto out; - } - - /* - * It is up to the caller to add the new buffer to a journal - * list of some description. We don't know in advance whether - * the caller wants to use it as metadata or data. - */ - spin_lock(sb_bgl_lock(sbi, group_no)); - if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) - gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); - le16_add_cpu(&gdp->bg_free_blocks_count, -num); - gdp->bg_checksum = ext4_group_desc_csum(sbi, group_no, gdp); - spin_unlock(sb_bgl_lock(sbi, group_no)); - percpu_counter_sub(&sbi->s_freeblocks_counter, num); - /* - * Now reduce the dirty block count also. Should not go negative - */ - if (!EXT4_I(inode)->i_delalloc_reserved_flag) - percpu_counter_sub(&sbi->s_dirtyblocks_counter, *count); - else - percpu_counter_sub(&sbi->s_dirtyblocks_counter, num); - if (sbi->s_log_groups_per_flex) { - ext4_group_t flex_group = ext4_flex_group(sbi, group_no); - spin_lock(sb_bgl_lock(sbi, flex_group)); - sbi->s_flex_groups[flex_group].free_blocks -= num; - spin_unlock(sb_bgl_lock(sbi, flex_group)); - } - - BUFFER_TRACE(gdp_bh, "journal_dirty_metadata for group descriptor"); - err = ext4_journal_dirty_metadata(handle, gdp_bh); - if (!fatal) - fatal = err; - - sb->s_dirt = 1; - if (fatal) - goto out; - - *errp = 0; - brelse(bitmap_bh); - DQUOT_FREE_BLOCK(inode, *count-num); - *count = num; - return ret_block; - -io_error: - *errp = -EIO; -out: - if (fatal) { - *errp = fatal; - ext4_std_error(sb, fatal); - } - /* - * Undo the block allocation - */ - if (!performed_allocation) - DQUOT_FREE_BLOCK(inode, *count); - brelse(bitmap_bh); - return 0; -} - #define EXT4_META_BLOCK 0x1 static ext4_fsblk_t do_blk_alloc(handle_t *handle, struct inode *inode, @@ -2018,10 +688,6 @@ static ext4_fsblk_t do_blk_alloc(handle_t *handle, struct inode *inode, struct ext4_allocation_request ar; ext4_fsblk_t ret; - if (!test_opt(inode->i_sb, MBALLOC)) { - return ext4_old_new_blocks(handle, inode, goal, count, errp); - } - memset(&ar, 0, sizeof(ar)); /* Fill with neighbour allocated blocks */ @@ -2242,3 +908,4 @@ unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group) return ext4_bg_num_gdb_meta(sb,group); } + -- cgit v1.2.3