diff options
Diffstat (limited to 'fs/ext3/balloc.c')
| -rw-r--r-- | fs/ext3/balloc.c | 878 |
1 files changed, 712 insertions, 166 deletions
diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c index 063d994bda0..158b5d4ce06 100644 --- a/fs/ext3/balloc.c +++ b/fs/ext3/balloc.c @@ -11,14 +11,9 @@ * David S. Miller (davem@caip.rutgers.edu), 1995 */ -#include <linux/time.h> -#include <linux/capability.h> -#include <linux/fs.h> -#include <linux/jbd.h> -#include <linux/ext3_fs.h> -#include <linux/ext3_jbd.h> #include <linux/quotaops.h> -#include <linux/buffer_head.h> +#include <linux/blkdev.h> +#include "ext3.h" /* * balloc.c contains the blocks allocation and deallocation routines @@ -32,12 +27,34 @@ * The file system contains group descriptors which are located after the * super block. Each descriptor contains the number of the bitmap block and * the free blocks count in the block. The descriptors are loaded in memory - * when a file system is mounted (see ext3_read_super). + * when a file system is mounted (see ext3_fill_super). */ #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) +/* + * Calculate the block group number and offset, given a block number + */ +static void ext3_get_group_no_and_offset(struct super_block *sb, + ext3_fsblk_t blocknr, unsigned long *blockgrpp, ext3_grpblk_t *offsetp) +{ + struct ext3_super_block *es = EXT3_SB(sb)->s_es; + + blocknr = blocknr - le32_to_cpu(es->s_first_data_block); + if (offsetp) + *offsetp = blocknr % EXT3_BLOCKS_PER_GROUP(sb); + if (blockgrpp) + *blockgrpp = blocknr / EXT3_BLOCKS_PER_GROUP(sb); +} + +/** + * ext3_get_group_desc() -- load group descriptor from disk + * @sb: super block + * @block_group: given block group + * @bh: pointer to the buffer head to store the block + * group descriptor + */ struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb, unsigned int block_group, struct buffer_head ** bh) @@ -73,9 +90,57 @@ struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb, return desc + offset; } -/* - * Read the bitmap for a given block_group, reading into the specified - * slot in the superblock's bitmap cache. +static int ext3_valid_block_bitmap(struct super_block *sb, + struct ext3_group_desc *desc, + unsigned int block_group, + struct buffer_head *bh) +{ + ext3_grpblk_t offset; + ext3_grpblk_t next_zero_bit; + ext3_fsblk_t bitmap_blk; + ext3_fsblk_t group_first_block; + + group_first_block = ext3_group_first_block_no(sb, block_group); + + /* check whether block bitmap block number is set */ + bitmap_blk = le32_to_cpu(desc->bg_block_bitmap); + offset = bitmap_blk - group_first_block; + if (!ext3_test_bit(offset, bh->b_data)) + /* bad block bitmap */ + goto err_out; + + /* check whether the inode bitmap block number is set */ + bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap); + offset = bitmap_blk - group_first_block; + if (!ext3_test_bit(offset, bh->b_data)) + /* bad block bitmap */ + goto err_out; + + /* check whether the inode table block number is set */ + bitmap_blk = le32_to_cpu(desc->bg_inode_table); + offset = bitmap_blk - group_first_block; + next_zero_bit = ext3_find_next_zero_bit(bh->b_data, + offset + EXT3_SB(sb)->s_itb_per_group, + offset); + if (next_zero_bit >= offset + EXT3_SB(sb)->s_itb_per_group) + /* good bitmap for inode tables */ + return 1; + +err_out: + ext3_error(sb, __func__, + "Invalid block bitmap - " + "block_group = %d, block = %lu", + block_group, bitmap_blk); + return 0; +} + +/** + * read_block_bitmap() + * @sb: super block + * @block_group: given block group + * + * Read the bitmap for a given block_group,and validate the + * bits for block/inode/inode tables are set in the bitmaps * * Return buffer_head on success or NULL in case of failure. */ @@ -84,17 +149,37 @@ read_block_bitmap(struct super_block *sb, unsigned int block_group) { struct ext3_group_desc * desc; struct buffer_head * bh = NULL; + ext3_fsblk_t bitmap_blk; - desc = ext3_get_group_desc (sb, block_group, NULL); + desc = ext3_get_group_desc(sb, block_group, NULL); if (!desc) - goto error_out; - bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap)); - if (!bh) - ext3_error (sb, "read_block_bitmap", + return NULL; + trace_ext3_read_block_bitmap(sb, block_group); + bitmap_blk = le32_to_cpu(desc->bg_block_bitmap); + bh = sb_getblk(sb, bitmap_blk); + if (unlikely(!bh)) { + ext3_error(sb, __func__, + "Cannot read block bitmap - " + "block_group = %d, block_bitmap = %u", + block_group, le32_to_cpu(desc->bg_block_bitmap)); + return NULL; + } + if (likely(bh_uptodate_or_lock(bh))) + return bh; + + if (bh_submit_read(bh) < 0) { + brelse(bh); + ext3_error(sb, __func__, "Cannot read block bitmap - " "block_group = %d, block_bitmap = %u", block_group, le32_to_cpu(desc->bg_block_bitmap)); -error_out: + return NULL; + } + ext3_valid_block_bitmap(sb, desc, block_group, bh); + /* + * file system mounted not to panic on error, continue with corrupt + * bitmap + */ return bh; } /* @@ -103,15 +188,22 @@ error_out: * Operations include: * dump, find, add, remove, is_empty, find_next_reservable_window, etc. * - * We use sorted double linked list for the per-filesystem reservation - * window list. (like in vm_region). + * 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 * - * Initially, we keep those small operations in the abstract functions, - * so later if we need a better searching tree than double linked-list, - * we could easily switch to that without changing too much - * code. + * 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 0 +#if 1 static void __rsv_window_dump(struct rb_root *root, int verbose, const char *fn) { @@ -126,10 +218,10 @@ restart: printk("Block Allocation Reservation Windows Map (%s):\n", fn); while (n) { - rsv = list_entry(n, struct ext3_reserve_window_node, rsv_node); + rsv = rb_entry(n, struct ext3_reserve_window_node, rsv_node); if (verbose) printk("reservation window 0x%p " - "start: %d, end: %d\n", + "start: %lu, end: %lu\n", rsv, rsv->rsv_start, rsv->rsv_end); if (rsv->rsv_start && rsv->rsv_start >= rsv->rsv_end) { printk("Bad reservation %p (start >= end)\n", @@ -152,15 +244,30 @@ restart: prev = rsv; } printk("Window map complete.\n"); - if (bad) - BUG(); + BUG_ON(bad); } #define rsv_window_dump(root, verbose) \ - __rsv_window_dump((root), (verbose), __FUNCTION__) + __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 ext3_reserve_window *rsv, ext3_grpblk_t grp_goal, unsigned int group, struct super_block * sb) @@ -168,7 +275,7 @@ goal_in_my_reservation(struct ext3_reserve_window *rsv, ext3_grpblk_t grp_goal, ext3_fsblk_t group_first_block, group_last_block; group_first_block = ext3_group_first_block_no(sb, group); - group_last_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1; + group_last_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1); if ((rsv->_rsv_start > group_last_block) || (rsv->_rsv_end < group_first_block)) @@ -179,7 +286,11 @@ goal_in_my_reservation(struct ext3_reserve_window *rsv, ext3_grpblk_t grp_goal, 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. @@ -216,6 +327,13 @@ search_reserve_window(struct rb_root *root, ext3_fsblk_t goal) return rsv; } +/** + * ext3_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 ext3_rsv_window_add(struct super_block *sb, struct ext3_reserve_window_node *rsv) { @@ -227,6 +345,7 @@ void ext3_rsv_window_add(struct super_block *sb, struct rb_node * parent = NULL; struct ext3_reserve_window_node *this; + trace_ext3_rsv_window_add(sb, rsv); while (*p) { parent = *p; @@ -236,14 +355,25 @@ void ext3_rsv_window_add(struct super_block *sb, p = &(*p)->rb_left; else if (start > this->rsv_end) p = &(*p)->rb_right; - else + else { + rsv_window_dump(root, 1); BUG(); + } } rb_link_node(node, parent, p); rb_insert_color(node, root); } +/** + * ext3_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 ext3_reserve_window_node *rsv) { @@ -253,15 +383,43 @@ static void rsv_window_remove(struct super_block *sb, rb_erase(&rsv->rsv_node, &EXT3_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 EXT3_RESERVE_WINDOW_NOT_ALLOCATED. + */ static inline int rsv_is_empty(struct ext3_reserve_window *rsv) { /* a valid reservation end block could not be 0 */ - return (rsv->_rsv_end == EXT3_RESERVE_WINDOW_NOT_ALLOCATED); + return rsv->_rsv_end == EXT3_RESERVE_WINDOW_NOT_ALLOCATED; } + +/** + * ext3_init_block_alloc_info() + * @inode: file inode structure + * + * Allocate and initialize the reservation window structure, and + * link the window to the ext3 inode structure at last + * + * The reservation window structure is only dynamically allocated + * and linked to ext3 inode the first time the open file + * needs a new block. So, before every ext3_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 ext3_get_blocks_handle(), also called + * when setting the reservation window size through ioctl before the file + * is open for write (needs block allocation). + * + * Needs truncate_mutex protection prior to call this function. + */ void ext3_init_block_alloc_info(struct inode *inode) { struct ext3_inode_info *ei = EXT3_I(inode); - struct ext3_block_alloc_info *block_i = ei->i_block_alloc_info; + struct ext3_block_alloc_info *block_i; struct super_block *sb = inode->i_sb; block_i = kmalloc(sizeof(*block_i), GFP_NOFS); @@ -271,7 +429,7 @@ void ext3_init_block_alloc_info(struct inode *inode) rsv->rsv_start = EXT3_RESERVE_WINDOW_NOT_ALLOCATED; rsv->rsv_end = EXT3_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 @@ -287,6 +445,19 @@ void ext3_init_block_alloc_info(struct inode *inode) ei->i_block_alloc_info = block_i; } +/** + * ext3_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: + * ext3_release_file(): last writer close the file + * ext3_clear_inode(): last iput(), when nobody link to this file. + * ext3_truncate(): when the block indirect map is about to change. + * + */ void ext3_discard_reservation(struct inode *inode) { struct ext3_inode_info *ei = EXT3_I(inode); @@ -300,13 +471,22 @@ void ext3_discard_reservation(struct inode *inode) rsv = &block_i->rsv_window_node; if (!rsv_is_empty(&rsv->rsv_window)) { spin_lock(rsv_lock); - if (!rsv_is_empty(&rsv->rsv_window)) + if (!rsv_is_empty(&rsv->rsv_window)) { + trace_ext3_discard_reservation(inode, rsv); rsv_window_remove(inode->i_sb, rsv); + } spin_unlock(rsv_lock); } } -/* Free given blocks, update quota and i_blocks field */ +/** + * ext3_free_blocks_sb() -- Free given blocks and update quota + * @handle: handle to this transaction + * @sb: super block + * @block: start physical block to free + * @count: number of blocks to free + * @pdquot_freed_blocks: pointer to quota + */ void ext3_free_blocks_sb(handle_t *handle, struct super_block *sb, ext3_fsblk_t block, unsigned long count, unsigned long *pdquot_freed_blocks) @@ -364,11 +544,13 @@ do_more: in_range (block, le32_to_cpu(desc->bg_inode_table), sbi->s_itb_per_group) || in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table), - sbi->s_itb_per_group)) + sbi->s_itb_per_group)) { ext3_error (sb, "ext3_free_blocks", "Freeing blocks in system zones - " "Block = "E3FSBLK", count = %lu", block, count); + goto error_return; + } /* * We are about to start releasing blocks in the bitmap, @@ -405,7 +587,7 @@ do_more: BUFFER_TRACE(debug_bh, "Deleted!"); if (!bh2jh(bitmap_bh)->b_committed_data) BUFFER_TRACE(debug_bh, - "No commited data in bitmap"); + "No committed data in bitmap"); BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap"); __brelse(debug_bh); } @@ -419,8 +601,8 @@ do_more: } /* @@@ This prevents newly-allocated data from being * freed and then reallocated within the same - * transaction. - * + * transaction. + * * Ideally we would want to allow that to happen, but to * do so requires making journal_forget() capable of * revoking the queued write of a data block, which @@ -433,7 +615,7 @@ do_more: * safe not to set the allocation bit in the committed * bitmap, because we know that there is no outstanding * activity on the buffer any more and so it is safe to - * reallocate it. + * reallocate it. */ BUFFER_TRACE(bitmap_bh, "set in b_committed_data"); J_ASSERT_BH(bitmap_bh, @@ -450,7 +632,7 @@ do_more: if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, block_group), bit + i, bitmap_bh->b_data)) { jbd_unlock_bh_state(bitmap_bh); - ext3_error(sb, __FUNCTION__, + ext3_error(sb, __func__, "bit already cleared for block "E3FSBLK, block + i); jbd_lock_bh_state(bitmap_bh); @@ -462,11 +644,9 @@ do_more: jbd_unlock_bh_state(bitmap_bh); spin_lock(sb_bgl_lock(sbi, block_group)); - desc->bg_free_blocks_count = - cpu_to_le16(le16_to_cpu(desc->bg_free_blocks_count) + - group_freed); + le16_add_cpu(&desc->bg_free_blocks_count, group_freed); spin_unlock(sb_bgl_lock(sbi, block_group)); - percpu_counter_mod(&sbi->s_freeblocks_counter, count); + percpu_counter_add(&sbi->s_freeblocks_counter, count); /* We dirtied the bitmap block */ BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); @@ -483,32 +663,38 @@ do_more: count = overflow; goto do_more; } - sb->s_dirt = 1; + error_return: brelse(bitmap_bh); ext3_std_error(sb, err); return; } -/* Free given blocks, update quota and i_blocks field */ +/** + * ext3_free_blocks() -- Free given blocks and update quota + * @handle: handle for this transaction + * @inode: inode + * @block: start physical block to free + * @count: number of blocks to count + */ void ext3_free_blocks(handle_t *handle, struct inode *inode, ext3_fsblk_t block, unsigned long count) { - struct super_block * sb; + struct super_block *sb = inode->i_sb; unsigned long dquot_freed_blocks; - sb = inode->i_sb; - if (!sb) { - printk ("ext3_free_blocks: nonexistent device"); - return; - } + trace_ext3_free_blocks(inode, block, count); ext3_free_blocks_sb(handle, sb, block, count, &dquot_freed_blocks); if (dquot_freed_blocks) - DQUOT_FREE_BLOCK(inode, dquot_freed_blocks); + dquot_free_block(inode, dquot_freed_blocks); return; } -/* +/** + * ext3_test_allocatable() + * @nr: given allocation block group + * @bh: bufferhead contains the bitmap of the given block group + * * For ext3 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 @@ -518,7 +704,7 @@ void ext3_free_blocks(handle_t *handle, struct inode *inode, * 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. + * 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 @@ -541,6 +727,16 @@ static int ext3_test_allocatable(ext3_grpblk_t nr, struct buffer_head *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 ext3_grpblk_t bitmap_search_next_usable_block(ext3_grpblk_t start, struct buffer_head *bh, ext3_grpblk_t maxblocks) @@ -548,11 +744,6 @@ bitmap_search_next_usable_block(ext3_grpblk_t start, struct buffer_head *bh, ext3_grpblk_t next; struct journal_head *jh = bh2jh(bh); - /* - * The bitmap search --- search forward alternately through the actual - * bitmap and the last-committed copy until we find a bit free in - * both - */ while (start < maxblocks) { next = ext3_find_next_zero_bit(bh->b_data, maxblocks, start); if (next >= maxblocks) @@ -562,14 +753,20 @@ bitmap_search_next_usable_block(ext3_grpblk_t start, struct buffer_head *bh, jbd_lock_bh_state(bh); if (jh->b_committed_data) start = ext3_find_next_zero_bit(jh->b_committed_data, - maxblocks, next); + maxblocks, next); jbd_unlock_bh_state(bh); } return -1; } -/* - * Find an allocatable block in a bitmap. We honour both the bitmap and +/** + * 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 @@ -584,7 +781,7 @@ find_next_usable_block(ext3_grpblk_t start, struct buffer_head *bh, if (start > 0) { /* - * The goal was occupied; search forward for a free + * 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 @@ -604,9 +801,9 @@ find_next_usable_block(ext3_grpblk_t start, struct buffer_head *bh, if (here < 0) here = 0; - p = ((char *)bh->b_data) + (here >> 3); - r = memscan(p, 0, (maxblocks - here + 7) >> 3); - next = (r - ((char *)bh->b_data)) << 3; + p = bh->b_data + (here >> 3); + r = memscan(p, 0, ((maxblocks + 7) >> 3) - (here >> 3)); + next = (r - bh->b_data) << 3; if (next < maxblocks && next >= start && ext3_test_allocatable(next, bh)) return next; @@ -620,7 +817,12 @@ find_next_usable_block(ext3_grpblk_t start, struct buffer_head *bh, return here; } -/* +/** + * claim_block() + * @lock: the spin lock for this block group + * @block: the free block (group relative) to allocate + * @bh: the buffer_head contains 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_ @@ -646,7 +848,26 @@ claim_block(spinlock_t *lock, ext3_grpblk_t block, struct buffer_head *bh) return ret; } -/* +/** + * ext3_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 * ext3_journal_release_buffer(), else we'll run out of credits. @@ -703,7 +924,8 @@ repeat: } start = grp_goal; - if (!claim_block(sb_bgl_lock(EXT3_SB(sb), group), grp_goal, bitmap_bh)) { + if (!claim_block(sb_bgl_lock(EXT3_SB(sb), group), + grp_goal, bitmap_bh)) { /* * The block was allocated by another thread, or it was * allocated and then freed by another thread @@ -718,7 +940,8 @@ repeat: grp_goal++; while (num < *count && grp_goal < end && ext3_test_allocatable(grp_goal, bitmap_bh) - && claim_block(sb_bgl_lock(EXT3_SB(sb), group), grp_goal, bitmap_bh)) { + && claim_block(sb_bgl_lock(EXT3_SB(sb), group), + grp_goal, bitmap_bh)) { num++; grp_goal++; } @@ -730,12 +953,12 @@ fail_access: } /** - * find_next_reservable_window(): + * 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; + * @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 @@ -743,12 +966,14 @@ fail_access: * 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 + * @my_rsv: the reservation window + * + * @sb: the super block * - * @group_first_block: the first block we consider to start + * @start_block: the first block we consider to start * the real search from * - * @last_block: + * @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 @@ -756,10 +981,10 @@ fail_access: * 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. + * 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( @@ -799,7 +1024,7 @@ static int find_next_reservable_window( prev = rsv; next = rb_next(&rsv->rsv_node); - rsv = list_entry(next,struct ext3_reserve_window_node,rsv_node); + rsv = rb_entry(next,struct ext3_reserve_window_node,rsv_node); /* * Reached the last reservation, we can just append to the @@ -812,7 +1037,7 @@ static int find_next_reservable_window( /* * Found a reserveable space big enough. We could * have a reservation across the group boundary here - */ + */ break; } } @@ -831,7 +1056,7 @@ static int find_next_reservable_window( rsv_window_remove(sb, my_rsv); /* - * Let's book the whole avaliable window for now. We will check the + * Let's book the whole available 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 @@ -848,7 +1073,7 @@ static int find_next_reservable_window( } /** - * alloc_new_reservation()--allocate a new reservation window + * 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 @@ -871,7 +1096,7 @@ static int find_next_reservable_window( * * failed: we failed to find a reservation window in this group * - * @rsv: the reservation + * @my_rsv: the reservation window * * @grp_goal: The goal (group-relative). It is where the search for a * free reservable space should start from. @@ -897,13 +1122,14 @@ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv, spinlock_t *rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock; group_first_block = ext3_group_first_block_no(sb, group); - group_end_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1; + group_end_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1); if (grp_goal < 0) start_block = group_first_block; else start_block = grp_goal + group_first_block; + trace_ext3_alloc_new_reservation(sb, start_block); size = my_rsv->rsv_goal_size; if (!rsv_is_empty(&my_rsv->rsv_window)) { @@ -929,9 +1155,10 @@ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv, if ((my_rsv->rsv_alloc_hit > (my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) { /* - * if we previously allocation hit ration is greater than half - * we double the size of reservation window next time - * otherwise keep the same + * 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 > EXT3_MAX_RESERVE_BLOCKS) @@ -997,8 +1224,11 @@ retry: * 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) + if (start_block >= my_rsv->rsv_start && + start_block <= my_rsv->rsv_end) { + trace_ext3_reserved(sb, start_block, my_rsv); return 0; /* success */ + } /* * if the first free bit we found is out of the reservable space * continue search for next reservable space, @@ -1010,6 +1240,23 @@ retry: 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 ext3_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 ext3_new_blocks() tries to allocate blocks, + */ static void try_to_extend_reservation(struct ext3_reserve_window_node *my_rsv, struct super_block *sb, int size) { @@ -1025,7 +1272,7 @@ static void try_to_extend_reservation(struct ext3_reserve_window_node *my_rsv, if (!next) my_rsv->rsv_end += size; else { - next_rsv = list_entry(next, struct ext3_reserve_window_node, rsv_node); + next_rsv = rb_entry(next, struct ext3_reserve_window_node, rsv_node); if ((next_rsv->rsv_start - my_rsv->rsv_end - 1) >= size) my_rsv->rsv_end += size; @@ -1035,7 +1282,17 @@ static void try_to_extend_reservation(struct ext3_reserve_window_node *my_rsv, spin_unlock(rsv_lock); } -/* +/** + * ext3_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 + * @my_rsv: reservation window + * @count: target number of blocks to allocate + * @errp: pointer to store the error code + * * This is the main function used to allocate a new block and its reservation * window. * @@ -1051,9 +1308,7 @@ static void try_to_extend_reservation(struct ext3_reserve_window_node *my_rsv, * reservation), and there are lots of free blocks, but they are all * being reserved. * - * We use a sorted double linked list for the per-filesystem reservation list. - * The insert, remove and find a free space(non-reserved) operations for the - * sorted double linked list should be fast. + * We use a red-black tree for the per-filesystem reservation list. * */ static ext3_grpblk_t @@ -1063,7 +1318,7 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle, struct ext3_reserve_window_node * my_rsv, unsigned long *count, int *errp) { - ext3_fsblk_t group_first_block; + ext3_fsblk_t group_first_block, group_last_block; ext3_grpblk_t ret = 0; int fatal; unsigned long num = *count; @@ -1095,11 +1350,12 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle, } /* * grp_goal is a group relative block number (if there is a goal) - * 0 < grp_goal < EXT3_BLOCKS_PER_GROUP(sb) + * 0 <= grp_goal < EXT3_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 = ext3_group_first_block_no(sb, group); + group_last_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1); /* * Basically we will allocate a new block from inode's reservation @@ -1118,7 +1374,8 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle, */ while (1) { if (rsv_is_empty(&my_rsv->rsv_window) || (ret < 0) || - !goal_in_my_reservation(&my_rsv->rsv_window, grp_goal, group, sb)) { + !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, @@ -1126,17 +1383,25 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle, if (ret < 0) break; /* failed */ - if (!goal_in_my_reservation(&my_rsv->rsv_window, grp_goal, group, sb)) + if (!goal_in_my_reservation(&my_rsv->rsv_window, + grp_goal, group, sb)) grp_goal = -1; - } else if (grp_goal > 0 && (my_rsv->rsv_end-grp_goal+1) < *count) - try_to_extend_reservation(my_rsv, sb, - *count-my_rsv->rsv_end + grp_goal - 1); + } else if (grp_goal >= 0) { + int curr = my_rsv->rsv_end - + (grp_goal + group_first_block) + 1; - if ((my_rsv->rsv_start >= group_first_block + EXT3_BLOCKS_PER_GROUP(sb)) - || (my_rsv->rsv_end < group_first_block)) + 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(&EXT3_SB(sb)->s_rsv_window_root, 1); BUG(); - ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, grp_goal, - &num, &my_rsv->rsv_window); + } + ret = ext3_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; @@ -1161,29 +1426,42 @@ out: return ret; } -static int ext3_has_free_blocks(struct ext3_sb_info *sbi) +/** + * ext3_has_free_blocks() + * @sbi: in-core super block structure. + * + * Check if filesystem has at least 1 free block available for allocation. + */ +static int ext3_has_free_blocks(struct ext3_sb_info *sbi, int use_reservation) { ext3_fsblk_t free_blocks, root_blocks; free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count); if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) && - sbi->s_resuid != current->fsuid && - (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) { + !use_reservation && !uid_eq(sbi->s_resuid, current_fsuid()) && + (gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) || + !in_group_p (sbi->s_resgid))) { return 0; } return 1; } -/* +/** + * ext3_should_retry_alloc() + * @sb: super block + * @retries number of attemps has been made + * * ext3_should_retry_alloc() is called when ENOSPC is returned, and if * it is profitable to retry the operation, this function will wait - * for the current or commiting transaction to complete, and then + * for the current or committing transaction to complete, and then * return TRUE. + * + * if the total number of retries exceed three times, return FALSE. */ int ext3_should_retry_alloc(struct super_block *sb, int *retries) { - if (!ext3_has_free_blocks(EXT3_SB(sb)) || (*retries)++ > 3) + if (!ext3_has_free_blocks(EXT3_SB(sb), 0) || (*retries)++ > 3) return 0; jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id); @@ -1191,13 +1469,19 @@ int ext3_should_retry_alloc(struct super_block *sb, int *retries) return journal_force_commit_nested(EXT3_SB(sb)->s_journal); } -/* - * ext3_new_block uses a goal block to assist allocation. If the goal is - * free, or there is a free block within 32 blocks of the goal, that block - * is allocated. Otherwise a forward search is made for a free block; within - * each block group the search first looks for an entire free byte in the block - * bitmap, and then for any free bit if that fails. - * This function also updates quota and i_blocks field. +/** + * ext3_new_blocks() -- core block(s) 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 + * + * ext3_new_blocks uses a goal block to assist 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. + * */ ext3_fsblk_t ext3_new_blocks(handle_t *handle, struct inode *inode, ext3_fsblk_t goal, unsigned long *count, int *errp) @@ -1228,21 +1512,20 @@ ext3_fsblk_t ext3_new_blocks(handle_t *handle, struct inode *inode, *errp = -ENOSPC; sb = inode->i_sb; - if (!sb) { - printk("ext3_new_block: nonexistent device"); - return 0; - } /* * Check quota for allocation of this block. */ - if (DQUOT_ALLOC_BLOCK(inode, num)) { - *errp = -EDQUOT; + err = dquot_alloc_block(inode, num); + if (err) { + *errp = err; return 0; } + trace_ext3_request_blocks(inode, goal, num); + sbi = EXT3_SB(sb); - es = EXT3_SB(sb)->s_es; + es = sbi->s_es; ext3_debug("goal=%lu.\n", goal); /* * Allocate a block from reservation only when @@ -1256,7 +1539,7 @@ ext3_fsblk_t ext3_new_blocks(handle_t *handle, struct inode *inode, if (block_i && ((windowsz = block_i->rsv_window_node.rsv_goal_size) > 0)) my_rsv = &block_i->rsv_window_node; - if (!ext3_has_free_blocks(sbi)) { + if (!ext3_has_free_blocks(sbi, IS_NOQUOTA(inode))) { *errp = -ENOSPC; goto out; } @@ -1281,6 +1564,7 @@ retry_alloc: * turn off reservation for this allocation */ if (my_rsv && (free_blocks < windowsz) + && (free_blocks > 0) && (rsv_is_empty(&my_rsv->rsv_window))) my_rsv = NULL; @@ -1303,25 +1587,29 @@ retry_alloc: smp_rmb(); /* - * Now search the rest of the groups. We assume that - * i and gdp correctly point to the last group visited. + * 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 = ext3_get_group_desc(sb, group_no, &gdp_bh); - if (!gdp) { - *errp = -EIO; - goto out; - } + if (!gdp) + goto io_error; free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); /* + * skip this group (and avoid loading bitmap) if there + * are no free blocks + */ + if (!free_blocks) + continue; + /* * skip this group if the number of * free blocks is less than half of the reservation * window size. */ - if (free_blocks <= (windowsz/2)) + if (my_rsv && (free_blocks <= (windowsz/2))) continue; brelse(bitmap_bh); @@ -1340,14 +1628,15 @@ retry_alloc: goto allocated; } /* - * We may end up a bogus ealier ENOSPC error due to + * We may end up a bogus earlier ENOSPC error due to * filesystem is "full" of reservations, but - * there maybe indeed free blocks avaliable on disk + * there maybe indeed free blocks available 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; } @@ -1372,11 +1661,17 @@ allocated: in_range(ret_block, le32_to_cpu(gdp->bg_inode_table), EXT3_SB(sb)->s_itb_per_group) || in_range(ret_block + num - 1, le32_to_cpu(gdp->bg_inode_table), - EXT3_SB(sb)->s_itb_per_group)) + EXT3_SB(sb)->s_itb_per_group)) { ext3_error(sb, "ext3_new_block", "Allocating block in system zone - " "blocks from "E3FSBLK", 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; @@ -1401,7 +1696,7 @@ allocated: if (ext3_test_bit(grp_alloc_blk+i, bh2jh(bitmap_bh)->b_committed_data)) { printk("%s: block was unexpectedly set in " - "b_committed_data\n", __FUNCTION__); + "b_committed_data\n", __func__); } } } @@ -1427,24 +1722,26 @@ allocated: ret_block, goal_hits, goal_attempts); spin_lock(sb_bgl_lock(sbi, group_no)); - gdp->bg_free_blocks_count = - cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) - num); + le16_add_cpu(&gdp->bg_free_blocks_count, -num); spin_unlock(sb_bgl_lock(sbi, group_no)); - percpu_counter_mod(&sbi->s_freeblocks_counter, -num); + percpu_counter_sub(&sbi->s_freeblocks_counter, num); BUFFER_TRACE(gdp_bh, "journal_dirty_metadata for group descriptor"); - err = ext3_journal_dirty_metadata(handle, gdp_bh); - if (!fatal) - fatal = err; - - sb->s_dirt = 1; + fatal = ext3_journal_dirty_metadata(handle, gdp_bh); if (fatal) goto out; *errp = 0; brelse(bitmap_bh); - DQUOT_FREE_BLOCK(inode, *count-num); - *count = num; + + if (num < *count) { + dquot_free_block(inode, *count-num); + *count = num; + } + + trace_ext3_allocate_blocks(inode, goal, num, + (unsigned long long)ret_block); + return ret_block; io_error: @@ -1458,7 +1755,7 @@ out: * Undo the block allocation */ if (!performed_allocation) - DQUOT_FREE_BLOCK(inode, *count); + dquot_free_block(inode, *count); brelse(bitmap_bh); return 0; } @@ -1471,6 +1768,12 @@ ext3_fsblk_t ext3_new_block(handle_t *handle, struct inode *inode, return ext3_new_blocks(handle, inode, goal, &count, errp); } +/** + * ext3_count_free_blocks() -- count filesystem free blocks + * @sb: superblock + * + * Adds up the number of free blocks from each block group. + */ ext3_fsblk_t ext3_count_free_blocks(struct super_block *sb) { ext3_fsblk_t desc_count; @@ -1507,7 +1810,7 @@ ext3_fsblk_t ext3_count_free_blocks(struct super_block *sb) brelse(bitmap_bh); printk("ext3_count_free_blocks: stored = "E3FSBLK ", computed = "E3FSBLK", "E3FSBLK"\n", - le32_to_cpu(es->s_free_blocks_count), + (ext3_fsblk_t)le32_to_cpu(es->s_free_blocks_count), desc_count, bitmap_count); return bitmap_count; #else @@ -1524,14 +1827,6 @@ ext3_fsblk_t ext3_count_free_blocks(struct super_block *sb) #endif } -static inline int -block_in_use(ext3_fsblk_t block, struct super_block *sb, unsigned char *map) -{ - return ext3_test_bit ((block - - le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block)) % - EXT3_BLOCKS_PER_GROUP(sb), map); -} - static inline int test_root(int a, int b) { int num = b; @@ -1581,11 +1876,7 @@ static unsigned long ext3_bg_num_gdb_meta(struct super_block *sb, int group) static unsigned long ext3_bg_num_gdb_nometa(struct super_block *sb, int group) { - if (EXT3_HAS_RO_COMPAT_FEATURE(sb, - EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER) && - !ext3_group_sparse(group)) - return 0; - return EXT3_SB(sb)->s_gdb_count; + return ext3_bg_has_super(sb, group) ? EXT3_SB(sb)->s_gdb_count : 0; } /** @@ -1610,3 +1901,258 @@ unsigned long ext3_bg_num_gdb(struct super_block *sb, int group) return ext3_bg_num_gdb_meta(sb,group); } + +/** + * ext3_trim_all_free -- function to trim all free space in alloc. group + * @sb: super block for file system + * @group: allocation group to trim + * @start: first group block to examine + * @max: last group block to examine + * @gdp: allocation group description structure + * @minblocks: minimum extent block count + * + * ext3_trim_all_free walks through group's block bitmap searching for free + * blocks. When the free block is found, it tries to allocate this block and + * consequent free block to get the biggest free extent possible, until it + * reaches any used block. Then issue a TRIM command on this extent and free + * the extent in the block bitmap. This is done until whole group is scanned. + */ +static ext3_grpblk_t ext3_trim_all_free(struct super_block *sb, + unsigned int group, + ext3_grpblk_t start, ext3_grpblk_t max, + ext3_grpblk_t minblocks) +{ + handle_t *handle; + ext3_grpblk_t next, free_blocks, bit, freed, count = 0; + ext3_fsblk_t discard_block; + struct ext3_sb_info *sbi; + struct buffer_head *gdp_bh, *bitmap_bh = NULL; + struct ext3_group_desc *gdp; + int err = 0, ret = 0; + + /* + * We will update one block bitmap, and one group descriptor + */ + handle = ext3_journal_start_sb(sb, 2); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + bitmap_bh = read_block_bitmap(sb, group); + if (!bitmap_bh) { + err = -EIO; + goto err_out; + } + + BUFFER_TRACE(bitmap_bh, "getting undo access"); + err = ext3_journal_get_undo_access(handle, bitmap_bh); + if (err) + goto err_out; + + gdp = ext3_get_group_desc(sb, group, &gdp_bh); + if (!gdp) { + err = -EIO; + goto err_out; + } + + BUFFER_TRACE(gdp_bh, "get_write_access"); + err = ext3_journal_get_write_access(handle, gdp_bh); + if (err) + goto err_out; + + free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); + sbi = EXT3_SB(sb); + + /* Walk through the whole group */ + while (start <= max) { + start = bitmap_search_next_usable_block(start, bitmap_bh, max); + if (start < 0) + break; + next = start; + + /* + * Allocate contiguous free extents by setting bits in the + * block bitmap + */ + while (next <= max + && claim_block(sb_bgl_lock(sbi, group), + next, bitmap_bh)) { + next++; + } + + /* We did not claim any blocks */ + if (next == start) + continue; + + discard_block = (ext3_fsblk_t)start + + ext3_group_first_block_no(sb, group); + + /* Update counters */ + spin_lock(sb_bgl_lock(sbi, group)); + le16_add_cpu(&gdp->bg_free_blocks_count, start - next); + spin_unlock(sb_bgl_lock(sbi, group)); + percpu_counter_sub(&sbi->s_freeblocks_counter, next - start); + + free_blocks -= next - start; + /* Do not issue a TRIM on extents smaller than minblocks */ + if ((next - start) < minblocks) + goto free_extent; + + trace_ext3_discard_blocks(sb, discard_block, next - start); + /* Send the TRIM command down to the device */ + err = sb_issue_discard(sb, discard_block, next - start, + GFP_NOFS, 0); + count += (next - start); +free_extent: + freed = 0; + + /* + * Clear bits in the bitmap + */ + for (bit = start; bit < next; bit++) { + BUFFER_TRACE(bitmap_bh, "clear bit"); + if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, group), + bit, bitmap_bh->b_data)) { + ext3_error(sb, __func__, + "bit already cleared for block "E3FSBLK, + (unsigned long)bit); + BUFFER_TRACE(bitmap_bh, "bit already cleared"); + } else { + freed++; + } + } + + /* Update couters */ + spin_lock(sb_bgl_lock(sbi, group)); + le16_add_cpu(&gdp->bg_free_blocks_count, freed); + spin_unlock(sb_bgl_lock(sbi, group)); + percpu_counter_add(&sbi->s_freeblocks_counter, freed); + + start = next; + if (err < 0) { + if (err != -EOPNOTSUPP) + ext3_warning(sb, __func__, "Discard command " + "returned error %d\n", err); + break; + } + + if (fatal_signal_pending(current)) { + err = -ERESTARTSYS; + break; + } + + cond_resched(); + + /* No more suitable extents */ + if (free_blocks < minblocks) + break; + } + + /* We dirtied the bitmap block */ + BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); + ret = ext3_journal_dirty_metadata(handle, bitmap_bh); + if (!err) + err = ret; + + /* And the group descriptor block */ + BUFFER_TRACE(gdp_bh, "dirtied group descriptor block"); + ret = ext3_journal_dirty_metadata(handle, gdp_bh); + if (!err) + err = ret; + + ext3_debug("trimmed %d blocks in the group %d\n", + count, group); + +err_out: + if (err) + count = err; + ext3_journal_stop(handle); + brelse(bitmap_bh); + + return count; +} + +/** + * ext3_trim_fs() -- trim ioctl handle function + * @sb: superblock for filesystem + * @start: First Byte to trim + * @len: number of Bytes to trim from start + * @minlen: minimum extent length in Bytes + * + * ext3_trim_fs goes through all allocation groups containing Bytes from + * start to start+len. For each such a group ext3_trim_all_free function + * is invoked to trim all free space. + */ +int ext3_trim_fs(struct super_block *sb, struct fstrim_range *range) +{ + ext3_grpblk_t last_block, first_block; + unsigned long group, first_group, last_group; + struct ext3_group_desc *gdp; + struct ext3_super_block *es = EXT3_SB(sb)->s_es; + uint64_t start, minlen, end, trimmed = 0; + ext3_fsblk_t first_data_blk = + le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block); + ext3_fsblk_t max_blks = le32_to_cpu(es->s_blocks_count); + int ret = 0; + + start = range->start >> sb->s_blocksize_bits; + end = start + (range->len >> sb->s_blocksize_bits) - 1; + minlen = range->minlen >> sb->s_blocksize_bits; + + if (minlen > EXT3_BLOCKS_PER_GROUP(sb) || + start >= max_blks || + range->len < sb->s_blocksize) + return -EINVAL; + if (end >= max_blks) + end = max_blks - 1; + if (end <= first_data_blk) + goto out; + if (start < first_data_blk) + start = first_data_blk; + + smp_rmb(); + + /* Determine first and last group to examine based on start and len */ + ext3_get_group_no_and_offset(sb, (ext3_fsblk_t) start, + &first_group, &first_block); + ext3_get_group_no_and_offset(sb, (ext3_fsblk_t) end, + &last_group, &last_block); + + /* end now represents the last block to discard in this group */ + end = EXT3_BLOCKS_PER_GROUP(sb) - 1; + + for (group = first_group; group <= last_group; group++) { + gdp = ext3_get_group_desc(sb, group, NULL); + if (!gdp) + break; + + /* + * For all the groups except the last one, last block will + * always be EXT3_BLOCKS_PER_GROUP(sb)-1, so we only need to + * change it for the last group, note that last_block is + * already computed earlier by ext3_get_group_no_and_offset() + */ + if (group == last_group) + end = last_block; + + if (le16_to_cpu(gdp->bg_free_blocks_count) >= minlen) { + ret = ext3_trim_all_free(sb, group, first_block, + end, minlen); + if (ret < 0) + break; + trimmed += ret; + } + + /* + * For every group except the first one, we are sure + * that the first block to discard will be block #0. + */ + first_block = 0; + } + + if (ret > 0) + ret = 0; + +out: + range->len = trimmed * sb->s_blocksize; + return ret; +} |