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Commit c2177057 authored by Theodore Ts'o's avatar Theodore Ts'o
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ext4: Define a new set of flags for ext4_get_blocks() 



The functions ext4_get_blocks(), ext4_ext_get_blocks(), and
ext4_ind_get_blocks() used an ad-hoc set of integer variables used as
boolean flags passed in as arguments.  Use a single flags parameter
and a setandard set of bitfield flags instead.  This saves space on
the call stack, and it also makes the code a bit more understandable.

Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 12b7ac17

fs/ext4/dir.c

+1 −1
Original line number Diff line number Diff line
@@ -131,7 +131,7 @@ static int ext4_readdir(struct file *filp, 
		struct buffer_head *bh = NULL;



		map_bh.b_state = 0;

		err = ext4_get_blocks(NULL, inode, blk, 1, &map_bh, 0, 0, 0);

		err = ext4_get_blocks(NULL, inode, blk, 1, &map_bh, 0);

		if (err > 0) {

			pgoff_t index = map_bh.b_blocknr >>

					(PAGE_CACHE_SHIFT - inode->i_blkbits);

fs/ext4/ext4.h

+15 −7
Original line number Diff line number Diff line
@@ -314,10 +314,20 @@ struct ext4_new_group_data { 
};



/*

 * Following is used by preallocation code to tell get_blocks() that we

 * want uninitialzed extents.

 * Flags used by ext4_get_blocks()

 */

#define EXT4_CREATE_UNINITIALIZED_EXT		2

	/* Allocate any needed blocks and/or convert an unitialized

	   extent to be an initialized ext4 */

#define EXT4_GET_BLOCKS_CREATE			1

	/* Request the creation of an unitialized extent */

#define EXT4_GET_BLOCKS_UNINIT_EXT		2

#define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT	(EXT4_GET_BLOCKS_UNINIT_EXT|\

						 EXT4_GET_BLOCKS_CREATE)

	/* Update the ext4_inode_info i_disksize field */

#define EXT4_GET_BLOCKS_EXTEND_DISKSIZE		4

	/* Caller is from the delayed allocation writeout path,

	   so the filesystem blocks have already been accounted for */

#define EXT4_GET_BLOCKS_DELALLOC_RESERVE	8



/*

 * ioctl commands
@@ -1610,8 +1620,7 @@ extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, 
				       int chunk);

extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,

			       ext4_lblk_t iblock, unsigned int max_blocks,

			       struct buffer_head *bh_result,

			       int create, int extend_disksize);

			       struct buffer_head *bh_result, int flags);

extern void ext4_ext_truncate(struct inode *);

extern void ext4_ext_init(struct super_block *);

extern void ext4_ext_release(struct super_block *);
@@ -1619,8 +1628,7 @@ extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset, 
			  loff_t len);

extern int ext4_get_blocks(handle_t *handle, struct inode *inode,

			   sector_t block, unsigned int max_blocks,

			   struct buffer_head *bh, int create,

			   int extend_disksize, int flag);

			   struct buffer_head *bh, int flags);

extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,

			__u64 start, __u64 len);

fs/ext4/extents.c

+11 −11
Original line number Diff line number Diff line
@@ -2784,7 +2784,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, 
int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,

			ext4_lblk_t iblock,

			unsigned int max_blocks, struct buffer_head *bh_result,

			int create, int extend_disksize)

			int flags)

{

	struct ext4_ext_path *path = NULL;

	struct ext4_extent_header *eh;
@@ -2803,7 +2803,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, 
	cache_type = ext4_ext_in_cache(inode, iblock, &newex);

	if (cache_type) {

		if (cache_type == EXT4_EXT_CACHE_GAP) {

			if (!create) {

			if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {

				/*

				 * block isn't allocated yet and

				 * user doesn't want to allocate it
@@ -2869,9 +2869,9 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, 
							EXT4_EXT_CACHE_EXTENT);

				goto out;

			}

			if (create == EXT4_CREATE_UNINITIALIZED_EXT)

			if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)

				goto out;

			if (!create) {

			if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {

				if (allocated > max_blocks)

					allocated = max_blocks;

				/*
@@ -2903,7 +2903,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, 
	 * requested block isn't allocated yet;

	 * we couldn't try to create block if create flag is zero

	 */

	if (!create) {

	if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {

		/*

		 * put just found gap into cache to speed up

		 * subsequent requests
@@ -2932,10 +2932,10 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, 
	 * EXT_UNINIT_MAX_LEN.

	 */

	if (max_blocks > EXT_INIT_MAX_LEN &&

	    create != EXT4_CREATE_UNINITIALIZED_EXT)

	    !(flags & EXT4_GET_BLOCKS_UNINIT_EXT))

		max_blocks = EXT_INIT_MAX_LEN;

	else if (max_blocks > EXT_UNINIT_MAX_LEN &&

		 create == EXT4_CREATE_UNINITIALIZED_EXT)

		 (flags & EXT4_GET_BLOCKS_UNINIT_EXT))

		max_blocks = EXT_UNINIT_MAX_LEN;



	/* Check if we can really insert (iblock)::(iblock+max_blocks) extent */
@@ -2966,7 +2966,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, 
	/* try to insert new extent into found leaf and return */

	ext4_ext_store_pblock(&newex, newblock);

	newex.ee_len = cpu_to_le16(ar.len);

	if (create == EXT4_CREATE_UNINITIALIZED_EXT)  /* Mark uninitialized */

	if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)  /* Mark uninitialized */

		ext4_ext_mark_uninitialized(&newex);

	err = ext4_ext_insert_extent(handle, inode, path, &newex);

	if (err) {
@@ -2983,7 +2983,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, 
	newblock = ext_pblock(&newex);

	allocated = ext4_ext_get_actual_len(&newex);

outnew:

	if (extend_disksize) {

	if (flags & EXT4_GET_BLOCKS_EXTEND_DISKSIZE) {

		disksize = ((loff_t) iblock + ar.len) << inode->i_blkbits;

		if (disksize > i_size_read(inode))

			disksize = i_size_read(inode);
@@ -2994,7 +2994,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, 
	set_buffer_new(bh_result);



	/* Cache only when it is _not_ an uninitialized extent */

	if (create != EXT4_CREATE_UNINITIALIZED_EXT)

	if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0)

		ext4_ext_put_in_cache(inode, iblock, allocated, newblock,

						EXT4_EXT_CACHE_EXTENT);

out:
@@ -3153,7 +3153,7 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len) 
		map_bh.b_state = 0;

		ret = ext4_get_blocks(handle, inode, block,

				      max_blocks, &map_bh,

				      EXT4_CREATE_UNINITIALIZED_EXT, 0, 0);

				      EXT4_GET_BLOCKS_CREATE_UNINIT_EXT);

		if (ret <= 0) {

#ifdef EXT4FS_DEBUG

			WARN_ON(ret <= 0);

fs/ext4/inode.c

+30 −27
Original line number Diff line number Diff line
@@ -917,7 +917,7 @@ static int ext4_splice_branch(handle_t *handle, struct inode *inode, 
static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode,

				  ext4_lblk_t iblock, unsigned int maxblocks,

				  struct buffer_head *bh_result,

				  int create, int extend_disksize)

				  int flags)

{

	int err = -EIO;

	ext4_lblk_t offsets[4];
@@ -934,7 +934,7 @@ static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode, 




	J_ASSERT(!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL));

	J_ASSERT(handle != NULL || create == 0);

	J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);

	depth = ext4_block_to_path(inode, iblock, offsets,

					&blocks_to_boundary);
@@ -963,7 +963,7 @@ static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode, 
	}



	/* Next simple case - plain lookup or failed read of indirect block */

	if (!create || err == -EIO)

	if ((flags & EXT4_GET_BLOCKS_CREATE) == 0 || err == -EIO)

		goto cleanup;



	/*
@@ -1002,7 +1002,7 @@ static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode, 
	 * protect it if you're about to implement concurrent

	 * ext4_get_block() -bzzz

	*/

	if (!err && extend_disksize) {

	if (!err && (flags & EXT4_GET_BLOCKS_EXTEND_DISKSIZE)) {

		disksize = ((loff_t) iblock + count) << inode->i_blkbits;

		if (disksize > i_size_read(inode))

			disksize = i_size_read(inode);
@@ -1144,7 +1144,7 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used) 
 */

int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,

		    unsigned int max_blocks, struct buffer_head *bh,

		    int create, int extend_disksize, int flag)

		    int flags)

{

	int retval;
@@ -1158,15 +1158,15 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block, 
	down_read((&EXT4_I(inode)->i_data_sem));

	if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {

		retval =  ext4_ext_get_blocks(handle, inode, block, max_blocks,

				bh, 0, 0);

				bh, 0);

	} else {

		retval = ext4_ind_get_blocks(handle, inode, block, max_blocks,

					     bh, 0, 0);

					     bh, 0);

	}

	up_read((&EXT4_I(inode)->i_data_sem));



	/* If it is only a block(s) look up */

	if (!create)

	if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)

		return retval;



	/*
@@ -1205,7 +1205,7 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block, 
	 * let the underlying get_block() function know to

	 * avoid double accounting

	 */

	if (flag)

	if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)

		EXT4_I(inode)->i_delalloc_reserved_flag = 1;

	/*

	 * We need to check for EXT4 here because migrate
@@ -1213,10 +1213,10 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block, 
	 */

	if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {

		retval =  ext4_ext_get_blocks(handle, inode, block, max_blocks,

				bh, create, extend_disksize);

					      bh, flags);

	} else {

		retval = ext4_ind_get_blocks(handle, inode, block,

				max_blocks, bh, create, extend_disksize);

					     max_blocks, bh, flags);



		if (retval > 0 && buffer_new(bh)) {

			/*
@@ -1229,7 +1229,7 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block, 
		}

	}



	if (flag) {

	if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {

		EXT4_I(inode)->i_delalloc_reserved_flag = 0;

		/*

		 * Update reserved blocks/metadata blocks
@@ -1269,7 +1269,7 @@ int ext4_get_block(struct inode *inode, sector_t iblock, 
	}



	ret = ext4_get_blocks(handle, inode, iblock, max_blocks, bh_result,

			      create, 0, 0);

			      create ? EXT4_GET_BLOCKS_CREATE : 0);

	if (ret > 0) {

		bh_result->b_size = (ret << inode->i_blkbits);

		ret = 0;
@@ -1288,16 +1288,19 @@ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode, 
{

	struct buffer_head dummy;

	int fatal = 0, err;

	int flags = EXT4_GET_BLOCKS_EXTEND_DISKSIZE;



	J_ASSERT(handle != NULL || create == 0);



	dummy.b_state = 0;

	dummy.b_blocknr = -1000;

	buffer_trace_init(&dummy.b_history);

	err = ext4_get_blocks(handle, inode, block, 1, &dummy, create, 1, 0);

	if (create)

		flags |= EXT4_GET_BLOCKS_CREATE;

	err = ext4_get_blocks(handle, inode, block, 1, &dummy, flags);

	/*

	 * ext4_get_blocks() returns number of blocks

	 * mapped. 0 in case of a HOLE.

	 * ext4_get_blocks() returns number of blocks mapped. 0 in

	 * case of a HOLE.

	 */

	if (err > 0) {

		if (err > 1)
@@ -1997,7 +2000,6 @@ static void ext4_print_free_blocks(struct inode *inode) 
	return;

}



#define		EXT4_DELALLOC_RSVED	1

static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,

				   struct buffer_head *bh_result)

{
@@ -2009,7 +2011,8 @@ static int ext4_da_get_block_write(struct inode *inode, sector_t iblock, 
	handle = ext4_journal_current_handle();

	BUG_ON(!handle);

	ret = ext4_get_blocks(handle, inode, iblock, max_blocks,

			      bh_result, 1, 0, EXT4_DELALLOC_RSVED);

			      bh_result, EXT4_GET_BLOCKS_CREATE|

			      EXT4_GET_BLOCKS_DELALLOC_RESERVE);

	if (ret <= 0)

		return ret;
@@ -2065,16 +2068,17 @@ static int mpage_da_map_blocks(struct mpage_da_data *mpd) 
		return 0;

	/*

	 * We need to make sure the BH_Delay flag is passed down to

	 * ext4_da_get_block_write(), since it calls

	 * ext4_get_blocks() with the EXT4_DELALLOC_RSVED flag.

	 * This flag causes ext4_get_blocks() to call

	 * ext4_da_get_block_write(), since it calls ext4_get_blocks()

	 * with the EXT4_GET_BLOCKS_DELALLOC_RESERVE flag.  This flag

	 * causes ext4_get_blocks() to call

	 * ext4_da_update_reserve_space() if the passed buffer head

	 * has the BH_Delay flag set.  In the future, once we clean up

	 * the interfaces to ext4_get_blocks(), we should pass in

	 * a separate flag which requests that the delayed allocation

	 * the interfaces to ext4_get_blocks(), we should pass in a

	 * separate flag which requests that the delayed allocation

	 * statistics should be updated, instead of depending on the

	 * state information getting passed down via the map_bh's

	 * state bitmasks plus the magic EXT4_DELALLOC_RSVED flag.

	 * state bitmasks plus the magic

	 * EXT4_GET_BLOCKS_DELALLOC_RESERVE flag.

	 */

	new.b_state = mpd->b_state & (1 << BH_Delay);

	new.b_blocknr = 0;
@@ -2362,7 +2366,7 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock, 
	 * preallocated blocks are unmapped but should treated

	 * the same as allocated blocks.

	 */

	ret = ext4_get_blocks(NULL, inode, iblock, 1,  bh_result, 0, 0, 0);

	ret = ext4_get_blocks(NULL, inode, iblock, 1,  bh_result, 0);

	if ((ret == 0) && !buffer_delay(bh_result)) {

		/* the block isn't (pre)allocated yet, let's reserve space */

		/*
@@ -2406,8 +2410,7 @@ static int ext4_normal_get_block_write(struct inode *inode, sector_t iblock, 
	 * we don't want to do block allocation in writepage

	 * so call get_block_wrap with create = 0

	 */

	ret = ext4_get_blocks(NULL, inode, iblock, max_blocks,

			      bh_result, 0, 0, 0);

	ret = ext4_get_blocks(NULL, inode, iblock, max_blocks, bh_result, 0);

	if (ret > 0) {

		bh_result->b_size = (ret << inode->i_blkbits);

		ret = 0;