|
|
@@ -133,41 +133,6 @@ error_out:
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|
|
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);
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|
|
- 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)
|
|
|
}
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|
|
}
|
|
|
|
|
|
-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,
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|
}
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|
|
}
|
|
|
|
|
|
-/* 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
|
Martin J. Bligh