diff options
| -rw-r--r-- | fs/ext4/extents.c | 226 | ||||
| -rw-r--r-- | include/linux/ext4_fs_extents.h | 54 | ||||
| -rw-r--r-- | include/linux/ext4_jbd2.h | 4 | 
3 files changed, 157 insertions, 127 deletions
| diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 32526061a17d..e06e937a52b8 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -44,7 +44,10 @@  #include <asm/uaccess.h> -/* this macro combines low and hi parts of phys. blocknr into ext4_fsblk_t */ +/* + * ext_pblock: + * combine low and high parts of physical block number into ext4_fsblk_t + */  static inline ext4_fsblk_t ext_pblock(struct ext4_extent *ex)  {  	ext4_fsblk_t block; @@ -55,7 +58,10 @@ static inline ext4_fsblk_t ext_pblock(struct ext4_extent *ex)  	return block;  } -/* this macro combines low and hi parts of phys. blocknr into ext4_fsblk_t */ +/* + * idx_pblock: + * combine low and high parts of a leaf physical block number into ext4_fsblk_t + */  static inline ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix)  {  	ext4_fsblk_t block; @@ -66,7 +72,11 @@ static inline ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix)  	return block;  } -/* the routine stores large phys. blocknr into extent breaking it into parts */ +/* + * ext4_ext_store_pblock: + * stores a large physical block number into an extent struct, + * breaking it into parts + */  static inline void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb)  {  	ex->ee_start = cpu_to_le32((unsigned long) (pb & 0xffffffff)); @@ -74,7 +84,11 @@ static inline void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb  		ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);  } -/* the routine stores large phys. blocknr into index breaking it into parts */ +/* + * ext4_idx_store_pblock: + * stores a large physical block number into an index struct, + * breaking it into parts + */  static inline void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb)  {  	ix->ei_leaf = cpu_to_le32((unsigned long) (pb & 0xffffffff)); @@ -179,8 +193,8 @@ static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,  		if ((ex = path[depth].p_ext))  			return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block)); -		/* it looks index is empty -		 * try to find starting from index itself */ +		/* it looks like index is empty; +		 * try to find starting block from index itself */  		if (path[depth].p_bh)  			return path[depth].p_bh->b_blocknr;  	} @@ -317,7 +331,8 @@ static void ext4_ext_drop_refs(struct ext4_ext_path *path)  }  /* - * binary search for closest index by given block + * ext4_ext_binsearch_idx: + * binary search for the closest index of the given block   */  static void  ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int block) @@ -375,7 +390,8 @@ ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int bloc  }  /* - * binary search for closest extent by given block + * ext4_ext_binsearch: + * binary search for closest extent of the given block   */  static void  ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block) @@ -388,8 +404,8 @@ ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)  	if (eh->eh_entries == 0) {  		/* -		 * this leaf is empty yet: -		 *  we get such a leaf in split/add case +		 * this leaf is empty: +		 * we get such a leaf in split/add case  		 */  		return;  	} @@ -520,8 +536,9 @@ err:  }  /* - * insert new index [logical;ptr] into the block at cupr - * it check where to insert: before curp or after curp + * ext4_ext_insert_index: + * insert new index [@logical;@ptr] into the block at @curp; + * check where to insert: before @curp or after @curp   */  static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,  				struct ext4_ext_path *curp, @@ -574,13 +591,14 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,  }  /* - * routine inserts new subtree into the path, using free index entry - * at depth 'at: - *  - allocates all needed blocks (new leaf and all intermediate index blocks) - *  - makes decision where to split - *  - moves remaining extens and index entries (right to the split point) - *    into the newly allocated blocks - *  - initialize subtree + * ext4_ext_split: + * inserts new subtree into the path, using free index entry + * at depth @at: + * - allocates all needed blocks (new leaf and all intermediate index blocks) + * - makes decision where to split + * - moves remaining extents and index entries (right to the split point) + *   into the newly allocated blocks + * - initializes subtree   */  static int ext4_ext_split(handle_t *handle, struct inode *inode,  				struct ext4_ext_path *path, @@ -598,14 +616,14 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,  	int err = 0;  	/* make decision: where to split? */ -	/* FIXME: now desicion is simplest: at current extent */ +	/* FIXME: now decision is simplest: at current extent */ -	/* if current leaf will be splitted, then we should use +	/* if current leaf will be split, then we should use  	 * border from split point */  	BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr));  	if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {  		border = path[depth].p_ext[1].ee_block; -		ext_debug("leaf will be splitted." +		ext_debug("leaf will be split."  				" next leaf starts at %d\n",  			          le32_to_cpu(border));  	} else { @@ -616,16 +634,16 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,  	}  	/* -	 * if error occurs, then we break processing -	 * and turn filesystem read-only. so, index won't +	 * If error occurs, then we break processing +	 * and mark filesystem read-only. index won't  	 * be inserted and tree will be in consistent -	 * state. next mount will repair buffers too +	 * state. Next mount will repair buffers too.  	 */  	/* -	 * get array to track all allocated blocks -	 * we need this to handle errors and free blocks -	 * upon them +	 * Get array to track all allocated blocks. +	 * We need this to handle errors and free blocks +	 * upon them.  	 */  	ablocks = kmalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);  	if (!ablocks) @@ -661,7 +679,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,  	neh->eh_depth = 0;  	ex = EXT_FIRST_EXTENT(neh); -	/* move remain of path[depth] to the new leaf */ +	/* move remainder of path[depth] to the new leaf */  	BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max);  	/* start copy from next extent */  	/* TODO: we could do it by single memmove */ @@ -813,11 +831,12 @@ cleanup:  }  /* - * routine implements tree growing procedure: - *  - allocates new block - *  - moves top-level data (index block or leaf) into the new block - *  - initialize new top-level, creating index that points to the - *    just created block + * ext4_ext_grow_indepth: + * implements tree growing procedure: + * - allocates new block + * - moves top-level data (index block or leaf) into the new block + * - initializes new top-level, creating index that points to the + *   just created block   */  static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,  					struct ext4_ext_path *path, @@ -892,8 +911,9 @@ out:  }  /* - * routine finds empty index and adds new leaf. if no free index found - * then it requests in-depth growing + * ext4_ext_create_new_leaf: + * finds empty index and adds new leaf. + * if no free index is found, then it requests in-depth growing.   */  static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,  					struct ext4_ext_path *path, @@ -912,8 +932,8 @@ repeat:  		curp--;  	} -	/* we use already allocated block for index block -	 * so, subsequent data blocks should be contigoues */ +	/* we use already allocated block for index block, +	 * so subsequent data blocks should be contiguous */  	if (EXT_HAS_FREE_INDEX(curp)) {  		/* if we found index with free entry, then use that  		 * entry: create all needed subtree and add new leaf */ @@ -943,12 +963,12 @@ repeat:  		}  		/* -		 * only first (depth 0 -> 1) produces free space -		 * in all other cases we have to split growed tree +		 * only first (depth 0 -> 1) produces free space; +		 * in all other cases we have to split the grown tree  		 */  		depth = ext_depth(inode);  		if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { -			/* now we need split */ +			/* now we need to split */  			goto repeat;  		}  	} @@ -958,10 +978,11 @@ out:  }  /* - * returns allocated block in subsequent extent or EXT_MAX_BLOCK - * NOTE: it consider block number from index entry as - * allocated block. thus, index entries have to be consistent - * with leafs + * ext4_ext_next_allocated_block: + * returns allocated block in subsequent extent or EXT_MAX_BLOCK. + * NOTE: it considers block number from index entry as + * allocated block. Thus, index entries have to be consistent + * with leaves.   */  static unsigned long  ext4_ext_next_allocated_block(struct ext4_ext_path *path) @@ -993,6 +1014,7 @@ ext4_ext_next_allocated_block(struct ext4_ext_path *path)  }  /* + * ext4_ext_next_leaf_block:   * returns first allocated block from next leaf or EXT_MAX_BLOCK   */  static unsigned ext4_ext_next_leaf_block(struct inode *inode, @@ -1021,8 +1043,9 @@ static unsigned ext4_ext_next_leaf_block(struct inode *inode,  }  /* - * if leaf gets modified and modified extent is first in the leaf - * then we have to correct all indexes above + * ext4_ext_correct_indexes: + * if leaf gets modified and modified extent is first in the leaf, + * then we have to correct all indexes above.   * TODO: do we need to correct tree in all cases?   */  int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, @@ -1050,7 +1073,7 @@ int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,  	}  	/* -	 * TODO: we need correction if border is smaller then current one +	 * TODO: we need correction if border is smaller than current one  	 */  	k = depth - 1;  	border = path[depth].p_ext->ee_block; @@ -1085,7 +1108,7 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,  	/*  	 * To allow future support for preallocated extents to be added  	 * as an RO_COMPAT feature, refuse to merge to extents if -	 * can result in the top bit of ee_len being set +	 * this can result in the top bit of ee_len being set.  	 */  	if (le16_to_cpu(ex1->ee_len) + le16_to_cpu(ex2->ee_len) > EXT_MAX_LEN)  		return 0; @@ -1100,9 +1123,10 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,  }  /* - * this routine tries to merge requsted extent into the existing - * extent or inserts requested extent as new one into the tree, - * creating new leaf in no-space case + * ext4_ext_insert_extent: + * tries to merge requsted extent into the existing extent or + * inserts requested extent as new one into the tree, + * creating new leaf in the no-space case.   */  int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,  				struct ext4_ext_path *path, @@ -1163,8 +1187,8 @@ repeat:  	}  	/* -	 * there is no free space in found leaf -	 * we're gonna add new leaf in the tree +	 * There is no free space in the found leaf. +	 * We're gonna add a new leaf in the tree.  	 */  	err = ext4_ext_create_new_leaf(handle, inode, path, newext);  	if (err) @@ -1377,7 +1401,8 @@ ext4_ext_put_in_cache(struct inode *inode, __u32 block,  }  /* - * this routine calculate boundaries of the gap requested block fits into + * ext4_ext_put_gap_in_cache: + * calculate boundaries of the gap that the requested block fits into   * and cache this gap   */  static inline void @@ -1452,9 +1477,10 @@ ext4_ext_in_cache(struct inode *inode, unsigned long block,  }  /* - * routine removes index from the index block - * it's used in truncate case only. thus all requests are for - * last index in the block only + * ext4_ext_rm_idx: + * removes index from the index block. + * It's used in truncate case only, thus all requests are for + * last index in the block only.   */  int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,  			struct ext4_ext_path *path) @@ -1480,11 +1506,12 @@ int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,  }  /* - * This routine returns max. credits extent tree can consume. + * ext4_ext_calc_credits_for_insert: + * This routine returns max. credits that the extent tree can consume.   * It should be OK for low-performance paths like ->writepage() - * To allow many writing process to fit a single transaction, - * caller should calculate credits under truncate_mutex and - * pass actual path. + * To allow many writing processes to fit into a single transaction, + * the caller should calculate credits under truncate_mutex and + * pass the actual path.   */  int inline ext4_ext_calc_credits_for_insert(struct inode *inode,  						struct ext4_ext_path *path) @@ -1500,9 +1527,9 @@ int inline ext4_ext_calc_credits_for_insert(struct inode *inode,  	}  	/* -	 * given 32bit logical block (4294967296 blocks), max. tree +	 * given 32-bit logical block (4294967296 blocks), max. tree  	 * can be 4 levels in depth -- 4 * 340^4 == 53453440000. -	 * let's also add one more level for imbalance. +	 * Let's also add one more level for imbalance.  	 */  	depth = 5; @@ -1510,13 +1537,13 @@ int inline ext4_ext_calc_credits_for_insert(struct inode *inode,  	needed = 2;  	/* -	 * tree can be full, so it'd need to grow in depth: +	 * tree can be full, so it would need to grow in depth:  	 * allocation + old root + new root  	 */  	needed += 2 + 1 + 1;  	/* -	 * Index split can happen, we'd need: +	 * Index split can happen, we would need:  	 *    allocate intermediate indexes (bitmap + group)  	 *  + change two blocks at each level, but root (already included)  	 */ @@ -1634,7 +1661,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,  			BUG_ON(b != ex_ee_block + ex_ee_len - 1);  		} -		/* at present, extent can't cross block group */ +		/* at present, extent can't cross block group: */  		/* leaf + bitmap + group desc + sb + inode */  		credits = 5;  		if (ex == EXT_FIRST_EXTENT(eh)) { @@ -1660,7 +1687,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,  			goto out;  		if (num == 0) { -			/* this extent is removed entirely mark slot unused */ +			/* this extent is removed; mark slot entirely unused */  			ext4_ext_store_pblock(ex, 0);  			eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1);  		} @@ -1692,7 +1719,8 @@ out:  }  /* - * returns 1 if current index have to be freed (even partial) + * ext4_ext_more_to_rm: + * returns 1 if current index has to be freed (even partial)   */  static int inline  ext4_ext_more_to_rm(struct ext4_ext_path *path) @@ -1703,7 +1731,7 @@ ext4_ext_more_to_rm(struct ext4_ext_path *path)  		return 0;  	/* -	 * if truncate on deeper level happened it it wasn't partial +	 * if truncate on deeper level happened, it wasn't partial,  	 * so we have to consider current index for truncation  	 */  	if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) @@ -1729,8 +1757,8 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)  	ext4_ext_invalidate_cache(inode);  	/* -	 * we start scanning from right side freeing all the blocks -	 * after i_size and walking into the deep +	 * We start scanning from right side, freeing all the blocks +	 * after i_size and walking into the tree depth-wise.  	 */  	path = kmalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL);  	if (path == NULL) { @@ -1749,7 +1777,7 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)  		if (i == depth) {  			/* this is leaf block */  			err = ext4_ext_rm_leaf(handle, inode, path, start); -			/* root level have p_bh == NULL, brelse() eats this */ +			/* root level has p_bh == NULL, brelse() eats this */  			brelse(path[i].p_bh);  			path[i].p_bh = NULL;  			i--; @@ -1772,14 +1800,14 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)  		BUG_ON(path[i].p_hdr->eh_magic != EXT4_EXT_MAGIC);  		if (!path[i].p_idx) { -			/* this level hasn't touched yet */ +			/* this level hasn't been touched yet */  			path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);  			path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;  			ext_debug("init index ptr: hdr 0x%p, num %d\n",  				  path[i].p_hdr,  				  le16_to_cpu(path[i].p_hdr->eh_entries));  		} else { -			/* we've already was here, see at next index */ +			/* we were already here, see at next index */  			path[i].p_idx--;  		} @@ -1799,19 +1827,19 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)  				break;  			} -			/* put actual number of indexes to know is this -			 * number got changed at the next iteration */ +			/* save actual number of indexes since this +			 * number is changed at the next iteration */  			path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);  			i++;  		} else { -			/* we finish processing this index, go up */ +			/* we finished processing this index, go up */  			if (path[i].p_hdr->eh_entries == 0 && i > 0) { -				/* index is empty, remove it +				/* index is empty, remove it;  				 * handle must be already prepared by the  				 * truncatei_leaf() */  				err = ext4_ext_rm_idx(handle, inode, path + i);  			} -			/* root level have p_bh == NULL, brelse() eats this */ +			/* root level has p_bh == NULL, brelse() eats this */  			brelse(path[i].p_bh);  			path[i].p_bh = NULL;  			i--; @@ -1822,8 +1850,8 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)  	/* TODO: flexible tree reduction should be here */  	if (path->p_hdr->eh_entries == 0) {  		/* -		 * truncate to zero freed all the tree -		 * so, we need to correct eh_depth +		 * truncate to zero freed all the tree, +		 * so we need to correct eh_depth  		 */  		err = ext4_ext_get_access(handle, inode, path);  		if (err == 0) { @@ -1912,7 +1940,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,  		if (goal == EXT4_EXT_CACHE_GAP) {  			if (!create) {  				/* block isn't allocated yet and -				 * user don't want to allocate it */ +				 * user doesn't want to allocate it */  				goto out2;  			}  			/* we should allocate requested block */ @@ -1921,7 +1949,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,  		        newblock = iblock  		                   - le32_to_cpu(newex.ee_block)  			           + ext_pblock(&newex); -			/* number of remain blocks in the extent */ +			/* number of remaining blocks in the extent */  			allocated = le16_to_cpu(newex.ee_len) -  					(iblock - le32_to_cpu(newex.ee_block));  			goto out; @@ -1941,8 +1969,8 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,  	depth = ext_depth(inode);  	/* -	 * consistent leaf must not be empty -	 * this situations is possible, though, _during_ tree modification +	 * consistent leaf must not be empty; +	 * this situation is possible, though, _during_ tree modification;  	 * this is why assert can't be put in ext4_ext_find_extent()  	 */  	BUG_ON(path[depth].p_ext == NULL && depth != 0); @@ -1960,10 +1988,10 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,  		 */  		if (ee_len > EXT_MAX_LEN)  			goto out2; -		/* if found exent covers block, simple return it */ +		/* if found extent covers block, simply return it */  	        if (iblock >= ee_block && iblock < ee_block + ee_len) {  			newblock = iblock - ee_block + ee_start; -			/* number of remain blocks in the extent */ +			/* number of remaining blocks in the extent */  			allocated = ee_len - (iblock - ee_block);  			ext_debug("%d fit into %lu:%d -> "E3FSBLK"\n", (int) iblock,  					ee_block, ee_len, newblock); @@ -1974,17 +2002,18 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,  	}  	/* -	 * requested block isn't allocated yet +	 * requested block isn't allocated yet;  	 * we couldn't try to create block if create flag is zero  	 */  	if (!create) { -		/* put just found gap into cache to speedup subsequest reqs */ +		/* put just found gap into cache to speed up +		 * subsequent requests */  		ext4_ext_put_gap_in_cache(inode, path, iblock);  		goto out2;  	}  	/*           * Okay, we need to do block allocation.  Lazily initialize the block -         * allocation info here if necessary +         * allocation info here if necessary.          */  	if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info))  		ext4_init_block_alloc_info(inode); @@ -2062,9 +2091,9 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)  	ext4_ext_invalidate_cache(inode);  	/* -	 * TODO: optimization is possible here -	 * probably we need not scaning at all, -	 * because page truncation is enough +	 * TODO: optimization is possible here. +	 * Probably we need not scan at all, +	 * because page truncation is enough.  	 */  	if (ext4_orphan_add(handle, inode))  		goto out_stop; @@ -2078,13 +2107,13 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)  	err = ext4_ext_remove_space(inode, last_block);  	/* In a multi-transaction truncate, we only make the final -	 * transaction synchronous */ +	 * transaction synchronous. */  	if (IS_SYNC(inode))  		handle->h_sync = 1;  out_stop:  	/* -	 * If this was a simple ftruncate(), and the file will remain alive +	 * If this was a simple ftruncate() and the file will remain alive,  	 * then we need to clear up the orphan record which we created above.  	 * However, if this was a real unlink then we were called by  	 * ext4_delete_inode(), and we allow that function to clean up the @@ -2098,7 +2127,8 @@ out_stop:  }  /* - * this routine calculate max number of blocks we could modify + * ext4_ext_writepage_trans_blocks: + * calculate max number of blocks we could modify   * in order to allocate new block for an inode   */  int ext4_ext_writepage_trans_blocks(struct inode *inode, int num) @@ -2107,7 +2137,7 @@ int ext4_ext_writepage_trans_blocks(struct inode *inode, int num)  	needed = ext4_ext_calc_credits_for_insert(inode, NULL); -	/* caller want to allocate num blocks, but note it includes sb */ +	/* caller wants to allocate num blocks, but note it includes sb */  	needed = needed * num - (num - 1);  #ifdef CONFIG_QUOTA diff --git a/include/linux/ext4_fs_extents.h b/include/linux/ext4_fs_extents.h index 0eba0acf6ba6..a41cc24568ca 100644 --- a/include/linux/ext4_fs_extents.h +++ b/include/linux/ext4_fs_extents.h @@ -22,29 +22,29 @@  #include <linux/ext4_fs.h>  /* - * with AGRESSIVE_TEST defined capacity of index/leaf blocks - * become very little, so index split, in-depth growing and - * other hard changes happens much more often - * this is for debug purposes only + * With AGRESSIVE_TEST defined, the capacity of index/leaf blocks + * becomes very small, so index split, in-depth growing and + * other hard changes happen much more often. + * This is for debug purposes only.   */  #define AGRESSIVE_TEST_  /* - * with EXTENTS_STATS defined number of blocks and extents - * are collected in truncate path. they'll be showed at - * umount time + * With EXTENTS_STATS defined, the number of blocks and extents + * are collected in the truncate path. They'll be shown at + * umount time.   */  #define EXTENTS_STATS__  /* - * if CHECK_BINSEARCH defined, then results of binary search - * will be checked by linear search + * If CHECK_BINSEARCH is defined, then the results of the binary search + * will also be checked by linear search.   */  #define CHECK_BINSEARCH__  /* - * if EXT_DEBUG is defined you can use 'extdebug' mount option - * to get lots of info what's going on + * If EXT_DEBUG is defined you can use the 'extdebug' mount option + * to get lots of info about what's going on.   */  #define EXT_DEBUG__  #ifdef EXT_DEBUG @@ -54,58 +54,58 @@  #endif  /* - * if EXT_STATS is defined then stats numbers are collected - * these number will be displayed at umount time + * If EXT_STATS is defined then stats numbers are collected. + * These number will be displayed at umount time.   */  #define EXT_STATS_  /* - * ext4_inode has i_block array (60 bytes total) - * first 12 bytes store ext4_extent_header - * the remain stores array of ext4_extent + * ext4_inode has i_block array (60 bytes total). + * The first 12 bytes store ext4_extent_header; + * the remainder stores an array of ext4_extent.   */  /* - * this is extent on-disk structure - * it's used at the bottom of the tree + * This is the extent on-disk structure. + * It's used at the bottom of the tree.   */  struct ext4_extent {  	__le32	ee_block;	/* first logical block extent covers */  	__le16	ee_len;		/* number of blocks covered by extent */  	__le16	ee_start_hi;	/* high 16 bits of physical block */ -	__le32	ee_start;	/* low 32 bigs of physical block */ +	__le32	ee_start;	/* low 32 bits of physical block */  };  /* - * this is index on-disk structure - * it's used at all the levels, but the bottom + * This is index on-disk structure. + * It's used at all the levels except the bottom.   */  struct ext4_extent_idx {  	__le32	ei_block;	/* index covers logical blocks from 'block' */  	__le32	ei_leaf;	/* pointer to the physical block of the next * -				 * level. leaf or next index could bet here */ +				 * level. leaf or next index could be there */  	__le16	ei_leaf_hi;	/* high 16 bits of physical block */  	__u16	ei_unused;  };  /* - * each block (leaves and indexes), even inode-stored has header + * Each block (leaves and indexes), even inode-stored has header.   */  struct ext4_extent_header {  	__le16	eh_magic;	/* probably will support different formats */  	__le16	eh_entries;	/* number of valid entries */  	__le16	eh_max;		/* capacity of store in entries */ -	__le16	eh_depth;	/* has tree real underlaying blocks? */ +	__le16	eh_depth;	/* has tree real underlying blocks? */  	__le32	eh_generation;	/* generation of the tree */  };  #define EXT4_EXT_MAGIC		cpu_to_le16(0xf30a)  /* - * array of ext4_ext_path contains path to some extent - * creation/lookup routines use it for traversal/splitting/etc - * truncate uses it to simulate recursive walking + * Array of ext4_ext_path contains path to some extent. + * Creation/lookup routines use it for traversal/splitting/etc. + * Truncate uses it to simulate recursive walking.   */  struct ext4_ext_path {  	ext4_fsblk_t			p_block; diff --git a/include/linux/ext4_jbd2.h b/include/linux/ext4_jbd2.h index aa273f024ad0..f69af60d7692 100644 --- a/include/linux/ext4_jbd2.h +++ b/include/linux/ext4_jbd2.h @@ -28,8 +28,8 @@   * indirection blocks, the group and superblock summaries, and the data   * block to complete the transaction.   * - * For extents-enabled fs we may have to allocate and modify upto - * 5 levels of tree + root which is stored in inode. */ + * For extents-enabled fs we may have to allocate and modify up to + * 5 levels of tree + root which are stored in the inode. */  #define EXT4_SINGLEDATA_TRANS_BLOCKS(sb)				\  	(EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)	\ | 
