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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-07-25 19:16:11 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-07-25 19:16:11 +0200
commitf49fe3bbf0d52e2afcc1ace8c1f48dee9349d4f8 (patch)
tree41e55971f8f1052c0457332dbf5718f7b7a9c661
parent798abd9eaf3c9e8aa83c4dca28cdd44890253efe (diff)
Cleanup sqfs_write_table
This commit attempts to make the generic table writer more readable. A few changes are made, including heap allocation of the block list. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
-rw-r--r--include/highlevel.h15
-rw-r--r--lib/sqfs/data_writer.c13
-rw-r--r--lib/sqfs/id_table_write.c4
-rw-r--r--lib/sqfs/write_export_table.c8
-rw-r--r--lib/sqfs/write_table.c71
5 files changed, 62 insertions, 49 deletions
diff --git a/include/highlevel.h b/include/highlevel.h
index 23f5b68..16db1cf 100644
--- a/include/highlevel.h
+++ b/include/highlevel.h
@@ -23,17 +23,16 @@ enum RDTREE_FLAGS {
/*
Convenience function for writing meta data to a SquashFS image
- This function internally creates a meta data writer and writes 'count'
- blocks of data from 'data' to it, each 'entsize' bytes in size. For each
- meta data block, it remembers the 64 bit start address, writes out all
- addresses to an uncompressed address list and returns the location where
- the address list starts.
+ This function internally creates a meta data writer and writes the given
+ 'data' blob with 'table_size' bytes to disk, neatly partitioned into meta
+ data blocks. For each meta data block, it remembers the 64 bit start address,
+ writes out all addresses to an uncompressed list and returns the location
+ where the address list starts in 'start'.
Returns 0 on success. Internally prints error messages to stderr.
*/
-int sqfs_write_table(int outfd, sqfs_super_t *super, const void *data,
- size_t entsize, size_t count, uint64_t *startblock,
- compressor_t *cmp);
+int sqfs_write_table(int outfd, sqfs_super_t *super, compressor_t *cmp,
+ const void *data, size_t table_size, uint64_t *start);
/*
High level helper function to serialize an entire file system tree to
diff --git a/lib/sqfs/data_writer.c b/lib/sqfs/data_writer.c
index 74701fd..ae8257c 100644
--- a/lib/sqfs/data_writer.c
+++ b/lib/sqfs/data_writer.c
@@ -295,6 +295,8 @@ void data_writer_destroy(data_writer_t *data)
int data_writer_write_fragment_table(data_writer_t *data)
{
uint64_t start;
+ size_t size;
+ int ret;
if (data->num_fragments == 0) {
data->super->fragment_entry_count = 0;
@@ -302,14 +304,13 @@ int data_writer_write_fragment_table(data_writer_t *data)
return 0;
}
- data->super->fragment_entry_count = data->num_fragments;
-
- if (sqfs_write_table(data->outfd, data->super, data->fragments,
- sizeof(data->fragments[0]), data->num_fragments,
- &start, data->cmp)) {
+ size = sizeof(data->fragments[0]) * data->num_fragments;
+ ret = sqfs_write_table(data->outfd, data->super, data->cmp,
+ data->fragments, size, &start);
+ if (ret)
return -1;
- }
+ data->super->fragment_entry_count = data->num_fragments;
data->super->fragment_table_start = start;
return 0;
}
diff --git a/lib/sqfs/id_table_write.c b/lib/sqfs/id_table_write.c
index c2ed353..3bbe302 100644
--- a/lib/sqfs/id_table_write.c
+++ b/lib/sqfs/id_table_write.c
@@ -15,8 +15,8 @@ int id_table_write(id_table_t *tbl, int outfd, sqfs_super_t *super,
super->id_count = tbl->num_ids;
- ret = sqfs_write_table(outfd, super, tbl->ids, sizeof(tbl->ids[0]),
- tbl->num_ids, &start, cmp);
+ ret = sqfs_write_table(outfd, super, cmp, tbl->ids,
+ sizeof(tbl->ids[0]) * tbl->num_ids, &start);
super->id_table_start = start;
diff --git a/lib/sqfs/write_export_table.c b/lib/sqfs/write_export_table.c
index a0d81eb..8794609 100644
--- a/lib/sqfs/write_export_table.c
+++ b/lib/sqfs/write_export_table.c
@@ -10,10 +10,11 @@ int write_export_table(int outfd, fstree_t *fs, sqfs_super_t *super,
compressor_t *cmp)
{
uint64_t *table, start;
- size_t i;
+ size_t i, size;
int ret;
- table = malloc(sizeof(uint64_t) * (fs->inode_tbl_size - 1));
+ size = sizeof(uint64_t) * (fs->inode_tbl_size - 1);
+ table = malloc(size);
if (table == NULL) {
perror("Allocating NFS export table");
@@ -28,8 +29,7 @@ int write_export_table(int outfd, fstree_t *fs, sqfs_super_t *super,
}
}
- ret = sqfs_write_table(outfd, super, table, sizeof(table[0]),
- fs->inode_tbl_size - 1, &start, cmp);
+ ret = sqfs_write_table(outfd, super, cmp, table, size, &start);
super->export_table_start = start;
super->flags |= SQFS_FLAG_EXPORTABLE;
diff --git a/lib/sqfs/write_table.c b/lib/sqfs/write_table.c
index fc90a3f..23ba5a8 100644
--- a/lib/sqfs/write_table.c
+++ b/lib/sqfs/write_table.c
@@ -6,56 +6,69 @@
#include "util.h"
#include <endian.h>
+#include <stdlib.h>
#include <stdio.h>
-int sqfs_write_table(int outfd, sqfs_super_t *super, const void *data,
- size_t entsize, size_t count, uint64_t *startblock,
- compressor_t *cmp)
+int sqfs_write_table(int outfd, sqfs_super_t *super, compressor_t *cmp,
+ const void *data, size_t table_size, uint64_t *start)
{
- size_t ent_per_blocks = SQFS_META_BLOCK_SIZE / entsize;
- uint64_t blocks[count / ent_per_blocks + 1], block;
- size_t i, blkidx = 0, tblsize;
+ size_t block_count, list_size, diff, blkidx = 0;
+ uint64_t block, *locations;
meta_writer_t *m;
uint32_t offset;
+ int ret = -1;
- /* Write actual data. Whenever we cross a block boundary, remember
- the block start offset */
+ block_count = table_size / SQFS_META_BLOCK_SIZE;
+ if ((table_size % SQFS_META_BLOCK_SIZE) != 0)
+ ++block_count;
+
+ list_size = sizeof(uint64_t) * block_count;
+ locations = malloc(list_size);
+
+ if (locations == NULL) {
+ perror("writing table");
+ return -1;
+ }
+
+ /* Write actual data */
m = meta_writer_create(outfd, cmp, false);
if (m == NULL)
- return -1;
+ goto out_idx;
- for (i = 0; i < count; ++i) {
+ while (table_size > 0) {
meta_writer_get_position(m, &block, &offset);
+ locations[blkidx++] = htole64(super->bytes_used + block);
- if (blkidx == 0 || block > blocks[blkidx - 1])
- blocks[blkidx++] = block;
+ diff = SQFS_META_BLOCK_SIZE;
+ if (diff > table_size)
+ diff = table_size;
- if (meta_writer_append(m, data, entsize))
- goto fail;
+ if (meta_writer_append(m, data, diff))
+ goto out;
- data = (const char *)data + entsize;
+ data = (const char *)data + diff;
+ table_size -= diff;
}
if (meta_writer_flush(m))
- goto fail;
-
- for (i = 0; i < blkidx; ++i)
- blocks[i] = htole64(blocks[i] + super->bytes_used);
+ goto out;
meta_writer_get_position(m, &block, &offset);
super->bytes_used += block;
- meta_writer_destroy(m);
- /* write new index table */
- *startblock = super->bytes_used;
- tblsize = sizeof(blocks[0]) * blkidx;
+ /* write location list */
+ *start = super->bytes_used;
- if (write_data("writing table index", outfd, blocks, tblsize))
- return -1;
+ if (write_data("writing table locations", outfd, locations, list_size))
+ goto out;
+
+ super->bytes_used += list_size;
- super->bytes_used += tblsize;
- return 0;
-fail:
+ /* cleanup */
+ ret = 0;
+out:
meta_writer_destroy(m);
- return -1;
+out_idx:
+ free(locations);
+ return ret;
}