#include "acl.h"
#include "ext4_extents.h"
+#define MPAGE_DA_EXTENT_TAIL 0x01
+
static inline int ext4_begin_ordered_truncate(struct inode *inode,
loff_t new_size)
{
void ext4_delete_inode (struct inode * inode)
{
handle_t *handle;
+ int err;
if (ext4_should_order_data(inode))
ext4_begin_ordered_truncate(inode, 0);
if (is_bad_inode(inode))
goto no_delete;
- handle = start_transaction(inode);
+ handle = ext4_journal_start(inode, blocks_for_truncate(inode)+3);
if (IS_ERR(handle)) {
+ ext4_std_error(inode->i_sb, PTR_ERR(handle));
/*
* If we're going to skip the normal cleanup, we still need to
* make sure that the in-core orphan linked list is properly
if (IS_SYNC(inode))
handle->h_sync = 1;
inode->i_size = 0;
+ err = ext4_mark_inode_dirty(handle, inode);
+ if (err) {
+ ext4_warning(inode->i_sb, __func__,
+ "couldn't mark inode dirty (err %d)", err);
+ goto stop_handle;
+ }
if (inode->i_blocks)
ext4_truncate(inode);
+
+ /*
+ * ext4_ext_truncate() doesn't reserve any slop when it
+ * restarts journal transactions; therefore there may not be
+ * enough credits left in the handle to remove the inode from
+ * the orphan list and set the dtime field.
+ */
+ if (handle->h_buffer_credits < 3) {
+ err = ext4_journal_extend(handle, 3);
+ if (err > 0)
+ err = ext4_journal_restart(handle, 3);
+ if (err != 0) {
+ ext4_warning(inode->i_sb, __func__,
+ "couldn't extend journal (err %d)", err);
+ stop_handle:
+ ext4_journal_stop(handle);
+ goto no_delete;
+ }
+ }
+
/*
* Kill off the orphan record which ext4_truncate created.
* AKPM: I think this can be inside the above `if'.
return err;
}
-/* Maximum number of blocks we map for direct IO at once. */
-#define DIO_MAX_BLOCKS 4096
/*
- * Number of credits we need for writing DIO_MAX_BLOCKS:
- * We need sb + group descriptor + bitmap + inode -> 4
- * For B blocks with A block pointers per block we need:
- * 1 (triple ind.) + (B/A/A + 2) (doubly ind.) + (B/A + 2) (indirect).
- * If we plug in 4096 for B and 256 for A (for 1KB block size), we get 25.
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate @blocks for non extent file based file
*/
-#define DIO_CREDITS 25
+static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks)
+{
+ int icap = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+ int ind_blks, dind_blks, tind_blks;
+ /* number of new indirect blocks needed */
+ ind_blks = (blocks + icap - 1) / icap;
+
+ dind_blks = (ind_blks + icap - 1) / icap;
+
+ tind_blks = 1;
+
+ return ind_blks + dind_blks + tind_blks;
+}
/*
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate given number of blocks
+ */
+static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
+{
+ if (!blocks)
+ return 0;
+
+ if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
+ return ext4_ext_calc_metadata_amount(inode, blocks);
+
+ return ext4_indirect_calc_metadata_amount(inode, blocks);
+}
+
+static void ext4_da_update_reserve_space(struct inode *inode, int used)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ int total, mdb, mdb_free;
+
+ spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+ /* recalculate the number of metablocks still need to be reserved */
+ total = EXT4_I(inode)->i_reserved_data_blocks - used;
+ mdb = ext4_calc_metadata_amount(inode, total);
+
+ /* figure out how many metablocks to release */
+ BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
+ mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
+
+ /* Account for allocated meta_blocks */
+ mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
+
+ /* update fs free blocks counter for truncate case */
+ percpu_counter_add(&sbi->s_freeblocks_counter, mdb_free);
+
+ /* update per-inode reservations */
+ BUG_ON(used > EXT4_I(inode)->i_reserved_data_blocks);
+ EXT4_I(inode)->i_reserved_data_blocks -= used;
+
+ BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
+ EXT4_I(inode)->i_reserved_meta_blocks = mdb;
+ EXT4_I(inode)->i_allocated_meta_blocks = 0;
+ spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+}
+
+/*
+ * The ext4_get_blocks_wrap() function try to look up the requested blocks,
+ * and returns if the blocks are already mapped.
*
- *
- * ext4_ext4 get_block() wrapper function
- * It will do a look up first, and returns if the blocks already mapped.
* Otherwise it takes the write lock of the i_data_sem and allocate blocks
* and store the allocated blocks in the result buffer head and mark it
* mapped.
* which were deferred till now
*/
if ((retval > 0) && buffer_delay(bh))
- ext4_da_release_space(inode, retval, 0);
+ ext4_da_update_reserve_space(inode, retval);
}
up_write((&EXT4_I(inode)->i_data_sem));
return retval;
}
+/* Maximum number of blocks we map for direct IO at once. */
+#define DIO_MAX_BLOCKS 4096
+
static int ext4_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
handle_t *handle = ext4_journal_current_handle();
int ret = 0, started = 0;
unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
+ int dio_credits;
if (create && !handle) {
/* Direct IO write... */
if (max_blocks > DIO_MAX_BLOCKS)
max_blocks = DIO_MAX_BLOCKS;
- handle = ext4_journal_start(inode, DIO_CREDITS +
- 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb));
+ dio_credits = ext4_chunk_trans_blocks(inode, max_blocks);
+ handle = ext4_journal_start(inode, dio_credits);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
goto out;
{
handle_t *handle = ext4_journal_current_handle();
struct inode *inode = mapping->host;
- unsigned from, to;
int ret = 0, ret2;
- from = pos & (PAGE_CACHE_SIZE - 1);
- to = from + len;
-
ret = ext4_jbd2_file_inode(handle, inode);
if (ret == 0) {
return ret ? ret : copied;
}
-/*
- * Calculate the number of metadata blocks need to reserve
- * to allocate @blocks for non extent file based file
- */
-static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks)
-{
- int icap = EXT4_ADDR_PER_BLOCK(inode->i_sb);
- int ind_blks, dind_blks, tind_blks;
-
- /* number of new indirect blocks needed */
- ind_blks = (blocks + icap - 1) / icap;
-
- dind_blks = (ind_blks + icap - 1) / icap;
-
- tind_blks = 1;
-
- return ind_blks + dind_blks + tind_blks;
-}
-
-/*
- * Calculate the number of metadata blocks need to reserve
- * to allocate given number of blocks
- */
-static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
-{
- if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
- return ext4_ext_calc_metadata_amount(inode, blocks);
-
- return ext4_indirect_calc_metadata_amount(inode, blocks);
-}
static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
{
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
return -ENOSPC;
}
-
/* reduce fs free blocks counter */
percpu_counter_sub(&sbi->s_freeblocks_counter, total);
return 0; /* success */
}
-void ext4_da_release_space(struct inode *inode, int used, int to_free)
+static void ext4_da_release_space(struct inode *inode, int to_free)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
int total, mdb, mdb_free, release;
+ if (!to_free)
+ return; /* Nothing to release, exit */
+
spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+
+ if (!EXT4_I(inode)->i_reserved_data_blocks) {
+ /*
+ * if there is no reserved blocks, but we try to free some
+ * then the counter is messed up somewhere.
+ * but since this function is called from invalidate
+ * page, it's harmless to return without any action
+ */
+ printk(KERN_INFO "ext4 delalloc try to release %d reserved "
+ "blocks for inode %lu, but there is no reserved "
+ "data blocks\n", to_free, inode->i_ino);
+ spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+ return;
+ }
+
/* recalculate the number of metablocks still need to be reserved */
- total = EXT4_I(inode)->i_reserved_data_blocks - used - to_free;
+ total = EXT4_I(inode)->i_reserved_data_blocks - to_free;
mdb = ext4_calc_metadata_amount(inode, total);
/* figure out how many metablocks to release */
BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
- /* Account for allocated meta_blocks */
- mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
-
release = to_free + mdb_free;
/* update fs free blocks counter for truncate case */
percpu_counter_add(&sbi->s_freeblocks_counter, release);
/* update per-inode reservations */
- BUG_ON(used + to_free > EXT4_I(inode)->i_reserved_data_blocks);
- EXT4_I(inode)->i_reserved_data_blocks -= (used + to_free);
+ BUG_ON(to_free > EXT4_I(inode)->i_reserved_data_blocks);
+ EXT4_I(inode)->i_reserved_data_blocks -= to_free;
BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
EXT4_I(inode)->i_reserved_meta_blocks = mdb;
- EXT4_I(inode)->i_allocated_meta_blocks = 0;
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
}
}
curr_off = next_off;
} while ((bh = bh->b_this_page) != head);
- ext4_da_release_space(page->mapping->host, 0, to_release);
+ ext4_da_release_space(page->mapping->host, to_release);
}
/*
unsigned long first_page, next_page; /* extent of pages */
get_block_t *get_block;
struct writeback_control *wbc;
+ int io_done;
+ long pages_written;
};
/*
* mpage_da_submit_io - walks through extent of pages and try to write
- * them with __mpage_writepage()
+ * them with writepage() call back
*
* @mpd->inode: inode
* @mpd->first_page: first page of the extent
static int mpage_da_submit_io(struct mpage_da_data *mpd)
{
struct address_space *mapping = mpd->inode->i_mapping;
- struct mpage_data mpd_pp = {
- .bio = NULL,
- .last_block_in_bio = 0,
- .get_block = mpd->get_block,
- .use_writepage = 1,
- };
int ret = 0, err, nr_pages, i;
unsigned long index, end;
struct pagevec pvec;
BUG_ON(mpd->next_page <= mpd->first_page);
-
pagevec_init(&pvec, 0);
index = mpd->first_page;
end = mpd->next_page - 1;
break;
index++;
- err = __mpage_writepage(page, mpd->wbc, &mpd_pp);
-
+ err = mapping->a_ops->writepage(page, mpd->wbc);
+ if (!err)
+ mpd->pages_written++;
/*
* In error case, we have to continue because
* remaining pages are still locked
}
pagevec_release(&pvec);
}
- if (mpd_pp.bio)
- mpage_bio_submit(WRITE, mpd_pp.bio);
-
return ret;
}
int blocks = exbh->b_size >> inode->i_blkbits;
sector_t pblock = exbh->b_blocknr, cur_logical;
struct buffer_head *head, *bh;
- unsigned long index, end;
+ pgoff_t index, end;
struct pagevec pvec;
int nr_pages, i;
if (buffer_delay(bh)) {
bh->b_blocknr = pblock;
clear_buffer_delay(bh);
+ bh->b_bdev = inode->i_sb->s_bdev;
+ } else if (buffer_unwritten(bh)) {
+ bh->b_blocknr = pblock;
+ clear_buffer_unwritten(bh);
+ set_buffer_mapped(bh);
+ set_buffer_new(bh);
+ bh->b_bdev = inode->i_sb->s_bdev;
} else if (buffer_mapped(bh))
BUG_ON(bh->b_blocknr != pblock);
*
* The function skips space we know is already mapped to disk blocks.
*
- * The function ignores errors ->get_block() returns, thus real
- * error handling is postponed to __mpage_writepage()
*/
static void mpage_da_map_blocks(struct mpage_da_data *mpd)
{
+ int err = 0;
struct buffer_head *lbh = &mpd->lbh;
- int err = 0, remain = lbh->b_size;
sector_t next = lbh->b_blocknr;
struct buffer_head new;
if (buffer_mapped(lbh) && !buffer_delay(lbh))
return;
- while (remain) {
- new.b_state = lbh->b_state;
- new.b_blocknr = 0;
- new.b_size = remain;
- err = mpd->get_block(mpd->inode, next, &new, 1);
- if (err) {
- /*
- * Rather than implement own error handling
- * here, we just leave remaining blocks
- * unallocated and try again with ->writepage()
- */
- break;
- }
- BUG_ON(new.b_size == 0);
+ new.b_state = lbh->b_state;
+ new.b_blocknr = 0;
+ new.b_size = lbh->b_size;
- if (buffer_new(&new))
- __unmap_underlying_blocks(mpd->inode, &new);
+ /*
+ * If we didn't accumulate anything
+ * to write simply return
+ */
+ if (!new.b_size)
+ return;
+ err = mpd->get_block(mpd->inode, next, &new, 1);
+ if (err)
+ return;
+ BUG_ON(new.b_size == 0);
- /*
- * If blocks are delayed marked, we need to
- * put actual blocknr and drop delayed bit
- */
- if (buffer_delay(lbh))
- mpage_put_bnr_to_bhs(mpd, next, &new);
+ if (buffer_new(&new))
+ __unmap_underlying_blocks(mpd->inode, &new);
- /* go for the remaining blocks */
- next += new.b_size >> mpd->inode->i_blkbits;
- remain -= new.b_size;
- }
+ /*
+ * If blocks are delayed marked, we need to
+ * put actual blocknr and drop delayed bit
+ */
+ if (buffer_delay(lbh) || buffer_unwritten(lbh))
+ mpage_put_bnr_to_bhs(mpd, next, &new);
+
+ return;
}
-#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | (1 << BH_Delay))
+#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
+ (1 << BH_Delay) | (1 << BH_Unwritten))
/*
* mpage_add_bh_to_extent - try to add one more block to extent of blocks
* need to flush current extent and start new one
*/
mpage_da_map_blocks(mpd);
-
- /*
- * Now start a new extent
- */
- lbh->b_size = bh->b_size;
- lbh->b_state = bh->b_state & BH_FLAGS;
- lbh->b_blocknr = logical;
+ mpage_da_submit_io(mpd);
+ mpd->io_done = 1;
+ return;
}
/*
struct buffer_head *bh, *head, fake;
sector_t logical;
+ if (mpd->io_done) {
+ /*
+ * Rest of the page in the page_vec
+ * redirty then and skip then. We will
+ * try to to write them again after
+ * starting a new transaction
+ */
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ return MPAGE_DA_EXTENT_TAIL;
+ }
/*
* Can we merge this page to current extent?
*/
if (mpd->next_page != page->index) {
/*
* Nope, we can't. So, we map non-allocated blocks
- * and start IO on them using __mpage_writepage()
+ * and start IO on them using writepage()
*/
if (mpd->next_page != mpd->first_page) {
mpage_da_map_blocks(mpd);
mpage_da_submit_io(mpd);
+ /*
+ * skip rest of the page in the page_vec
+ */
+ mpd->io_done = 1;
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ return MPAGE_DA_EXTENT_TAIL;
}
/*
set_buffer_dirty(bh);
set_buffer_uptodate(bh);
mpage_add_bh_to_extent(mpd, logical, bh);
+ if (mpd->io_done)
+ return MPAGE_DA_EXTENT_TAIL;
} else {
/*
* Page with regular buffer heads, just add all dirty ones
bh = head;
do {
BUG_ON(buffer_locked(bh));
- if (buffer_dirty(bh))
+ if (buffer_dirty(bh) &&
+ (!buffer_mapped(bh) || buffer_delay(bh))) {
mpage_add_bh_to_extent(mpd, logical, bh);
+ if (mpd->io_done)
+ return MPAGE_DA_EXTENT_TAIL;
+ }
logical++;
} while ((bh = bh->b_this_page) != head);
}
*
* This is a library function, which implements the writepages()
* address_space_operation.
- *
- * In order to avoid duplication of logic that deals with partial pages,
- * multiple bio per page, etc, we find non-allocated blocks, allocate
- * them with minimal calls to ->get_block() and re-use __mpage_writepage()
- *
- * It's important that we call __mpage_writepage() only once for each
- * involved page, otherwise we'd have to implement more complicated logic
- * to deal with pages w/o PG_lock or w/ PG_writeback and so on.
- *
- * See comments to mpage_writepages()
*/
static int mpage_da_writepages(struct address_space *mapping,
struct writeback_control *wbc,
get_block_t get_block)
{
struct mpage_da_data mpd;
+ long to_write;
int ret;
if (!get_block)
mpd.first_page = 0;
mpd.next_page = 0;
mpd.get_block = get_block;
+ mpd.io_done = 0;
+ mpd.pages_written = 0;
+
+ to_write = wbc->nr_to_write;
ret = write_cache_pages(mapping, wbc, __mpage_da_writepage, &mpd);
/*
* Handle last extent of pages
*/
- if (mpd.next_page != mpd.first_page) {
+ if (!mpd.io_done && mpd.next_page != mpd.first_page) {
mpage_da_map_blocks(&mpd);
mpage_da_submit_io(&mpd);
}
+ wbc->nr_to_write = to_write - mpd.pages_written;
return ret;
}
* for DIO, writepages, and truncate
*/
#define EXT4_MAX_WRITEBACK_PAGES DIO_MAX_BLOCKS
-#define EXT4_MAX_WRITEBACK_CREDITS DIO_CREDITS
+#define EXT4_MAX_WRITEBACK_CREDITS 25
static int ext4_da_writepages(struct address_space *mapping,
- struct writeback_control *wbc)
+ struct writeback_control *wbc)
{
struct inode *inode = mapping->host;
handle_t *handle = NULL;
int ret = 0;
long to_write;
loff_t range_start = 0;
+ long pages_skipped = 0;
/*
* No pages to write? This is mainly a kludge to avoid starting
* a transaction for special inodes like journal inode on last iput()
* because that could violate lock ordering on umount
*/
- if (!mapping->nrpages)
+ if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
return 0;
- /*
- * Estimate the worse case needed credits to write out
- * EXT4_MAX_BUF_BLOCKS pages
- */
- needed_blocks = EXT4_MAX_WRITEBACK_CREDITS;
-
- to_write = wbc->nr_to_write;
- if (!wbc->range_cyclic) {
+ if (!wbc->range_cyclic)
/*
* If range_cyclic is not set force range_cont
* and save the old writeback_index
*/
wbc->range_cont = 1;
- range_start = wbc->range_start;
- }
- while (!ret && to_write) {
+ range_start = wbc->range_start;
+ pages_skipped = wbc->pages_skipped;
+
+restart_loop:
+ to_write = wbc->nr_to_write;
+ while (!ret && to_write > 0) {
+
+ /*
+ * we insert one extent at a time. So we need
+ * credit needed for single extent allocation.
+ * journalled mode is currently not supported
+ * by delalloc
+ */
+ BUG_ON(ext4_should_journal_data(inode));
+ needed_blocks = EXT4_DATA_TRANS_BLOCKS(inode->i_sb);
+
/* start a new transaction*/
handle = ext4_journal_start(inode, needed_blocks);
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
+ printk(KERN_EMERG "%s: jbd2_start: "
+ "%ld pages, ino %lu; err %d\n", __func__,
+ wbc->nr_to_write, inode->i_ino, ret);
+ dump_stack();
goto out_writepages;
}
if (ext4_should_order_data(inode)) {
/*
* With ordered mode we need to add
- * the inode to the journal handle
+ * the inode to the journal handl
* when we do block allocation.
*/
ret = ext4_jbd2_file_inode(handle, inode);
ext4_journal_stop(handle);
goto out_writepages;
}
-
}
- /*
- * set the max dirty pages could be write at a time
- * to fit into the reserved transaction credits
- */
- if (wbc->nr_to_write > EXT4_MAX_WRITEBACK_PAGES)
- wbc->nr_to_write = EXT4_MAX_WRITEBACK_PAGES;
to_write -= wbc->nr_to_write;
ret = mpage_da_writepages(mapping, wbc,
- ext4_da_get_block_write);
+ ext4_da_get_block_write);
ext4_journal_stop(handle);
- if (wbc->nr_to_write) {
+ if (ret == MPAGE_DA_EXTENT_TAIL) {
+ /*
+ * got one extent now try with
+ * rest of the pages
+ */
+ to_write += wbc->nr_to_write;
+ ret = 0;
+ } else if (wbc->nr_to_write) {
/*
* There is no more writeout needed
* or we requested for a noblocking writeout
wbc->nr_to_write = to_write;
}
+ if (wbc->range_cont && (pages_skipped != wbc->pages_skipped)) {
+ /* We skipped pages in this loop */
+ wbc->range_start = range_start;
+ wbc->nr_to_write = to_write +
+ wbc->pages_skipped - pages_skipped;
+ wbc->pages_skipped = pages_skipped;
+ goto restart_loop;
+ }
+
out_writepages:
wbc->nr_to_write = to_write;
- if (range_start)
- wbc->range_start = range_start;
+ wbc->range_start = range_start;
return ret;
}
}
page = __grab_cache_page(mapping, index);
- if (!page)
- return -ENOMEM;
+ if (!page) {
+ ext4_journal_stop(handle);
+ ret = -ENOMEM;
+ goto out;
+ }
*pagep = page;
ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
* modify the block allocation tree.
*/
down_write(&ei->i_data_sem);
+
+ ext4_discard_reservation(inode);
+
/*
* The orphan list entry will now protect us from any crash which
* occurs before the truncate completes, so it is now safe to propagate
;
}
- ext4_discard_reservation(inode);
-
up_write(&ei->i_data_sem);
inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
ext4_mark_inode_dirty(handle, inode);
}
if (!buffer_uptodate(bh)) {
lock_buffer(bh);
+
+ /*
+ * If the buffer has the write error flag, we have failed
+ * to write out another inode in the same block. In this
+ * case, we don't have to read the block because we may
+ * read the old inode data successfully.
+ */
+ if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
+ set_buffer_uptodate(bh);
+
if (buffer_uptodate(bh)) {
/* someone brought it uptodate while we waited */
unlock_buffer(bh);
return 0;
}
+static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks,
+ int chunk)
+{
+ int indirects;
+
+ /* if nrblocks are contiguous */
+ if (chunk) {
+ /*
+ * With N contiguous data blocks, it need at most
+ * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
+ * 2 dindirect blocks
+ * 1 tindirect block
+ */
+ indirects = nrblocks / EXT4_ADDR_PER_BLOCK(inode->i_sb);
+ return indirects + 3;
+ }
+ /*
+ * if nrblocks are not contiguous, worse case, each block touch
+ * a indirect block, and each indirect block touch a double indirect
+ * block, plus a triple indirect block
+ */
+ indirects = nrblocks * 2 + 1;
+ return indirects;
+}
+
+static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+{
+ if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
+ return ext4_indirect_trans_blocks(inode, nrblocks, 0);
+ return ext4_ext_index_trans_blocks(inode, nrblocks, 0);
+}
/*
- * How many blocks doth make a writepage()?
- *
- * With N blocks per page, it may be:
- * N data blocks
- * 2 indirect block
- * 2 dindirect
- * 1 tindirect
- * N+5 bitmap blocks (from the above)
- * N+5 group descriptor summary blocks
- * 1 inode block
- * 1 superblock.
- * 2 * EXT4_SINGLEDATA_TRANS_BLOCKS for the quote files
+ * Account for index blocks, block groups bitmaps and block group
+ * descriptor blocks if modify datablocks and index blocks
+ * worse case, the indexs blocks spread over different block groups
*
- * 3 * (N + 5) + 2 + 2 * EXT4_SINGLEDATA_TRANS_BLOCKS
+ * If datablocks are discontiguous, they are possible to spread over
+ * different block groups too. If they are contiugous, with flexbg,
+ * they could still across block group boundary.
*
- * With ordered or writeback data it's the same, less the N data blocks.
+ * Also account for superblock, inode, quota and xattr blocks
+ */
+int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+{
+ int groups, gdpblocks;
+ int idxblocks;
+ int ret = 0;
+
+ /*
+ * How many index blocks need to touch to modify nrblocks?
+ * The "Chunk" flag indicating whether the nrblocks is
+ * physically contiguous on disk
+ *
+ * For Direct IO and fallocate, they calls get_block to allocate
+ * one single extent at a time, so they could set the "Chunk" flag
+ */
+ idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
+
+ ret = idxblocks;
+
+ /*
+ * Now let's see how many group bitmaps and group descriptors need
+ * to account
+ */
+ groups = idxblocks;
+ if (chunk)
+ groups += 1;
+ else
+ groups += nrblocks;
+
+ gdpblocks = groups;
+ if (groups > EXT4_SB(inode->i_sb)->s_groups_count)
+ groups = EXT4_SB(inode->i_sb)->s_groups_count;
+ if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
+ gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
+
+ /* bitmaps and block group descriptor blocks */
+ ret += groups + gdpblocks;
+
+ /* Blocks for super block, inode, quota and xattr blocks */
+ ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
+
+ return ret;
+}
+
+/*
+ * Calulate the total number of credits to reserve to fit
+ * the modification of a single pages into a single transaction,
+ * which may include multiple chunks of block allocations.
*
- * If the inode's direct blocks can hold an integral number of pages then a
- * page cannot straddle two indirect blocks, and we can only touch one indirect
- * and dindirect block, and the "5" above becomes "3".
+ * This could be called via ext4_write_begin() or later
+ * ext4_da_writepages() in delalyed allocation case.
*
- * This still overestimates under most circumstances. If we were to pass the
- * start and end offsets in here as well we could do block_to_path() on each
- * block and work out the exact number of indirects which are touched. Pah.
+ * In both case it's possible that we could allocating multiple
+ * chunks of blocks. We need to consider the worse case, when
+ * one new block per extent.
*/
-
int ext4_writepage_trans_blocks(struct inode *inode)
{
int bpp = ext4_journal_blocks_per_page(inode);
- int indirects = (EXT4_NDIR_BLOCKS % bpp) ? 5 : 3;
int ret;
- if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
- return ext4_ext_writepage_trans_blocks(inode, bpp);
+ ret = ext4_meta_trans_blocks(inode, bpp, 0);
+ /* Account for data blocks for journalled mode */
if (ext4_should_journal_data(inode))
- ret = 3 * (bpp + indirects) + 2;
- else
- ret = 2 * (bpp + indirects) + 2;
-
-#ifdef CONFIG_QUOTA
- /* We know that structure was already allocated during DQUOT_INIT so
- * we will be updating only the data blocks + inodes */
- ret += 2*EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
-#endif
-
+ ret += bpp;
return ret;
}
+/*
+ * Calculate the journal credits for a chunk of data modification.
+ *
+ * This is called from DIO, fallocate or whoever calling
+ * ext4_get_blocks_wrap() to map/allocate a chunk of contigous disk blocks.
+ *
+ * journal buffers for data blocks are not included here, as DIO
+ * and fallocate do no need to journal data buffers.
+ */
+int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
+{
+ return ext4_meta_trans_blocks(inode, nrblocks, 1);
+}
+
/*
* The caller must have previously called ext4_reserve_inode_write().
* Give this, we know that the caller already has write access to iloc->bh.
projects / linux-2.6-omap-h63xx.git / blobdiff