fs/squashfs/decompressor_single.c
Source file repositories/reference/linux-study-clean/fs/squashfs/decompressor_single.c
File Facts
- System
- Linux kernel
- Corpus path
fs/squashfs/decompressor_single.c- Extension
.c- Size
- 1956 bytes
- Lines
- 92
- Domain
- Core OS
- Bucket
- VFS And Filesystem Core
- Inferred role
- Core OS: implementation source
- Status
- source implementation candidate
Why This File Exists
Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
- Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/types.hlinux/mutex.hlinux/slab.hlinux/bio.hsquashfs_fs.hsquashfs_fs_sb.hdecompressor.hsquashfs.h
Detected Declarations
struct squashfs_streamfunction squashfs_decompressor_destroyfunction squashfs_decompressfunction squashfs_max_decompressors
Annotated Snippet
struct squashfs_stream {
void *stream;
struct mutex mutex;
};
static void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
void *comp_opts)
{
struct squashfs_stream *stream;
int err = -ENOMEM;
stream = kmalloc_obj(*stream);
if (stream == NULL)
goto out;
stream->stream = msblk->decompressor->init(msblk, comp_opts);
if (IS_ERR(stream->stream)) {
err = PTR_ERR(stream->stream);
goto out;
}
kfree(comp_opts);
mutex_init(&stream->mutex);
return stream;
out:
kfree(stream);
return ERR_PTR(err);
}
static void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
{
struct squashfs_stream *stream = msblk->stream;
if (stream) {
msblk->decompressor->free(stream->stream);
kfree(stream);
}
}
static int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio,
int offset, int length,
struct squashfs_page_actor *output)
{
int res;
struct squashfs_stream *stream = msblk->stream;
mutex_lock(&stream->mutex);
res = msblk->decompressor->decompress(msblk, stream->stream, bio,
offset, length, output);
mutex_unlock(&stream->mutex);
if (res < 0)
ERROR("%s decompression failed, data probably corrupt\n",
msblk->decompressor->name);
return res;
}
static int squashfs_max_decompressors(void)
{
return 1;
}
const struct squashfs_decompressor_thread_ops squashfs_decompressor_single = {
.create = squashfs_decompressor_create,
.destroy = squashfs_decompressor_destroy,
.decompress = squashfs_decompress,
.max_decompressors = squashfs_max_decompressors,
};
Annotation
- Immediate include surface: `linux/types.h`, `linux/mutex.h`, `linux/slab.h`, `linux/bio.h`, `squashfs_fs.h`, `squashfs_fs_sb.h`, `decompressor.h`, `squashfs.h`.
- Detected declarations: `struct squashfs_stream`, `function squashfs_decompressor_destroy`, `function squashfs_decompress`, `function squashfs_max_decompressors`.
- Atlas domain: Core OS / VFS And Filesystem Core.
- Implementation status: source implementation candidate.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.