From: Martin J. Bligh Date: Wed, 17 Oct 2007 06:30:46 +0000 (-0700) Subject: ext2 reservations X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a686cd898bd999fd026a51e90fb0a3410d258ddb;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git ext2 reservations Val's cross-port of the ext3 reservations code into ext2. [mbligh@mbligh.org: Small type error for printk [akpm@linux-foundation.org: fix types, sync with ext3] [mbligh@mbligh.org: Bring ext2 reservations code in line with latest ext3] [akpm@linux-foundation.org: kill noisy printk] [akpm@linux-foundation.org: remember to dirty the gdp's block] [akpm@linux-foundation.org: cross-port the missed 5dea5176e5c32ef9f0d1a41d28427b3bf6881b3a] [akpm@linux-foundation.org: cross-port e6022603b9aa7d61d20b392e69edcdbbc1789969] [akpm@linux-foundation.org: Port the omitted 08fb306fe63d98eb86e3b16f4cc21816fa47f18e] [akpm@linux-foundation.org: Backport the missed 20acaa18d0c002fec180956f87adeb3f11f635a6] [akpm@linux-foundation.org: fixes] [cmm@us.ibm.com: fix reservation extension] [bunk@stusta.de: make ext2_get_blocks() static] [hugh@veritas.com: fix hang] [hugh@veritas.com: ext2_new_blocks should reset the reservation window size] [hugh@veritas.com: ext2 balloc: fix off-by-one against rsv_end] [hugh@veritas.com: grp_goal 0 is a genuine goal (unlike -1), so ext2_try_to_allocate_with_rsv should treat it as such] [hugh@veritas.com: rbtree usage cleanup] [pbadari@us.ibm.com: Fix for ext2 reservation] [bunk@kernel.org: remove fs/ext2/balloc.c:reserve_blocks()] [hugh@veritas.com: ext2 balloc: use io_error label] Cc: "Martin J. Bligh" Cc: Valerie Henson Cc: Mingming Cao Cc: Mel Gorman Cc: Hugh Dickins Signed-off-by: Adrian Bunk Signed-off-by: Hugh Dickins Signed-off-by: Badari Pulavarty Signed-off-by: Adrian Bunk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c index ffaa6d845442..18a42de25b55 100644 --- a/fs/ext2/balloc.c +++ b/fs/ext2/balloc.c @@ -133,41 +133,6 @@ error_out: return NULL; } -/* - * Set sb->s_dirt here because the superblock was "logically" altered. We - * need to recalculate its free blocks count and flush it out. - */ -static int reserve_blocks(struct super_block *sb, int count) -{ - struct ext2_sb_info *sbi = EXT2_SB(sb); - struct ext2_super_block *es = sbi->s_es; - unsigned free_blocks; - unsigned root_blocks; - - free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); - root_blocks = le32_to_cpu(es->s_r_blocks_count); - - if (free_blocks < count) - count = free_blocks; - - if (free_blocks < root_blocks + count && !capable(CAP_SYS_RESOURCE) && - sbi->s_resuid != current->fsuid && - (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) { - /* - * We are too close to reserve and we are not privileged. - * Can we allocate anything at all? - */ - if (free_blocks > root_blocks) - count = free_blocks - root_blocks; - else - return 0; - } - - percpu_counter_sub(&sbi->s_freeblocks_counter, count); - sb->s_dirt = 1; - return count; -} - static void release_blocks(struct super_block *sb, int count) { if (count) { @@ -178,25 +143,7 @@ static void release_blocks(struct super_block *sb, int count) } } -static int group_reserve_blocks(struct ext2_sb_info *sbi, int group_no, - struct ext2_group_desc *desc, struct buffer_head *bh, int count) -{ - unsigned free_blocks; - - if (!desc->bg_free_blocks_count) - return 0; - - spin_lock(sb_bgl_lock(sbi, group_no)); - free_blocks = le16_to_cpu(desc->bg_free_blocks_count); - if (free_blocks < count) - count = free_blocks; - desc->bg_free_blocks_count = cpu_to_le16(free_blocks - count); - spin_unlock(sb_bgl_lock(sbi, group_no)); - mark_buffer_dirty(bh); - return count; -} - -static void group_release_blocks(struct super_block *sb, int group_no, +static void group_adjust_blocks(struct super_block *sb, int group_no, struct ext2_group_desc *desc, struct buffer_head *bh, int count) { if (count) { @@ -212,7 +159,306 @@ static void group_release_blocks(struct super_block *sb, int group_no, } } -/* Free given blocks, update quota and i_blocks field */ +/* + * 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 ext2_reserve_window_node *rsv, *prev; + int bad; + +restart: + n = rb_first(root); + bad = 0; + prev = NULL; + + printk("Block Allocation Reservation Windows Map (%s):\n", fn); + while (n) { + rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node); + if (verbose) + printk("reservation window 0x%p " + "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", + rsv); + bad = 1; + } + if (prev && prev->rsv_end >= rsv->rsv_start) { + printk("Bad reservation %p (prev->end >= start)\n", + rsv); + bad = 1; + } + if (bad) { + if (!verbose) { + printk("Restarting reservation walk in verbose mode\n"); + verbose = 1; + goto restart; + } + } + n = rb_next(n); + prev = rsv; + } + printk("Window map complete.\n"); + if (bad) + BUG(); +} +#define rsv_window_dump(root, verbose) \ + __rsv_window_dump((root), (verbose), __FUNCTION__) +#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 ext2_reserve_window *rsv, ext2_grpblk_t grp_goal, + unsigned int group, struct super_block * sb) +{ + ext2_fsblk_t group_first_block, group_last_block; + + group_first_block = ext2_group_first_block_no(sb, group); + group_last_block = group_first_block + EXT2_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 ext2_reserve_window_node * +search_reserve_window(struct rb_root *root, ext2_fsblk_t goal) +{ + struct rb_node *n = root->rb_node; + struct ext2_reserve_window_node *rsv; + + if (!n) + return NULL; + + do { + rsv = rb_entry(n, struct ext2_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 ext2_reserve_window_node, rsv_node); + } + return rsv; +} + +/* + * ext2_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 held. + */ +void ext2_rsv_window_add(struct super_block *sb, + struct ext2_reserve_window_node *rsv) +{ + struct rb_root *root = &EXT2_SB(sb)->s_rsv_window_root; + struct rb_node *node = &rsv->rsv_node; + ext2_fsblk_t start = rsv->rsv_start; + + struct rb_node ** p = &root->rb_node; + struct rb_node * parent = NULL; + struct ext2_reserve_window_node *this; + + while (*p) + { + parent = *p; + this = rb_entry(parent, struct ext2_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); +} + +/** + * 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 held. + */ +static void rsv_window_remove(struct super_block *sb, + struct ext2_reserve_window_node *rsv) +{ + rsv->rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; + rsv->rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; + rsv->rsv_alloc_hit = 0; + rb_erase(&rsv->rsv_node, &EXT2_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 EXT2_RESERVE_WINDOW_NOT_ALLOCATED. + */ +static inline int rsv_is_empty(struct ext2_reserve_window *rsv) +{ + /* a valid reservation end block could not be 0 */ + return (rsv->_rsv_end == EXT2_RESERVE_WINDOW_NOT_ALLOCATED); +} + +/** + * ext2_init_block_alloc_info() + * @inode: file inode structure + * + * Allocate and initialize the reservation window structure, and + * link the window to the ext2 inode structure at last + * + * The reservation window structure is only dynamically allocated + * and linked to ext2 inode the first time the open file + * needs a new block. So, before every ext2_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 ext2_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 calling this function. + */ +void ext2_init_block_alloc_info(struct inode *inode) +{ + struct ext2_inode_info *ei = EXT2_I(inode); + struct ext2_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 ext2_reserve_window_node *rsv = &block_i->rsv_window_node; + + rsv->rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; + rsv->rsv_end = EXT2_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 = EXT2_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; +} + +/** + * ext2_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: + * ext2_release_file(): last writer closes the file + * ext2_clear_inode(): last iput(), when nobody links to this file. + * ext2_truncate(): when the block indirect map is about to change. + */ +void ext2_discard_reservation(struct inode *inode) +{ + struct ext2_inode_info *ei = EXT2_I(inode); + struct ext2_block_alloc_info *block_i = ei->i_block_alloc_info; + struct ext2_reserve_window_node *rsv; + spinlock_t *rsv_lock = &EXT2_SB(inode->i_sb)->s_rsv_window_lock; + + 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); + } +} + +/** + * ext2_free_blocks_sb() -- Free given blocks and update quota and i_blocks + * @inode: inode + * @block: start physcial block to free + * @count: number of blocks to free + */ void ext2_free_blocks (struct inode * inode, unsigned long block, unsigned long count) { @@ -287,7 +533,7 @@ do_more: if (sb->s_flags & MS_SYNCHRONOUS) sync_dirty_buffer(bitmap_bh); - group_release_blocks(sb, block_group, desc, bh2, group_freed); + group_adjust_blocks(sb, block_group, desc, bh2, group_freed); freed += group_freed; if (overflow) { @@ -301,16 +547,46 @@ error_return: DQUOT_FREE_BLOCK(inode, freed); } -static int grab_block(spinlock_t *lock, char *map, unsigned size, int goal) +/** + * 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 through the actual bitmap on disk until + * we find a bit free. + */ +static ext2_grpblk_t +bitmap_search_next_usable_block(ext2_grpblk_t start, struct buffer_head *bh, + ext2_grpblk_t maxblocks) { - int k; - char *p, *r; + ext2_grpblk_t next; - if (!ext2_test_bit(goal, map)) - goto got_it; + next = ext2_find_next_zero_bit(bh->b_data, maxblocks, start); + if (next >= maxblocks) + return -1; + return next; +} -repeat: - if (goal) { +/** + * 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 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 ext2_grpblk_t +find_next_usable_block(int start, struct buffer_head *bh, int maxblocks) +{ + ext2_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. @@ -319,244 +595,807 @@ repeat: * less than EXT2_BLOCKS_PER_GROUP. Aligning up to the * next 64-bit boundary is simple.. */ - k = (goal + 63) & ~63; - goal = ext2_find_next_zero_bit(map, k, goal); - if (goal < k) - goto got_it; + ext2_grpblk_t end_goal = (start + 63) & ~63; + if (end_goal > maxblocks) + end_goal = maxblocks; + here = ext2_find_next_zero_bit(bh->b_data, end_goal, start); + if (here < end_goal) + return here; + ext2_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 >= here) + return next; + + here = bitmap_search_next_usable_block(here, bh, maxblocks); + return here; +} + +/* + * ext2_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. + */ +static int +ext2_try_to_allocate(struct super_block *sb, int group, + struct buffer_head *bitmap_bh, ext2_grpblk_t grp_goal, + unsigned long *count, + struct ext2_reserve_window *my_rsv) +{ + ext2_fsblk_t group_first_block; + ext2_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 = ext2_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 > EXT2_BLOCKS_PER_GROUP(sb)) + /* reservation window crosses group boundary */ + end = EXT2_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 = EXT2_BLOCKS_PER_GROUP(sb); + } + + BUG_ON(start > EXT2_BLOCKS_PER_GROUP(sb)); + +repeat: + if (grp_goal < 0) { + 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 && + !ext2_test_bit(grp_goal - 1, + bitmap_bh->b_data); + i++, grp_goal--) + ; + } + } + start = grp_goal; + + if (ext2_set_bit_atomic(sb_bgl_lock(EXT2_SB(sb), group), grp_goal, + bitmap_bh->b_data)) { + /* + * 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 + && !ext2_set_bit_atomic(sb_bgl_lock(EXT2_SB(sb), group), + grp_goal, bitmap_bh->b_data)) { + 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 ext2_reserve_window_node *search_head, + struct ext2_reserve_window_node *my_rsv, + struct super_block * sb, + ext2_fsblk_t start_block, + ext2_fsblk_t last_block) +{ + struct rb_node *next; + struct ext2_reserve_window_node *rsv, *prev; + ext2_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 ext2_reserve_window_node,rsv_node); + /* - * Search in the remainder of the current group. + * 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. + */ - p = map + (goal >> 3); - r = memscan(p, 0, (size - goal + 7) >> 3); - k = (r - map) << 3; - if (k < size) { - /* - * We have succeeded in finding a free byte in the block - * bitmap. Now search backwards to find the start of this - * group of free blocks - won't take more than 7 iterations. + 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) + ext2_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 goal(goal >0 ), then start from there, + * no goal(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 ext2_reserve_window_node *my_rsv, + ext2_grpblk_t grp_goal, struct super_block *sb, + unsigned int group, struct buffer_head *bitmap_bh) +{ + struct ext2_reserve_window_node *search_head; + ext2_fsblk_t group_first_block, group_end_block, start_block; + ext2_grpblk_t first_free_block; + struct rb_root *fs_rsv_root = &EXT2_SB(sb)->s_rsv_window_root; + unsigned long size; + int ret; + spinlock_t *rsv_lock = &EXT2_SB(sb)->s_rsv_window_lock; + + group_first_block = ext2_group_first_block_no(sb, group); + group_end_block = group_first_block + (EXT2_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. */ - for (goal = k; goal && !ext2_test_bit (goal - 1, map); goal--) - ; - goto got_it; + + 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 > EXT2_MAX_RESERVE_BLOCKS) + size = EXT2_MAX_RESERVE_BLOCKS; + my_rsv->rsv_goal_size= size; + } } - k = ext2_find_next_zero_bit ((u32 *)map, size, goal); - if (k < size) { - goal = k; - goto got_it; + 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; } - return -1; -got_it: - if (ext2_set_bit_atomic(lock, goal, (void *) map)) - goto repeat; - return goal; + + /* + * 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. + * + * Search the first free bit on the block bitmap. Search starts 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 ext2_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 ext2_new_blocks() tries to allocate blocks. + */ +static void try_to_extend_reservation(struct ext2_reserve_window_node *my_rsv, + struct super_block *sb, int size) +{ + struct ext2_reserve_window_node *next_rsv; + struct rb_node *next; + spinlock_t *rsv_lock = &EXT2_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 ext2_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); +} + +/** + * ext2_try_to_allocate_with_rsv() + * @sb: superblock + * @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 + * + * 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 ext2_grpblk_t +ext2_try_to_allocate_with_rsv(struct super_block *sb, unsigned int group, + struct buffer_head *bitmap_bh, ext2_grpblk_t grp_goal, + struct ext2_reserve_window_node * my_rsv, + unsigned long *count) +{ + ext2_fsblk_t group_first_block, group_last_block; + ext2_grpblk_t ret = 0; + unsigned long num = *count; + + /* + * 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) { + return ext2_try_to_allocate(sb, group, bitmap_bh, + grp_goal, count, NULL); + } + /* + * grp_goal is a group relative block number (if there is a goal) + * 0 <= grp_goal < EXT2_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 = ext2_group_first_block_no(sb, group); + group_last_block = group_first_block + (EXT2_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(&EXT2_SB(sb)->s_rsv_window_root, 1); + BUG(); + } + ret = ext2_try_to_allocate(sb, 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; + } + return ret; +} + +/** + * ext2_has_free_blocks() + * @sbi: in-core super block structure. + * + * Check if filesystem has at least 1 free block available for allocation. + */ +static int ext2_has_free_blocks(struct ext2_sb_info *sbi) +{ + ext2_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))) { + return 0; + } + return 1; } /* - * ext2_new_block uses a goal block to assist allocation. If the goal is + * ext2_new_blocks() -- core block(s) allocation function + * @inode: file inode + * @goal: given target block(filesystem wide) + * @count: target number of blocks to allocate + * @errp: error code + * + * ext2_new_blocks 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. */ -int ext2_new_block(struct inode *inode, unsigned long goal, - u32 *prealloc_count, u32 *prealloc_block, int *err) +ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal, + unsigned long *count, int *errp) { struct buffer_head *bitmap_bh = NULL; - struct buffer_head *gdp_bh; /* bh2 */ - struct ext2_group_desc *desc; - int group_no; /* i */ - int ret_block; /* j */ - int group_idx; /* k */ - int target_block; /* tmp */ - int block = 0; - struct super_block *sb = inode->i_sb; - struct ext2_sb_info *sbi = EXT2_SB(sb); - struct ext2_super_block *es = sbi->s_es; - unsigned group_size = EXT2_BLOCKS_PER_GROUP(sb); - unsigned prealloc_goal = es->s_prealloc_blocks; - unsigned group_alloc = 0, es_alloc, dq_alloc; - int nr_scanned_groups; - - if (!prealloc_goal--) - prealloc_goal = EXT2_DEFAULT_PREALLOC_BLOCKS - 1; - if (!prealloc_count || *prealloc_count) - prealloc_goal = 0; - - if (DQUOT_ALLOC_BLOCK(inode, 1)) { - *err = -EDQUOT; - goto out; + struct buffer_head *gdp_bh; + int group_no; + int goal_group; + ext2_grpblk_t grp_target_blk; /* blockgroup relative goal block */ + ext2_grpblk_t grp_alloc_blk; /* blockgroup-relative allocated block*/ + ext2_fsblk_t ret_block; /* filesyetem-wide allocated block */ + int bgi; /* blockgroup iteration index */ + int performed_allocation = 0; + ext2_grpblk_t free_blocks; /* number of free blocks in a group */ + struct super_block *sb; + struct ext2_group_desc *gdp; + struct ext2_super_block *es; + struct ext2_sb_info *sbi; + struct ext2_reserve_window_node *my_rsv = NULL; + struct ext2_block_alloc_info *block_i; + unsigned short windowsz = 0; + unsigned long ngroups; + unsigned long num = *count; + + *errp = -ENOSPC; + sb = inode->i_sb; + if (!sb) { + printk("ext2_new_blocks: nonexistent device"); + return 0; } - while (prealloc_goal && DQUOT_PREALLOC_BLOCK(inode, prealloc_goal)) - prealloc_goal--; + /* + * Check quota for allocation of this block. + */ + if (DQUOT_ALLOC_BLOCK(inode, num)) { + *errp = -EDQUOT; + return 0; + } - dq_alloc = prealloc_goal + 1; - es_alloc = reserve_blocks(sb, dq_alloc); - if (!es_alloc) { - *err = -ENOSPC; - goto out_dquot; + sbi = EXT2_SB(sb); + es = EXT2_SB(sb)->s_es; + ext2_debug("goal=%lu.\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 EXT2_IOC_SETRSVSZ to set the window size to 0 to turn off + * reservation on that particular file) + */ + block_i = EXT2_I(inode)->i_block_alloc_info; + if (block_i) { + windowsz = block_i->rsv_window_node.rsv_goal_size; + if (windowsz > 0) + my_rsv = &block_i->rsv_window_node; } - ext2_debug ("goal=%lu.\n", goal); + if (!ext2_has_free_blocks(sbi)) { + *errp = -ENOSPC; + goto out; + } + /* + * First, test whether the goal block is free. + */ if (goal < le32_to_cpu(es->s_first_data_block) || goal >= le32_to_cpu(es->s_blocks_count)) goal = le32_to_cpu(es->s_first_data_block); - group_no = (goal - le32_to_cpu(es->s_first_data_block)) / group_size; - desc = ext2_get_group_desc (sb, group_no, &gdp_bh); - if (!desc) { - /* - * gdp_bh may still be uninitialised. But group_release_blocks - * will not touch it because group_alloc is zero. - */ + group_no = (goal - le32_to_cpu(es->s_first_data_block)) / + EXT2_BLOCKS_PER_GROUP(sb); + goal_group = group_no; +retry_alloc: + gdp = ext2_get_group_desc(sb, group_no, &gdp_bh); + if (!gdp) goto io_error; - } - group_alloc = group_reserve_blocks(sbi, group_no, desc, - gdp_bh, es_alloc); - if (group_alloc) { - ret_block = ((goal - le32_to_cpu(es->s_first_data_block)) % - group_size); - brelse(bitmap_bh); + free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); + /* + * if there is not enough free blocks to make a new resevation + * turn off reservation for this allocation + */ + if (my_rsv && (free_blocks < windowsz) + && (rsv_is_empty(&my_rsv->rsv_window))) + my_rsv = NULL; + + if (free_blocks > 0) { + grp_target_blk = ((goal - le32_to_cpu(es->s_first_data_block)) % + EXT2_BLOCKS_PER_GROUP(sb)); bitmap_bh = read_block_bitmap(sb, group_no); if (!bitmap_bh) goto io_error; - - ext2_debug("goal is at %d:%d.\n", group_no, ret_block); - - ret_block = grab_block(sb_bgl_lock(sbi, group_no), - bitmap_bh->b_data, group_size, ret_block); - if (ret_block >= 0) - goto got_block; - group_release_blocks(sb, group_no, desc, gdp_bh, group_alloc); - group_alloc = 0; + grp_alloc_blk = ext2_try_to_allocate_with_rsv(sb, group_no, + bitmap_bh, grp_target_blk, + my_rsv, &num); + if (grp_alloc_blk >= 0) + goto allocated; } - ext2_debug ("Bit not found in block group %d.\n", group_no); + ngroups = EXT2_SB(sb)->s_groups_count; + smp_rmb(); /* * Now search the rest of the groups. We assume that - * i and desc correctly point to the last group visited. + * i and gdp correctly point to the last group visited. */ - nr_scanned_groups = 0; -retry: - for (group_idx = 0; !group_alloc && - group_idx < sbi->s_groups_count; group_idx++) { + for (bgi = 0; bgi < ngroups; bgi++) { group_no++; - if (group_no >= sbi->s_groups_count) + if (group_no >= ngroups) group_no = 0; - desc = ext2_get_group_desc(sb, group_no, &gdp_bh); - if (!desc) + gdp = ext2_get_group_desc(sb, group_no, &gdp_bh); + if (!gdp) goto io_error; - group_alloc = group_reserve_blocks(sbi, group_no, desc, - gdp_bh, es_alloc); - } - if (!group_alloc) { - *err = -ENOSPC; - goto out_release; - } - brelse(bitmap_bh); - bitmap_bh = read_block_bitmap(sb, group_no); - if (!bitmap_bh) - goto io_error; - ret_block = grab_block(sb_bgl_lock(sbi, group_no), bitmap_bh->b_data, - group_size, 0); - if (ret_block < 0) { + free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); /* - * If a free block counter is corrupted we can loop inifintely. - * Detect that here. + * skip this group if the number of + * free blocks is less than half of the reservation + * window size. */ - nr_scanned_groups++; - if (nr_scanned_groups > 2 * sbi->s_groups_count) { - ext2_error(sb, "ext2_new_block", - "corrupted free blocks counters"); + if (free_blocks <= (windowsz/2)) + continue; + + brelse(bitmap_bh); + bitmap_bh = read_block_bitmap(sb, group_no); + if (!bitmap_bh) goto io_error; - } /* - * Someone else grabbed the last free block in this blockgroup - * before us. Retry the scan. + * try to allocate block(s) from this group, without a goal(-1). */ - group_release_blocks(sb, group_no, desc, gdp_bh, group_alloc); - group_alloc = 0; - goto retry; + grp_alloc_blk = ext2_try_to_allocate_with_rsv(sb, group_no, + bitmap_bh, -1, my_rsv, &num); + 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: -got_block: ext2_debug("using block group %d(%d)\n", - group_no, desc->bg_free_blocks_count); + group_no, gdp->bg_free_blocks_count); - target_block = ret_block + group_no * group_size + - le32_to_cpu(es->s_first_data_block); + ret_block = grp_alloc_blk + ext2_group_first_block_no(sb, group_no); - if (target_block == le32_to_cpu(desc->bg_block_bitmap) || - target_block == le32_to_cpu(desc->bg_inode_bitmap) || - in_range(target_block, le32_to_cpu(desc->bg_inode_table), - sbi->s_itb_per_group)) - ext2_error (sb, "ext2_new_block", + if (in_range(le32_to_cpu(gdp->bg_block_bitmap), ret_block, num) || + in_range(le32_to_cpu(gdp->bg_inode_bitmap), ret_block, num) || + in_range(ret_block, le32_to_cpu(gdp->bg_inode_table), + EXT2_SB(sb)->s_itb_per_group) || + in_range(ret_block + num - 1, le32_to_cpu(gdp->bg_inode_table), + EXT2_SB(sb)->s_itb_per_group)) + ext2_error(sb, "ext2_new_blocks", "Allocating block in system zone - " - "block = %u", target_block); + "blocks from "E2FSBLK", length %lu", + ret_block, num); - if (target_block >= le32_to_cpu(es->s_blocks_count)) { - ext2_error (sb, "ext2_new_block", - "block(%d) >= blocks count(%d) - " + performed_allocation = 1; + + if (ret_block + num - 1 >= le32_to_cpu(es->s_blocks_count)) { + ext2_error(sb, "ext2_new_blocks", + "block("E2FSBLK") >= blocks count(%d) - " "block_group = %d, es == %p ", ret_block, le32_to_cpu(es->s_blocks_count), group_no, es); - goto io_error; + goto out; } - block = target_block; - - /* OK, we _had_ allocated something */ - ext2_debug("found bit %d\n", ret_block); - - dq_alloc--; - es_alloc--; - group_alloc--; - /* - * Do block preallocation now if required. - */ - write_lock(&EXT2_I(inode)->i_meta_lock); - if (group_alloc && !*prealloc_count) { - unsigned n; - - for (n = 0; n < group_alloc && ++ret_block < group_size; n++) { - if (ext2_set_bit_atomic(sb_bgl_lock(sbi, group_no), - ret_block, - (void*) bitmap_bh->b_data)) - break; - } - *prealloc_block = block + 1; - *prealloc_count = n; - es_alloc -= n; - dq_alloc -= n; - group_alloc -= n; - } - write_unlock(&EXT2_I(inode)->i_meta_lock); + group_adjust_blocks(sb, group_no, gdp, gdp_bh, -num); + percpu_counter_sub(&sbi->s_freeblocks_counter, num); mark_buffer_dirty(bitmap_bh); if (sb->s_flags & MS_SYNCHRONOUS) sync_dirty_buffer(bitmap_bh); - ext2_debug ("allocating block %d. ", block); + *errp = 0; + brelse(bitmap_bh); + DQUOT_FREE_BLOCK(inode, *count-num); + *count = num; + return ret_block; - *err = 0; -out_release: - group_release_blocks(sb, group_no, desc, gdp_bh, group_alloc); - release_blocks(sb, es_alloc); -out_dquot: - DQUOT_FREE_BLOCK(inode, dq_alloc); +io_error: + *errp = -EIO; out: + /* + * Undo the block allocation + */ + if (!performed_allocation) + DQUOT_FREE_BLOCK(inode, *count); brelse(bitmap_bh); - return block; + return 0; +} -io_error: - *err = -EIO; - goto out_release; +ext2_fsblk_t ext2_new_block(struct inode *inode, unsigned long goal, int *errp) +{ + unsigned long count = 1; + + return ext2_new_blocks(inode, goal, &count, errp); } #ifdef EXT2FS_DEBUG diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h index a08052d2c008..7730388c4931 100644 --- a/fs/ext2/ext2.h +++ b/fs/ext2/ext2.h @@ -33,22 +33,9 @@ struct ext2_inode_info { */ __u32 i_block_group; - /* - * i_next_alloc_block is the logical (file-relative) number of the - * most-recently-allocated block in this file. Yes, it is misnamed. - * We use this for detecting linearly ascending allocation requests. - */ - __u32 i_next_alloc_block; + /* block reservation info */ + struct ext2_block_alloc_info *i_block_alloc_info; - /* - * i_next_alloc_goal is the *physical* companion to i_next_alloc_block. - * it the the physical block number of the block which was most-recently - * allocated to this file. This give us the goal (target) for the next - * allocation when we detect linearly ascending requests. - */ - __u32 i_next_alloc_goal; - __u32 i_prealloc_block; - __u32 i_prealloc_count; __u32 i_dir_start_lookup; #ifdef CONFIG_EXT2_FS_XATTR /* @@ -65,7 +52,16 @@ struct ext2_inode_info { struct posix_acl *i_default_acl; #endif rwlock_t i_meta_lock; + + /* + * truncate_mutex is for serialising ext2_truncate() against + * ext2_getblock(). It also protects the internals of the inode's + * reservation data structures: ext2_reserve_window and + * ext2_reserve_window_node. + */ + struct mutex truncate_mutex; struct inode vfs_inode; + struct list_head i_orphan; /* unlinked but open inodes */ }; /* @@ -91,8 +87,9 @@ static inline struct ext2_inode_info *EXT2_I(struct inode *inode) /* balloc.c */ extern int ext2_bg_has_super(struct super_block *sb, int group); extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group); -extern int ext2_new_block (struct inode *, unsigned long, - __u32 *, __u32 *, int *); +extern ext2_fsblk_t ext2_new_block(struct inode *, unsigned long, int *); +extern ext2_fsblk_t ext2_new_blocks(struct inode *, unsigned long, + unsigned long *, int *); extern void ext2_free_blocks (struct inode *, unsigned long, unsigned long); extern unsigned long ext2_count_free_blocks (struct super_block *); @@ -101,6 +98,10 @@ extern void ext2_check_blocks_bitmap (struct super_block *); extern struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb, unsigned int block_group, struct buffer_head ** bh); +extern void ext2_discard_reservation (struct inode *); +extern int ext2_should_retry_alloc(struct super_block *sb, int *retries); +extern void ext2_init_block_alloc_info(struct inode *); +extern void ext2_rsv_window_add(struct super_block *sb, struct ext2_reserve_window_node *rsv); /* dir.c */ extern int ext2_add_link (struct dentry *, struct inode *); @@ -128,7 +129,6 @@ extern int ext2_write_inode (struct inode *, int); extern void ext2_put_inode (struct inode *); extern void ext2_delete_inode (struct inode *); extern int ext2_sync_inode (struct inode *); -extern void ext2_discard_prealloc (struct inode *); extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int); extern void ext2_truncate (struct inode *); extern int ext2_setattr (struct dentry *, struct iattr *); diff --git a/fs/ext2/file.c b/fs/ext2/file.c index ab7961260c49..c051798459a1 100644 --- a/fs/ext2/file.c +++ b/fs/ext2/file.c @@ -30,8 +30,11 @@ */ static int ext2_release_file (struct inode * inode, struct file * filp) { - if (filp->f_mode & FMODE_WRITE) - ext2_discard_prealloc (inode); + if (filp->f_mode & FMODE_WRITE) { + mutex_lock(&EXT2_I(inode)->truncate_mutex); + ext2_discard_reservation(inode); + mutex_unlock(&EXT2_I(inode)->truncate_mutex); + } return 0; } diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c index 2625a00c4669..5deb8b74e649 100644 --- a/fs/ext2/ialloc.c +++ b/fs/ext2/ialloc.c @@ -581,11 +581,8 @@ got: ei->i_file_acl = 0; ei->i_dir_acl = 0; ei->i_dtime = 0; + ei->i_block_alloc_info = NULL; ei->i_block_group = group; - ei->i_next_alloc_block = 0; - ei->i_next_alloc_goal = 0; - ei->i_prealloc_block = 0; - ei->i_prealloc_count = 0; ei->i_dir_start_lookup = 0; ei->i_state = EXT2_STATE_NEW; ext2_set_inode_flags(inode); diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 84818176fd9d..b1ab32ab5a77 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -53,19 +53,6 @@ static inline int ext2_inode_is_fast_symlink(struct inode *inode) inode->i_blocks - ea_blocks == 0); } -/* - * Called at each iput(). - * - * The inode may be "bad" if ext2_read_inode() saw an error from - * ext2_get_inode(), so we need to check that to avoid freeing random disk - * blocks. - */ -void ext2_put_inode(struct inode *inode) -{ - if (!is_bad_inode(inode)) - ext2_discard_prealloc(inode); -} - /* * Called at the last iput() if i_nlink is zero. */ @@ -89,61 +76,6 @@ no_delete: clear_inode(inode); /* We must guarantee clearing of inode... */ } -void ext2_discard_prealloc (struct inode * inode) -{ -#ifdef EXT2_PREALLOCATE - struct ext2_inode_info *ei = EXT2_I(inode); - write_lock(&ei->i_meta_lock); - if (ei->i_prealloc_count) { - unsigned short total = ei->i_prealloc_count; - unsigned long block = ei->i_prealloc_block; - ei->i_prealloc_count = 0; - ei->i_prealloc_block = 0; - write_unlock(&ei->i_meta_lock); - ext2_free_blocks (inode, block, total); - return; - } else - write_unlock(&ei->i_meta_lock); -#endif -} - -static int ext2_alloc_block (struct inode * inode, unsigned long goal, int *err) -{ -#ifdef EXT2FS_DEBUG - static unsigned long alloc_hits, alloc_attempts; -#endif - unsigned long result; - - -#ifdef EXT2_PREALLOCATE - struct ext2_inode_info *ei = EXT2_I(inode); - write_lock(&ei->i_meta_lock); - if (ei->i_prealloc_count && - (goal == ei->i_prealloc_block || goal + 1 == ei->i_prealloc_block)) - { - result = ei->i_prealloc_block++; - ei->i_prealloc_count--; - write_unlock(&ei->i_meta_lock); - ext2_debug ("preallocation hit (%lu/%lu).\n", - ++alloc_hits, ++alloc_attempts); - } else { - write_unlock(&ei->i_meta_lock); - ext2_discard_prealloc (inode); - ext2_debug ("preallocation miss (%lu/%lu).\n", - alloc_hits, ++alloc_attempts); - if (S_ISREG(inode->i_mode)) - result = ext2_new_block (inode, goal, - &ei->i_prealloc_count, - &ei->i_prealloc_block, err); - else - result = ext2_new_block(inode, goal, NULL, NULL, err); - } -#else - result = ext2_new_block (inode, goal, 0, 0, err); -#endif - return result; -} - typedef struct { __le32 *p; __le32 key; @@ -228,7 +160,8 @@ static int ext2_block_to_path(struct inode *inode, ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big"); } if (boundary) - *boundary = (i_block & (ptrs - 1)) == (final - 1); + *boundary = final - 1 - (i_block & (ptrs - 1)); + return n; } @@ -355,39 +288,129 @@ static unsigned long ext2_find_near(struct inode *inode, Indirect *ind) * @block: block we want * @chain: chain of indirect blocks * @partial: pointer to the last triple within a chain - * @goal: place to store the result. * - * Normally this function find the prefered place for block allocation, - * stores it in *@goal and returns zero. If the branch had been changed - * under us we return -EAGAIN. + * Returns preferred place for a block (the goal). */ static inline int ext2_find_goal(struct inode *inode, long block, Indirect chain[4], - Indirect *partial, - unsigned long *goal) + Indirect *partial) { - struct ext2_inode_info *ei = EXT2_I(inode); - write_lock(&ei->i_meta_lock); - if ((block == ei->i_next_alloc_block + 1) && ei->i_next_alloc_goal) { - ei->i_next_alloc_block++; - ei->i_next_alloc_goal++; - } - if (verify_chain(chain, partial)) { - /* - * try the heuristic for sequential allocation, - * failing that at least try to get decent locality. - */ - if (block == ei->i_next_alloc_block) - *goal = ei->i_next_alloc_goal; - if (!*goal) - *goal = ext2_find_near(inode, partial); - write_unlock(&ei->i_meta_lock); - return 0; + struct ext2_block_alloc_info *block_i; + + block_i = EXT2_I(inode)->i_block_alloc_info; + + /* + * try the heuristic for sequential allocation, + * failing that at least try to get decent locality. + */ + if (block_i && (block == block_i->last_alloc_logical_block + 1) + && (block_i->last_alloc_physical_block != 0)) { + return block_i->last_alloc_physical_block + 1; } - write_unlock(&ei->i_meta_lock); - return -EAGAIN; + + return ext2_find_near(inode, partial); +} + +/** + * ext2_blks_to_allocate: Look up the block map and count the number + * of direct blocks need to be allocated for the given branch. + * + * @branch: chain of indirect blocks + * @k: number of blocks need for indirect blocks + * @blks: number of data blocks to be mapped. + * @blocks_to_boundary: the offset in the indirect block + * + * return the total number of blocks to be allocate, including the + * direct and indirect blocks. + */ +static int +ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, + int blocks_to_boundary) +{ + unsigned long count = 0; + + /* + * Simple case, [t,d]Indirect block(s) has not allocated yet + * then it's clear blocks on that path have not allocated + */ + if (k > 0) { + /* right now don't hanel cross boundary allocation */ + if (blks < blocks_to_boundary + 1) + count += blks; + else + count += blocks_to_boundary + 1; + return count; + } + + count++; + while (count < blks && count <= blocks_to_boundary + && le32_to_cpu(*(branch[0].p + count)) == 0) { + count++; + } + return count; +} + +/** + * ext2_alloc_blocks: multiple allocate blocks needed for a branch + * @indirect_blks: the number of blocks need to allocate for indirect + * blocks + * + * @new_blocks: on return it will store the new block numbers for + * the indirect blocks(if needed) and the first direct block, + * @blks: on return it will store the total number of allocated + * direct blocks + */ +static int ext2_alloc_blocks(struct inode *inode, + ext2_fsblk_t goal, int indirect_blks, int blks, + ext2_fsblk_t new_blocks[4], int *err) +{ + int target, i; + unsigned long count = 0; + int index = 0; + ext2_fsblk_t current_block = 0; + int ret = 0; + + /* + * Here we try to allocate the requested multiple blocks at once, + * on a best-effort basis. + * To build a branch, we should allocate blocks for + * the indirect blocks(if not allocated yet), and at least + * the first direct block of this branch. That's the + * minimum number of blocks need to allocate(required) + */ + target = blks + indirect_blks; + + while (1) { + count = target; + /* allocating blocks for indirect blocks and direct blocks */ + current_block = ext2_new_blocks(inode,goal,&count,err); + if (*err) + goto failed_out; + + target -= count; + /* allocate blocks for indirect blocks */ + while (index < indirect_blks && count) { + new_blocks[index++] = current_block++; + count--; + } + + if (count > 0) + break; + } + + /* save the new block number for the first direct block */ + new_blocks[index] = current_block; + + /* total number of blocks allocated for direct blocks */ + ret = count; + *err = 0; + return ret; +failed_out: + for (i = 0; i i_sb->s_blocksize; - int n = 0; - int err; - int i; - int parent = ext2_alloc_block(inode, goal, &err); - - branch[0].key = cpu_to_le32(parent); - if (parent) for (n = 1; n < num; n++) { - struct buffer_head *bh; - /* Allocate the next block */ - int nr = ext2_alloc_block(inode, parent, &err); - if (!nr) - break; - branch[n].key = cpu_to_le32(nr); + int i, n = 0; + int err = 0; + struct buffer_head *bh; + int num; + ext2_fsblk_t new_blocks[4]; + ext2_fsblk_t current_block; + + num = ext2_alloc_blocks(inode, goal, indirect_blks, + *blks, new_blocks, &err); + if (err) + return err; + + branch[0].key = cpu_to_le32(new_blocks[0]); + /* + * metadata blocks and data blocks are allocated. + */ + for (n = 1; n <= indirect_blks; n++) { /* - * Get buffer_head for parent block, zero it out and set - * the pointer to new one, then send parent to disk. + * Get buffer_head for parent block, zero it out + * and set the pointer to new one, then send + * parent to disk. */ - bh = sb_getblk(inode->i_sb, parent); - if (!bh) { - err = -EIO; - break; - } + bh = sb_getblk(inode->i_sb, new_blocks[n-1]); + branch[n].bh = bh; lock_buffer(bh); memset(bh->b_data, 0, blocksize); - branch[n].bh = bh; branch[n].p = (__le32 *) bh->b_data + offsets[n]; + branch[n].key = cpu_to_le32(new_blocks[n]); *branch[n].p = branch[n].key; + if ( n == indirect_blks) { + current_block = new_blocks[n]; + /* + * End of chain, update the last new metablock of + * the chain to point to the new allocated + * data blocks numbers + */ + for (i=1; i < num; i++) + *(branch[n].p + i) = cpu_to_le32(++current_block); + } set_buffer_uptodate(bh); unlock_buffer(bh); mark_buffer_dirty_inode(bh, inode); @@ -458,77 +491,68 @@ static int ext2_alloc_branch(struct inode *inode, */ if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) sync_dirty_buffer(bh); - parent = nr; } - if (n == num) - return 0; - - /* Allocation failed, free what we already allocated */ - for (i = 1; i < n; i++) - bforget(branch[i].bh); - for (i = 0; i < n; i++) - ext2_free_blocks(inode, le32_to_cpu(branch[i].key), 1); + *blks = num; return err; } /** - * ext2_splice_branch - splice the allocated branch onto inode. - * @inode: owner - * @block: (logical) number of block we are adding - * @chain: chain of indirect blocks (with a missing link - see - * ext2_alloc_branch) - * @where: location of missing link - * @num: number of blocks we are adding + * ext2_splice_branch - splice the allocated branch onto inode. + * @inode: owner + * @block: (logical) number of block we are adding + * @chain: chain of indirect blocks (with a missing link - see + * ext2_alloc_branch) + * @where: location of missing link + * @num: number of indirect blocks we are adding + * @blks: number of direct blocks we are adding * - * This function verifies that chain (up to the missing link) had not - * changed, fills the missing link and does all housekeeping needed in - * inode (->i_blocks, etc.). In case of success we end up with the full - * chain to new block and return 0. Otherwise (== chain had been changed) - * we free the new blocks (forgetting their buffer_heads, indeed) and - * return -EAGAIN. + * This function fills the missing link and does all housekeeping needed in + * inode (->i_blocks, etc.). In case of success we end up with the full + * chain to new block and return 0. */ - -static inline int ext2_splice_branch(struct inode *inode, - long block, - Indirect chain[4], - Indirect *where, - int num) +static void ext2_splice_branch(struct inode *inode, + long block, Indirect *where, int num, int blks) { - struct ext2_inode_info *ei = EXT2_I(inode); int i; + struct ext2_block_alloc_info *block_i; + ext2_fsblk_t current_block; - /* Verify that place we are splicing to is still there and vacant */ - - write_lock(&ei->i_meta_lock); - if (!verify_chain(chain, where-1) || *where->p) - goto changed; + block_i = EXT2_I(inode)->i_block_alloc_info; + /* XXX LOCKING probably should have i_meta_lock ?*/ /* That's it */ *where->p = where->key; - ei->i_next_alloc_block = block; - ei->i_next_alloc_goal = le32_to_cpu(where[num-1].key); - write_unlock(&ei->i_meta_lock); + /* + * Update the host buffer_head or inode to point to more just allocated + * direct blocks blocks + */ + if (num == 0 && blks > 1) { + current_block = le32_to_cpu(where->key) + 1; + for (i = 1; i < blks; i++) + *(where->p + i ) = cpu_to_le32(current_block++); + } - /* We are done with atomic stuff, now do the rest of housekeeping */ + /* + * update the most recently allocated logical & physical block + * in i_block_alloc_info, to assist find the proper goal block for next + * allocation + */ + if (block_i) { + block_i->last_alloc_logical_block = block + blks - 1; + block_i->last_alloc_physical_block = + le32_to_cpu(where[num].key) + blks - 1; + } - inode->i_ctime = CURRENT_TIME_SEC; + /* We are done with atomic stuff, now do the rest of housekeeping */ /* had we spliced it onto indirect block? */ if (where->bh) mark_buffer_dirty_inode(where->bh, inode); + inode->i_ctime = CURRENT_TIME_SEC; mark_inode_dirty(inode); - return 0; - -changed: - write_unlock(&ei->i_meta_lock); - for (i = 1; i < num; i++) - bforget(where[i].bh); - for (i = 0; i < num; i++) - ext2_free_blocks(inode, le32_to_cpu(where[i].key), 1); - return -EAGAIN; } /* @@ -542,64 +566,99 @@ changed: * That has a nice additional property: no special recovery from the failed * allocations is needed - we simply release blocks and do not touch anything * reachable from inode. + * + * `handle' can be NULL if create == 0. + * + * The BKL may not be held on entry here. Be sure to take it early. + * return > 0, # of blocks mapped or allocated. + * return = 0, if plain lookup failed. + * return < 0, error case. */ - -int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) +static int ext2_get_blocks(struct inode *inode, + sector_t iblock, unsigned long maxblocks, + struct buffer_head *bh_result, + int create) { int err = -EIO; int offsets[4]; Indirect chain[4]; Indirect *partial; - unsigned long goal; - int left; - int boundary = 0; - int depth = ext2_block_to_path(inode, iblock, offsets, &boundary); + ext2_fsblk_t goal; + int indirect_blks; + int blocks_to_boundary = 0; + int depth; + struct ext2_inode_info *ei = EXT2_I(inode); + int count = 0; + ext2_fsblk_t first_block = 0; - if (depth == 0) - goto out; + depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); + if (depth == 0) + return (err); reread: partial = ext2_get_branch(inode, depth, offsets, chain, &err); /* Simplest case - block found, no allocation needed */ if (!partial) { -got_it: - map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); - if (boundary) - set_buffer_boundary(bh_result); - /* Clean up and exit */ - partial = chain+depth-1; /* the whole chain */ - goto cleanup; + first_block = le32_to_cpu(chain[depth - 1].key); + clear_buffer_new(bh_result); /* What's this do? */ + count++; + /*map more blocks*/ + while (count < maxblocks && count <= blocks_to_boundary) { + ext2_fsblk_t blk; + + if (!verify_chain(chain, partial)) { + /* + * Indirect block might be removed by + * truncate while we were reading it. + * Handling of that case: forget what we've + * got now, go to reread. + */ + count = 0; + goto changed; + } + blk = le32_to_cpu(*(chain[depth-1].p + count)); + if (blk == first_block + count) + count++; + else + break; + } + goto got_it; } /* Next simple case - plain lookup or failed read of indirect block */ - if (!create || err == -EIO) { -cleanup: - while (partial > chain) { - brelse(partial->bh); - partial--; - } -out: - return err; - } + if (!create || err == -EIO) + goto cleanup; + + mutex_lock(&ei->truncate_mutex); /* - * Indirect block might be removed by truncate while we were - * reading it. Handling of that case (forget what we've got and - * reread) is taken out of the main path. - */ - if (err == -EAGAIN) - goto changed; + * Okay, we need to do block allocation. Lazily initialize the block + * allocation info here if necessary + */ + if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) + ext2_init_block_alloc_info(inode); - goal = 0; - if (ext2_find_goal(inode, iblock, chain, partial, &goal) < 0) - goto changed; + goal = ext2_find_goal(inode, iblock, chain, partial); - left = (chain + depth) - partial; - err = ext2_alloc_branch(inode, left, goal, - offsets+(partial-chain), partial); - if (err) + /* the number of blocks need to allocate for [d,t]indirect blocks */ + indirect_blks = (chain + depth) - partial - 1; + /* + * Next look up the indirect map to count the totoal number of + * direct blocks to allocate for this branch. + */ + count = ext2_blks_to_allocate(partial, indirect_blks, + maxblocks, blocks_to_boundary); + /* + * XXX ???? Block out ext2_truncate while we alter the tree + */ + err = ext2_alloc_branch(inode, indirect_blks, &count, goal, + offsets + (partial - chain), partial); + + if (err) { + mutex_unlock(&ei->truncate_mutex); goto cleanup; + } if (ext2_use_xip(inode->i_sb)) { /* @@ -607,16 +666,28 @@ out: */ err = ext2_clear_xip_target (inode, le32_to_cpu(chain[depth-1].key)); - if (err) + if (err) { + mutex_unlock(&ei->truncate_mutex); goto cleanup; + } } - if (ext2_splice_branch(inode, iblock, chain, partial, left) < 0) - goto changed; - + ext2_splice_branch(inode, iblock, partial, indirect_blks, count); + mutex_unlock(&ei->truncate_mutex); set_buffer_new(bh_result); - goto got_it; - +got_it: + map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); + if (count > blocks_to_boundary) + set_buffer_boundary(bh_result); + err = count; + /* Clean up and exit */ + partial = chain + depth - 1; /* the whole chain */ +cleanup: + while (partial > chain) { + brelse(partial->bh); + partial--; + } + return err; changed: while (partial > chain) { brelse(partial->bh); @@ -625,6 +696,19 @@ changed: goto reread; } +int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) +{ + unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; + int ret = ext2_get_blocks(inode, iblock, max_blocks, + bh_result, create); + if (ret > 0) { + bh_result->b_size = (ret << inode->i_blkbits); + ret = 0; + } + return ret; + +} + static int ext2_writepage(struct page *page, struct writeback_control *wbc) { return block_write_full_page(page, ext2_get_block, wbc); @@ -913,9 +997,10 @@ static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int de ext2_free_data(inode, p, q); } -void ext2_truncate (struct inode * inode) +void ext2_truncate(struct inode *inode) { __le32 *i_data = EXT2_I(inode)->i_data; + struct ext2_inode_info *ei = EXT2_I(inode); int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); int offsets[4]; Indirect chain[4]; @@ -933,8 +1018,6 @@ void ext2_truncate (struct inode * inode) if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) return; - ext2_discard_prealloc(inode); - blocksize = inode->i_sb->s_blocksize; iblock = (inode->i_size + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); @@ -952,6 +1035,12 @@ void ext2_truncate (struct inode * inode) if (n == 0) return; + /* + * From here we block out all ext2_get_block() callers who want to + * modify the block allocation tree. + */ + mutex_lock(&ei->truncate_mutex); + if (n == 1) { ext2_free_data(inode, i_data+offsets[0], i_data + EXT2_NDIR_BLOCKS); @@ -1004,6 +1093,10 @@ do_indirects: case EXT2_TIND_BLOCK: ; } + + ext2_discard_reservation(inode); + + mutex_unlock(&ei->truncate_mutex); inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; if (inode_needs_sync(inode)) { sync_mapping_buffers(inode->i_mapping); @@ -1104,6 +1197,8 @@ void ext2_read_inode (struct inode * inode) ei->i_acl = EXT2_ACL_NOT_CACHED; ei->i_default_acl = EXT2_ACL_NOT_CACHED; #endif + ei->i_block_alloc_info = NULL; + if (IS_ERR(raw_inode)) goto bad_inode; @@ -1145,9 +1240,6 @@ void ext2_read_inode (struct inode * inode) ei->i_dtime = 0; inode->i_generation = le32_to_cpu(raw_inode->i_generation); ei->i_state = 0; - ei->i_next_alloc_block = 0; - ei->i_next_alloc_goal = 0; - ei->i_prealloc_count = 0; ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); ei->i_dir_start_lookup = 0; diff --git a/fs/ext2/ioctl.c b/fs/ext2/ioctl.c index 3bcd25422ee4..c2324d5fe4ac 100644 --- a/fs/ext2/ioctl.c +++ b/fs/ext2/ioctl.c @@ -22,6 +22,7 @@ int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd, { struct ext2_inode_info *ei = EXT2_I(inode); unsigned int flags; + unsigned short rsv_window_size; ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg); @@ -83,6 +84,50 @@ int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd, inode->i_ctime = CURRENT_TIME_SEC; mark_inode_dirty(inode); return 0; + case EXT2_IOC_GETRSVSZ: + if (test_opt(inode->i_sb, RESERVATION) + && S_ISREG(inode->i_mode) + && ei->i_block_alloc_info) { + rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size; + return put_user(rsv_window_size, (int __user *)arg); + } + return -ENOTTY; + case EXT2_IOC_SETRSVSZ: { + + if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode)) + return -ENOTTY; + + if (IS_RDONLY(inode)) + return -EROFS; + + if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) + return -EACCES; + + if (get_user(rsv_window_size, (int __user *)arg)) + return -EFAULT; + + if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS) + rsv_window_size = EXT2_MAX_RESERVE_BLOCKS; + + /* + * need to allocate reservation structure for this inode + * before set the window size + */ + /* + * XXX What lock should protect the rsv_goal_size? + * Accessed in ext2_get_block only. ext3 uses i_truncate. + */ + mutex_lock(&ei->truncate_mutex); + if (!ei->i_block_alloc_info) + ext2_init_block_alloc_info(inode); + + if (ei->i_block_alloc_info){ + struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node; + rsv->rsv_goal_size = rsv_window_size; + } + mutex_unlock(&ei->truncate_mutex); + return 0; + } default: return -ENOTTY; } diff --git a/fs/ext2/super.c b/fs/ext2/super.c index 51b4c43b97e4..77bd5f9262f9 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -149,6 +149,7 @@ static struct inode *ext2_alloc_inode(struct super_block *sb) ei->i_acl = EXT2_ACL_NOT_CACHED; ei->i_default_acl = EXT2_ACL_NOT_CACHED; #endif + ei->i_block_alloc_info = NULL; ei->vfs_inode.i_version = 1; return &ei->vfs_inode; } @@ -166,6 +167,7 @@ static void init_once(struct kmem_cache * cachep, void *foo) #ifdef CONFIG_EXT2_FS_XATTR init_rwsem(&ei->xattr_sem); #endif + mutex_init(&ei->truncate_mutex); inode_init_once(&ei->vfs_inode); } @@ -188,6 +190,7 @@ static void destroy_inodecache(void) static void ext2_clear_inode(struct inode *inode) { + struct ext2_block_alloc_info *rsv = EXT2_I(inode)->i_block_alloc_info; #ifdef CONFIG_EXT2_FS_POSIX_ACL struct ext2_inode_info *ei = EXT2_I(inode); @@ -200,6 +203,10 @@ static void ext2_clear_inode(struct inode *inode) ei->i_default_acl = EXT2_ACL_NOT_CACHED; } #endif + ext2_discard_reservation(inode); + EXT2_I(inode)->i_block_alloc_info = NULL; + if (unlikely(rsv)) + kfree(rsv); } static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) @@ -291,7 +298,6 @@ static const struct super_operations ext2_sops = { .destroy_inode = ext2_destroy_inode, .read_inode = ext2_read_inode, .write_inode = ext2_write_inode, - .put_inode = ext2_put_inode, .delete_inode = ext2_delete_inode, .put_super = ext2_put_super, .write_super = ext2_write_super, @@ -379,7 +385,7 @@ enum { Opt_err_ro, Opt_nouid32, Opt_nocheck, Opt_debug, Opt_oldalloc, Opt_orlov, Opt_nobh, Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl, Opt_xip, Opt_ignore, Opt_err, Opt_quota, - Opt_usrquota, Opt_grpquota + Opt_usrquota, Opt_grpquota, Opt_reservation, Opt_noreservation }; static match_table_t tokens = { @@ -411,6 +417,8 @@ static match_table_t tokens = { {Opt_ignore, "noquota"}, {Opt_quota, "quota"}, {Opt_usrquota, "usrquota"}, + {Opt_reservation, "reservation"}, + {Opt_noreservation, "noreservation"}, {Opt_err, NULL} }; @@ -543,6 +551,14 @@ static int parse_options (char * options, break; #endif + case Opt_reservation: + set_opt(sbi->s_mount_opt, RESERVATION); + printk("reservations ON\n"); + break; + case Opt_noreservation: + clear_opt(sbi->s_mount_opt, RESERVATION); + printk("reservations OFF\n"); + break; case Opt_ignore: break; default: @@ -784,6 +800,8 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) sbi->s_resuid = le16_to_cpu(es->s_def_resuid); sbi->s_resgid = le16_to_cpu(es->s_def_resgid); + set_opt(sbi->s_mount_opt, RESERVATION); + if (!parse_options ((char *) data, sbi)) goto failed_mount; @@ -965,6 +983,21 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) get_random_bytes(&sbi->s_next_generation, sizeof(u32)); spin_lock_init(&sbi->s_next_gen_lock); + /* per fileystem reservation list head & lock */ + spin_lock_init(&sbi->s_rsv_window_lock); + sbi->s_rsv_window_root = RB_ROOT; + /* + * Add a single, static dummy reservation to the start of the + * reservation window list --- it gives us a placeholder for + * append-at-start-of-list which makes the allocation logic + * _much_ simpler. + */ + sbi->s_rsv_window_head.rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; + sbi->s_rsv_window_head.rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; + sbi->s_rsv_window_head.rsv_alloc_hit = 0; + sbi->s_rsv_window_head.rsv_goal_size = 0; + ext2_rsv_window_add(sb, &sbi->s_rsv_window_head); + err = percpu_counter_init(&sbi->s_freeblocks_counter, ext2_count_free_blocks(sb)); if (!err) { @@ -1260,7 +1293,7 @@ static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, tmp_bh.b_state = 0; err = ext2_get_block(inode, blk, &tmp_bh, 0); - if (err) + if (err < 0) return err; if (!buffer_mapped(&tmp_bh)) /* A hole? */ memset(data, 0, tocopy); @@ -1299,7 +1332,7 @@ static ssize_t ext2_quota_write(struct super_block *sb, int type, tmp_bh.b_state = 0; err = ext2_get_block(inode, blk, &tmp_bh, 1); - if (err) + if (err < 0) goto out; if (offset || tocopy != EXT2_BLOCK_SIZE(sb)) bh = sb_bread(sb, tmp_bh.b_blocknr); diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c index 247efd0b51d6..3e8683dbb13f 100644 --- a/fs/ext2/xattr.c +++ b/fs/ext2/xattr.c @@ -664,8 +664,7 @@ ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh, s_first_data_block) + EXT2_I(inode)->i_block_group * EXT2_BLOCKS_PER_GROUP(sb); - int block = ext2_new_block(inode, goal, - NULL, NULL, &error); + int block = ext2_new_block(inode, goal, &error); if (error) goto cleanup; ea_idebug(inode, "creating block %d", block); diff --git a/include/linux/ext2_fs.h b/include/linux/ext2_fs.h index 153d755376a4..c77c3bbfe4bb 100644 --- a/include/linux/ext2_fs.h +++ b/include/linux/ext2_fs.h @@ -29,11 +29,12 @@ #undef EXT2FS_DEBUG /* - * Define EXT2_PREALLOCATE to preallocate data blocks for expanding files + * Define EXT2_RESERVATION to reserve data blocks for expanding files */ -#define EXT2_PREALLOCATE -#define EXT2_DEFAULT_PREALLOC_BLOCKS 8 - +#define EXT2_DEFAULT_RESERVE_BLOCKS 8 +/*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */ +#define EXT2_MAX_RESERVE_BLOCKS 1027 +#define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0 /* * The second extended file system version */ @@ -200,6 +201,8 @@ struct ext2_group_desc #define EXT2_IOC_SETFLAGS FS_IOC_SETFLAGS #define EXT2_IOC_GETVERSION FS_IOC_GETVERSION #define EXT2_IOC_SETVERSION FS_IOC_SETVERSION +#define EXT2_IOC_GETRSVSZ _IOR('f', 5, long) +#define EXT2_IOC_SETRSVSZ _IOW('f', 6, long) /* * ioctl commands in 32 bit emulation @@ -317,8 +320,9 @@ struct ext2_inode { #define EXT2_MOUNT_XATTR_USER 0x004000 /* Extended user attributes */ #define EXT2_MOUNT_POSIX_ACL 0x008000 /* POSIX Access Control Lists */ #define EXT2_MOUNT_XIP 0x010000 /* Execute in place */ -#define EXT2_MOUNT_USRQUOTA 0x020000 /* user quota */ -#define EXT2_MOUNT_GRPQUOTA 0x040000 /* group quota */ +#define EXT2_MOUNT_USRQUOTA 0x020000 /* user quota */ +#define EXT2_MOUNT_GRPQUOTA 0x040000 /* group quota */ +#define EXT2_MOUNT_RESERVATION 0x080000 /* Preallocation */ #define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt @@ -558,4 +562,11 @@ enum { #define EXT2_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT2_DIR_ROUND) & \ ~EXT2_DIR_ROUND) +static inline ext2_fsblk_t +ext2_group_first_block_no(struct super_block *sb, unsigned long group_no) +{ + return group_no * (ext2_fsblk_t)EXT2_BLOCKS_PER_GROUP(sb) + + le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block); +} + #endif /* _LINUX_EXT2_FS_H */ diff --git a/include/linux/ext2_fs_sb.h b/include/linux/ext2_fs_sb.h index 199ef37b0a19..f273415ab6f1 100644 --- a/include/linux/ext2_fs_sb.h +++ b/include/linux/ext2_fs_sb.h @@ -18,6 +18,52 @@ #include #include +#include + +/* XXX Here for now... not interested in restructing headers JUST now */ + +/* data type for block offset of block group */ +typedef int ext2_grpblk_t; + +/* data type for filesystem-wide blocks number */ +typedef unsigned long ext2_fsblk_t; + +#define E2FSBLK "%lu" + +struct ext2_reserve_window { + ext2_fsblk_t _rsv_start; /* First byte reserved */ + ext2_fsblk_t _rsv_end; /* Last byte reserved or 0 */ +}; + +struct ext2_reserve_window_node { + struct rb_node rsv_node; + __u32 rsv_goal_size; + __u32 rsv_alloc_hit; + struct ext2_reserve_window rsv_window; +}; + +struct ext2_block_alloc_info { + /* information about reservation window */ + struct ext2_reserve_window_node rsv_window_node; + /* + * was i_next_alloc_block in ext2_inode_info + * is the logical (file-relative) number of the + * most-recently-allocated block in this file. + * We use this for detecting linearly ascending allocation requests. + */ + __u32 last_alloc_logical_block; + /* + * Was i_next_alloc_goal in ext2_inode_info + * is the *physical* companion to i_next_alloc_block. + * it the the physical block number of the block which was most-recentl + * allocated to this file. This give us the goal (target) for the next + * allocation when we detect linearly ascending requests. + */ + ext2_fsblk_t last_alloc_physical_block; +}; + +#define rsv_start rsv_window._rsv_start +#define rsv_end rsv_window._rsv_end /* * second extended-fs super-block data in memory @@ -56,6 +102,10 @@ struct ext2_sb_info { struct percpu_counter s_freeinodes_counter; struct percpu_counter s_dirs_counter; struct blockgroup_lock s_blockgroup_lock; + /* root of the per fs reservation window tree */ + spinlock_t s_rsv_window_lock; + struct rb_root s_rsv_window_root; + struct ext2_reserve_window_node s_rsv_window_head; }; #endif /* _LINUX_EXT2_FS_SB */