diff options
Diffstat (limited to 'fs/ext4/inode.c')
| -rw-r--r-- | fs/ext4/inode.c | 45 |
1 files changed, 24 insertions, 21 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index a2712906514..ffc95ba4885 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1044,18 +1044,6 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used) spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); } -/* 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. - */ -#define DIO_CREDITS 25 - - /* * The ext4_get_blocks_wrap() function try to look up the requested blocks, * and returns if the blocks are already mapped. @@ -1167,19 +1155,23 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block, 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; @@ -2243,7 +2235,7 @@ static int ext4_da_writepage(struct page *page, * 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) @@ -4441,7 +4433,8 @@ int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk) /* * Calulate the total number of credits to reserve to fit - * the modification of a single pages into a single transaction + * the modification of a single pages into a single transaction, + * which may include multiple chunks of block allocations. * * This could be called via ext4_write_begin() or later * ext4_da_writepages() in delalyed allocation case. @@ -4449,11 +4442,6 @@ int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk) * 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. - * - * For Direct IO and fallocate, the journal credits reservation - * is based on one single extent allocation, so they could use - * EXT4_DATA_TRANS_BLOCKS to get the needed credit to log a single - * chunk of allocation needs. */ int ext4_writepage_trans_blocks(struct inode *inode) { @@ -4467,6 +4455,21 @@ int ext4_writepage_trans_blocks(struct inode *inode) 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. |