* David S. Miller (davem@caip.rutgers.edu), 1995
*/
-#include <linux/config.h>
#include <linux/time.h>
+#include <linux/capability.h>
#include <linux/fs.h>
#include <linux/jbd.h>
#include <linux/ext3_fs.h>
#include <linux/quotaops.h>
#include <linux/buffer_head.h>
-#include "bitmap.h"
-
/*
* balloc.c contains the blocks allocation and deallocation routines
*/
* The file system contains group descriptors which are located after the
* super block. Each descriptor contains the number of the bitmap block and
* the free blocks count in the block. The descriptors are loaded in memory
- * when a file system is mounted (see ext3_read_super).
+ * when a file system is mounted (see ext3_fill_super).
*/
#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
+/**
+ * ext3_get_group_desc() -- load group descriptor from disk
+ * @sb: super block
+ * @block_group: given block group
+ * @bh: pointer to the buffer head to store the block
+ * group descriptor
+ */
struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb,
unsigned int block_group,
struct buffer_head ** bh)
return desc + offset;
}
-/*
- * Read the bitmap for a given block_group, reading into the specified
- * slot in the superblock's bitmap cache.
+static int ext3_valid_block_bitmap(struct super_block *sb,
+ struct ext3_group_desc *desc,
+ unsigned int block_group,
+ struct buffer_head *bh)
+{
+ ext3_grpblk_t offset;
+ ext3_grpblk_t next_zero_bit;
+ ext3_fsblk_t bitmap_blk;
+ ext3_fsblk_t group_first_block;
+
+ group_first_block = ext3_group_first_block_no(sb, block_group);
+
+ /* check whether block bitmap block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+ offset = bitmap_blk - group_first_block;
+ if (!ext3_test_bit(offset, bh->b_data))
+ /* bad block bitmap */
+ goto err_out;
+
+ /* check whether the inode bitmap block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap);
+ offset = bitmap_blk - group_first_block;
+ if (!ext3_test_bit(offset, bh->b_data))
+ /* bad block bitmap */
+ goto err_out;
+
+ /* check whether the inode table block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_inode_table);
+ offset = bitmap_blk - group_first_block;
+ next_zero_bit = ext3_find_next_zero_bit(bh->b_data,
+ offset + EXT3_SB(sb)->s_itb_per_group,
+ offset);
+ if (next_zero_bit >= offset + EXT3_SB(sb)->s_itb_per_group)
+ /* good bitmap for inode tables */
+ return 1;
+
+err_out:
+ ext3_error(sb, __func__,
+ "Invalid block bitmap - "
+ "block_group = %d, block = %lu",
+ block_group, bitmap_blk);
+ return 0;
+}
+
+/**
+ * read_block_bitmap()
+ * @sb: super block
+ * @block_group: given block group
+ *
+ * Read the bitmap for a given block_group,and validate the
+ * bits for block/inode/inode tables are set in the bitmaps
*
* Return buffer_head on success or NULL in case of failure.
*/
{
struct ext3_group_desc * desc;
struct buffer_head * bh = NULL;
+ ext3_fsblk_t bitmap_blk;
- desc = ext3_get_group_desc (sb, block_group, NULL);
+ desc = ext3_get_group_desc(sb, block_group, NULL);
if (!desc)
- goto error_out;
- bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap));
- if (!bh)
- ext3_error (sb, "read_block_bitmap",
+ return NULL;
+ bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+ bh = sb_getblk(sb, bitmap_blk);
+ if (unlikely(!bh)) {
+ ext3_error(sb, __func__,
+ "Cannot read block bitmap - "
+ "block_group = %d, block_bitmap = %u",
+ block_group, le32_to_cpu(desc->bg_block_bitmap));
+ return NULL;
+ }
+ if (likely(bh_uptodate_or_lock(bh)))
+ return bh;
+
+ if (bh_submit_read(bh) < 0) {
+ brelse(bh);
+ ext3_error(sb, __func__,
"Cannot read block bitmap - "
"block_group = %d, block_bitmap = %u",
block_group, le32_to_cpu(desc->bg_block_bitmap));
-error_out:
+ return NULL;
+ }
+ ext3_valid_block_bitmap(sb, desc, block_group, bh);
+ /*
+ * file system mounted not to panic on error, continue with corrupt
+ * bitmap
+ */
return bh;
}
/*
* Operations include:
* dump, find, add, remove, is_empty, find_next_reservable_window, etc.
*
- * We use sorted double linked list for the per-filesystem reservation
- * window list. (like in vm_region).
+ * We use a red-black tree to represent per-filesystem reservation
+ * windows.
+ *
+ */
+
+/**
+ * __rsv_window_dump() -- Dump the filesystem block allocation reservation map
+ * @rb_root: root of per-filesystem reservation rb tree
+ * @verbose: verbose mode
+ * @fn: function which wishes to dump the reservation map
*
- * Initially, we keep those small operations in the abstract functions,
- * so later if we need a better searching tree than double linked-list,
- * we could easily switch to that without changing too much
- * code.
+ * If verbose is turned on, it will print the whole block reservation
+ * windows(start, end). Otherwise, it will only print out the "bad" windows,
+ * those windows that overlap with their immediate neighbors.
*/
-#if 0
+#if 1
static void __rsv_window_dump(struct rb_root *root, int verbose,
const char *fn)
{
printk("Block Allocation Reservation Windows Map (%s):\n", fn);
while (n) {
- rsv = list_entry(n, struct ext3_reserve_window_node, rsv_node);
+ rsv = rb_entry(n, struct ext3_reserve_window_node, rsv_node);
if (verbose)
printk("reservation window 0x%p "
- "start: %d, end: %d\n",
+ "start: %lu, end: %lu\n",
rsv, rsv->rsv_start, rsv->rsv_end);
if (rsv->rsv_start && rsv->rsv_start >= rsv->rsv_end) {
printk("Bad reservation %p (start >= end)\n",
prev = rsv;
}
printk("Window map complete.\n");
- if (bad)
- BUG();
+ BUG_ON(bad);
}
#define rsv_window_dump(root, verbose) \
- __rsv_window_dump((root), (verbose), __FUNCTION__)
+ __rsv_window_dump((root), (verbose), __func__)
#else
#define rsv_window_dump(root, verbose) do {} while (0)
#endif
+/**
+ * goal_in_my_reservation()
+ * @rsv: inode's reservation window
+ * @grp_goal: given goal block relative to the allocation block group
+ * @group: the current allocation block group
+ * @sb: filesystem super block
+ *
+ * Test if the given goal block (group relative) is within the file's
+ * own block reservation window range.
+ *
+ * If the reservation window is outside the goal allocation group, return 0;
+ * grp_goal (given goal block) could be -1, which means no specific
+ * goal block. In this case, always return 1.
+ * If the goal block is within the reservation window, return 1;
+ * otherwise, return 0;
+ */
static int
-goal_in_my_reservation(struct ext3_reserve_window *rsv, int goal,
+goal_in_my_reservation(struct ext3_reserve_window *rsv, ext3_grpblk_t grp_goal,
unsigned int group, struct super_block * sb)
{
- unsigned long group_first_block, group_last_block;
+ ext3_fsblk_t group_first_block, group_last_block;
- group_first_block = le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) +
- group * EXT3_BLOCKS_PER_GROUP(sb);
- group_last_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1;
+ group_first_block = ext3_group_first_block_no(sb, group);
+ group_last_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
if ((rsv->_rsv_start > group_last_block) ||
(rsv->_rsv_end < group_first_block))
return 0;
- if ((goal >= 0) && ((goal + group_first_block < rsv->_rsv_start)
- || (goal + group_first_block > rsv->_rsv_end)))
+ 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 ext3_reserve_window_node *
-search_reserve_window(struct rb_root *root, unsigned long goal)
+search_reserve_window(struct rb_root *root, ext3_fsblk_t goal)
{
struct rb_node *n = root->rb_node;
struct ext3_reserve_window_node *rsv;
return rsv;
}
+/**
+ * ext3_rsv_window_add() -- Insert a window to the block reservation rb tree.
+ * @sb: super block
+ * @rsv: reservation window to add
+ *
+ * Must be called with rsv_lock hold.
+ */
void ext3_rsv_window_add(struct super_block *sb,
struct ext3_reserve_window_node *rsv)
{
struct rb_root *root = &EXT3_SB(sb)->s_rsv_window_root;
struct rb_node *node = &rsv->rsv_node;
- unsigned int start = rsv->rsv_start;
+ ext3_fsblk_t start = rsv->rsv_start;
struct rb_node ** p = &root->rb_node;
struct rb_node * parent = NULL;
p = &(*p)->rb_left;
else if (start > this->rsv_end)
p = &(*p)->rb_right;
- else
+ else {
+ rsv_window_dump(root, 1);
BUG();
+ }
}
rb_link_node(node, parent, p);
rb_insert_color(node, root);
}
+/**
+ * ext3_rsv_window_remove() -- unlink a window from the reservation rb tree
+ * @sb: super block
+ * @rsv: reservation window to remove
+ *
+ * Mark the block reservation window as not allocated, and unlink it
+ * from the filesystem reservation window rb tree. Must be called with
+ * rsv_lock hold.
+ */
static void rsv_window_remove(struct super_block *sb,
struct ext3_reserve_window_node *rsv)
{
rb_erase(&rsv->rsv_node, &EXT3_SB(sb)->s_rsv_window_root);
}
+/*
+ * rsv_is_empty() -- Check if the reservation window is allocated.
+ * @rsv: given reservation window to check
+ *
+ * returns 1 if the end block is EXT3_RESERVE_WINDOW_NOT_ALLOCATED.
+ */
static inline int rsv_is_empty(struct ext3_reserve_window *rsv)
{
/* a valid reservation end block could not be 0 */
- return (rsv->_rsv_end == EXT3_RESERVE_WINDOW_NOT_ALLOCATED);
+ return rsv->_rsv_end == EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
}
+
+/**
+ * ext3_init_block_alloc_info()
+ * @inode: file inode structure
+ *
+ * Allocate and initialize the reservation window structure, and
+ * link the window to the ext3 inode structure at last
+ *
+ * The reservation window structure is only dynamically allocated
+ * and linked to ext3 inode the first time the open file
+ * needs a new block. So, before every ext3_new_block(s) call, for
+ * regular files, we should check whether the reservation window
+ * structure exists or not. In the latter case, this function is called.
+ * Fail to do so will result in block reservation being turned off for that
+ * open file.
+ *
+ * This function is called from ext3_get_blocks_handle(), also called
+ * when setting the reservation window size through ioctl before the file
+ * is open for write (needs block allocation).
+ *
+ * Needs truncate_mutex protection prior to call this function.
+ */
void ext3_init_block_alloc_info(struct inode *inode)
{
struct ext3_inode_info *ei = EXT3_I(inode);
rsv->rsv_start = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
rsv->rsv_end = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
- /*
+ /*
* if filesystem is mounted with NORESERVATION, the goal
* reservation window size is set to zero to indicate
* block reservation is off
ei->i_block_alloc_info = block_i;
}
+/**
+ * ext3_discard_reservation()
+ * @inode: inode
+ *
+ * Discard(free) block reservation window on last file close, or truncate
+ * or at last iput().
+ *
+ * It is being called in three cases:
+ * ext3_release_file(): last writer close the file
+ * ext3_clear_inode(): last iput(), when nobody link to this file.
+ * ext3_truncate(): when the block indirect map is about to change.
+ *
+ */
void ext3_discard_reservation(struct inode *inode)
{
struct ext3_inode_info *ei = EXT3_I(inode);
}
}
-/* Free given blocks, update quota and i_blocks field */
+/**
+ * ext3_free_blocks_sb() -- Free given blocks and update quota
+ * @handle: handle to this transaction
+ * @sb: super block
+ * @block: start physcial block to free
+ * @count: number of blocks to free
+ * @pdquot_freed_blocks: pointer to quota
+ */
void ext3_free_blocks_sb(handle_t *handle, struct super_block *sb,
- unsigned long block, unsigned long count,
- int *pdquot_freed_blocks)
+ ext3_fsblk_t block, unsigned long count,
+ unsigned long *pdquot_freed_blocks)
{
struct buffer_head *bitmap_bh = NULL;
struct buffer_head *gd_bh;
unsigned long block_group;
- unsigned long bit;
+ ext3_grpblk_t bit;
unsigned long i;
unsigned long overflow;
struct ext3_group_desc * desc;
struct ext3_super_block * es;
struct ext3_sb_info *sbi;
int err = 0, ret;
- unsigned group_freed;
+ ext3_grpblk_t group_freed;
*pdquot_freed_blocks = 0;
sbi = EXT3_SB(sb);
block + count > le32_to_cpu(es->s_blocks_count)) {
ext3_error (sb, "ext3_free_blocks",
"Freeing blocks not in datazone - "
- "block = %lu, count = %lu", block, count);
+ "block = "E3FSBLK", count = %lu", block, count);
goto error_return;
}
in_range (block, le32_to_cpu(desc->bg_inode_table),
sbi->s_itb_per_group) ||
in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table),
- sbi->s_itb_per_group))
+ sbi->s_itb_per_group)) {
ext3_error (sb, "ext3_free_blocks",
"Freeing blocks in system zones - "
- "Block = %lu, count = %lu",
+ "Block = "E3FSBLK", count = %lu",
block, count);
+ goto error_return;
+ }
/*
* We are about to start releasing blocks in the bitmap,
}
/* @@@ This prevents newly-allocated data from being
* freed and then reallocated within the same
- * transaction.
- *
+ * transaction.
+ *
* Ideally we would want to allow that to happen, but to
* do so requires making journal_forget() capable of
* revoking the queued write of a data block, which
* safe not to set the allocation bit in the committed
* bitmap, because we know that there is no outstanding
* activity on the buffer any more and so it is safe to
- * reallocate it.
+ * reallocate it.
*/
BUFFER_TRACE(bitmap_bh, "set in b_committed_data");
J_ASSERT_BH(bitmap_bh,
if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
bit + i, bitmap_bh->b_data)) {
jbd_unlock_bh_state(bitmap_bh);
- ext3_error(sb, __FUNCTION__,
- "bit already cleared for block %lu", block + i);
+ ext3_error(sb, __func__,
+ "bit already cleared for block "E3FSBLK,
+ block + i);
jbd_lock_bh_state(bitmap_bh);
BUFFER_TRACE(bitmap_bh, "bit already cleared");
} else {
jbd_unlock_bh_state(bitmap_bh);
spin_lock(sb_bgl_lock(sbi, block_group));
- desc->bg_free_blocks_count =
- cpu_to_le16(le16_to_cpu(desc->bg_free_blocks_count) +
- group_freed);
+ le16_add_cpu(&desc->bg_free_blocks_count, group_freed);
spin_unlock(sb_bgl_lock(sbi, block_group));
- percpu_counter_mod(&sbi->s_freeblocks_counter, count);
+ percpu_counter_add(&sbi->s_freeblocks_counter, count);
/* We dirtied the bitmap block */
BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
return;
}
-/* Free given blocks, update quota and i_blocks field */
+/**
+ * ext3_free_blocks() -- Free given blocks and update quota
+ * @handle: handle for this transaction
+ * @inode: inode
+ * @block: start physical block to free
+ * @count: number of blocks to count
+ */
void ext3_free_blocks(handle_t *handle, struct inode *inode,
- unsigned long block, unsigned long count)
+ ext3_fsblk_t block, unsigned long count)
{
struct super_block * sb;
- int dquot_freed_blocks;
+ unsigned long dquot_freed_blocks;
sb = inode->i_sb;
if (!sb) {
return;
}
-/*
+/**
+ * ext3_test_allocatable()
+ * @nr: given allocation block group
+ * @bh: bufferhead contains the bitmap of the given block group
+ *
* For ext3 allocations, we must not reuse any blocks which are
* allocated in the bitmap buffer's "last committed data" copy. This
* prevents deletes from freeing up the page for reuse until we have
* data would allow the old block to be overwritten before the
* transaction committed (because we force data to disk before commit).
* This would lead to corruption if we crashed between overwriting the
- * data and committing the delete.
+ * data and committing the delete.
*
* @@@ We may want to make this allocation behaviour conditional on
* data-writes at some point, and disable it for metadata allocations or
* sync-data inodes.
*/
-static int ext3_test_allocatable(int nr, struct buffer_head *bh)
+static int ext3_test_allocatable(ext3_grpblk_t nr, struct buffer_head *bh)
{
int ret;
struct journal_head *jh = bh2jh(bh);
return ret;
}
-static int
-bitmap_search_next_usable_block(int start, struct buffer_head *bh,
- int maxblocks)
+/**
+ * bitmap_search_next_usable_block()
+ * @start: the starting block (group relative) of the search
+ * @bh: bufferhead contains the block group bitmap
+ * @maxblocks: the ending block (group relative) of the reservation
+ *
+ * The bitmap search --- search forward alternately through the actual
+ * bitmap on disk and the last-committed copy in journal, until we find a
+ * bit free in both bitmaps.
+ */
+static ext3_grpblk_t
+bitmap_search_next_usable_block(ext3_grpblk_t start, struct buffer_head *bh,
+ ext3_grpblk_t maxblocks)
{
- int next;
+ ext3_grpblk_t next;
struct journal_head *jh = bh2jh(bh);
- /*
- * The bitmap search --- search forward alternately through the actual
- * bitmap and the last-committed copy until we find a bit free in
- * both
- */
while (start < maxblocks) {
next = ext3_find_next_zero_bit(bh->b_data, maxblocks, start);
if (next >= maxblocks)
jbd_lock_bh_state(bh);
if (jh->b_committed_data)
start = ext3_find_next_zero_bit(jh->b_committed_data,
- maxblocks, next);
+ maxblocks, next);
jbd_unlock_bh_state(bh);
}
return -1;
}
-/*
- * Find an allocatable block in a bitmap. We honour both the bitmap and
+/**
+ * find_next_usable_block()
+ * @start: the starting block (group relative) to find next
+ * allocatable block in bitmap.
+ * @bh: bufferhead contains the block group bitmap
+ * @maxblocks: the ending block (group relative) for the search
+ *
+ * Find an allocatable block in a bitmap. We honor both the bitmap and
* its last-committed copy (if that exists), and perform the "most
* appropriate allocation" algorithm of looking for a free block near
* the initial goal; then for a free byte somewhere in the bitmap; then
* for any free bit in the bitmap.
*/
-static int
-find_next_usable_block(int start, struct buffer_head *bh, int maxblocks)
+static ext3_grpblk_t
+find_next_usable_block(ext3_grpblk_t start, struct buffer_head *bh,
+ ext3_grpblk_t maxblocks)
{
- int here, next;
+ ext3_grpblk_t here, next;
char *p, *r;
if (start > 0) {
/*
- * The goal was occupied; search forward for a free
+ * The goal was occupied; search forward for a free
* block within the next XX blocks.
*
* end_goal is more or less random, but it has to be
* less than EXT3_BLOCKS_PER_GROUP. Aligning up to the
* next 64-bit boundary is simple..
*/
- int end_goal = (start + 63) & ~63;
+ ext3_grpblk_t end_goal = (start + 63) & ~63;
if (end_goal > maxblocks)
end_goal = maxblocks;
here = ext3_find_next_zero_bit(bh->b_data, end_goal, start);
here = 0;
p = ((char *)bh->b_data) + (here >> 3);
- r = memscan(p, 0, (maxblocks - here + 7) >> 3);
+ r = memscan(p, 0, ((maxblocks + 7) >> 3) - (here >> 3));
next = (r - ((char *)bh->b_data)) << 3;
if (next < maxblocks && next >= start && ext3_test_allocatable(next, bh))
return here;
}
-/*
+/**
+ * claim_block()
+ * @block: the free block (group relative) to allocate
+ * @bh: the bufferhead containts the block group bitmap
+ *
* We think we can allocate this block in this bitmap. Try to set the bit.
* If that succeeds then check that nobody has allocated and then freed the
* block since we saw that is was not marked in b_committed_data. If it _was_
* zero (failure).
*/
static inline int
-claim_block(spinlock_t *lock, int block, struct buffer_head *bh)
+claim_block(spinlock_t *lock, ext3_grpblk_t block, struct buffer_head *bh)
{
struct journal_head *jh = bh2jh(bh);
int ret;
return ret;
}
-/*
+/**
+ * ext3_try_to_allocate()
+ * @sb: superblock
+ * @handle: handle to this transaction
+ * @group: given allocation block group
+ * @bitmap_bh: bufferhead holds the block bitmap
+ * @grp_goal: given target block within the group
+ * @count: target number of blocks to allocate
+ * @my_rsv: reservation window
+ *
+ * Attempt to allocate blocks within a give range. Set the range of allocation
+ * first, then find the first free bit(s) from the bitmap (within the range),
+ * and at last, allocate the blocks by claiming the found free bit as allocated.
+ *
+ * To set the range of this allocation:
+ * if there is a reservation window, only try to allocate block(s) from the
+ * file's own reservation window;
+ * Otherwise, the allocation range starts from the give goal block, ends at
+ * the block group's last block.
+ *
* If we failed to allocate the desired block then we may end up crossing to a
* new bitmap. In that case we must release write access to the old one via
* ext3_journal_release_buffer(), else we'll run out of credits.
*/
-static int
+static ext3_grpblk_t
ext3_try_to_allocate(struct super_block *sb, handle_t *handle, int group,
- struct buffer_head *bitmap_bh, int goal, struct ext3_reserve_window *my_rsv)
+ struct buffer_head *bitmap_bh, ext3_grpblk_t grp_goal,
+ unsigned long *count, struct ext3_reserve_window *my_rsv)
{
- int group_first_block, start, end;
+ ext3_fsblk_t group_first_block;
+ ext3_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 =
- le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) +
- group * EXT3_BLOCKS_PER_GROUP(sb);
+ group_first_block = ext3_group_first_block_no(sb, group);
if (my_rsv->_rsv_start >= group_first_block)
start = my_rsv->_rsv_start - group_first_block;
else
if (end > EXT3_BLOCKS_PER_GROUP(sb))
/* reservation window crosses group boundary */
end = EXT3_BLOCKS_PER_GROUP(sb);
- if ((start <= goal) && (goal < end))
- start = goal;
+ if ((start <= grp_goal) && (grp_goal < end))
+ start = grp_goal;
else
- goal = -1;
+ grp_goal = -1;
} else {
- if (goal > 0)
- start = goal;
+ if (grp_goal > 0)
+ start = grp_goal;
else
start = 0;
end = EXT3_BLOCKS_PER_GROUP(sb);
BUG_ON(start > EXT3_BLOCKS_PER_GROUP(sb));
repeat:
- if (goal < 0 || !ext3_test_allocatable(goal, bitmap_bh)) {
- goal = find_next_usable_block(start, bitmap_bh, end);
- if (goal < 0)
+ if (grp_goal < 0 || !ext3_test_allocatable(grp_goal, bitmap_bh)) {
+ grp_goal = find_next_usable_block(start, bitmap_bh, end);
+ if (grp_goal < 0)
goto fail_access;
if (!my_rsv) {
int i;
- for (i = 0; i < 7 && goal > start &&
- ext3_test_allocatable(goal - 1,
+ for (i = 0; i < 7 && grp_goal > start &&
+ ext3_test_allocatable(grp_goal - 1,
bitmap_bh);
- i++, goal--)
+ i++, grp_goal--)
;
}
}
- start = goal;
+ start = grp_goal;
- if (!claim_block(sb_bgl_lock(EXT3_SB(sb), group), goal, bitmap_bh)) {
+ if (!claim_block(sb_bgl_lock(EXT3_SB(sb), group),
+ grp_goal, bitmap_bh)) {
/*
* The block was allocated by another thread, or it was
* allocated and then freed by another thread
*/
start++;
- goal++;
+ grp_goal++;
if (start >= end)
goto fail_access;
goto repeat;
}
- return goal;
+ num++;
+ grp_goal++;
+ while (num < *count && grp_goal < end
+ && ext3_test_allocatable(grp_goal, bitmap_bh)
+ && claim_block(sb_bgl_lock(EXT3_SB(sb), group),
+ grp_goal, bitmap_bh)) {
+ num++;
+ grp_goal++;
+ }
+ *count = num;
+ return grp_goal - num;
fail_access:
+ *count = num;
return -1;
}
/**
- * find_next_reservable_window():
+ * find_next_reservable_window():
* find a reservable space within the given range.
* It does not allocate the reservation window for now:
* alloc_new_reservation() will do the work later.
*
- * @search_head: the head of the searching list;
+ * @search_head: the head of the searching list;
* This is not necessarily the list head of the whole filesystem
*
* We have both head and start_block to assist the search
* 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
+ * @size: the target new reservation window size
*
- * @group_first_block: the first block we consider to start
+ * @group_first_block: the first block we consider to start
* the real search from
*
- * @last_block:
+ * @last_block:
* the maximum block number that our goal reservable space
* could start from. This is normally the last block in this
* group. The search will end when we found the start of next
* This could handle the cross boundary reservation window
* request.
*
- * basically we search from the given range, rather than the whole
- * reservation double linked list, (start_block, last_block)
- * to find a free region that is of my size and has not
- * been reserved.
+ * basically we search from the given range, rather than the whole
+ * reservation double linked list, (start_block, last_block)
+ * to find a free region that is of my size and has not
+ * been reserved.
*
*/
static int find_next_reservable_window(
struct ext3_reserve_window_node *search_head,
struct ext3_reserve_window_node *my_rsv,
- struct super_block * sb, int start_block,
- int last_block)
+ struct super_block * sb,
+ ext3_fsblk_t start_block,
+ ext3_fsblk_t last_block)
{
struct rb_node *next;
struct ext3_reserve_window_node *rsv, *prev;
- int cur;
+ ext3_fsblk_t cur;
int size = my_rsv->rsv_goal_size;
/* TODO: make the start of the reservation window byte-aligned */
prev = rsv;
next = rb_next(&rsv->rsv_node);
- rsv = list_entry(next,struct ext3_reserve_window_node,rsv_node);
+ rsv = rb_entry(next,struct ext3_reserve_window_node,rsv_node);
/*
* Reached the last reservation, we can just append to the
/*
* Found a reserveable space big enough. We could
* have a reservation across the group boundary here
- */
+ */
break;
}
}
}
/**
- * alloc_new_reservation()--allocate a new reservation window
+ * alloc_new_reservation()--allocate a new reservation window
*
* To make a new reservation, we search part of the filesystem
* reservation list (the list that inside the group). We try to
*
* @rsv: the reservation
*
- * @goal: The goal (group-relative). It is where the search for a
+ * @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
+ * if we have a grp_goal(grp_goal >0 ), then start from there,
+ * no grp_goal(grp_goal = -1), we start from the first block
* of the group.
*
* @sb: the super block
*
*/
static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv,
- int goal, struct super_block *sb,
+ ext3_grpblk_t grp_goal, struct super_block *sb,
unsigned int group, struct buffer_head *bitmap_bh)
{
struct ext3_reserve_window_node *search_head;
- int group_first_block, group_end_block, start_block;
- int first_free_block;
+ ext3_fsblk_t group_first_block, group_end_block, start_block;
+ ext3_grpblk_t first_free_block;
struct rb_root *fs_rsv_root = &EXT3_SB(sb)->s_rsv_window_root;
unsigned long size;
int ret;
spinlock_t *rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock;
- group_first_block = le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) +
- group * EXT3_BLOCKS_PER_GROUP(sb);
- group_end_block = group_first_block + EXT3_BLOCKS_PER_GROUP(sb) - 1;
+ group_first_block = ext3_group_first_block_no(sb, group);
+ group_end_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
- if (goal < 0)
+ if (grp_goal < 0)
start_block = group_first_block;
else
- start_block = goal + group_first_block;
+ start_block = grp_goal + group_first_block;
size = my_rsv->rsv_goal_size;
if ((my_rsv->rsv_alloc_hit >
(my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) {
/*
- * if we previously allocation hit ration is greater than half
- * we double the size of reservation window next time
- * otherwise keep the same
+ * if the previously allocation hit ratio is
+ * greater than 1/2, then we double the size of
+ * the reservation window the next time,
+ * otherwise we keep the same size window
*/
size = size * 2;
if (size > EXT3_MAX_RESERVE_BLOCKS)
* check if the first free block is within the
* free space we just reserved
*/
- if (start_block >= my_rsv->rsv_start && start_block < my_rsv->rsv_end)
+ if (start_block >= my_rsv->rsv_start && start_block <= my_rsv->rsv_end)
return 0; /* success */
/*
* if the first free bit we found is out of the reservable space
goto retry;
}
-/*
+/**
+ * try_to_extend_reservation()
+ * @my_rsv: given reservation window
+ * @sb: super block
+ * @size: the delta to extend
+ *
+ * Attempt to expand the reservation window large enough to have
+ * required number of free blocks
+ *
+ * Since ext3_try_to_allocate() will always allocate blocks within
+ * the reservation window range, if the window size is too small,
+ * multiple blocks allocation has to stop at the end of the reservation
+ * window. To make this more efficient, given the total number of
+ * blocks needed and the current size of the window, we try to
+ * expand the reservation window size if necessary on a best-effort
+ * basis before ext3_new_blocks() tries to allocate blocks,
+ */
+static void try_to_extend_reservation(struct ext3_reserve_window_node *my_rsv,
+ struct super_block *sb, int size)
+{
+ struct ext3_reserve_window_node *next_rsv;
+ struct rb_node *next;
+ spinlock_t *rsv_lock = &EXT3_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 ext3_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);
+}
+
+/**
+ * ext3_try_to_allocate_with_rsv()
+ * @sb: superblock
+ * @handle: handle to this transaction
+ * @group: given allocation block group
+ * @bitmap_bh: bufferhead holds the block bitmap
+ * @grp_goal: given target block within the group
+ * @count: target number of blocks to allocate
+ * @my_rsv: reservation window
+ * @errp: pointer to store the error code
+ *
* This is the main function used to allocate a new block and its reservation
* window.
*
* reservation), and there are lots of free blocks, but they are all
* being reserved.
*
- * We use a sorted double linked list for the per-filesystem reservation list.
- * The insert, remove and find a free space(non-reserved) operations for the
- * sorted double linked list should be fast.
+ * We use a red-black tree for the per-filesystem reservation list.
*
*/
-static int
+static ext3_grpblk_t
ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle,
unsigned int group, struct buffer_head *bitmap_bh,
- int goal, struct ext3_reserve_window_node * my_rsv,
- int *errp)
+ ext3_grpblk_t grp_goal,
+ struct ext3_reserve_window_node * my_rsv,
+ unsigned long *count, int *errp)
{
- unsigned long group_first_block;
- int ret = 0;
+ ext3_fsblk_t group_first_block, group_last_block;
+ ext3_grpblk_t ret = 0;
int fatal;
+ unsigned long num = *count;
*errp = 0;
* or last attempt to allocate a block with reservation turned on failed
*/
if (my_rsv == NULL ) {
- ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, goal, NULL);
+ ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh,
+ grp_goal, count, NULL);
goto out;
}
/*
- * goal is a group relative block number (if there is a goal)
- * 0 < goal < EXT3_BLOCKS_PER_GROUP(sb)
+ * grp_goal is a group relative block number (if there is a goal)
+ * 0 <= grp_goal < EXT3_BLOCKS_PER_GROUP(sb)
* first block is a filesystem wide block number
* first block is the block number of the first block in this group
*/
- group_first_block = le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) +
- group * EXT3_BLOCKS_PER_GROUP(sb);
+ group_first_block = ext3_group_first_block_no(sb, group);
+ group_last_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1);
/*
* Basically we will allocate a new block from inode's reservation
*/
while (1) {
if (rsv_is_empty(&my_rsv->rsv_window) || (ret < 0) ||
- !goal_in_my_reservation(&my_rsv->rsv_window, goal, group, sb)) {
- ret = alloc_new_reservation(my_rsv, goal, sb,
+ !goal_in_my_reservation(&my_rsv->rsv_window,
+ grp_goal, group, sb)) {
+ if (my_rsv->rsv_goal_size < *count)
+ my_rsv->rsv_goal_size = *count;
+ ret = alloc_new_reservation(my_rsv, grp_goal, sb,
group, bitmap_bh);
if (ret < 0)
break; /* failed */
- if (!goal_in_my_reservation(&my_rsv->rsv_window, goal, group, sb))
- goal = -1;
+ 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_first_block + EXT3_BLOCKS_PER_GROUP(sb))
- || (my_rsv->rsv_end < group_first_block))
+
+ if ((my_rsv->rsv_start > group_last_block) ||
+ (my_rsv->rsv_end < group_first_block)) {
+ rsv_window_dump(&EXT3_SB(sb)->s_rsv_window_root, 1);
BUG();
- ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, goal,
- &my_rsv->rsv_window);
+ }
+ ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh,
+ grp_goal, &num, &my_rsv->rsv_window);
if (ret >= 0) {
- my_rsv->rsv_alloc_hit++;
+ my_rsv->rsv_alloc_hit += num;
+ *count = num;
break; /* succeed */
}
+ num = *count;
}
out:
if (ret >= 0) {
return ret;
}
+/**
+ * ext3_has_free_blocks()
+ * @sbi: in-core super block structure.
+ *
+ * Check if filesystem has at least 1 free block available for allocation.
+ */
static int ext3_has_free_blocks(struct ext3_sb_info *sbi)
{
- int free_blocks, root_blocks;
+ ext3_fsblk_t free_blocks, root_blocks;
free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count);
return 1;
}
-/*
+/**
+ * ext3_should_retry_alloc()
+ * @sb: super block
+ * @retries number of attemps has been made
+ *
* ext3_should_retry_alloc() is called when ENOSPC is returned, and if
* it is profitable to retry the operation, this function will wait
* for the current or commiting transaction to complete, and then
* return TRUE.
+ *
+ * if the total number of retries exceed three times, return FALSE.
*/
int ext3_should_retry_alloc(struct super_block *sb, int *retries)
{
return journal_force_commit_nested(EXT3_SB(sb)->s_journal);
}
-/*
- * ext3_new_block uses a goal block to assist allocation. If the goal is
- * free, or there is a free block within 32 blocks of the goal, that block
- * is allocated. Otherwise a forward search is made for a free block; within
- * each block group the search first looks for an entire free byte in the block
- * bitmap, and then for any free bit if that fails.
- * This function also updates quota and i_blocks field.
+/**
+ * ext3_new_blocks() -- core block(s) allocation function
+ * @handle: handle to this transaction
+ * @inode: file inode
+ * @goal: given target block(filesystem wide)
+ * @count: target number of blocks to allocate
+ * @errp: error code
+ *
+ * ext3_new_blocks uses a goal block to assist allocation. It tries to
+ * allocate block(s) from the block group contains the goal block first. If that
+ * fails, it will try to allocate block(s) from other block groups without
+ * any specific goal block.
+ *
*/
-int ext3_new_block(handle_t *handle, struct inode *inode,
- unsigned long goal, int *errp)
+ext3_fsblk_t ext3_new_blocks(handle_t *handle, struct inode *inode,
+ ext3_fsblk_t goal, unsigned long *count, int *errp)
{
struct buffer_head *bitmap_bh = NULL;
struct buffer_head *gdp_bh;
int group_no;
int goal_group;
- int ret_block;
+ ext3_grpblk_t grp_target_blk; /* blockgroup relative goal block */
+ ext3_grpblk_t grp_alloc_blk; /* blockgroup-relative allocated block*/
+ ext3_fsblk_t ret_block; /* filesyetem-wide allocated block */
int bgi; /* blockgroup iteration index */
- int target_block;
int fatal = 0, err;
int performed_allocation = 0;
- int free_blocks;
+ ext3_grpblk_t free_blocks; /* number of free blocks in a group */
struct super_block *sb;
struct ext3_group_desc *gdp;
struct ext3_super_block *es;
static int goal_hits, goal_attempts;
#endif
unsigned long ngroups;
+ unsigned long num = *count;
*errp = -ENOSPC;
sb = inode->i_sb;
/*
* Check quota for allocation of this block.
*/
- if (DQUOT_ALLOC_BLOCK(inode, 1)) {
+ if (DQUOT_ALLOC_BLOCK(inode, num)) {
*errp = -EDQUOT;
return 0;
}
goal = le32_to_cpu(es->s_first_data_block);
group_no = (goal - le32_to_cpu(es->s_first_data_block)) /
EXT3_BLOCKS_PER_GROUP(sb);
+ goal_group = group_no;
+retry_alloc:
gdp = ext3_get_group_desc(sb, group_no, &gdp_bh);
if (!gdp)
goto io_error;
- goal_group = group_no;
-retry:
free_blocks = le16_to_cpu(gdp->bg_free_blocks_count);
/*
* if there is not enough free blocks to make a new resevation
my_rsv = NULL;
if (free_blocks > 0) {
- ret_block = ((goal - le32_to_cpu(es->s_first_data_block)) %
+ grp_target_blk = ((goal - le32_to_cpu(es->s_first_data_block)) %
EXT3_BLOCKS_PER_GROUP(sb));
bitmap_bh = read_block_bitmap(sb, group_no);
if (!bitmap_bh)
goto io_error;
- ret_block = ext3_try_to_allocate_with_rsv(sb, handle, group_no,
- bitmap_bh, ret_block, my_rsv, &fatal);
+ grp_alloc_blk = ext3_try_to_allocate_with_rsv(sb, handle,
+ group_no, bitmap_bh, grp_target_blk,
+ my_rsv, &num, &fatal);
if (fatal)
goto out;
- if (ret_block >= 0)
+ if (grp_alloc_blk >= 0)
goto allocated;
}
smp_rmb();
/*
- * Now search the rest of the groups. We assume that
- * i and gdp correctly point to the last group visited.
+ * Now search the rest of the groups. We assume that
+ * group_no and gdp correctly point to the last group visited.
*/
for (bgi = 0; bgi < ngroups; bgi++) {
group_no++;
if (group_no >= ngroups)
group_no = 0;
gdp = ext3_get_group_desc(sb, group_no, &gdp_bh);
- if (!gdp) {
- *errp = -EIO;
- goto out;
- }
+ if (!gdp)
+ goto io_error;
free_blocks = le16_to_cpu(gdp->bg_free_blocks_count);
/*
* skip this group if the number of
bitmap_bh = read_block_bitmap(sb, group_no);
if (!bitmap_bh)
goto io_error;
- ret_block = ext3_try_to_allocate_with_rsv(sb, handle, group_no,
- bitmap_bh, -1, my_rsv, &fatal);
+ /*
+ * try to allocate block(s) from this group, without a goal(-1).
+ */
+ grp_alloc_blk = ext3_try_to_allocate_with_rsv(sb, handle,
+ group_no, bitmap_bh, -1, my_rsv,
+ &num, &fatal);
if (fatal)
goto out;
- if (ret_block >= 0)
+ if (grp_alloc_blk >= 0)
goto allocated;
}
/*
*/
if (my_rsv) {
my_rsv = NULL;
+ windowsz = 0;
group_no = goal_group;
- goto retry;
+ goto retry_alloc;
}
/* No space left on the device */
*errp = -ENOSPC;
if (fatal)
goto out;
- target_block = ret_block + group_no * EXT3_BLOCKS_PER_GROUP(sb)
- + le32_to_cpu(es->s_first_data_block);
+ ret_block = grp_alloc_blk + ext3_group_first_block_no(sb, group_no);
- if (target_block == le32_to_cpu(gdp->bg_block_bitmap) ||
- target_block == le32_to_cpu(gdp->bg_inode_bitmap) ||
- in_range(target_block, le32_to_cpu(gdp->bg_inode_table),
- EXT3_SB(sb)->s_itb_per_group))
+ 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),
+ EXT3_SB(sb)->s_itb_per_group) ||
+ in_range(ret_block + num - 1, le32_to_cpu(gdp->bg_inode_table),
+ EXT3_SB(sb)->s_itb_per_group)) {
ext3_error(sb, "ext3_new_block",
"Allocating block in system zone - "
- "block = %u", target_block);
+ "blocks from "E3FSBLK", length %lu",
+ ret_block, num);
+ /*
+ * claim_block() marked the blocks we allocated as in use. So we
+ * may want to selectively mark some of the blocks as free.
+ */
+ goto retry_alloc;
+ }
performed_allocation = 1;
struct buffer_head *debug_bh;
/* Record bitmap buffer state in the newly allocated block */
- debug_bh = sb_find_get_block(sb, target_block);
+ debug_bh = sb_find_get_block(sb, ret_block);
if (debug_bh) {
BUFFER_TRACE(debug_bh, "state when allocated");
BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap state");
jbd_lock_bh_state(bitmap_bh);
spin_lock(sb_bgl_lock(sbi, group_no));
if (buffer_jbd(bitmap_bh) && bh2jh(bitmap_bh)->b_committed_data) {
- if (ext3_test_bit(ret_block,
- bh2jh(bitmap_bh)->b_committed_data)) {
- printk("%s: block was unexpectedly set in "
- "b_committed_data\n", __FUNCTION__);
+ int i;
+
+ for (i = 0; i < num; i++) {
+ if (ext3_test_bit(grp_alloc_blk+i,
+ bh2jh(bitmap_bh)->b_committed_data)) {
+ printk("%s: block was unexpectedly set in "
+ "b_committed_data\n", __func__);
+ }
}
}
- ext3_debug("found bit %d\n", ret_block);
+ ext3_debug("found bit %d\n", grp_alloc_blk);
spin_unlock(sb_bgl_lock(sbi, group_no));
jbd_unlock_bh_state(bitmap_bh);
#endif
- /* ret_block was blockgroup-relative. Now it becomes fs-relative */
- ret_block = target_block;
-
- if (ret_block >= le32_to_cpu(es->s_blocks_count)) {
+ if (ret_block + num - 1 >= le32_to_cpu(es->s_blocks_count)) {
ext3_error(sb, "ext3_new_block",
- "block(%d) >= blocks count(%d) - "
+ "block("E3FSBLK") >= blocks count(%d) - "
"block_group = %d, es == %p ", ret_block,
le32_to_cpu(es->s_blocks_count), group_no, es);
goto out;
* list of some description. We don't know in advance whether
* the caller wants to use it as metadata or data.
*/
- ext3_debug("allocating block %d. Goal hits %d of %d.\n",
+ ext3_debug("allocating block %lu. Goal hits %d of %d.\n",
ret_block, goal_hits, goal_attempts);
spin_lock(sb_bgl_lock(sbi, group_no));
- gdp->bg_free_blocks_count =
- cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) - 1);
+ le16_add_cpu(&gdp->bg_free_blocks_count, -num);
spin_unlock(sb_bgl_lock(sbi, group_no));
- percpu_counter_mod(&sbi->s_freeblocks_counter, -1);
+ percpu_counter_sub(&sbi->s_freeblocks_counter, num);
BUFFER_TRACE(gdp_bh, "journal_dirty_metadata for group descriptor");
err = ext3_journal_dirty_metadata(handle, gdp_bh);
*errp = 0;
brelse(bitmap_bh);
+ DQUOT_FREE_BLOCK(inode, *count-num);
+ *count = num;
return ret_block;
io_error:
* Undo the block allocation
*/
if (!performed_allocation)
- DQUOT_FREE_BLOCK(inode, 1);
+ DQUOT_FREE_BLOCK(inode, *count);
brelse(bitmap_bh);
return 0;
}
-unsigned long ext3_count_free_blocks(struct super_block *sb)
+ext3_fsblk_t ext3_new_block(handle_t *handle, struct inode *inode,
+ ext3_fsblk_t goal, int *errp)
+{
+ unsigned long count = 1;
+
+ return ext3_new_blocks(handle, inode, goal, &count, errp);
+}
+
+/**
+ * ext3_count_free_blocks() -- count filesystem free blocks
+ * @sb: superblock
+ *
+ * Adds up the number of free blocks from each block group.
+ */
+ext3_fsblk_t ext3_count_free_blocks(struct super_block *sb)
{
- unsigned long desc_count;
+ ext3_fsblk_t desc_count;
struct ext3_group_desc *gdp;
int i;
unsigned long ngroups = EXT3_SB(sb)->s_groups_count;
#ifdef EXT3FS_DEBUG
struct ext3_super_block *es;
- unsigned long bitmap_count, x;
+ ext3_fsblk_t bitmap_count;
+ unsigned long x;
struct buffer_head *bitmap_bh = NULL;
es = EXT3_SB(sb)->s_es;
bitmap_count += x;
}
brelse(bitmap_bh);
- printk("ext3_count_free_blocks: stored = %u, computed = %lu, %lu\n",
- le32_to_cpu(es->s_free_blocks_count), desc_count, bitmap_count);
+ printk("ext3_count_free_blocks: stored = "E3FSBLK
+ ", computed = "E3FSBLK", "E3FSBLK"\n",
+ le32_to_cpu(es->s_free_blocks_count),
+ desc_count, bitmap_count);
return bitmap_count;
#else
desc_count = 0;
#endif
}
-static inline int
-block_in_use(unsigned long block, struct super_block *sb, unsigned char *map)
-{
- return ext3_test_bit ((block -
- le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block)) %
- EXT3_BLOCKS_PER_GROUP(sb), map);
-}
-
static inline int test_root(int a, int b)
{
int num = b;
*/
int ext3_bg_has_super(struct super_block *sb, int group)
{
- if (EXT3_HAS_RO_COMPAT_FEATURE(sb,EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
- !ext3_group_sparse(group))
+ if (EXT3_HAS_RO_COMPAT_FEATURE(sb,
+ EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER) &&
+ !ext3_group_sparse(group))
return 0;
return 1;
}
+static unsigned long ext3_bg_num_gdb_meta(struct super_block *sb, int group)
+{
+ unsigned long metagroup = group / EXT3_DESC_PER_BLOCK(sb);
+ unsigned long first = metagroup * EXT3_DESC_PER_BLOCK(sb);
+ unsigned long last = first + EXT3_DESC_PER_BLOCK(sb) - 1;
+
+ if (group == first || group == first + 1 || group == last)
+ return 1;
+ return 0;
+}
+
+static unsigned long ext3_bg_num_gdb_nometa(struct super_block *sb, int group)
+{
+ return ext3_bg_has_super(sb, group) ? EXT3_SB(sb)->s_gdb_count : 0;
+}
+
/**
* ext3_bg_num_gdb - number of blocks used by the group table in group
* @sb: superblock for filesystem
*/
unsigned long ext3_bg_num_gdb(struct super_block *sb, int group)
{
- if (EXT3_HAS_RO_COMPAT_FEATURE(sb,EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
- !ext3_group_sparse(group))
- return 0;
- return EXT3_SB(sb)->s_gdb_count;
-}
+ unsigned long first_meta_bg =
+ le32_to_cpu(EXT3_SB(sb)->s_es->s_first_meta_bg);
+ unsigned long metagroup = group / EXT3_DESC_PER_BLOCK(sb);
+
+ if (!EXT3_HAS_INCOMPAT_FEATURE(sb,EXT3_FEATURE_INCOMPAT_META_BG) ||
+ metagroup < first_meta_bg)
+ return ext3_bg_num_gdb_nometa(sb,group);
+ return ext3_bg_num_gdb_meta(sb,group);
+
+}