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ext4: Define a new set of flags for ext4_get_blocks()

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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: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o
2009-05-14 00:58:52 -04:00
parent 12b7ac1768
commit c217705733
4 changed files with 57 additions and 46 deletions
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57
fs/ext4/inode.c
View File

@@ -917,7 +917,7 @@ err_out:
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;