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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-07-15 14:44:44 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-07-15 14:47:03 +0200
commit14a925f6da442ecade7df75eb46a6edb9a1499af (patch)
treed63d56ec17e1d8bcbf310273f199f4891718a6b5
parent1b35319762cd83982dacbe96eccf07fd00d7858a (diff)
Add flags to data writer to micro manage behaviour
The added flags allow controlling the following on a per file level: - forcing a file to be written uncompressed - forcing a file to not have a fragment, i.e. the last truncated block actually being written as a block - padding a file to be alligned to device block size The flags are not yet exposed to anything user controllable (such as command line flags). Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
-rw-r--r--include/data_writer.h27
-rw-r--r--lib/sqfs/data_writer.c63
-rw-r--r--mkfs/mkfs.c4
-rw-r--r--tar/tar2sqfs.c6
4 files changed, 77 insertions, 23 deletions
diff --git a/include/data_writer.h b/include/data_writer.h
index 2ace899..a52b37f 100644
--- a/include/data_writer.h
+++ b/include/data_writer.h
@@ -9,6 +9,22 @@
typedef struct data_writer_t data_writer_t;
+enum {
+ /* Don't generate fragments, always write the last block to disk as a
+ block, even if it is incomplete. */
+ DW_DONT_FRAGMENT = 0x01,
+
+ /* Intentionally write all blocks uncompressed. This implies
+ DW_DONT_FRAGMENT since sharing a fragment block with other files
+ would otherwise require the entire fragment block to be
+ uncompressed. */
+ DW_DONT_COMPRESS = 0x03,
+
+ /* Make sure the first block of a file is alligned to
+ device block size */
+ DW_ALLIGN_DEVBLK = 0x04,
+};
+
/*
Create a data writer. The pointer to the super block is kept internally and
used to automatically update various counters when writing data.
@@ -16,7 +32,7 @@ typedef struct data_writer_t data_writer_t;
Returns NULL on failure and prints errors to stderr.
*/
data_writer_t *data_writer_create(sqfs_super_t *super, compressor_t *cmp,
- int outfd);
+ int outfd, size_t devblksize);
void data_writer_destroy(data_writer_t *data);
@@ -46,18 +62,23 @@ int data_writer_flush_fragments(data_writer_t *data);
Blocks or fragments that are all zero bytes automatically detected,
not written out and the sparse file accounting updated accordingly.
+ The flags argument is a combination of DW_* flags.
+
Returns 0 on success, prints errors to stderr.
*/
-int write_data_from_fd(data_writer_t *data, file_info_t *fi, int infd);
+int write_data_from_fd(data_writer_t *data, file_info_t *fi, int infd,
+ int flags);
/*
Does the same as write_data_from_fd but the input file is the condensed
representation of a sparse file. The layout must be in order and
non-overlapping.
+ The flags argument is a combination of DW_* flags.
+
Returns 0 on success, prints errors to stderr.
*/
int write_data_from_fd_condensed(data_writer_t *data, file_info_t *fi,
- int infd, sparse_map_t *map);
+ int infd, sparse_map_t *map, int flags);
#endif /* DATA_WRITER_H */
diff --git a/lib/sqfs/data_writer.c b/lib/sqfs/data_writer.c
index 557b85b..cbe2351 100644
--- a/lib/sqfs/data_writer.c
+++ b/lib/sqfs/data_writer.c
@@ -18,6 +18,8 @@ struct data_writer_t {
size_t max_fragments;
size_t frag_offset;
+ size_t devblksz;
+
int block_idx;
sqfs_super_t *super;
@@ -26,14 +28,16 @@ struct data_writer_t {
};
static int write_compressed(data_writer_t *data, const void *in, size_t size,
- uint32_t *outsize)
+ uint32_t *outsize, int flags)
{
- ssize_t ret;
+ ssize_t ret = 0;
- ret = data->cmp->do_block(data->cmp, in, size, data->scratch,
- data->super->block_size);
- if (ret < 0)
- return -1;
+ if (!(flags & DW_DONT_COMPRESS)) {
+ ret = data->cmp->do_block(data->cmp, in, size, data->scratch,
+ data->super->block_size);
+ if (ret < 0)
+ return -1;
+ }
if (ret > 0 && (size_t)ret < size) {
size = ret;
@@ -85,6 +89,20 @@ static bool is_zero_block(unsigned char *ptr, size_t size)
return ptr[0] == 0 && memcmp(ptr, ptr + 1, size - 1) == 0;
}
+static int allign_file(data_writer_t *data)
+{
+ size_t diff = data->super->bytes_used % data->devblksz;
+
+ if (diff == 0)
+ return 0;
+
+ if (padd_file(data->outfd, data->super->bytes_used, data->devblksz))
+ return -1;
+
+ data->super->bytes_used += data->devblksz - diff;
+ return 0;
+}
+
int data_writer_flush_fragments(data_writer_t *data)
{
uint64_t offset;
@@ -98,7 +116,7 @@ int data_writer_flush_fragments(data_writer_t *data)
offset = data->super->bytes_used;
- if (write_compressed(data, data->fragment, data->frag_offset, &out))
+ if (write_compressed(data, data->fragment, data->frag_offset, &out, 0))
return -1;
data->fragments[data->num_fragments].start_offset = htole64(offset);
@@ -113,7 +131,8 @@ int data_writer_flush_fragments(data_writer_t *data)
return 0;
}
-static int flush_data_block(data_writer_t *data, size_t size, file_info_t *fi)
+static int flush_data_block(data_writer_t *data, size_t size,
+ file_info_t *fi, int flags)
{
uint32_t out;
@@ -123,7 +142,7 @@ static int flush_data_block(data_writer_t *data, size_t size, file_info_t *fi)
return 0;
}
- if (size < data->super->block_size) {
+ if (size < data->super->block_size && !(flags & DW_DONT_FRAGMENT)) {
if (data->frag_offset + size > data->super->block_size) {
if (data_writer_flush_fragments(data))
return -1;
@@ -136,7 +155,7 @@ static int flush_data_block(data_writer_t *data, size_t size, file_info_t *fi)
data->block, size);
data->frag_offset += size;
} else {
- if (write_compressed(data, data->block, size, &out))
+ if (write_compressed(data, data->block, size, &out, flags))
return -1;
fi->blocksizes[data->block_idx++] = out;
@@ -145,12 +164,16 @@ static int flush_data_block(data_writer_t *data, size_t size, file_info_t *fi)
return 0;
}
-int write_data_from_fd(data_writer_t *data, file_info_t *fi, int infd)
+int write_data_from_fd(data_writer_t *data, file_info_t *fi,
+ int infd, int flags)
{
uint64_t count;
ssize_t ret;
size_t diff;
+ if ((flags & DW_ALLIGN_DEVBLK) && allign_file(data) != 0)
+ return -1;
+
fi->startblock = data->super->bytes_used;
fi->sparse = 0;
data->block_idx = 0;
@@ -165,10 +188,13 @@ int write_data_from_fd(data_writer_t *data, file_info_t *fi, int infd)
if ((size_t)ret < diff)
goto fail_trunc;
- if (flush_data_block(data, diff, fi))
+ if (flush_data_block(data, diff, fi, flags))
return -1;
}
+ if ((flags & DW_ALLIGN_DEVBLK) && allign_file(data) != 0)
+ return -1;
+
return 0;
fail_read:
perror(fi->input_file);
@@ -179,13 +205,16 @@ fail_trunc:
}
int write_data_from_fd_condensed(data_writer_t *data, file_info_t *fi,
- int infd, sparse_map_t *map)
+ int infd, sparse_map_t *map, int flags)
{
size_t start, count, diff;
sparse_map_t *m;
uint64_t offset;
ssize_t ret;
+ if ((flags & DW_ALLIGN_DEVBLK) && allign_file(data) != 0)
+ return -1;
+
fi->startblock = data->super->bytes_used;
fi->sparse = 0;
data->block_idx = 0;
@@ -235,10 +264,13 @@ int write_data_from_fd_condensed(data_writer_t *data, file_info_t *fi,
map = map->next;
}
- if (flush_data_block(data, diff, fi))
+ if (flush_data_block(data, diff, fi, flags))
return -1;
}
+ if ((flags & DW_ALLIGN_DEVBLK) && allign_file(data) != 0)
+ return -1;
+
return 0;
fail_map_size:
fprintf(stderr, "%s: sparse file map spans beyond file size\n",
@@ -258,7 +290,7 @@ fail_trunc:
}
data_writer_t *data_writer_create(sqfs_super_t *super, compressor_t *cmp,
- int outfd)
+ int outfd, size_t devblksize)
{
data_writer_t *data;
@@ -275,6 +307,7 @@ data_writer_t *data_writer_create(sqfs_super_t *super, compressor_t *cmp,
data->super = super;
data->cmp = cmp;
data->outfd = outfd;
+ data->devblksz = devblksize;
return data;
}
diff --git a/mkfs/mkfs.c b/mkfs/mkfs.c
index e72b669..f1c1f1b 100644
--- a/mkfs/mkfs.c
+++ b/mkfs/mkfs.c
@@ -18,7 +18,7 @@ static int process_file(data_writer_t *data, tree_node_t *n, bool quiet)
return -1;
}
- ret = write_data_from_fd(data, n->data.file, infd);
+ ret = write_data_from_fd(data, n->data.file, infd, 0);
close(infd);
return ret;
@@ -172,7 +172,7 @@ int main(int argc, char **argv)
super.bytes_used += ret;
}
- data = data_writer_create(&super, cmp, outfd);
+ data = data_writer_create(&super, cmp, outfd, opt.devblksz);
if (data == NULL)
goto out_cmp;
diff --git a/tar/tar2sqfs.c b/tar/tar2sqfs.c
index 1b7d3aa..3417fd0 100644
--- a/tar/tar2sqfs.c
+++ b/tar/tar2sqfs.c
@@ -185,14 +185,14 @@ static int write_file(tar_header_decoded_t *hdr, file_info_t *fi,
if (hdr->sparse != NULL) {
ret = write_data_from_fd_condensed(data, fi, STDIN_FILENO,
- hdr->sparse);
+ hdr->sparse, 0);
if (ret)
return -1;
return skip_padding(STDIN_FILENO, hdr->record_size);
}
- if (write_data_from_fd(data, fi, STDIN_FILENO))
+ if (write_data_from_fd(data, fi, STDIN_FILENO, 0))
return -1;
return skip_padding(STDIN_FILENO, fi->size);
@@ -361,7 +361,7 @@ int main(int argc, char **argv)
super.bytes_used += ret;
}
- data = data_writer_create(&super, cmp, outfd);
+ data = data_writer_create(&super, cmp, outfd, devblksize);
if (data == NULL)
goto out_cmp;