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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /fs/erofs/decompressor.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'fs/erofs/decompressor.c')
-rw-r--r--fs/erofs/decompressor.c517
1 files changed, 517 insertions, 0 deletions
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
new file mode 100644
index 000000000..27caf4beb
--- /dev/null
+++ b/fs/erofs/decompressor.c
@@ -0,0 +1,517 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2019 HUAWEI, Inc.
+ * https://www.huawei.com/
+ * Copyright (C) 2024 Alibaba Cloud
+ */
+#include "compress.h"
+#include <linux/lz4.h>
+
+#define LZ4_MAX_DISTANCE_PAGES (DIV_ROUND_UP(LZ4_DISTANCE_MAX, PAGE_SIZE) + 1)
+
+static int z_erofs_load_lz4_config(struct super_block *sb,
+ struct erofs_super_block *dsb, void *data, int size)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ struct z_erofs_lz4_cfgs *lz4 = data;
+ u16 distance;
+
+ if (lz4) {
+ if (size < sizeof(struct z_erofs_lz4_cfgs)) {
+ erofs_err(sb, "invalid lz4 cfgs, size=%u", size);
+ return -EINVAL;
+ }
+ distance = le16_to_cpu(lz4->max_distance);
+
+ sbi->lz4.max_pclusterblks = le16_to_cpu(lz4->max_pclusterblks);
+ if (!sbi->lz4.max_pclusterblks) {
+ sbi->lz4.max_pclusterblks = 1; /* reserved case */
+ } else if (sbi->lz4.max_pclusterblks >
+ erofs_blknr(sb, Z_EROFS_PCLUSTER_MAX_SIZE)) {
+ erofs_err(sb, "too large lz4 pclusterblks %u",
+ sbi->lz4.max_pclusterblks);
+ return -EINVAL;
+ }
+ } else {
+ distance = le16_to_cpu(dsb->u1.lz4_max_distance);
+ if (!distance && !erofs_sb_has_lz4_0padding(sbi))
+ return 0;
+ sbi->lz4.max_pclusterblks = 1;
+ sbi->available_compr_algs = 1 << Z_EROFS_COMPRESSION_LZ4;
+ }
+
+ sbi->lz4.max_distance_pages = distance ?
+ DIV_ROUND_UP(distance, PAGE_SIZE) + 1 :
+ LZ4_MAX_DISTANCE_PAGES;
+ return z_erofs_gbuf_growsize(sbi->lz4.max_pclusterblks);
+}
+
+/*
+ * Fill all gaps with bounce pages if it's a sparse page list. Also check if
+ * all physical pages are consecutive, which can be seen for moderate CR.
+ */
+static int z_erofs_lz4_prepare_dstpages(struct z_erofs_decompress_req *rq,
+ struct page **pagepool)
+{
+ struct page *availables[LZ4_MAX_DISTANCE_PAGES] = { NULL };
+ unsigned long bounced[DIV_ROUND_UP(LZ4_MAX_DISTANCE_PAGES,
+ BITS_PER_LONG)] = { 0 };
+ unsigned int lz4_max_distance_pages =
+ EROFS_SB(rq->sb)->lz4.max_distance_pages;
+ void *kaddr = NULL;
+ unsigned int i, j, top;
+
+ top = 0;
+ for (i = j = 0; i < rq->outpages; ++i, ++j) {
+ struct page *const page = rq->out[i];
+ struct page *victim;
+
+ if (j >= lz4_max_distance_pages)
+ j = 0;
+
+ /* 'valid' bounced can only be tested after a complete round */
+ if (!rq->fillgaps && test_bit(j, bounced)) {
+ DBG_BUGON(i < lz4_max_distance_pages);
+ DBG_BUGON(top >= lz4_max_distance_pages);
+ availables[top++] = rq->out[i - lz4_max_distance_pages];
+ }
+
+ if (page) {
+ __clear_bit(j, bounced);
+ if (!PageHighMem(page)) {
+ if (!i) {
+ kaddr = page_address(page);
+ continue;
+ }
+ if (kaddr &&
+ kaddr + PAGE_SIZE == page_address(page)) {
+ kaddr += PAGE_SIZE;
+ continue;
+ }
+ }
+ kaddr = NULL;
+ continue;
+ }
+ kaddr = NULL;
+ __set_bit(j, bounced);
+
+ if (top) {
+ victim = availables[--top];
+ } else {
+ victim = __erofs_allocpage(pagepool, rq->gfp, true);
+ if (!victim)
+ return -ENOMEM;
+ set_page_private(victim, Z_EROFS_SHORTLIVED_PAGE);
+ }
+ rq->out[i] = victim;
+ }
+ return kaddr ? 1 : 0;
+}
+
+static void *z_erofs_lz4_handle_overlap(const struct z_erofs_decompress_req *rq,
+ void *inpage, void *out, unsigned int *inputmargin,
+ int *maptype, bool may_inplace)
+{
+ unsigned int oend, omargin, cnt, i;
+ struct page **in;
+ void *src;
+
+ /*
+ * If in-place I/O isn't used, for example, the bounce compressed cache
+ * can hold data for incomplete read requests. Just map the compressed
+ * buffer as well and decompress directly.
+ */
+ if (!rq->inplace_io) {
+ if (rq->inpages <= 1) {
+ *maptype = 0;
+ return inpage;
+ }
+ kunmap_local(inpage);
+ src = erofs_vm_map_ram(rq->in, rq->inpages);
+ if (!src)
+ return ERR_PTR(-ENOMEM);
+ *maptype = 1;
+ return src;
+ }
+ /*
+ * Then, deal with in-place I/Os. The reasons why in-place I/O is useful
+ * are: (1) It minimizes memory footprint during the I/O submission,
+ * which is useful for slow storage (including network devices and
+ * low-end HDDs/eMMCs) but with a lot inflight I/Os; (2) If in-place
+ * decompression can also be applied, it will reuse the unique buffer so
+ * that no extra CPU D-cache is polluted with temporary compressed data
+ * for extreme performance.
+ */
+ oend = rq->pageofs_out + rq->outputsize;
+ omargin = PAGE_ALIGN(oend) - oend;
+ if (!rq->partial_decoding && may_inplace &&
+ omargin >= LZ4_DECOMPRESS_INPLACE_MARGIN(rq->inputsize)) {
+ for (i = 0; i < rq->inpages; ++i)
+ if (rq->out[rq->outpages - rq->inpages + i] !=
+ rq->in[i])
+ break;
+ if (i >= rq->inpages) {
+ kunmap_local(inpage);
+ *maptype = 3;
+ return out + ((rq->outpages - rq->inpages) << PAGE_SHIFT);
+ }
+ }
+ /*
+ * If in-place decompression can't be applied, copy compressed data that
+ * may potentially overlap during decompression to a per-CPU buffer.
+ */
+ src = z_erofs_get_gbuf(rq->inpages);
+ if (!src) {
+ DBG_BUGON(1);
+ kunmap_local(inpage);
+ return ERR_PTR(-EFAULT);
+ }
+
+ for (i = 0, in = rq->in; i < rq->inputsize; i += cnt, ++in) {
+ cnt = min_t(u32, rq->inputsize - i, PAGE_SIZE - *inputmargin);
+ if (!inpage)
+ inpage = kmap_local_page(*in);
+ memcpy(src + i, inpage + *inputmargin, cnt);
+ kunmap_local(inpage);
+ inpage = NULL;
+ *inputmargin = 0;
+ }
+ *maptype = 2;
+ return src;
+}
+
+/*
+ * Get the exact on-disk size of the compressed data:
+ * - For LZ4, it should apply if the zero_padding feature is on (5.3+);
+ * - For others, zero_padding is enabled all the time.
+ */
+const char *z_erofs_fixup_insize(struct z_erofs_decompress_req *rq,
+ const char *padbuf, unsigned int padbufsize)
+{
+ const char *padend;
+
+ padend = memchr_inv(padbuf, 0, padbufsize);
+ if (!padend)
+ return "compressed data start not found";
+ rq->inputsize -= padend - padbuf;
+ rq->pageofs_in += padend - padbuf;
+ return NULL;
+}
+
+static const char *__z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,
+ u8 *dst)
+{
+ bool may_inplace = false;
+ unsigned int inputmargin;
+ u8 *out, *headpage, *src;
+ const char *reason;
+ int ret, maptype;
+
+ headpage = kmap_local_page(*rq->in);
+ reason = z_erofs_fixup_insize(rq, headpage + rq->pageofs_in,
+ min_t(unsigned int, rq->inputsize,
+ rq->sb->s_blocksize - rq->pageofs_in));
+ if (reason) {
+ kunmap_local(headpage);
+ return reason;
+ }
+ may_inplace = !((rq->pageofs_in + rq->inputsize) &
+ (rq->sb->s_blocksize - 1));
+
+ inputmargin = rq->pageofs_in;
+ src = z_erofs_lz4_handle_overlap(rq, headpage, dst, &inputmargin,
+ &maptype, may_inplace);
+ if (IS_ERR(src))
+ return ERR_CAST(src);
+
+ out = dst + rq->pageofs_out;
+ if (rq->partial_decoding)
+ ret = LZ4_decompress_safe_partial(src + inputmargin, out,
+ rq->inputsize, rq->outputsize, rq->outputsize);
+ else
+ ret = LZ4_decompress_safe(src + inputmargin, out,
+ rq->inputsize, rq->outputsize);
+ if (ret == rq->outputsize)
+ reason = NULL;
+ else if (ret < 0)
+ reason = "corrupted compressed data";
+ else
+ reason = "unexpected end of stream";
+
+ if (!maptype) {
+ kunmap_local(headpage);
+ } else if (maptype == 1) {
+ vm_unmap_ram(src, rq->inpages);
+ } else if (maptype == 2) {
+ z_erofs_put_gbuf(src);
+ } else if (maptype != 3) {
+ DBG_BUGON(1);
+ return ERR_PTR(-EFAULT);
+ }
+ return reason;
+}
+
+static const char *z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,
+ struct page **pagepool)
+{
+ unsigned int dst_maptype;
+ const char *reason;
+ void *dst;
+ int ret;
+
+ /* one optimized fast path only for non bigpcluster cases yet */
+ if (rq->inpages == 1 && rq->outpages == 1 && !rq->inplace_io) {
+ DBG_BUGON(!*rq->out);
+ dst = kmap_local_page(*rq->out);
+ dst_maptype = 0;
+ } else {
+ /* general decoding path which can be used for all cases */
+ ret = z_erofs_lz4_prepare_dstpages(rq, pagepool);
+ if (ret < 0)
+ return ERR_PTR(ret);
+ if (ret > 0) {
+ dst = page_address(*rq->out);
+ dst_maptype = 1;
+ } else {
+ dst = erofs_vm_map_ram(rq->out, rq->outpages);
+ if (!dst)
+ return ERR_PTR(-ENOMEM);
+ dst_maptype = 2;
+ }
+ }
+ reason = __z_erofs_lz4_decompress(rq, dst);
+ if (!dst_maptype)
+ kunmap_local(dst);
+ else if (dst_maptype == 2)
+ vm_unmap_ram(dst, rq->outpages);
+ return reason;
+}
+
+static const char *z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
+ struct page **pagepool)
+{
+ const unsigned int nrpages_in = rq->inpages, nrpages_out = rq->outpages;
+ const unsigned int bs = rq->sb->s_blocksize;
+ unsigned int cur = 0, ni = 0, no, pi, po, insz, cnt;
+ u8 *kin;
+
+ if (rq->outputsize > rq->inputsize)
+ return ERR_PTR(-EOPNOTSUPP);
+ if (rq->alg == Z_EROFS_COMPRESSION_INTERLACED) {
+ cur = bs - (rq->pageofs_out & (bs - 1));
+ DBG_BUGON(rq->pageofs_in & (bs - 1));
+ pi = (rq->pageofs_in + rq->inputsize - cur) & ~PAGE_MASK;
+ cur = min(cur, rq->outputsize);
+ if (cur && rq->out[0]) {
+ kin = kmap_local_page(rq->in[nrpages_in - 1]);
+ if (rq->out[0] == rq->in[nrpages_in - 1])
+ memmove(kin + rq->pageofs_out, kin + pi, cur);
+ else
+ memcpy_to_page(rq->out[0], rq->pageofs_out,
+ kin + pi, cur);
+ kunmap_local(kin);
+ }
+ rq->outputsize -= cur;
+ }
+
+ for (; rq->outputsize; rq->pageofs_in = 0, cur += insz, ni++) {
+ insz = min(PAGE_SIZE - rq->pageofs_in, rq->outputsize);
+ rq->outputsize -= insz;
+ if (!rq->in[ni])
+ continue;
+ kin = kmap_local_page(rq->in[ni]);
+ pi = 0;
+ do {
+ no = (rq->pageofs_out + cur + pi) >> PAGE_SHIFT;
+ po = (rq->pageofs_out + cur + pi) & ~PAGE_MASK;
+ DBG_BUGON(no >= nrpages_out);
+ cnt = min(insz - pi, PAGE_SIZE - po);
+ if (rq->out[no] == rq->in[ni])
+ memmove(kin + po,
+ kin + rq->pageofs_in + pi, cnt);
+ else if (rq->out[no])
+ memcpy_to_page(rq->out[no], po,
+ kin + rq->pageofs_in + pi, cnt);
+ pi += cnt;
+ } while (pi < insz);
+ kunmap_local(kin);
+ }
+ DBG_BUGON(ni > nrpages_in);
+ return NULL;
+}
+
+const char *z_erofs_stream_switch_bufs(struct z_erofs_stream_dctx *dctx,
+ void **dst, void **src, struct page **pgpl)
+{
+ struct z_erofs_decompress_req *rq = dctx->rq;
+ struct page **pgo, *tmppage;
+ unsigned int j;
+
+ if (!dctx->avail_out) {
+ if (++dctx->no >= rq->outpages || !rq->outputsize)
+ return "insufficient space for decompressed data";
+
+ if (dctx->kout)
+ kunmap_local(dctx->kout);
+ dctx->avail_out = min(rq->outputsize, PAGE_SIZE - rq->pageofs_out);
+ rq->outputsize -= dctx->avail_out;
+ pgo = &rq->out[dctx->no];
+ if (!*pgo && rq->fillgaps) { /* deduped */
+ *pgo = erofs_allocpage(pgpl, rq->gfp);
+ if (!*pgo) {
+ dctx->kout = NULL;
+ return ERR_PTR(-ENOMEM);
+ }
+ set_page_private(*pgo, Z_EROFS_SHORTLIVED_PAGE);
+ }
+ if (*pgo) {
+ dctx->kout = kmap_local_page(*pgo);
+ *dst = dctx->kout + rq->pageofs_out;
+ } else {
+ *dst = dctx->kout = NULL;
+ }
+ rq->pageofs_out = 0;
+ }
+
+ if (dctx->inbuf_pos == dctx->inbuf_sz && rq->inputsize) {
+ if (++dctx->ni >= rq->inpages)
+ return "invalid compressed data";
+ if (dctx->kout) /* unlike kmap(), take care of the orders */
+ kunmap_local(dctx->kout);
+ kunmap_local(dctx->kin);
+
+ dctx->inbuf_sz = min_t(u32, rq->inputsize, PAGE_SIZE);
+ rq->inputsize -= dctx->inbuf_sz;
+ dctx->kin = kmap_local_page(rq->in[dctx->ni]);
+ *src = dctx->kin;
+ dctx->bounced = false;
+ if (dctx->kout) {
+ j = (u8 *)*dst - dctx->kout;
+ dctx->kout = kmap_local_page(rq->out[dctx->no]);
+ *dst = dctx->kout + j;
+ }
+ dctx->inbuf_pos = 0;
+ }
+
+ /*
+ * Handle overlapping: Use the given bounce buffer if the input data is
+ * under processing; Or utilize short-lived pages from the on-stack page
+ * pool, where pages are shared among the same request. Note that only
+ * a few inplace I/O pages need to be doubled.
+ */
+ if (!dctx->bounced && rq->out[dctx->no] == rq->in[dctx->ni]) {
+ memcpy(dctx->bounce, *src, dctx->inbuf_sz);
+ *src = dctx->bounce;
+ dctx->bounced = true;
+ }
+
+ for (j = dctx->ni + 1; j < rq->inpages; ++j) {
+ if (rq->out[dctx->no] != rq->in[j])
+ continue;
+ tmppage = erofs_allocpage(pgpl, rq->gfp);
+ if (!tmppage)
+ return ERR_PTR(-ENOMEM);
+ set_page_private(tmppage, Z_EROFS_SHORTLIVED_PAGE);
+ copy_highpage(tmppage, rq->in[j]);
+ rq->in[j] = tmppage;
+ }
+ return NULL;
+}
+
+const struct z_erofs_decompressor *z_erofs_decomp[] = {
+ [Z_EROFS_COMPRESSION_SHIFTED] = &(const struct z_erofs_decompressor) {
+ .decompress = z_erofs_transform_plain,
+ .name = "shifted"
+ },
+ [Z_EROFS_COMPRESSION_INTERLACED] = &(const struct z_erofs_decompressor) {
+ .decompress = z_erofs_transform_plain,
+ .name = "interlaced"
+ },
+ [Z_EROFS_COMPRESSION_LZ4] = &(const struct z_erofs_decompressor) {
+ .config = z_erofs_load_lz4_config,
+ .decompress = z_erofs_lz4_decompress,
+ .init = z_erofs_gbuf_init,
+ .exit = z_erofs_gbuf_exit,
+ .name = "lz4"
+ },
+#ifdef CONFIG_EROFS_FS_ZIP_LZMA
+ [Z_EROFS_COMPRESSION_LZMA] = &z_erofs_lzma_decomp,
+#endif
+#ifdef CONFIG_EROFS_FS_ZIP_DEFLATE
+ [Z_EROFS_COMPRESSION_DEFLATE] = &z_erofs_deflate_decomp,
+#endif
+#ifdef CONFIG_EROFS_FS_ZIP_ZSTD
+ [Z_EROFS_COMPRESSION_ZSTD] = &z_erofs_zstd_decomp,
+#endif
+};
+
+int z_erofs_parse_cfgs(struct super_block *sb, struct erofs_super_block *dsb)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
+ unsigned long algs, alg;
+ erofs_off_t offset;
+ int size, ret = 0;
+
+ if (!erofs_sb_has_compr_cfgs(sbi))
+ return z_erofs_load_lz4_config(sb, dsb, NULL, 0);
+
+ algs = le16_to_cpu(dsb->u1.available_compr_algs);
+ sbi->available_compr_algs = algs;
+ if (algs & ~Z_EROFS_ALL_COMPR_ALGS) {
+ erofs_err(sb, "unidentified algorithms %lx, please upgrade kernel",
+ algs & ~Z_EROFS_ALL_COMPR_ALGS);
+ return -EOPNOTSUPP;
+ }
+
+ (void)erofs_init_metabuf(&buf, sb, false);
+ offset = EROFS_SUPER_OFFSET + sbi->sb_size;
+ for_each_set_bit(alg, &algs, Z_EROFS_COMPRESSION_MAX) {
+ const struct z_erofs_decompressor *dec = z_erofs_decomp[alg];
+ void *data;
+
+ data = erofs_read_metadata(sb, &buf, &offset, &size);
+ if (IS_ERR(data)) {
+ ret = PTR_ERR(data);
+ break;
+ }
+
+ if (dec && dec->config) {
+ ret = dec->config(sb, dsb, data, size);
+ } else {
+ erofs_err(sb, "algorithm %ld isn't enabled on this kernel",
+ alg);
+ ret = -EOPNOTSUPP;
+ }
+ kfree(data);
+ if (ret)
+ break;
+ }
+ erofs_put_metabuf(&buf);
+ return ret;
+}
+
+int __init z_erofs_init_decompressor(void)
+{
+ int i, err;
+
+ for (i = 0; i < Z_EROFS_COMPRESSION_MAX; ++i) {
+ err = z_erofs_decomp[i] ? z_erofs_decomp[i]->init() : 0;
+ if (err) {
+ while (i--)
+ if (z_erofs_decomp[i])
+ z_erofs_decomp[i]->exit();
+ return err;
+ }
+ }
+ return 0;
+}
+
+void z_erofs_exit_decompressor(void)
+{
+ int i;
+
+ for (i = 0; i < Z_EROFS_COMPRESSION_MAX; ++i)
+ if (z_erofs_decomp[i])
+ z_erofs_decomp[i]->exit();
+}