ext4: Use helper function to access group descriptor and its fields
The descriptor size is variable, thus array indices are not generically
applicable. The larger group descriptors also contain e.g. high parts
of block numbers, which have to be read and written.
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
diff --git a/fs/ext4/ext4_write.c b/fs/ext4/ext4_write.c
index e4f0905..2c123e3 100644
--- a/fs/ext4/ext4_write.c
+++ b/fs/ext4/ext4_write.c
@@ -53,21 +53,26 @@
short i;
ext4fs_update_journal();
struct ext_filesystem *fs = get_fs();
+ struct ext2_block_group *bgd = NULL;
/* update super block */
put_ext4((uint64_t)(SUPERBLOCK_SIZE),
(struct ext2_sblock *)fs->sb, (uint32_t)SUPERBLOCK_SIZE);
- /* update block groups */
+ /* update block bitmaps */
for (i = 0; i < fs->no_blkgrp; i++) {
- fs->bgd[i].bg_checksum = cpu_to_le16(ext4fs_checksum_update(i));
- put_ext4((uint64_t)le32_to_cpu(fs->bgd[i].block_id) * fs->blksz,
+ bgd = ext4fs_get_group_descriptor(fs, i);
+ bgd->bg_checksum = cpu_to_le16(ext4fs_checksum_update(i));
+ uint64_t b_bitmap_blk = ext4fs_bg_get_block_id(bgd, fs);
+ put_ext4(b_bitmap_blk * fs->blksz,
fs->blk_bmaps[i], fs->blksz);
}
- /* update inode table groups */
+ /* update inode bitmaps */
for (i = 0; i < fs->no_blkgrp; i++) {
- put_ext4((uint64_t)le32_to_cpu(fs->bgd[i].inode_id) * fs->blksz,
+ bgd = ext4fs_get_group_descriptor(fs, i);
+ uint64_t i_bitmap_blk = ext4fs_bg_get_inode_id(bgd, fs);
+ put_ext4(i_bitmap_blk * fs->blksz,
fs->inode_bmaps[i], fs->blksz);
}
@@ -85,15 +90,12 @@
int ext4fs_get_bgdtable(void)
{
int status;
- int grp_desc_size;
struct ext_filesystem *fs = get_fs();
- grp_desc_size = sizeof(struct ext2_block_group);
- fs->no_blk_pergdt = (fs->no_blkgrp * grp_desc_size) / fs->blksz;
- if ((fs->no_blkgrp * grp_desc_size) % fs->blksz)
- fs->no_blk_pergdt++;
+ int gdsize_total = ROUND(fs->no_blkgrp * fs->gdsize, fs->blksz);
+ fs->no_blk_pergdt = gdsize_total / fs->blksz;
/* allocate memory for gdtable */
- fs->gdtable = zalloc(fs->blksz * fs->no_blk_pergdt);
+ fs->gdtable = zalloc(gdsize_total);
if (!fs->gdtable)
return -ENOMEM;
/* read the group descriptor table */
@@ -130,8 +132,6 @@
printf("No memory\n");
return;
}
- /* get block group descriptor table */
- bgd = (struct ext2_block_group *)fs->gdtable;
/* deleting the single indirect block associated with inode */
if (inode->b.blocks.indir_block != 0) {
@@ -144,18 +144,19 @@
bg_idx--;
}
ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
- ext4fs_bg_free_blocks_inc(&bgd[bg_idx]);
+ /* get block group descriptor table */
+ bgd = ext4fs_get_group_descriptor(fs, bg_idx);
+ ext4fs_bg_free_blocks_inc(bgd);
ext4fs_sb_free_blocks_inc(fs->sb);
/* journal backup */
if (prev_bg_bmap_idx != bg_idx) {
+ uint64_t b_bitmap_blk = ext4fs_bg_get_block_id(bgd, fs);
status = ext4fs_devread(
- (lbaint_t)le32_to_cpu(bgd[bg_idx].block_id) *
- fs->sect_perblk, 0, fs->blksz,
- journal_buffer);
+ b_bitmap_blk * fs->sect_perblk,
+ 0, fs->blksz, journal_buffer);
if (status == 0)
goto fail;
- if (ext4fs_log_journal
- (journal_buffer, le32_to_cpu(bgd[bg_idx].block_id)))
+ if (ext4fs_log_journal(journal_buffer, b_bitmap_blk))
goto fail;
prev_bg_bmap_idx = bg_idx;
}
@@ -182,8 +183,6 @@
printf("No memory\n");
return;
}
- /* get the block group descriptor table */
- bgd = (struct ext2_block_group *)fs->gdtable;
if (inode->b.blocks.double_indir_block != 0) {
di_buffer = zalloc(fs->blksz);
@@ -206,15 +205,18 @@
if (!remainder)
bg_idx--;
}
+ /* get block group descriptor table */
+ bgd = ext4fs_get_group_descriptor(fs, bg_idx);
ext4fs_reset_block_bmap(le32_to_cpu(*di_buffer),
fs->blk_bmaps[bg_idx], bg_idx);
di_buffer++;
- ext4fs_bg_free_blocks_inc(&bgd[bg_idx]);
+ ext4fs_bg_free_blocks_inc(bgd);
ext4fs_sb_free_blocks_inc(fs->sb);
/* journal backup */
if (prev_bg_bmap_idx != bg_idx) {
- status = ext4fs_devread(
- (lbaint_t)le32_to_cpu(bgd[bg_idx].block_id)
+ uint64_t b_bitmap_blk =
+ ext4fs_bg_get_block_id(bgd, fs);
+ status = ext4fs_devread(b_bitmap_blk
* fs->sect_perblk, 0,
fs->blksz,
journal_buffer);
@@ -222,7 +224,7 @@
goto fail;
if (ext4fs_log_journal(journal_buffer,
- le32_to_cpu(bgd[bg_idx].block_id)))
+ b_bitmap_blk))
goto fail;
prev_bg_bmap_idx = bg_idx;
}
@@ -236,20 +238,20 @@
if (!remainder)
bg_idx--;
}
+ /* get block group descriptor table */
+ bgd = ext4fs_get_group_descriptor(fs, bg_idx);
ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
- ext4fs_bg_free_blocks_inc(&bgd[bg_idx]);
+ ext4fs_bg_free_blocks_inc(bgd);
ext4fs_sb_free_blocks_inc(fs->sb);
/* journal backup */
if (prev_bg_bmap_idx != bg_idx) {
- memset(journal_buffer, '\0', fs->blksz);
- status = ext4fs_devread((lbaint_t)le32_to_cpu(bgd[bg_idx].block_id) *
- fs->sect_perblk, 0, fs->blksz,
- journal_buffer);
+ uint64_t b_bitmap_blk = ext4fs_bg_get_block_id(bgd, fs);
+ status = ext4fs_devread(b_bitmap_blk * fs->sect_perblk,
+ 0, fs->blksz, journal_buffer);
if (status == 0)
goto fail;
- if (ext4fs_log_journal(journal_buffer,
- le32_to_cpu(bgd[bg_idx].block_id)))
+ if (ext4fs_log_journal(journal_buffer, b_bitmap_blk))
goto fail;
prev_bg_bmap_idx = bg_idx;
}
@@ -280,8 +282,6 @@
printf("No memory\n");
return;
}
- /* get block group descriptor table */
- bgd = (struct ext2_block_group *)fs->gdtable;
if (inode->b.blocks.triple_indir_block != 0) {
tigp_buffer = zalloc(fs->blksz);
@@ -320,13 +320,17 @@
bg_idx);
tip_buffer++;
- ext4fs_bg_free_blocks_inc(&bgd[bg_idx]);
+ /* get block group descriptor table */
+ bgd = ext4fs_get_group_descriptor(fs, bg_idx);
+ ext4fs_bg_free_blocks_inc(bgd);
ext4fs_sb_free_blocks_inc(fs->sb);
/* journal backup */
if (prev_bg_bmap_idx != bg_idx) {
+ uint64_t b_bitmap_blk =
+ ext4fs_bg_get_block_id(bgd, fs);
status =
ext4fs_devread(
- (lbaint_t)le32_to_cpu(bgd[bg_idx].block_id) *
+ b_bitmap_blk *
fs->sect_perblk, 0,
fs->blksz,
journal_buffer);
@@ -334,7 +338,7 @@
goto fail;
if (ext4fs_log_journal(journal_buffer,
- le32_to_cpu(bgd[bg_idx].block_id)))
+ b_bitmap_blk))
goto fail;
prev_bg_bmap_idx = bg_idx;
}
@@ -356,21 +360,24 @@
fs->blk_bmaps[bg_idx], bg_idx);
tigp_buffer++;
- ext4fs_bg_free_blocks_inc(&bgd[bg_idx]);
+ /* get block group descriptor table */
+ bgd = ext4fs_get_group_descriptor(fs, bg_idx);
+ ext4fs_bg_free_blocks_inc(bgd);
ext4fs_sb_free_blocks_inc(fs->sb);
/* journal backup */
if (prev_bg_bmap_idx != bg_idx) {
+ uint64_t b_bitmap_blk =
+ ext4fs_bg_get_block_id(bgd, fs);
memset(journal_buffer, '\0', fs->blksz);
- status =
- ext4fs_devread(
- (lbaint_t)le32_to_cpu(bgd[bg_idx].block_id) *
- fs->sect_perblk, 0,
- fs->blksz, journal_buffer);
+ status = ext4fs_devread(b_bitmap_blk *
+ fs->sect_perblk, 0,
+ fs->blksz,
+ journal_buffer);
if (status == 0)
goto fail;
if (ext4fs_log_journal(journal_buffer,
- le32_to_cpu(bgd[bg_idx].block_id)))
+ b_bitmap_blk))
goto fail;
prev_bg_bmap_idx = bg_idx;
}
@@ -385,20 +392,19 @@
bg_idx--;
}
ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
- ext4fs_bg_free_blocks_inc(&bgd[bg_idx]);
+ /* get block group descriptor table */
+ bgd = ext4fs_get_group_descriptor(fs, bg_idx);
+ ext4fs_bg_free_blocks_inc(bgd);
ext4fs_sb_free_blocks_inc(fs->sb);
/* journal backup */
if (prev_bg_bmap_idx != bg_idx) {
- memset(journal_buffer, '\0', fs->blksz);
- status = ext4fs_devread(
- (lbaint_t)le32_to_cpu(bgd[bg_idx].block_id) *
- fs->sect_perblk, 0, fs->blksz,
- journal_buffer);
+ uint64_t b_bitmap_blk = ext4fs_bg_get_block_id(bgd, fs);
+ status = ext4fs_devread(b_bitmap_blk * fs->sect_perblk,
+ 0, fs->blksz, journal_buffer);
if (status == 0)
goto fail;
- if (ext4fs_log_journal(journal_buffer,
- le32_to_cpu(bgd[bg_idx].block_id)))
+ if (ext4fs_log_journal(journal_buffer, b_bitmap_blk))
goto fail;
prev_bg_bmap_idx = bg_idx;
}
@@ -435,8 +441,6 @@
char *journal_buffer = zalloc(fs->blksz);
if (!journal_buffer)
return -ENOMEM;
- /* get the block group descriptor table */
- bgd = (struct ext2_block_group *)fs->gdtable;
status = ext4fs_read_inode(ext4fs_root, inodeno, &inode);
if (status == 0)
goto fail;
@@ -475,18 +479,19 @@
bg_idx);
debug("EXT4 Block releasing %ld: %d\n", blknr, bg_idx);
- ext4fs_bg_free_blocks_inc(&bgd[bg_idx]);
+ /* get block group descriptor table */
+ bgd = ext4fs_get_group_descriptor(fs, bg_idx);
+ ext4fs_bg_free_blocks_inc(bgd);
ext4fs_sb_free_blocks_inc(fs->sb);
/* journal backup */
if (prev_bg_bmap_idx != bg_idx) {
- uint32_t bgd_blknr = le32_to_cpu(bgd[bg_idx].block_id);
- status = ext4fs_devread((lbaint_t)bgd_blknr *
- fs->sect_perblk,
+ uint64_t b_bitmap_blk = ext4fs_bg_get_block_id(bgd, fs);
+ status = ext4fs_devread(b_bitmap_blk * fs->sect_perblk,
0, fs->blksz,
journal_buffer);
if (status == 0)
goto fail;
- if (ext4fs_log_journal(journal_buffer, bgd_blknr))
+ if (ext4fs_log_journal(journal_buffer, b_bitmap_blk))
goto fail;
prev_bg_bmap_idx = bg_idx;
}
@@ -499,7 +504,9 @@
/* get the block no */
inodeno--;
- blkno = le32_to_cpu(bgd[ibmap_idx].inode_table_id) +
+ /* get block group descriptor table */
+ bgd = ext4fs_get_group_descriptor(fs, ibmap_idx);
+ blkno = ext4fs_bg_get_inode_table_id(bgd, fs) +
(inodeno % inode_per_grp) / inodes_per_block;
/* get the offset of the inode */
@@ -529,15 +536,15 @@
/* update the respective inode bitmaps */
inodeno++;
ext4fs_reset_inode_bmap(inodeno, fs->inode_bmaps[ibmap_idx], ibmap_idx);
- ext4fs_bg_free_inodes_inc(&bgd[ibmap_idx]);
+ ext4fs_bg_free_inodes_inc(bgd);
ext4fs_sb_free_inodes_inc(fs->sb);
/* journal backup */
memset(journal_buffer, '\0', fs->blksz);
- status = ext4fs_devread((lbaint_t)le32_to_cpu(bgd[ibmap_idx].inode_id) *
+ status = ext4fs_devread(ext4fs_bg_get_inode_id(bgd, fs) *
fs->sect_perblk, 0, fs->blksz, journal_buffer);
if (status == 0)
goto fail;
- if (ext4fs_log_journal(journal_buffer, le32_to_cpu(bgd[ibmap_idx].inode_id)))
+ if (ext4fs_log_journal(journal_buffer, ext4fs_bg_get_inode_id(bgd, fs)))
goto fail;
ext4fs_update();
@@ -594,7 +601,6 @@
printf("Error in getting the block group descriptor table\n");
goto fail;
}
- fs->bgd = (struct ext2_block_group *)fs->gdtable;
/* load all the available bitmap block of the partition */
fs->blk_bmaps = zalloc(fs->no_blkgrp * sizeof(char *));
@@ -607,9 +613,9 @@
}
for (i = 0; i < fs->no_blkgrp; i++) {
- status =
- ext4fs_devread(
- (lbaint_t)le32_to_cpu(fs->bgd[i].block_id) *
+ struct ext2_block_group *bgd =
+ ext4fs_get_group_descriptor(fs, i);
+ status = ext4fs_devread(ext4fs_bg_get_block_id(bgd, fs) *
fs->sect_perblk, 0,
fs->blksz, (char *)fs->blk_bmaps[i]);
if (status == 0)
@@ -627,8 +633,9 @@
}
for (i = 0; i < fs->no_blkgrp; i++) {
- status = ext4fs_devread(
- (lbaint_t)le32_to_cpu(fs->bgd[i].inode_id) *
+ struct ext2_block_group *bgd =
+ ext4fs_get_group_descriptor(fs, i);
+ status = ext4fs_devread(ext4fs_bg_get_inode_id(bgd, fs) *
fs->sect_perblk,
0, fs->blksz,
(char *)fs->inode_bmaps[i]);
@@ -642,10 +649,14 @@
* with the blockgroups freeblocks when improper
* reboot of a linux kernel
*/
- for (i = 0; i < fs->no_blkgrp; i++)
- real_free_blocks = real_free_blocks + le16_to_cpu(fs->bgd[i].free_blocks);
- if (real_free_blocks != le32_to_cpu(fs->sb->free_blocks))
- fs->sb->free_blocks = cpu_to_le32(real_free_blocks);
+ for (i = 0; i < fs->no_blkgrp; i++) {
+ struct ext2_block_group *bgd =
+ ext4fs_get_group_descriptor(fs, i);
+ real_free_blocks = real_free_blocks +
+ ext4fs_bg_get_free_blocks(bgd, fs);
+ }
+ if (real_free_blocks != ext4fs_sb_get_free_blocks(fs->sb))
+ ext4fs_sb_set_free_blocks(fs->sb, real_free_blocks);
return 0;
fail:
@@ -711,7 +722,6 @@
free(fs->gdtable);
fs->gdtable = NULL;
- fs->bgd = NULL;
/*
* reinitiliazed the global inode and
* block bitmap first execution check variables
@@ -826,6 +836,7 @@
struct ext2_sblock *sblock = &(ext4fs_root->sblock);
unsigned int inodes_per_block;
unsigned int ibmap_idx;
+ struct ext2_block_group *bgd = NULL;
struct ext_filesystem *fs = get_fs();
ALLOC_CACHE_ALIGN_BUFFER(char, filename, 256);
memset(filename, 0x00, 256);
@@ -903,7 +914,8 @@
goto fail;
ibmap_idx = inodeno / le32_to_cpu(ext4fs_root->sblock.inodes_per_group);
inodeno--;
- itable_blkno = le32_to_cpu(fs->bgd[ibmap_idx].inode_table_id) +
+ bgd = ext4fs_get_group_descriptor(fs, ibmap_idx);
+ itable_blkno = ext4fs_bg_get_inode_table_id(bgd, fs) +
(inodeno % le32_to_cpu(sblock->inodes_per_group)) /
inodes_per_block;
blkoff = (inodeno % inodes_per_block) * fs->inodesz;
@@ -923,7 +935,8 @@
}
ibmap_idx = parent_inodeno / le32_to_cpu(ext4fs_root->sblock.inodes_per_group);
parent_inodeno--;
- parent_itable_blkno = le32_to_cpu(fs->bgd[ibmap_idx].inode_table_id) +
+ bgd = ext4fs_get_group_descriptor(fs, ibmap_idx);
+ parent_itable_blkno = ext4fs_bg_get_inode_table_id(bgd, fs) +
(parent_inodeno %
le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
blkoff = (parent_inodeno % inodes_per_block) * fs->inodesz;