From: Aneesh Kumar K.V Date: Thu, 17 Jul 2008 20:12:08 +0000 (-0400) Subject: ext4: Cleanup the block reservation code path X-Git-Tag: v2.6.27-rc2~71^2~4 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=12219aea6b944e36795267be31d43f9c484841be;p=linux-2.6-omap-h63xx.git ext4: Cleanup the block reservation code path The truncate patch should not use the i_allocated_meta_blocks value. So add seperate functions to be used in the truncate and alloc path. We also need to release the meta-data block that we reserved for the blocks that we are truncating. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Theodore Ts'o --- diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 303e41cf7b1..6c7924d9e35 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1044,7 +1044,6 @@ extern void ext4_mb_update_group_info(struct ext4_group_info *grp, /* inode.c */ -void ext4_da_release_space(struct inode *inode, int used, int to_free); int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode, struct buffer_head *bh, ext4_fsblk_t blocknr); struct buffer_head *ext4_getblk(handle_t *, struct inode *, diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 2697eaf0368..85a862c9c4c 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -980,6 +980,67 @@ out: return err; } +/* + * 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 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); +} + /* Maximum number of blocks we map for direct IO at once. */ #define DIO_MAX_BLOCKS 4096 /* @@ -1097,7 +1158,7 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block, * 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)); @@ -1465,36 +1526,6 @@ static int ext4_journalled_write_end(struct file *file, 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) { @@ -1518,7 +1549,6 @@ 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); @@ -1529,35 +1559,31 @@ static int ext4_da_reserve_space(struct inode *inode, int nrblocks) 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; 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 - 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); } @@ -1579,7 +1605,7 @@ static void ext4_da_page_release_reservation(struct page *page, } 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); } /*