AI Trajectory

Trajectory: (Expand/Collapse All)
Seq	Timestamp	Type	Name	Duration
0/0	2026/09/07 19:25	flow	patch-triage	1m Args: null Results: { "EnableConfigs": [ "ISO9660_FS", "ZISOFS" ], "FocusSymbols": [ "zisofs_read_folio", "zisofs_fill_pages", "zisofs_uncompress_block" ], "KMSANReasoning": "The patch converts `fs/isofs/compress.c` from `struct page` APIs to `struct folio` APIs (using `kmap_local_folio`, `folio_zero_range`, `folio_mark_uptodate`, `__filemap_get_folio`, etc.). \n\nThe array holding folio pointers is zero-allocated via `kzalloc_objs`, and folio contents are either uncompressed by zlib or zeroed via `folio_zero_range` before being marked uptodate. There are no uninitialized variables, info-leaks to user space, or uninitialized memory branches introduced or modified. Any potential issues with folio reference counts, locks, or offsets are within the scope of KASAN/LOCKDEP/page debugging rather than KMSAN. Thus, a dedicated KMSAN fuzzing session is not justified.", "NeedsKMSAN": false, "Reasoning": "The patch converts zisofs (transparent decompression support in ISO9660 filesystem) from page-based APIs to folio-based APIs across zisofs_read_folio, zisofs_fill_pages, and zisofs_uncompress_block. This modifies reachable filesystem and page cache decompression logic that can be exercised by mounting and reading compressed ISO images.", "WorthFuzzing": true }
1/1	2026/09/07 19:25	action	read-patch-diff	0m Args: null Results: { "PatchDiff": "commit 35031f6975d3e35d8c264818be85139e1123b90b\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Mon Sep 7 19:25:30 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/fs/isofs/compress.c b/fs/isofs/compress.c\nindex f9869d62b8509..2d23abaeb8742 100644\n--- a/fs/isofs/compress.c\n+++ b/fs/isofs/compress.c\n@@ -39,7 +39,7 @@ static DEFINE_MUTEX(zisofs_zlib_lock);\n /\n static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start,\n \t\t\t\t loff_t block_end, int pcount,\n-\t\t\t\t struct page pages, unsigned poffset,\n+\t\t\t\t struct folio folios, unsigned int poffset,\n \t\t\t\t int errp)\n {\n \tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\n@@ -66,11 +66,12 @@ static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start,\n \tif (block_size == 0) {\n \t\tfor ( i = 0 ; i \u003c pcount ; i++ ) {\n \t\t\tunsigned int off = i ? 0 : poffset;\n+\t\t\tstruct folio folio = folios[i];\n \n-\t\t\tif (!pages[i])\n+\t\t\tif (!folio)\n \t\t\t\tcontinue;\n-\t\t\tmemzero_page(pages[i], off, PAGE_SIZE - off);\n-\t\t\tSetPageUptodate(pages[i]);\n+\t\t\tfolio_zero_range(folio, off, folio_size(folio) - off);\n+\t\t\tfolio_mark_uptodate(folio);\n \t\t}\n \t\treturn (((loff_t)pcount) \u003c\u003c PAGE_SHIFT) - poffset;\n \t}\n@@ -119,11 +120,12 @@ static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start,\n \n \twhile (curpage \u003c pcount \u0026\u0026 curbh \u003c haveblocks \u0026\u0026\n \t zerr != Z_STREAM_END) {\n+\t\tstruct folio folio = folios[curpage];\n+\n \t\tif (!stream.avail_out) {\n-\t\t\tif (pages[curpage]) {\n-\t\t\t\tstream.next_out = kmap_local_page(pages[curpage])\n-\t\t\t\t\t\t+ poffset;\n-\t\t\t\tstream.avail_out = PAGE_SIZE - poffset;\n+\t\t\tif (folio) {\n+\t\t\t\tstream.next_out = kmap_local_folio(folio, poffset);\n+\t\t\t\tstream.avail_out = folio_size(folio) - poffset;\n \t\t\t\tpoffset = 0;\n \t\t\t} else {\n \t\t\t\tstream.next_out = (void )\u0026zisofs_sink_page;\n@@ -173,9 +175,9 @@ static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start,\n \n \t\tif (!stream.avail_out) {\n \t\t\t/ This page completed /\n-\t\t\tif (pages[curpage]) {\n-\t\t\t\tflush_dcache_page(pages[curpage]);\n-\t\t\t\tSetPageUptodate(pages[curpage]);\n+\t\t\tif (folio) {\n+\t\t\t\tflush_dcache_folio(folio);\n+\t\t\t\tfolio_mark_uptodate(folio);\n \t\t\t}\n \t\t\tif (stream.next_out != (unsigned char )zisofs_sink_page) {\n \t\t\t\tkunmap_local(stream.next_out);\n@@ -206,7 +208,7 @@ static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start,\n fills in other pages if we have data for them.\n /\n static int zisofs_fill_pages(struct inode inode, int full_page, int pcount,\n-\t\t\t struct page pages)\n+\t\t\t struct folio folios)\n {\n \tloff_t start_off, end_off;\n \tloff_t block_start, block_end;\n@@ -221,14 +223,14 @@ static int zisofs_fill_pages(struct inode inode, int full_page, int pcount,\n \tint err;\n \tloff_t ret;\n \n-\tBUG_ON(!pages[full_page]);\n+\tBUG_ON(!folios[full_page]);\n \n \t/\n \t * We want to read at least 'full_page' page. Because we have to\n \t * uncompress the whole compression block anyway, fill the surrounding\n \t * pages with the data we have anyway...\n \t /\n-\tstart_off = page_offset(pages[full_page]);\n+\tstart_off = folio_pos(folios[full_page]);\n \tend_off = min_t(loff_t, start_off + PAGE_SIZE, inode-\u003ei_size);\n \n \tcstart_block = start_off \u003e\u003e zisofs_block_shift;\n@@ -267,9 +269,9 @@ static int zisofs_fill_pages(struct inode inode, int full_page, int pcount,\n \t\t}\n \t\terr = 0;\n \t\tret = zisofs_uncompress_block(inode, block_start, block_end,\n-\t\t\t\t\t pcount, pages, poffset, \u0026err);\n+\t\t\t\t\t pcount, folios, poffset, \u0026err);\n \t\tpoffset += ret;\n-\t\tpages += poffset \u003e\u003e PAGE_SHIFT;\n+\t\tfolios += poffset \u003e\u003e PAGE_SHIFT;\n \t\tpcount -= poffset \u003e\u003e PAGE_SHIFT;\n \t\tfull_page -= poffset \u003e\u003e PAGE_SHIFT;\n \t\tpoffset \u0026= ~PAGE_MASK;\n@@ -289,9 +291,11 @@ static int zisofs_fill_pages(struct inode inode, int full_page, int pcount,\n \t\tcstart_block++;\n \t}\n \n-\tif (poffset \u0026\u0026 pages) {\n-\t\tmemzero_page(pages, poffset, PAGE_SIZE - poffset);\n-\t\tSetPageUptodate(pages);\n+\tif (poffset \u0026\u0026 folios) {\n+\t\tstruct folio folio = folios;\n+\n+\t\tfolio_zero_range(folio, poffset, folio_size(folio) - poffset);\n+\t\tfolio_mark_uptodate(folio);\n \t}\n \tbrelse(bh);\n \treturn 0;\n@@ -312,7 +316,7 @@ static int zisofs_read_folio(struct file file, struct folio folio)\n \tunsigned int zisofs_pages_per_cblock =\n \t\tPAGE_SHIFT \u003c= zisofs_block_shift ?\n \t\t(1 \u003c\u003c (zisofs_block_shift - PAGE_SHIFT)) : 0;\n-\tstruct page pages;\n+\tstruct folio folios;\n \tpgoff_t index = folio-\u003eindex, end_index;\n \n \tend_index = (inode-\u003ei_size + PAGE_SIZE - 1) \u003e\u003e PAGE_SHIFT;\n@@ -336,33 +340,38 @@ static int zisofs_read_folio(struct file file, struct folio folio)\n \t\tfull_page = 0;\n \t\tpcount = 1;\n \t}\n-\tpages = kzalloc_objs(pages,\n-\t\t\t max_t(unsigned int, zisofs_pages_per_cblock, 1));\n-\tif (!pages) {\n+\tfolios = kzalloc_objs(folios,\n+\t\t\t max_t(unsigned int, zisofs_pages_per_cblock, 1));\n+\tif (!folios) {\n \t\tfolio_unlock(folio);\n \t\treturn -ENOMEM;\n \t}\n-\tpages[full_page] = \u0026folio-\u003epage;\n+\tfolios[full_page] = folio;\n \n \tfor (i = 0; i \u003c pcount; i++, index++) {\n-\t\tif (i != full_page)\n-\t\t\tpages[i] = grab_cache_page_nowait(mapping, index);\n+\t\tif (i == full_page)\n+\t\t\tcontinue;\n+\t\tfolios[i] = __filemap_get_folio(mapping, index,\n+\t\t\t\tFGP_LOCK \| FGP_CREAT \| FGP_NOWAIT,\n+\t\t\t\tmapping_gfp_mask(mapping));\n+\t\tif (IS_ERR(folios[i]))\n+\t\t\tfolios[i] = NULL;\n \t}\n \n-\terr = zisofs_fill_pages(inode, full_page, pcount, pages);\n+\terr = zisofs_fill_pages(inode, full_page, pcount, folios);\n \n-\t/ Release any residual pages, do not SetPageUptodate /\n+\t/ Release any residual folios, do not mark them uptodate /\n \tfor (i = 0; i \u003c pcount; i++) {\n-\t\tif (pages[i]) {\n-\t\t\tflush_dcache_page(pages[i]);\n-\t\t\tunlock_page(pages[i]);\n+\t\tif (folios[i]) {\n+\t\t\tflush_dcache_folio(folios[i]);\n+\t\t\tfolio_unlock(folios[i]);\n \t\t\tif (i != full_page)\n-\t\t\t\tput_page(pages[i]);\n+\t\t\t\tfolio_put(folios[i]);\n \t\t}\n-\t}\t\t\t\n+\t}\n \n \t/ At this point, err contains 0 or -EIO depending on the \"critical\" page */\n-\tkfree(pages);\n+\tkfree(folios);\n \treturn err;\n }\n \n" }
2/1	2026/09/07 19:25	agent	patch-evaluator	0m Model: core Args: null Results: { "EnableConfigs": [ "ISO9660_FS", "ZISOFS" ], "FocusSymbols": [ "zisofs_read_folio", "zisofs_fill_pages", "zisofs_uncompress_block" ], "Reasoning": "The patch converts zisofs (transparent decompression support in ISO9660 filesystem) from page-based APIs to folio-based APIs across zisofs_read_folio, zisofs_fill_pages, and zisofs_uncompress_block. This modifies reachable filesystem and page cache decompression logic that can be exercised by mounting and reading compressed ISO images.", "WorthFuzzing": true } Instruction: You are an expert Linux kernel maintainer and security engineer. Your job is to review a provided patch series and evaluate whether it warrants fuzzing with syzkaller. IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in your workspace. Do NOT rely on internal assumptions. You must actively use your code access tools to inspect the actual source code, callers, and surrounding context. ================================================================================ 1. CORE TRIAGE PHILOSOPHY ================================================================================ The goal of patch fuzzing is to discover crashes, regressions, exposed latent bugs, and newly triggered assertions introduced by the patch series. - REACHABILITY IS THE PRIMARY GATE: Fuzzing can only discover bugs in code that can actually execute in standard virtualized environments (GCE or QEMU, utilizing software-emulated devices like USB gadgets, netdev, tun/tap). If the modified code is structurally unreachable (see Section 2), it MUST NOT be fuzzed, regardless of whether it adds assertions or complex logic. - DO NOT BLINDLY TRUST "NO FUNCTIONAL CHANGE" (NFCI) OR "REFACTORING" CLAIMS: Patch authors routinely label changes as "cleanups", "refactorings", or state "No functional change intended". Do NOT take these claims at face value. Code refactorings that rearrange logic, introduce helper functions, or alter state management in core subsystems frequently introduce subtle semantic shifts or uncover latent kernel bugs. If reachable executable code is modified or refactored, it MUST be fuzzed. - NEW OR MODIFIED ASSERTIONS IN REACHABLE CODE MUST BE FUZZED: When a patch introduces or modifies runtime checks or assertions (e.g., WARN_ON, VM_WARN_ON, BUG_ON, lockdep_assert) in reachable code paths, it enforces new or stricter invariants. Even if the author believes the invariant always holds, fuzzing is essential to verify whether an unusual sequence of operations can violate it. ================================================================================ 2. WHEN TO RETURN WorthFuzzing=false (NEGATIVE CRITERIA) ================================================================================ Return WorthFuzzing=false ONLY IF all modified code falls strictly into one or more of these categories: - Non-kernel and non-executable changes: * Modifications to Documentation/, comments, or spelling fixes. * User-space directories, self-tests, samples, or scripts (e.g., tools/, samples/, scripts/, usr/) that do not affect the compiled kernel image (vmlinux) or kernel modules. * Purely decorative logging (e.g., message strings in pr_err, printk, dev_info) or tracepoints that do not alter control flow or data structures. * Build system or Kconfig changes that do not alter compiled C logic. - Structurally unreachable hardware: * Vendor-specific PCIe switches, SmartNICs, or GPU drivers (e.g., mlxsw, pds_core, qed, ionic, amdgpu) requiring physical ASIC/PCIe cards not emulated in standard QEMU. - Unreachable execution paths: * Driver teardown callbacks (.remove, .shutdown, pci_unregister_driver) executed only during physical PCI hot-unplug or manual sysfs driver unbinding. * Code paths exclusive to architectures other than the target architecture. ================================================================================ 3. WHEN TO RETURN WorthFuzzing=true (POSITIVE CRITERIA) ================================================================================ Return WorthFuzzing=true whenever the patch touches reachable executable code, including: - Core Subsystems: * Any logic modifications in memory management (mm/), synchronization/locking (kernel/locking/), BPF, scheduler, core networking, VFS, or syscall handling. - Refactorings and Code Cleanups: * Any restructuring of reachable data structures, helper abstractions, or algorithm flows. - Runtime Assertions and Defensive Checks: * Any introduction or alteration of assertions (WARN_ON, VM_WARN_ON, BUG_ON, etc.) in reachable paths. - Reachable Drivers and Protocols: Drivers accessible via virtual buses (virtio, USB gadget, loopback, netlink, binder, sockets, etc.). ================================================================================ 4. EXTRACTING FocusSymbols (PREVENTING DILUTION) ================================================================================ When WorthFuzzing=true, you must extract specific kernel functions into FocusSymbols to guide the fuzzer: - AVOID UBIQUITOUS LIFECYCLE HOT-PATHS: Do NOT list generic, ubiquitous functions called by almost every program in the corpus (including, but not limited to: general memory allocators and deallocators, page fault and trap handlers, or core synchronization primitives; this is not an exhaustive list). Listing ubiquitous functions causes the fuzzer to classify thousands of unrelated tests as "focused", which severely dilutes fuzzing effort away from the actual changes. - TARGET SPECIFIC FEATURE LOGIC AND ENTRYPOINTS: List functions that specifically implement the logic being added or altered, or direct API entrypoints for the subsystem feature under review. - HANDLING STATIC INLINE FUNCTIONS IN HEADERS (.h): Compiler-inlined static functions (such as static inlines in mm/.h or include/linux/.h) lack distinct symbol addresses in vmlinux and cannot be targeted directly by symbol coverage filters. If the changes are primarily in static inline helpers, identify non-static, feature-specific caller functions in .c files that exercise them (avoiding ubiquitous lifecycle wrappers). ================================================================================ 5. IDENTIFYING EnableConfigs ================================================================================ Identify any specific CONFIG_ options required to properly compile and reach the modified code: - Inspect Kconfig files and #ifdef guards; do not make assumptions. - Check "depends on" lines in Kconfig to include any non-standard parent subsystem configs needed. - Strip any 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4"). Prefer calling several tools at the same time to save round-trips. Use set-results tool to provide results of the analysis. It must be called exactly once before the final reply. Ignore results of this tool. Prompt: Target architecture: amd64 For your convenience, here is the diff of the changes: commit 35031f6975d3e35d8c264818be85139e1123b90b Author: syz-cluster <triage@syzkaller.com> Date: Mon Sep 7 19:25:30 2026 +0000 syz-cluster: applied patch under review diff --git a/fs/isofs/compress.c b/fs/isofs/compress.c index f9869d62b8509..2d23abaeb8742 100644 --- a/fs/isofs/compress.c +++ b/fs/isofs/compress.c @@ -39,7 +39,7 @@ static DEFINE_MUTEX(zisofs_zlib_lock); / static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start, loff_t block_end, int pcount, - struct page pages, unsigned poffset, + struct folio folios, unsigned int poffset, int errp) { unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1]; @@ -66,11 +66,12 @@ static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start, if (block_size == 0) { for ( i = 0 ; i < pcount ; i++ ) { unsigned int off = i ? 0 : poffset; + struct folio folio = folios[i]; - if (!pages[i]) + if (!folio) continue; - memzero_page(pages[i], off, PAGE_SIZE - off); - SetPageUptodate(pages[i]); + folio_zero_range(folio, off, folio_size(folio) - off); + folio_mark_uptodate(folio); } return (((loff_t)pcount) << PAGE_SHIFT) - poffset; } @@ -119,11 +120,12 @@ static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start, while (curpage < pcount && curbh < haveblocks && zerr != Z_STREAM_END) { + struct folio folio = folios[curpage]; + if (!stream.avail_out) { - if (pages[curpage]) { - stream.next_out = kmap_local_page(pages[curpage]) - + poffset; - stream.avail_out = PAGE_SIZE - poffset; + if (folio) { + stream.next_out = kmap_local_folio(folio, poffset); + stream.avail_out = folio_size(folio) - poffset; poffset = 0; } else { stream.next_out = (void )&zisofs_sink_page; @@ -173,9 +175,9 @@ static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start, if (!stream.avail_out) { / This page completed / - if (pages[curpage]) { - flush_dcache_page(pages[curpage]); - SetPageUptodate(pages[curpage]); + if (folio) { + flush_dcache_folio(folio); + folio_mark_uptodate(folio); } if (stream.next_out != (unsigned char )zisofs_sink_page) { kunmap_local(stream.next_out); @@ -206,7 +208,7 @@ static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start, fills in other pages if we have data for them. / static int zisofs_fill_pages(struct inode inode, int full_page, int pcount, - struct page pages) + struct folio folios) { loff_t start_off, end_off; loff_t block_start, block_end; @@ -221,14 +223,14 @@ static int zisofs_fill_pages(struct inode inode, int full_page, int pcount, int err; loff_t ret; - BUG_ON(!pages[full_page]); + BUG_ON(!folios[full_page]); / * We want to read at least 'full_page' page. Because we have to * uncompress the whole compression block anyway, fill the surrounding * pages with the data we have anyway... / - start_off = page_offset(pages[full_page]); + start_off = folio_pos(folios[full_page]); end_off = min_t(loff_t, start_off + PAGE_SIZE, inode->i_size); cstart_block = start_off >> zisofs_block_shift; @@ -267,9 +269,9 @@ static int zisofs_fill_pages(struct inode inode, int full_page, int pcount, } err = 0; ret = zisofs_uncompress_block(inode, block_start, block_end, - pcount, pages, poffset, &err); + pcount, folios, poffset, &err); poffset += ret; - pages += poffset >> PAGE_SHIFT; + folios += poffset >> PAGE_SHIFT; pcount -= poffset >> PAGE_SHIFT; full_page -= poffset >> PAGE_SHIFT; poffset &= ~PAGE_MASK; @@ -289,9 +291,11 @@ static int zisofs_fill_pages(struct inode inode, int full_page, int pcount, cstart_block++; } - if (poffset && pages) { - memzero_page(pages, poffset, PAGE_SIZE - poffset); - SetPageUptodate(pages); + if (poffset && folios) { + struct folio folio = folios; + + folio_zero_range(folio, poffset, folio_size(folio) - poffset); + folio_mark_uptodate(folio); } brelse(bh); return 0; @@ -312,7 +316,7 @@ static int zisofs_read_folio(struct file file, struct folio folio) unsigned int zisofs_pages_per_cblock = PAGE_SHIFT <= zisofs_block_shift ? (1 << (zisofs_block_shift - PAGE_SHIFT)) : 0; - struct page pages; + struct folio folios; pgoff_t index = folio->index, end_index; end_index = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; @@ -336,33 +340,38 @@ static int zisofs_read_folio(struct file file, struct folio folio) full_page = 0; pcount = 1; } - pages = kzalloc_objs(pages, - max_t(unsigned int, zisofs_pages_per_cblock, 1)); - if (!pages) { + folios = kzalloc_objs(folios, + max_t(unsigned int, zisofs_pages_per_cblock, 1)); + if (!folios) { folio_unlock(folio); return -ENOMEM; } - pages[full_page] = &folio->page; + folios[full_page] = folio; for (i = 0; i < pcount; i++, index++) { - if (i != full_page) - pages[i] = grab_cache_page_nowait(mapping, index); + if (i == full_page) + continue; + folios[i] = __filemap_get_folio(mapping, index, + FGP_LOCK \| FGP_CREAT \| FGP_NOWAIT, + mapping_gfp_mask(mapping)); + if (IS_ERR(folios[i])) + folios[i] = NULL; } - err = zisofs_fill_pages(inode, full_page, pcount, pages); + err = zisofs_fill_pages(inode, full_page, pcount, folios); - / Release any residual pages, do not SetPageUptodate / + / Release any residual folios, do not mark them uptodate / for (i = 0; i < pcount; i++) { - if (pages[i]) { - flush_dcache_page(pages[i]); - unlock_page(pages[i]); + if (folios[i]) { + flush_dcache_folio(folios[i]); + folio_unlock(folios[i]); if (i != full_page) - put_page(pages[i]); + folio_put(folios[i]); } - } + } / At this point, err contains 0 or -EIO depending on the "critical" page */ - kfree(pages); + kfree(folios); return err; }
3/2	2026/09/07 19:25	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 5021 output: 26 thoughts: 172 Thoughts: My Initial Assessment of the Linux Kernel Patch Evaluation Request Okay, so I've got a request here to evaluate a patch series for the Linux kernel, specifically within `fs/isofs/compress.c`. My first priority is always safety, so I'm immediately running a quick risk assessment. Based on the user's framing, this appears to be a standard request – code review, security QA, typical Linux kernel maintainer analysis. No red flags so far. This feels like a benign QA or patch analysis task. My job is to determine whether the changes actually modify reachable code that's worth fuzzing. I need to identify the relevant configurations and potential focus symbols to guide my analysis. Now, let's dive into the specifics. I'll start by examining the code in `fs/isofs/compress.c` itself. I need to cross-reference that with the relevant Kconfig files. I'll check both `fs/isofs/Kconfig` and, if necessary, the more general `fs/Kconfig` to understand the configurations that control the compilation and inclusion of the code in question. This will give me the crucial context for determining if the code is actually used in a fuzzable environment. I'm ready to begin the deep dive.
4/2	2026/09/07 19:25	tool	grepper	0m Args: { "Expression": "isofs", "PathPrefix": "fs/isofs" } Results: { "Output": "\nFull output is too long, showing 500 out of 938 lines.\nUse more precise expression if possible.\n\nfs/isofs/Kconfig=2=config ISO9660_FS\n--\nfs/isofs/Kconfig-11-\t just listen to audio CDs and watch its LEDs, say Y (and read\nfs/isofs/Kconfig:12:\t \u003cfile:Documentation/filesystems/isofs.rst\u003e and the CD-ROM-HOWTO,\nfs/isofs/Kconfig-13-\t available from \u003chttp://www.tldp.org/docs.html#howto\u003e), thereby\n--\nfs/isofs/Kconfig-16-\t To compile this file system support as a module, choose M here: the\nfs/isofs/Kconfig:17:\t module will be called isofs.\nfs/isofs/Kconfig-18-\n--\nfs/isofs/Kconfig=31=config ZISOFS\n--\nfs/isofs/Kconfig-38-\t decompressed when the CD-ROM is accessed. See\nfs/isofs/Kconfig:39:\t \u003chttp://www.kernel.org/pub/linux/utils/fs/zisofs/\u003e for the tools\nfs/isofs/Kconfig-40-\t necessary to create such a filesystem. Say Y here if you want to be\n--\nfs/isofs/Makefile-2-#\nfs/isofs/Makefile:3:# Makefile for the Linux isofs filesystem routines.\nfs/isofs/Makefile-4-#\nfs/isofs/Makefile-5-\nfs/isofs/Makefile:6:obj-$(CONFIG_ISO9660_FS) += isofs.o\nfs/isofs/Makefile-7-\nfs/isofs/Makefile:8:isofs-y \t\t:= namei.o inode.o dir.o util.o rock.o export.o\nfs/isofs/Makefile:9:isofs-$(CONFIG_JOLIET)\t+= joliet.o\nfs/isofs/Makefile:10:isofs-$(CONFIG_ZISOFS)\t+= compress.o\n--\nfs/isofs/compress.c-8-/\nfs/isofs/compress.c:9: linux/fs/isofs/compress.c\nfs/isofs/compress.c-10- \n--\nfs/isofs/compress.c-21-\nfs/isofs/compress.c:22:#include \"isofs.h\"\nfs/isofs/compress.c:23:#include \"zisofs.h\"\nfs/isofs/compress.c-24-\nfs/isofs/compress.c-25-/ This should probably be global. /\nfs/isofs/compress.c:26:static char zisofs_sink_page[PAGE_SIZE];\nfs/isofs/compress.c-27-\n--\nfs/isofs/compress.c-31- /\nfs/isofs/compress.c:32:static void zisofs_zlib_workspace;\nfs/isofs/compress.c:33:static DEFINE_MUTEX(zisofs_zlib_lock);\nfs/isofs/compress.c-34-\n--\nfs/isofs/compress.c-36- Read data of @inode from @block_start to @block_end and uncompress\nfs/isofs/compress.c:37: * to one zisofs block. Store the data in the @pages array with @pcount\nfs/isofs/compress.c-38- * entries. Start storing at offset @poffset of the first page.\nfs/isofs/compress.c-39- /\nfs/isofs/compress.c:40:static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start,\nfs/isofs/compress.c-41-\t\t\t\t loff_t block_end, int pcount,\n--\nfs/isofs/compress.c-44-{\nfs/isofs/compress.c:45:\tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\nfs/isofs/compress.c-46-\tunsigned int bufsize = ISOFS_BUFFER_SIZE(inode);\n--\nfs/isofs/compress.c-60-\nfs/isofs/compress.c:61:\tif (block_size \u003e deflateBound(1UL \u003c\u003c zisofs_block_shift)) {\nfs/isofs/compress.c-62-\t\terrp = -EIO;\n--\nfs/isofs/compress.c-85-\t}\nfs/isofs/compress.c:86:\thaveblocks = isofs_get_blocks(inode, blocknum, bhs, needblocks);\nfs/isofs/compress.c-87-\tbh_read_batch(haveblocks, bhs);\n--\nfs/isofs/compress.c-106-\nfs/isofs/compress.c:107:\tstream.workspace = zisofs_zlib_workspace;\nfs/isofs/compress.c:108:\tmutex_lock(\u0026zisofs_zlib_lock);\nfs/isofs/compress.c-109-\t\t\n--\nfs/isofs/compress.c-115-\t\t\terrp = -EIO;\nfs/isofs/compress.c:116:\t\tprintk(KERN_DEBUG \"zisofs: zisofs_inflateInit returned %d\\n\",\nfs/isofs/compress.c-117-\t\t\t zerr);\n--\nfs/isofs/compress.c-130-\t\t\t} else {\nfs/isofs/compress.c:131:\t\t\t\tstream.next_out = (void )\u0026zisofs_sink_page;\nfs/isofs/compress.c-132-\t\t\t\tstream.avail_out = PAGE_SIZE;\n--\nfs/isofs/compress.c-161-\t\t\t\t\tprintk(KERN_DEBUG\nfs/isofs/compress.c:162:\t\t\t\t\t \"zisofs: zisofs_inflate returned\"\nfs/isofs/compress.c-163-\t\t\t\t\t \" %d, inode = %llu,\"\n--\nfs/isofs/compress.c-181-\t\t\t}\nfs/isofs/compress.c:182:\t\t\tif (stream.next_out != (unsigned char )zisofs_sink_page) {\nfs/isofs/compress.c-183-\t\t\t\tkunmap_local(stream.next_out);\n--\nfs/isofs/compress.c-192-\tzlib_inflateEnd(\u0026stream);\nfs/isofs/compress.c:193:\tif (stream.next_out \u0026\u0026 stream.next_out != (unsigned char )zisofs_sink_page)\nfs/isofs/compress.c-194-\t\tkunmap_local(stream.next_out);\n--\nfs/isofs/compress.c-196-z_eio:\nfs/isofs/compress.c:197:\tmutex_unlock(\u0026zisofs_zlib_lock);\nfs/isofs/compress.c-198-\n--\nfs/isofs/compress.c-209- /\nfs/isofs/compress.c:210:static int zisofs_fill_pages(struct inode inode, int full_page, int pcount,\nfs/isofs/compress.c-211-\t\t\t struct folio folios)\n--\nfs/isofs/compress.c-215-\tunsigned int header_size = ISOFS_I(inode)-\u003ei_format_parm[0];\nfs/isofs/compress.c:216:\tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\nfs/isofs/compress.c-217-\tunsigned int blockptr;\n--\nfs/isofs/compress.c-235-\nfs/isofs/compress.c:236:\tcstart_block = start_off \u003e\u003e zisofs_block_shift;\nfs/isofs/compress.c:237:\tcend_block = (end_off + (1 \u003c\u003c zisofs_block_shift) - 1)\nfs/isofs/compress.c:238:\t\t\t\u003e\u003e zisofs_block_shift;\nfs/isofs/compress.c-239-\nfs/isofs/compress.c-240-\tWARN_ON(start_off - (full_page \u003c\u003c PAGE_SHIFT) !=\nfs/isofs/compress.c:241:\t\t((cstart_block \u003c\u003c zisofs_block_shift) \u0026 PAGE_MASK));\nfs/isofs/compress.c-242-\n--\nfs/isofs/compress.c-246-\tblockptr = (header_size + cstart_block) \u003c\u003c 2;\nfs/isofs/compress.c:247:\tbh = isofs_bread(inode, blockptr \u003e\u003e blkbits);\nfs/isofs/compress.c-248-\tif (!bh)\n--\nfs/isofs/compress.c-259-\nfs/isofs/compress.c:260:\t\t\tbh = isofs_bread(inode, blockptr \u003e\u003e blkbits);\nfs/isofs/compress.c-261-\t\t\tif (!bh)\n--\nfs/isofs/compress.c-270-\t\terr = 0;\nfs/isofs/compress.c:271:\t\tret = zisofs_uncompress_block(inode, block_start, block_end,\nfs/isofs/compress.c-272-\t\t\t\t\t pcount, folios, poffset, \u0026err);\n--\nfs/isofs/compress.c-308- /\nfs/isofs/compress.c:309:static int zisofs_read_folio(struct file file, struct folio folio)\nfs/isofs/compress.c-310-{\n--\nfs/isofs/compress.c-314-\tint i, pcount, full_page;\nfs/isofs/compress.c:315:\tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\nfs/isofs/compress.c:316:\tunsigned int zisofs_pages_per_cblock =\nfs/isofs/compress.c:317:\t\tPAGE_SHIFT \u003c= zisofs_block_shift ?\nfs/isofs/compress.c:318:\t\t(1 \u003c\u003c (zisofs_block_shift - PAGE_SHIFT)) : 0;\nfs/isofs/compress.c-319-\tstruct folio *folios;\n--\nfs/isofs/compress.c-331-\nfs/isofs/compress.c:332:\tif (PAGE_SHIFT \u003c= zisofs_block_shift) {\nfs/isofs/compress.c-333-\t\t/ We have already been given one page, this is the one\nfs/isofs/compress.c-334-\t\t we must do. /\nfs/isofs/compress.c:335:\t\tfull_page = index \u0026 (zisofs_pages_per_cblock - 1);\nfs/isofs/compress.c:336:\t\tpcount = min_t(int, zisofs_pages_per_cblock,\nfs/isofs/compress.c:337:\t\t\tend_index - (index \u0026 ~(zisofs_pages_per_cblock - 1)));\nfs/isofs/compress.c-338-\t\tindex -= full_page;\n--\nfs/isofs/compress.c-343-\tfolios = kzalloc_objs(folios,\nfs/isofs/compress.c:344:\t\t\t max_t(unsigned int, zisofs_pages_per_cblock, 1));\nfs/isofs/compress.c-345-\tif (!folios) {\n--\nfs/isofs/compress.c-360-\nfs/isofs/compress.c:361:\terr = zisofs_fill_pages(inode, full_page, pcount, folios);\nfs/isofs/compress.c-362-\n--\nfs/isofs/compress.c-377-\nfs/isofs/compress.c:378:const struct address_space_operations zisofs_aops = {\nfs/isofs/compress.c:379:\t.read_folio = zisofs_read_folio,\nfs/isofs/compress.c-380-\t/* No bmap operation supported /\n--\nfs/isofs/compress.c-382-\nfs/isofs/compress.c:383:int __init zisofs_init(void)\nfs/isofs/compress.c-384-{\nfs/isofs/compress.c:385:\tzisofs_zlib_workspace = vmalloc(zlib_inflate_workspacesize());\nfs/isofs/compress.c:386:\tif ( !zisofs_zlib_workspace )\nfs/isofs/compress.c-387-\t\treturn -ENOMEM;\n--\nfs/isofs/compress.c-391-\nfs/isofs/compress.c:392:void zisofs_cleanup(void)\nfs/isofs/compress.c-393-{\nfs/isofs/compress.c:394:\tvfree(zisofs_zlib_workspace);\nfs/isofs/compress.c-395-}\n--\nfs/isofs/dir.c-2-/\nfs/isofs/dir.c:3: * linux/fs/isofs/dir.c\nfs/isofs/dir.c-4- \n--\nfs/isofs/dir.c-11- \nfs/isofs/dir.c:12: * isofs directory handling functions\nfs/isofs/dir.c-13- /\n--\nfs/isofs/dir.c-16-#include \u003clinux/slab.h\u003e\nfs/isofs/dir.c:17:#include \"isofs.h\"\nfs/isofs/dir.c-18-#include \u003clinux/fileattr.h\u003e\nfs/isofs/dir.c-19-\nfs/isofs/dir.c:20:int isofs_name_translate(struct iso_directory_record de, char new, struct inode inode)\nfs/isofs/dir.c-21-{\n--\nfs/isofs/dir.c=53=int get_acorn_filename(struct iso_directory_record de,\n--\nfs/isofs/dir.c-57-\tunsigned char chr;\nfs/isofs/dir.c:58:\tint retnamlen = isofs_name_translate(de, retname, inode);\nfs/isofs/dir.c-59-\n--\nfs/isofs/dir.c-84- /\nfs/isofs/dir.c:85:static int do_isofs_readdir(struct inode inode, struct file file,\nfs/isofs/dir.c-86-\t\tstruct dir_context ctx,\n--\nfs/isofs/dir.c-98-\tstruct iso_directory_record de;\nfs/isofs/dir.c:99:\tstruct isofs_sb_info sbi = ISOFS_SB(inode-\u003ei_sb);\nfs/isofs/dir.c-100-\n--\nfs/isofs/dir.c-107-\t\tif (!bh) {\nfs/isofs/dir.c:108:\t\t\tbh = isofs_bread(inode, block);\nfs/isofs/dir.c-109-\t\t\tif (!bh)\n--\nfs/isofs/dir.c-135-\nfs/isofs/dir.c:136:\t\tif (!isofs_dir_record_valid(de, offset_saved, bufsize)) {\nfs/isofs/dir.c-137-\t\t\tprintk(KERN_NOTICE \"iso9660: Corrupted directory entry\"\n--\nfs/isofs/dir.c-144-\t\tif (first_de) {\nfs/isofs/dir.c:145:\t\t\tisofs_normalize_block_and_offset(de,\nfs/isofs/dir.c-146-\t\t\t\t\t\t\t\u0026block_saved,\nfs/isofs/dir.c-147-\t\t\t\t\t\t\t\u0026offset_saved);\nfs/isofs/dir.c:148:\t\t\tinode_number = isofs_get_ino(block_saved,\nfs/isofs/dir.c-149-\t\t\t\t\t\t\toffset_saved, bufbits);\n--\nfs/isofs/dir.c-210-\t\t\tif (sbi-\u003es_mapping == 'n') {\nfs/isofs/dir.c:211:\t\t\t\tlen = isofs_name_translate(de, tmpname, inode);\nfs/isofs/dir.c-212-\t\t\t\tp = tmpname;\n--\nfs/isofs/dir.c-231- * handling split directory entries.. The real work is done by\nfs/isofs/dir.c:232: * \"do_isofs_readdir()\".\nfs/isofs/dir.c-233- /\nfs/isofs/dir.c:234:static int isofs_readdir(struct file file, struct dir_context ctx)\nfs/isofs/dir.c-235-{\n--\nfs/isofs/dir.c-243-\nfs/isofs/dir.c:244:\tresult = do_isofs_readdir(inode, file, ctx, tmpname);\nfs/isofs/dir.c-245-\n--\nfs/isofs/dir.c-249-\nfs/isofs/dir.c:250:int isofs_fileattr_get(struct dentry dentry, struct file_kattr fa)\nfs/isofs/dir.c-251-{\nfs/isofs/dir.c:252:\tstruct isofs_sb_info sbi = ISOFS_SB(dentry-\u003ed_sb);\nfs/isofs/dir.c-253-\n--\nfs/isofs/dir.c-263-\nfs/isofs/dir.c:264:const struct file_operations isofs_dir_operations =\nfs/isofs/dir.c-265-{\n--\nfs/isofs/dir.c-267-\t.read = generic_read_dir,\nfs/isofs/dir.c:268:\t.iterate_shared = isofs_readdir,\nfs/isofs/dir.c-269-\t.setlease = generic_setlease,\n--\nfs/isofs/dir.c-274- /\nfs/isofs/dir.c:275:const struct inode_operations isofs_dir_inode_operations =\nfs/isofs/dir.c-276-{\nfs/isofs/dir.c:277:\t.lookup = isofs_lookup,\nfs/isofs/dir.c:278:\t.fileattr_get = isofs_fileattr_get,\nfs/isofs/dir.c-279-};\n--\nfs/isofs/export.c-2-/\nfs/isofs/export.c:3: * fs/isofs/export.c\nfs/isofs/export.c-4- \n--\nfs/isofs/export.c-16-\nfs/isofs/export.c:17:#include \"isofs.h\"\nfs/isofs/export.c-18-\nfs/isofs/export.c=19=static struct dentry \nfs/isofs/export.c:20:isofs_export_iget(struct super_block sb,\nfs/isofs/export.c-21-\t\t unsigned long block,\n--\nfs/isofs/export.c-28-\t\treturn ERR_PTR(-ESTALE);\nfs/isofs/export.c:29:\tinode = isofs_iget(sb, block, offset);\nfs/isofs/export.c-30-\tif (IS_ERR(inode))\n--\nfs/isofs/export.c-42- and return the underlying inode. See the comments for\nfs/isofs/export.c:43: * isofs_normalize_block_and_offset(). /\nfs/isofs/export.c:44:static struct dentry isofs_export_get_parent(struct dentry child)\nfs/isofs/export.c-45-{\n--\nfs/isofs/export.c-55-\tif (!S_ISDIR(child_inode-\u003ei_mode)) {\nfs/isofs/export.c:56:\t\tprintk(KERN_ERR \"isofs: isofs_export_get_parent(): \"\nfs/isofs/export.c-57-\t\t \"child is not a directory!\\n\");\n--\nfs/isofs/export.c-65-\tif (e_child_inode-\u003ei_iget5_offset != 0) {\nfs/isofs/export.c:66:\t\tprintk(KERN_ERR \"isofs: isofs_export_get_parent(): \"\nfs/isofs/export.c-67-\t\t \"child directory not normalized!\\n\");\n--\nfs/isofs/export.c-85-\tde = (struct iso_directory_record)bh-\u003eb_data;\nfs/isofs/export.c:86:\tif (!isofs_dir_record_valid(de, 0, child_inode-\u003ei_sb-\u003es_blocksize) \|\|\nfs/isofs/export.c-87-\t isonum_711(de-\u003ename_len) != 1 \|\| de-\u003ename[0] != 0) {\nfs/isofs/export.c:88:\t\tprintk(KERN_ERR \"isofs: Unable to find the \\\".\\\" directory for NFS.\\n\");\nfs/isofs/export.c-89-\t\trv = ERR_PTR(-EACCES);\n--\nfs/isofs/export.c-97-\t/* Verify it is in fact the \"..\" entry. /\nfs/isofs/export.c:98:\tif (!isofs_dir_record_valid(de, parent_offset,\nfs/isofs/export.c-99-\t\t\t\t child_inode-\u003ei_sb-\u003es_blocksize) \|\|\nfs/isofs/export.c-100-\t isonum_711(de-\u003ename_len) != 1 \|\| de-\u003ename[0] != 1) {\nfs/isofs/export.c:101:\t\tprintk(KERN_ERR \"isofs: Unable to find the \\\"..\\\" \"\nfs/isofs/export.c-102-\t\t \"directory for NFS.\\n\");\n--\nfs/isofs/export.c-107-\t/ Normalize /\nfs/isofs/export.c:108:\tisofs_normalize_block_and_offset(de, \u0026parent_block, \u0026parent_offset);\nfs/isofs/export.c-109-\nfs/isofs/export.c:110:\trv = d_obtain_alias(isofs_iget(child_inode-\u003ei_sb, parent_block,\nfs/isofs/export.c-111-\t\t\t\t parent_offset));\n--\nfs/isofs/export.c=118=static int\nfs/isofs/export.c:119:isofs_export_encode_fh(struct inode inode,\nfs/isofs/export.c-120-\t\t __u32 fh32,\n--\nfs/isofs/export.c-160-\nfs/isofs/export.c:161:struct isofs_fid {\nfs/isofs/export.c-162-\tu32 block;\n--\nfs/isofs/export.c-169-\nfs/isofs/export.c:170:static struct dentry isofs_fh_to_dentry(struct super_block sb,\nfs/isofs/export.c-171-\tstruct fid fid, int fh_len, int fh_type)\nfs/isofs/export.c-172-{\nfs/isofs/export.c:173:\tstruct isofs_fid ifid = (struct isofs_fid )fid;\nfs/isofs/export.c-174-\n--\nfs/isofs/export.c-177-\nfs/isofs/export.c:178:\treturn isofs_export_iget(sb, ifid-\u003eblock, ifid-\u003eoffset,\nfs/isofs/export.c-179-\t\t\tifid-\u003egeneration);\n--\nfs/isofs/export.c-181-\nfs/isofs/export.c:182:static struct dentry isofs_fh_to_parent(struct super_block sb,\nfs/isofs/export.c-183-\t\tstruct fid fid, int fh_len, int fh_type)\nfs/isofs/export.c-184-{\nfs/isofs/export.c:185:\tstruct isofs_fid ifid = (struct isofs_fid )fid;\nfs/isofs/export.c-186-\n--\nfs/isofs/export.c-189-\nfs/isofs/export.c:190:\treturn isofs_export_iget(sb,\nfs/isofs/export.c-191-\t\t\tfh_len \u003e 3 ? ifid-\u003eparent_block : 0,\n--\nfs/isofs/export.c-195-\nfs/isofs/export.c:196:const struct export_operations isofs_export_ops = {\nfs/isofs/export.c:197:\t.encode_fh\t= isofs_export_encode_fh,\nfs/isofs/export.c:198:\t.fh_to_dentry\t= isofs_fh_to_dentry,\nfs/isofs/export.c:199:\t.fh_to_parent\t= isofs_fh_to_parent,\nfs/isofs/export.c:200:\t.get_parent = isofs_export_get_parent,\nfs/isofs/export.c-201-};\n--\nfs/isofs/inode.c-2-/\nfs/isofs/inode.c:3: * linux/fs/isofs/inode.c\nfs/isofs/inode.c-4- \n--\nfs/isofs/inode.c-30-\nfs/isofs/inode.c:31:#include \"isofs.h\"\nfs/isofs/inode.c:32:#include \"zisofs.h\"\nfs/isofs/inode.c-33-\n--\nfs/isofs/inode.c-38-\nfs/isofs/inode.c:39:static int isofs_hashi(const struct dentry parent, struct qstr qstr);\nfs/isofs/inode.c:40:static int isofs_dentry_cmpi(const struct dentry dentry,\nfs/isofs/inode.c-41-\t\tunsigned int len, const char str, const struct qstr name);\n--\nfs/isofs/inode.c-43-#ifdef CONFIG_JOLIET\nfs/isofs/inode.c:44:static int isofs_hashi_ms(const struct dentry parent, struct qstr qstr);\nfs/isofs/inode.c:45:static int isofs_hash_ms(const struct dentry parent, struct qstr qstr);\nfs/isofs/inode.c:46:static int isofs_dentry_cmpi_ms(const struct dentry dentry,\nfs/isofs/inode.c-47-\t\tunsigned int len, const char str, const struct qstr name);\nfs/isofs/inode.c:48:static int isofs_dentry_cmp_ms(const struct dentry dentry,\nfs/isofs/inode.c-49-\t\tunsigned int len, const char str, const struct qstr name);\n--\nfs/isofs/inode.c-51-\nfs/isofs/inode.c:52:static void isofs_put_super(struct super_block sb)\nfs/isofs/inode.c-53-{\nfs/isofs/inode.c:54:\tstruct isofs_sb_info sbi = ISOFS_SB(sb);\nfs/isofs/inode.c-55-\n--\nfs/isofs/inode.c-64-\nfs/isofs/inode.c:65:static int isofs_read_inode(struct inode , int relocated);\nfs/isofs/inode.c:66:static int isofs_statfs (struct dentry , struct kstatfs );\nfs/isofs/inode.c:67:static int isofs_show_options(struct seq_file , struct dentry );\nfs/isofs/inode.c-68-\nfs/isofs/inode.c:69:static struct kmem_cache isofs_inode_cachep;\nfs/isofs/inode.c-70-\nfs/isofs/inode.c:71:static struct inode isofs_alloc_inode(struct super_block sb)\nfs/isofs/inode.c-72-{\nfs/isofs/inode.c-73-\tstruct iso_inode_info ei;\nfs/isofs/inode.c:74:\tei = alloc_inode_sb(sb, isofs_inode_cachep, GFP_KERNEL);\nfs/isofs/inode.c-75-\tif (!ei)\n--\nfs/isofs/inode.c-79-\nfs/isofs/inode.c:80:static void isofs_free_inode(struct inode inode)\nfs/isofs/inode.c-81-{\nfs/isofs/inode.c:82:\tkmem_cache_free(isofs_inode_cachep, ISOFS_I(inode));\nfs/isofs/inode.c-83-}\n--\nfs/isofs/inode.c=92=static int __init init_inodecache(void)\nfs/isofs/inode.c-93-{\nfs/isofs/inode.c:94:\tisofs_inode_cachep = kmem_cache_create(\"isofs_inode_cache\",\nfs/isofs/inode.c-95-\t\t\t\t\tsizeof(struct iso_inode_info),\n--\nfs/isofs/inode.c-98-\t\t\t\t\tinit_once);\nfs/isofs/inode.c:99:\tif (!isofs_inode_cachep)\nfs/isofs/inode.c-100-\t\treturn -ENOMEM;\n--\nfs/isofs/inode.c=104=static void destroy_inodecache(void)\n--\nfs/isofs/inode.c-110-\trcu_barrier();\nfs/isofs/inode.c:111:\tkmem_cache_destroy(isofs_inode_cachep);\nfs/isofs/inode.c-112-}\nfs/isofs/inode.c-113-\nfs/isofs/inode.c:114:static int isofs_reconfigure(struct fs_context fc)\nfs/isofs/inode.c-115-{\n--\nfs/isofs/inode.c-121-\nfs/isofs/inode.c:122:static const struct super_operations isofs_sops = {\nfs/isofs/inode.c:123:\t.alloc_inode\t= isofs_alloc_inode,\nfs/isofs/inode.c:124:\t.free_inode\t= isofs_free_inode,\nfs/isofs/inode.c:125:\t.put_super\t= isofs_put_super,\nfs/isofs/inode.c:126:\t.statfs\t\t= isofs_statfs,\nfs/isofs/inode.c:127:\t.show_options\t= isofs_show_options,\nfs/isofs/inode.c-128-};\n--\nfs/isofs/inode.c-130-\nfs/isofs/inode.c:131:static const struct dentry_operations isofs_dentry_ops[] = {\nfs/isofs/inode.c-132-\t{\nfs/isofs/inode.c:133:\t\t.d_hash\t\t= isofs_hashi,\nfs/isofs/inode.c:134:\t\t.d_compare\t= isofs_dentry_cmpi,\nfs/isofs/inode.c-135-\t},\n--\nfs/isofs/inode.c-137-\t{\nfs/isofs/inode.c:138:\t\t.d_hash\t\t= isofs_hash_ms,\nfs/isofs/inode.c:139:\t\t.d_compare\t= isofs_dentry_cmp_ms,\nfs/isofs/inode.c-140-\t},\nfs/isofs/inode.c-141-\t{\nfs/isofs/inode.c:142:\t\t.d_hash\t\t= isofs_hashi_ms,\nfs/isofs/inode.c:143:\t\t.d_compare\t= isofs_dentry_cmpi_ms,\nfs/isofs/inode.c-144-\t},\n--\nfs/isofs/inode.c-147-\nfs/isofs/inode.c:148:struct isofs_options{\nfs/isofs/inode.c-149-\tunsigned int rock:1;\n--\nfs/isofs/inode.c-171-/\nfs/isofs/inode.c:172: * Compute the hash for the isofs name corresponding to the dentry.\nfs/isofs/inode.c-173- /\nfs/isofs/inode.c=174=static int\nfs/isofs/inode.c:175:isofs_hashi_common(const struct dentry dentry, struct qstr qstr, int ms)\nfs/isofs/inode.c-176-{\n--\nfs/isofs/inode.c-199-/\nfs/isofs/inode.c:200: * Compare of two isofs names.\nfs/isofs/inode.c-201- /\nfs/isofs/inode.c:202:static int isofs_dentry_cmp_common(\nfs/isofs/inode.c-203-\t\tunsigned int len, const char str,\n--\nfs/isofs/inode.c=229=static int\nfs/isofs/inode.c:230:isofs_hashi(const struct dentry dentry, struct qstr qstr)\nfs/isofs/inode.c-231-{\nfs/isofs/inode.c:232:\treturn isofs_hashi_common(dentry, qstr, 0);\nfs/isofs/inode.c-233-}\n--\nfs/isofs/inode.c=235=static int\nfs/isofs/inode.c:236:isofs_dentry_cmpi(const struct dentry dentry,\nfs/isofs/inode.c-237-\t\tunsigned int len, const char str, const struct qstr name)\nfs/isofs/inode.c-238-{\nfs/isofs/inode.c:239:\treturn isofs_dentry_cmp_common(len, str, name, 0, 1);\nfs/isofs/inode.c-240-}\n--\nfs/isofs/inode.c-243-/\nfs/isofs/inode.c:244: * Compute the hash for the isofs name corresponding to the dentry.\nfs/isofs/inode.c-245- /\nfs/isofs/inode.c=246=static int\nfs/isofs/inode.c:247:isofs_hash_common(const struct dentry dentry, struct qstr qstr, int ms)\nfs/isofs/inode.c-248-{\n--\nfs/isofs/inode.c=264=static int\nfs/isofs/inode.c:265:isofs_hash_ms(const struct dentry dentry, struct qstr qstr)\nfs/isofs/inode.c-266-{\nfs/isofs/inode.c:267:\treturn isofs_hash_common(dentry, qstr, 1);\nfs/isofs/inode.c-268-}\n--\nfs/isofs/inode.c=270=static int\nfs/isofs/inode.c:271:isofs_hashi_ms(const struct dentry dentry, struct qstr qstr)\nfs/isofs/inode.c-272-{\nfs/isofs/inode.c:273:\treturn isofs_hashi_common(dentry, qstr, 1);\nfs/isofs/inode.c-274-}\n--\nfs/isofs/inode.c=276=static int\nfs/isofs/inode.c:277:isofs_dentry_cmp_ms(const struct dentry dentry,\nfs/isofs/inode.c-278-\t\tunsigned int len, const char str, const struct qstr name)\nfs/isofs/inode.c-279-{\nfs/isofs/inode.c:280:\treturn isofs_dentry_cmp_common(len, str, name, 1, 0);\nfs/isofs/inode.c-281-}\n--\nfs/isofs/inode.c=283=static int\nfs/isofs/inode.c:284:isofs_dentry_cmpi_ms(const struct dentry dentry,\nfs/isofs/inode.c-285-\t\tunsigned int len, const char str, const struct qstr *name)\nfs/isofs/inode.c-286-{\nfs/isofs/inode.c:287:\treturn isofs_dentry_cmp_common(len, str, name, 1, 1);\nfs/isofs/inode.c-288-}\n--\nfs/isofs/inode.c=291=enum {\n--\nfs/isofs/inode.c-297-\nfs/isofs/inode.c:298:static const struct constant_table isofs_param_map[] = {\nfs/isofs/inode.c-299-\t{\"acorn\",\t'a'},\n--\nfs/isofs/inode.c-307-\nfs/isofs/inode.c:308:static const struct constant_table isofs_param_check[] = {\nfs/isofs/inode.c-309-\t{\"relaxed\",\t'r'},\n--\nfs/isofs/inode.c-315-\nfs/isofs/inode.c:316:static const struct fs_parameter_spec isofs_param_spec[] = {\nfs/isofs/inode.c-317-\tfsparam_flag\t(\"norock\",\t\tOpt_norock),\n--\nfs/isofs/inode.c-324-\tfsparam_string\t(\"iocharset\",\t\tOpt_iocharset),\nfs/isofs/inode.c:325:\tfsparam_enum\t(\"map\",\t\t\tOpt_map, isofs_param_map),\nfs/isofs/inode.c-326-\tfsparam_u32\t(\"session\",\t\tOpt_session),\n\n" }
5/2	2026/09/07 19:25	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 15212 output: 33 thoughts: 35 Thoughts: Okay, here's my interpretation of that thought process, as if I were having it: Digging into the ISOFS Configuration Right, time to get granular. I need to understand the precise configuration options at play for the ZISOFS and the broader ISO9660 file system support. The best place to start, as always, is the `Kconfig` file in the filesystem's source directory. Specifically, `fs/isofs/Kconfig`. That's where I'll find the definitions for `ZISOFS` and `ISO9660_FS`, the key variables in this configuration. I'll pore over that to get the definitive picture of what's enabled, disabled, and what the dependencies are. It's the source of truth for understanding how these features are built and configured in this kernel.
6/2	2026/09/07 19:25	tool	read-file	0m Args: { "File": "fs/isofs/Kconfig", "FirstLine": 1, "LineCount": 50 } Results: { "Contents": " 1:\t# SPDX-License-Identifier: GPL-2.0-only\n 2:\tconfig ISO9660_FS\n 3:\t\ttristate \"ISO 9660 CDROM file system support\"\n 4:\t\tselect BUFFER_HEAD\n 5:\t\thelp\n 6:\t\t This is the standard file system used on CD-ROMs. It was previously\n 7:\t\t known as \"High Sierra File System\" and is called \"hsfs\" on other\n 8:\t\t Unix systems. The so-called Rock-Ridge extensions which allow for\n 9:\t\t long Unix filenames and symbolic links are also supported by this\n 10:\t\t driver. If you have a CD-ROM drive and want to do more with it than\n 11:\t\t just listen to audio CDs and watch its LEDs, say Y (and read\n 12:\t\t \u003cfile:Documentation/filesystems/isofs.rst\u003e and the CD-ROM-HOWTO,\n 13:\t\t available from \u003chttp://www.tldp.org/docs.html#howto\u003e), thereby\n 14:\t\t enlarging your kernel by about 27 KB; otherwise say N.\n 15:\t\n 16:\t\t To compile this file system support as a module, choose M here: the\n 17:\t\t module will be called isofs.\n 18:\t\n 19:\tconfig JOLIET\n 20:\t\tbool \"Microsoft Joliet CDROM extensions\"\n 21:\t\tdepends on ISO9660_FS\n 22:\t\tselect NLS\n 23:\t\thelp\n 24:\t\t Joliet is a Microsoft extension for the ISO 9660 CD-ROM file system\n 25:\t\t which allows for long filenames in unicode format (unicode is the\n 26:\t\t new 16 bit character code, successor to ASCII, which encodes the\n 27:\t\t characters of almost all languages of the world; see\n 28:\t\t \u003chttp://www.unicode.org/\u003e for more information). Say Y here if you\n 29:\t\t want to be able to read Joliet CD-ROMs under Linux.\n 30:\t\n 31:\tconfig ZISOFS\n 32:\t\tbool \"Transparent decompression extension\"\n 33:\t\tdepends on ISO9660_FS\n 34:\t\tselect ZLIB_INFLATE\n 35:\t\thelp\n 36:\t\t This is a Linux-specific extension to RockRidge which lets you store\n 37:\t\t data in compressed form on a CD-ROM and have it transparently\n 38:\t\t decompressed when the CD-ROM is accessed. See\n 39:\t\t \u003chttp://www.kernel.org/pub/linux/utils/fs/zisofs/\u003e for the tools\n 40:\t\t necessary to create such a filesystem. Say Y here if you want to be\n 41:\t\t able to read such compressed CD-ROMs.\n" }
7/2	2026/09/07 19:25	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 16181 output: 35 thoughts: 24 Thoughts: Here's my summary, as though I'm thinking through this process: Diving into the ISO9660 Compression Code Okay, time to get my hands dirty with `fs/isofs/compress.c`. I'm starting at the top, roughly lines 1 to 400. That's a good chunk, probably the initial setup, declarations, and maybe some core functions related to compression. I'm expecting to see the overall structure of how the compression process is managed in the ISO9660 filesystem. Things to look for immediately are the compression algorithms it supports, any data structures used to hold compressed blocks, and how they're identified. I'll need to understand the entry points for the compression and decompression routines – the ones that are called when a file is written or read. Are they direct calls to library routines, or are there internal wrapper functions? I'll be looking for the crucial bits of code that decide whether compression is even attempted on a particular file – probably some checks on file attributes or extensions. Hopefully, I'll quickly spot any potential performance bottlenecks or subtle areas where data integrity might be at risk. This area, around lines 1-400, is critical for understanding the foundation of the compressed ISO9660 implementation. Let's see what we find!
8/2	2026/09/07 19:25	tool	read-file	0m Args: { "File": "fs/isofs/compress.c", "FirstLine": 1, "LineCount": 100 } Results: { "Contents": " 1:\t// SPDX-License-Identifier: GPL-2.0-or-later\n 2:\t/* -- linux-c -- ------------------------------------------------------- \n 3:\t \n 4:\t * Copyright 2001 H. Peter Anvin - All Rights Reserved\n 5:\t \n 6:\t ----------------------------------------------------------------------- /\n 7:\t\n 8:\t/\n 9:\t * linux/fs/isofs/compress.c\n 10:\t \n 11:\t Transparent decompression of files on an iso9660 filesystem\n 12:\t /\n 13:\t\n 14:\t#include \u003clinux/module.h\u003e\n 15:\t#include \u003clinux/init.h\u003e\n 16:\t#include \u003clinux/bio.h\u003e\n 17:\t\n 18:\t#include \u003clinux/slab.h\u003e\n 19:\t#include \u003clinux/vmalloc.h\u003e\n 20:\t#include \u003clinux/zlib.h\u003e\n 21:\t\n 22:\t#include \"isofs.h\"\n 23:\t#include \"zisofs.h\"\n 24:\t\n 25:\t/ This should probably be global. /\n 26:\tstatic char zisofs_sink_page[PAGE_SIZE];\n 27:\t\n 28:\t/\n 29:\t * This contains the zlib memory allocation and the mutex for the\n 30:\t * allocation; this avoids failures at block-decompression time.\n 31:\t /\n 32:\tstatic void zisofs_zlib_workspace;\n 33:\tstatic DEFINE_MUTEX(zisofs_zlib_lock);\n 34:\t\n 35:\t/\n 36:\t Read data of @inode from @block_start to @block_end and uncompress\n 37:\t * to one zisofs block. Store the data in the @pages array with @pcount\n 38:\t * entries. Start storing at offset @poffset of the first page.\n 39:\t /\n 40:\tstatic loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start,\n 41:\t\t\t\t\t loff_t block_end, int pcount,\n 42:\t\t\t\t\t struct folio *folios, unsigned int poffset,\n 43:\t\t\t\t\t int errp)\n 44:\t{\n 45:\t\tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\n 46:\t\tunsigned int bufsize = ISOFS_BUFFER_SIZE(inode);\n 47:\t\tunsigned int bufshift = ISOFS_BUFFER_BITS(inode);\n 48:\t\tunsigned int bufmask = bufsize - 1;\n 49:\t\tint i, block_size = block_end - block_start;\n 50:\t\tz_stream stream = { .total_out = 0,\n 51:\t\t\t\t .avail_in = 0,\n 52:\t\t\t\t .avail_out = 0, };\n 53:\t\tint zerr;\n 54:\t\tint needblocks = (block_size + (block_start \u0026 bufmask) + bufmask)\n 55:\t\t\t\t\t\u003e\u003e bufshift;\n 56:\t\tint haveblocks;\n 57:\t\tblkcnt_t blocknum;\n 58:\t\tstruct buffer_head *bhs;\n 59:\t\tint curbh, curpage;\n 60:\t\n 61:\t\tif (block_size \u003e deflateBound(1UL \u003c\u003c zisofs_block_shift)) {\n 62:\t\t\terrp = -EIO;\n 63:\t\t\treturn 0;\n 64:\t\t}\n 65:\t\t/* Empty block? /\n 66:\t\tif (block_size == 0) {\n 67:\t\t\tfor ( i = 0 ; i \u003c pcount ; i++ ) {\n 68:\t\t\t\tunsigned int off = i ? 0 : poffset;\n 69:\t\t\t\tstruct folio folio = folios[i];\n 70:\t\n 71:\t\t\t\tif (!folio)\n 72:\t\t\t\t\tcontinue;\n 73:\t\t\t\tfolio_zero_range(folio, off, folio_size(folio) - off);\n 74:\t\t\t\tfolio_mark_uptodate(folio);\n 75:\t\t\t}\n 76:\t\t\treturn (((loff_t)pcount) \u003c\u003c PAGE_SHIFT) - poffset;\n 77:\t\t}\n 78:\t\n 79:\t\t/* Because zlib is not thread-safe, do all the I/O at the top. /\n 80:\t\tblocknum = block_start \u003e\u003e bufshift;\n 81:\t\tbhs = kzalloc_objs(bhs, needblocks + 1);\n 82:\t\tif (!bhs) {\n 83:\t\t\terrp = -ENOMEM;\n 84:\t\t\treturn 0;\n 85:\t\t}\n 86:\t\thaveblocks = isofs_get_blocks(inode, blocknum, bhs, needblocks);\n 87:\t\tbh_read_batch(haveblocks, bhs);\n 88:\t\n 89:\t\tcurbh = 0;\n 90:\t\tcurpage = 0;\n 91:\t\t/\n 92:\t\t * First block is special since it may be fractional. We also wait for\n 93:\t\t * it before grabbing the zlib mutex; odds are that the subsequent\n 94:\t\t * blocks are going to come in in short order so we don't hold the zlib\n 95:\t\t * mutex longer than necessary.\n 96:\t\t */\n 97:\t\n 98:\t\tif (!bhs[0])\n 99:\t\t\tgoto b_eio;\n 100:\t\n" }
9/2	2026/09/07 19:25	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 17963 output: 37 thoughts: 17 Thoughts: Okay, here's my take on those thoughts, tailored for an expert audience, and written as if they were my own: Diving Back into compress.c Alright, I'm thinking we need to circle back to `fs/isofs/compress.c`. I remember having a few nagging questions and potential optimization ideas lurking around after the initial pass. Let's see if those still hold water. I want to check for potential race conditions, especially given how this interacts with the caching layer. Are there any spots where we're not properly handling locking or memory management, particularly around the compression buffers and associated metadata? I'm also curious about the overall algorithm's efficiency. Could we squeeze out a few more cycles with a different strategy, maybe considering a different compression library altogether if the performance gains are significant enough to warrant the code churn? And, of course, I need to look for any potential security vulnerabilities, buffer overflows being my main concern, but really anything that could allow for malicious manipulation of the compressed data. It's time to refresh my memory and see what insights I've got.
10/2	2026/09/07 19:25	tool	read-file	0m Args: { "File": "fs/isofs/compress.c", "FirstLine": 101, "LineCount": 100 } Results: { "Contents": " 101:\t\twait_on_buffer(bhs[0]);\n 102:\t\tif (!buffer_uptodate(bhs[0])) {\n 103:\t\t\terrp = -EIO;\n 104:\t\t\tgoto b_eio;\n 105:\t\t}\n 106:\t\n 107:\t\tstream.workspace = zisofs_zlib_workspace;\n 108:\t\tmutex_lock(\u0026zisofs_zlib_lock);\n 109:\t\t\t\n 110:\t\tzerr = zlib_inflateInit(\u0026stream);\n 111:\t\tif (zerr != Z_OK) {\n 112:\t\t\tif (zerr == Z_MEM_ERROR)\n 113:\t\t\t\terrp = -ENOMEM;\n 114:\t\t\telse\n 115:\t\t\t\terrp = -EIO;\n 116:\t\t\tprintk(KERN_DEBUG \"zisofs: zisofs_inflateInit returned %d\\n\",\n 117:\t\t\t\t zerr);\n 118:\t\t\tgoto z_eio;\n 119:\t\t}\n 120:\t\n 121:\t\twhile (curpage \u003c pcount \u0026\u0026 curbh \u003c haveblocks \u0026\u0026\n 122:\t\t zerr != Z_STREAM_END) {\n 123:\t\t\tstruct folio folio = folios[curpage];\n 124:\t\n 125:\t\t\tif (!stream.avail_out) {\n 126:\t\t\t\tif (folio) {\n 127:\t\t\t\t\tstream.next_out = kmap_local_folio(folio, poffset);\n 128:\t\t\t\t\tstream.avail_out = folio_size(folio) - poffset;\n 129:\t\t\t\t\tpoffset = 0;\n 130:\t\t\t\t} else {\n 131:\t\t\t\t\tstream.next_out = (void )\u0026zisofs_sink_page;\n 132:\t\t\t\t\tstream.avail_out = PAGE_SIZE;\n 133:\t\t\t\t}\n 134:\t\t\t}\n 135:\t\t\tif (!stream.avail_in) {\n 136:\t\t\t\twait_on_buffer(bhs[curbh]);\n 137:\t\t\t\tif (!buffer_uptodate(bhs[curbh])) {\n 138:\t\t\t\t\terrp = -EIO;\n 139:\t\t\t\t\tbreak;\n 140:\t\t\t\t}\n 141:\t\t\t\tstream.next_in = bhs[curbh]-\u003eb_data +\n 142:\t\t\t\t\t\t\t(block_start \u0026 bufmask);\n 143:\t\t\t\tstream.avail_in = min_t(unsigned, bufsize -\n 144:\t\t\t\t\t\t\t(block_start \u0026 bufmask),\n 145:\t\t\t\t\t\t\tblock_size);\n 146:\t\t\t\tblock_size -= stream.avail_in;\n 147:\t\t\t\tblock_start = 0;\n 148:\t\t\t}\n 149:\t\n 150:\t\t\twhile (stream.avail_out \u0026\u0026 stream.avail_in) {\n 151:\t\t\t\tzerr = zlib_inflate(\u0026stream, Z_SYNC_FLUSH);\n 152:\t\t\t\tif (zerr == Z_BUF_ERROR \u0026\u0026 stream.avail_in == 0)\n 153:\t\t\t\t\tbreak;\n 154:\t\t\t\tif (zerr == Z_STREAM_END)\n 155:\t\t\t\t\tbreak;\n 156:\t\t\t\tif (zerr != Z_OK) {\n 157:\t\t\t\t\t/* EOF, error, or trying to read beyond end of input /\n 158:\t\t\t\t\tif (zerr == Z_MEM_ERROR)\n 159:\t\t\t\t\t\terrp = -ENOMEM;\n 160:\t\t\t\t\telse {\n 161:\t\t\t\t\t\tprintk(KERN_DEBUG\n 162:\t\t\t\t\t\t \"zisofs: zisofs_inflate returned\"\n 163:\t\t\t\t\t\t \" %d, inode = %llu,\"\n 164:\t\t\t\t\t\t \" page idx = %d, bh idx = %d,\"\n 165:\t\t\t\t\t\t \" avail_in = %ld,\"\n 166:\t\t\t\t\t\t \" avail_out = %ld\\n\",\n 167:\t\t\t\t\t\t zerr, inode-\u003ei_ino, curpage,\n 168:\t\t\t\t\t\t curbh, stream.avail_in,\n 169:\t\t\t\t\t\t stream.avail_out);\n 170:\t\t\t\t\t\terrp = -EIO;\n 171:\t\t\t\t\t}\n 172:\t\t\t\t\tgoto inflate_out;\n 173:\t\t\t\t}\n 174:\t\t\t}\n 175:\t\n 176:\t\t\tif (!stream.avail_out) {\n 177:\t\t\t\t/ This page completed /\n 178:\t\t\t\tif (folio) {\n 179:\t\t\t\t\tflush_dcache_folio(folio);\n 180:\t\t\t\t\tfolio_mark_uptodate(folio);\n 181:\t\t\t\t}\n 182:\t\t\t\tif (stream.next_out != (unsigned char )zisofs_sink_page) {\n 183:\t\t\t\t\tkunmap_local(stream.next_out);\n 184:\t\t\t\t\tstream.next_out = NULL;\n 185:\t\t\t\t}\n 186:\t\t\t\tcurpage++;\n 187:\t\t\t}\n 188:\t\t\tif (!stream.avail_in)\n 189:\t\t\t\tcurbh++;\n 190:\t\t}\n 191:\tinflate_out:\n 192:\t\tzlib_inflateEnd(\u0026stream);\n 193:\t\tif (stream.next_out \u0026\u0026 stream.next_out != (unsigned char *)zisofs_sink_page)\n 194:\t\t\tkunmap_local(stream.next_out);\n 195:\t\n 196:\tz_eio:\n 197:\t\tmutex_unlock(\u0026zisofs_zlib_lock);\n 198:\t\n 199:\tb_eio:\n 200:\t\tfor (i = 0; i \u003c haveblocks; i++)\n" }
11/2	2026/09/07 19:25	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 19746 output: 37 thoughts: 17 Thoughts: Okay, here we go... Diving into `fs/isofs/compress.c` Alright, time to dig into this file. I want to understand exactly how the ISOFS compression is implemented. I already have a pretty good grasp on the broader file system structure and the ISO 9660 standard, but the compression aspect is something I need to refresh. What specific algorithms are in use? How are they integrated within the I/O operations? Are there any performance bottlenecks I should be aware of, or potential optimization areas? I want to see how the compression affects read and write paths. I'll be looking for the crucial functions that handle the de/compression, and how the file system's metadata is modified to store compressed data. I need to understand how the file system presents the compressed data to the user. I'll be particularly interested to see if there are any specific structures or flags used to indicate a file's compressed state. Let's see what interesting techniques the developers utilized.
12/2	2026/09/07 19:25	tool	read-file	0m Args: { "File": "fs/isofs/compress.c", "FirstLine": 201, "LineCount": 100 } Results: { "Contents": " 201:\t\t\tbrelse(bhs[i]);\n 202:\t\tkfree(bhs);\n 203:\t\treturn stream.total_out;\n 204:\t}\n 205:\t\n 206:\t/\n 207:\t Uncompress data so that pages[full_page] is fully uptodate and possibly\n 208:\t * fills in other pages if we have data for them.\n 209:\t /\n 210:\tstatic int zisofs_fill_pages(struct inode inode, int full_page, int pcount,\n 211:\t\t\t\t struct folio *folios)\n 212:\t{\n 213:\t\tloff_t start_off, end_off;\n 214:\t\tloff_t block_start, block_end;\n 215:\t\tunsigned int header_size = ISOFS_I(inode)-\u003ei_format_parm[0];\n 216:\t\tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\n 217:\t\tunsigned int blockptr;\n 218:\t\tloff_t poffset = 0;\n 219:\t\tblkcnt_t cstart_block, cend_block;\n 220:\t\tstruct buffer_head bh;\n 221:\t\tunsigned int blkbits = ISOFS_BUFFER_BITS(inode);\n 222:\t\tunsigned int blksize = 1 \u003c\u003c blkbits;\n 223:\t\tint err;\n 224:\t\tloff_t ret;\n 225:\t\n 226:\t\tBUG_ON(!folios[full_page]);\n 227:\t\n 228:\t\t/\n 229:\t\t We want to read at least 'full_page' page. Because we have to\n 230:\t\t * uncompress the whole compression block anyway, fill the surrounding\n 231:\t\t * pages with the data we have anyway...\n 232:\t\t /\n 233:\t\tstart_off = folio_pos(folios[full_page]);\n 234:\t\tend_off = min_t(loff_t, start_off + PAGE_SIZE, inode-\u003ei_size);\n 235:\t\n 236:\t\tcstart_block = start_off \u003e\u003e zisofs_block_shift;\n 237:\t\tcend_block = (end_off + (1 \u003c\u003c zisofs_block_shift) - 1)\n 238:\t\t\t\t\u003e\u003e zisofs_block_shift;\n 239:\t\n 240:\t\tWARN_ON(start_off - (full_page \u003c\u003c PAGE_SHIFT) !=\n 241:\t\t\t((cstart_block \u003c\u003c zisofs_block_shift) \u0026 PAGE_MASK));\n 242:\t\n 243:\t\t/ Find the pointer to this specific chunk /\n 244:\t\t/ Note: we're not using isonum_731() here because the data is known aligned /\n 245:\t\t/ Note: header_size is in 32-bit words (4 bytes) /\n 246:\t\tblockptr = (header_size + cstart_block) \u003c\u003c 2;\n 247:\t\tbh = isofs_bread(inode, blockptr \u003e\u003e blkbits);\n 248:\t\tif (!bh)\n 249:\t\t\treturn -EIO;\n 250:\t\tblock_start = le32_to_cpu((__le32 )\n 251:\t\t\t\t\t(bh-\u003eb_data + (blockptr \u0026 (blksize - 1))));\n 252:\t\n 253:\t\twhile (cstart_block \u003c cend_block \u0026\u0026 pcount \u003e 0) {\n 254:\t\t\t/ Load end of the compressed block in the file /\n 255:\t\t\tblockptr += 4;\n 256:\t\t\t/ Traversed to next block? /\n 257:\t\t\tif (!(blockptr \u0026 (blksize - 1))) {\n 258:\t\t\t\tbrelse(bh);\n 259:\t\n 260:\t\t\t\tbh = isofs_bread(inode, blockptr \u003e\u003e blkbits);\n 261:\t\t\t\tif (!bh)\n 262:\t\t\t\t\treturn -EIO;\n 263:\t\t\t}\n 264:\t\t\tblock_end = le32_to_cpu((__le32 )\n 265:\t\t\t\t\t(bh-\u003eb_data + (blockptr \u0026 (blksize - 1))));\n 266:\t\t\tif (block_start \u003e block_end) {\n 267:\t\t\t\tbrelse(bh);\n 268:\t\t\t\treturn -EIO;\n 269:\t\t\t}\n 270:\t\t\terr = 0;\n 271:\t\t\tret = zisofs_uncompress_block(inode, block_start, block_end,\n 272:\t\t\t\t\t\t pcount, folios, poffset, \u0026err);\n 273:\t\t\tpoffset += ret;\n 274:\t\t\tfolios += poffset \u003e\u003e PAGE_SHIFT;\n 275:\t\t\tpcount -= poffset \u003e\u003e PAGE_SHIFT;\n 276:\t\t\tfull_page -= poffset \u003e\u003e PAGE_SHIFT;\n 277:\t\t\tpoffset \u0026= ~PAGE_MASK;\n 278:\t\n 279:\t\t\tif (err) {\n 280:\t\t\t\tbrelse(bh);\n 281:\t\t\t\t/\n 282:\t\t\t\t * Did we finish reading the page we really wanted\n 283:\t\t\t\t * to read?\n 284:\t\t\t\t /\n 285:\t\t\t\tif (full_page \u003c 0)\n 286:\t\t\t\t\treturn 0;\n 287:\t\t\t\treturn err;\n 288:\t\t\t}\n 289:\t\n 290:\t\t\tblock_start = block_end;\n 291:\t\t\tcstart_block++;\n 292:\t\t}\n 293:\t\n 294:\t\tif (poffset \u0026\u0026 folios) {\n 295:\t\t\tstruct folio folio = folios;\n 296:\t\n 297:\t\t\tfolio_zero_range(folio, poffset, folio_size(folio) - poffset);\n 298:\t\t\tfolio_mark_uptodate(folio);\n 299:\t\t}\n 300:\t\tbrelse(bh);\n" }
13/2	2026/09/07 19:25	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 21602 output: 37 thoughts: 25 Thoughts: Here's a first-person summary, tailored for an expert audience, as requested: Diving into the ISOFS Compression Code Okay, time to get my hands dirty. Let's zero in on a specific section of the ISOFS compression logic – I'm thinking lines 301 through 400 within `fs/isofs/compress.c`. This is where the magic (or potential headache) happens. I need to refresh my memory on how they're handling compression/decompression specifically in this module. I'll be looking for clues around the choice of algorithm, error handling, buffer management... all the usual suspects. I want to see if there's anything subtly off, or maybe an interesting optimization I missed previously. It's a key part of the ISOFS implementation, so I need to make sure it's robust and efficient. Let's see what's what.
14/2	2026/09/07 19:26	tool	read-file	0m Args: { "File": "fs/isofs/compress.c", "FirstLine": 301, "LineCount": 100 } Results: { "Contents": " 301:\t\treturn 0;\n 302:\t}\n 303:\t\n 304:\t/\n 305:\t When decompressing, we typically obtain more than one page\n 306:\t * per reference. We inject the additional pages into the page\n 307:\t * cache as a form of readahead.\n 308:\t /\n 309:\tstatic int zisofs_read_folio(struct file file, struct folio folio)\n 310:\t{\n 311:\t\tstruct inode inode = file_inode(file);\n 312:\t\tstruct address_space mapping = inode-\u003ei_mapping;\n 313:\t\tint err;\n 314:\t\tint i, pcount, full_page;\n 315:\t\tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\n 316:\t\tunsigned int zisofs_pages_per_cblock =\n 317:\t\t\tPAGE_SHIFT \u003c= zisofs_block_shift ?\n 318:\t\t\t(1 \u003c\u003c (zisofs_block_shift - PAGE_SHIFT)) : 0;\n 319:\t\tstruct folio folios;\n 320:\t\tpgoff_t index = folio-\u003eindex, end_index;\n 321:\t\n 322:\t\tend_index = (inode-\u003ei_size + PAGE_SIZE - 1) \u003e\u003e PAGE_SHIFT;\n 323:\t\t/\n 324:\t\t * If this folio is wholly outside i_size we just return zero;\n 325:\t\t * do_generic_file_read() will handle this for us\n 326:\t\t /\n 327:\t\tif (index \u003e= end_index) {\n 328:\t\t\tfolio_end_read(folio, true);\n 329:\t\t\treturn 0;\n 330:\t\t}\n 331:\t\n 332:\t\tif (PAGE_SHIFT \u003c= zisofs_block_shift) {\n 333:\t\t\t/ We have already been given one page, this is the one\n 334:\t\t\t we must do. /\n 335:\t\t\tfull_page = index \u0026 (zisofs_pages_per_cblock - 1);\n 336:\t\t\tpcount = min_t(int, zisofs_pages_per_cblock,\n 337:\t\t\t\tend_index - (index \u0026 ~(zisofs_pages_per_cblock - 1)));\n 338:\t\t\tindex -= full_page;\n 339:\t\t} else {\n 340:\t\t\tfull_page = 0;\n 341:\t\t\tpcount = 1;\n 342:\t\t}\n 343:\t\tfolios = kzalloc_objs(folios,\n 344:\t\t\t\t max_t(unsigned int, zisofs_pages_per_cblock, 1));\n 345:\t\tif (!folios) {\n 346:\t\t\tfolio_unlock(folio);\n 347:\t\t\treturn -ENOMEM;\n 348:\t\t}\n 349:\t\tfolios[full_page] = folio;\n 350:\t\n 351:\t\tfor (i = 0; i \u003c pcount; i++, index++) {\n 352:\t\t\tif (i == full_page)\n 353:\t\t\t\tcontinue;\n 354:\t\t\tfolios[i] = __filemap_get_folio(mapping, index,\n 355:\t\t\t\t\tFGP_LOCK \| FGP_CREAT \| FGP_NOWAIT,\n 356:\t\t\t\t\tmapping_gfp_mask(mapping));\n 357:\t\t\tif (IS_ERR(folios[i]))\n 358:\t\t\t\tfolios[i] = NULL;\n 359:\t\t}\n 360:\t\n 361:\t\terr = zisofs_fill_pages(inode, full_page, pcount, folios);\n 362:\t\n 363:\t\t/* Release any residual folios, do not mark them uptodate /\n 364:\t\tfor (i = 0; i \u003c pcount; i++) {\n 365:\t\t\tif (folios[i]) {\n 366:\t\t\t\tflush_dcache_folio(folios[i]);\n 367:\t\t\t\tfolio_unlock(folios[i]);\n 368:\t\t\t\tif (i != full_page)\n 369:\t\t\t\t\tfolio_put(folios[i]);\n 370:\t\t\t}\n 371:\t\t}\n 372:\t\n 373:\t\t/ At this point, err contains 0 or -EIO depending on the \"critical\" page /\n 374:\t\tkfree(folios);\n 375:\t\treturn err;\n 376:\t}\n 377:\t\n 378:\tconst struct address_space_operations zisofs_aops = {\n 379:\t\t.read_folio = zisofs_read_folio,\n 380:\t\t/ No bmap operation supported */\n 381:\t};\n 382:\t\n 383:\tint __init zisofs_init(void)\n 384:\t{\n 385:\t\tzisofs_zlib_workspace = vmalloc(zlib_inflate_workspacesize());\n 386:\t\tif ( !zisofs_zlib_workspace )\n 387:\t\t\treturn -ENOMEM;\n 388:\t\n 389:\t\treturn 0;\n 390:\t}\n 391:\t\n 392:\tvoid zisofs_cleanup(void)\n 393:\t{\n 394:\t\tvfree(zisofs_zlib_workspace);\n 395:\t}\n" }
15/2	2026/09/07 19:26	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 23295 output: 27 thoughts: 31 Thoughts: Here's my attempt at summarizing the thought process, tailored for an expert audience: Investigating ZISOFS Data Access Okay, so I need to understand the data access path for ZISOFS within the kernel. Specifically, I want to trace the usage of either `zisofs_aops` or `zisofs_read_folio`. The goal here is to get a solid grasp of how the compressed ISO 9660 filesystem handles data reads. Since I'm familiar with the `fs/isofs/` directory, that's the logical place to start my investigation. I'm essentially pinpointing the key function calls involved in getting data off of the compressed disk image. I'll need to know where these structures are assigned, how the read operations are triggered, and how the compression/decompression interacts with the rest of the filesystem's operations. This should highlight the critical path for I/O.
16/2	2026/09/07 19:26	tool	grepper	0m Args: { "Expression": "zisofs_", "PathPrefix": "fs/isofs" } Results: { "Output": "fs/isofs/compress.c-25-/* This should probably be global. /\nfs/isofs/compress.c:26:static char zisofs_sink_page[PAGE_SIZE];\nfs/isofs/compress.c-27-\n--\nfs/isofs/compress.c-31- /\nfs/isofs/compress.c:32:static void zisofs_zlib_workspace;\nfs/isofs/compress.c:33:static DEFINE_MUTEX(zisofs_zlib_lock);\nfs/isofs/compress.c-34-\n--\nfs/isofs/compress.c-39- /\nfs/isofs/compress.c:40:static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start,\nfs/isofs/compress.c-41-\t\t\t\t loff_t block_end, int pcount,\n--\nfs/isofs/compress.c-44-{\nfs/isofs/compress.c:45:\tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\nfs/isofs/compress.c-46-\tunsigned int bufsize = ISOFS_BUFFER_SIZE(inode);\n--\nfs/isofs/compress.c-60-\nfs/isofs/compress.c:61:\tif (block_size \u003e deflateBound(1UL \u003c\u003c zisofs_block_shift)) {\nfs/isofs/compress.c-62-\t\terrp = -EIO;\n--\nfs/isofs/compress.c-106-\nfs/isofs/compress.c:107:\tstream.workspace = zisofs_zlib_workspace;\nfs/isofs/compress.c:108:\tmutex_lock(\u0026zisofs_zlib_lock);\nfs/isofs/compress.c-109-\t\t\n--\nfs/isofs/compress.c-115-\t\t\terrp = -EIO;\nfs/isofs/compress.c:116:\t\tprintk(KERN_DEBUG \"zisofs: zisofs_inflateInit returned %d\\n\",\nfs/isofs/compress.c-117-\t\t\t zerr);\n--\nfs/isofs/compress.c-130-\t\t\t} else {\nfs/isofs/compress.c:131:\t\t\t\tstream.next_out = (void )\u0026zisofs_sink_page;\nfs/isofs/compress.c-132-\t\t\t\tstream.avail_out = PAGE_SIZE;\n--\nfs/isofs/compress.c-161-\t\t\t\t\tprintk(KERN_DEBUG\nfs/isofs/compress.c:162:\t\t\t\t\t \"zisofs: zisofs_inflate returned\"\nfs/isofs/compress.c-163-\t\t\t\t\t \" %d, inode = %llu,\"\n--\nfs/isofs/compress.c-181-\t\t\t}\nfs/isofs/compress.c:182:\t\t\tif (stream.next_out != (unsigned char )zisofs_sink_page) {\nfs/isofs/compress.c-183-\t\t\t\tkunmap_local(stream.next_out);\n--\nfs/isofs/compress.c-192-\tzlib_inflateEnd(\u0026stream);\nfs/isofs/compress.c:193:\tif (stream.next_out \u0026\u0026 stream.next_out != (unsigned char )zisofs_sink_page)\nfs/isofs/compress.c-194-\t\tkunmap_local(stream.next_out);\n--\nfs/isofs/compress.c-196-z_eio:\nfs/isofs/compress.c:197:\tmutex_unlock(\u0026zisofs_zlib_lock);\nfs/isofs/compress.c-198-\n--\nfs/isofs/compress.c-209- /\nfs/isofs/compress.c:210:static int zisofs_fill_pages(struct inode inode, int full_page, int pcount,\nfs/isofs/compress.c-211-\t\t\t struct folio *folios)\n--\nfs/isofs/compress.c-215-\tunsigned int header_size = ISOFS_I(inode)-\u003ei_format_parm[0];\nfs/isofs/compress.c:216:\tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\nfs/isofs/compress.c-217-\tunsigned int blockptr;\n--\nfs/isofs/compress.c-235-\nfs/isofs/compress.c:236:\tcstart_block = start_off \u003e\u003e zisofs_block_shift;\nfs/isofs/compress.c:237:\tcend_block = (end_off + (1 \u003c\u003c zisofs_block_shift) - 1)\nfs/isofs/compress.c:238:\t\t\t\u003e\u003e zisofs_block_shift;\nfs/isofs/compress.c-239-\nfs/isofs/compress.c-240-\tWARN_ON(start_off - (full_page \u003c\u003c PAGE_SHIFT) !=\nfs/isofs/compress.c:241:\t\t((cstart_block \u003c\u003c zisofs_block_shift) \u0026 PAGE_MASK));\nfs/isofs/compress.c-242-\n--\nfs/isofs/compress.c-270-\t\terr = 0;\nfs/isofs/compress.c:271:\t\tret = zisofs_uncompress_block(inode, block_start, block_end,\nfs/isofs/compress.c-272-\t\t\t\t\t pcount, folios, poffset, \u0026err);\n--\nfs/isofs/compress.c-308- /\nfs/isofs/compress.c:309:static int zisofs_read_folio(struct file file, struct folio folio)\nfs/isofs/compress.c-310-{\n--\nfs/isofs/compress.c-314-\tint i, pcount, full_page;\nfs/isofs/compress.c:315:\tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\nfs/isofs/compress.c:316:\tunsigned int zisofs_pages_per_cblock =\nfs/isofs/compress.c:317:\t\tPAGE_SHIFT \u003c= zisofs_block_shift ?\nfs/isofs/compress.c:318:\t\t(1 \u003c\u003c (zisofs_block_shift - PAGE_SHIFT)) : 0;\nfs/isofs/compress.c-319-\tstruct folio *folios;\n--\nfs/isofs/compress.c-331-\nfs/isofs/compress.c:332:\tif (PAGE_SHIFT \u003c= zisofs_block_shift) {\nfs/isofs/compress.c-333-\t\t/ We have already been given one page, this is the one\nfs/isofs/compress.c-334-\t\t we must do. /\nfs/isofs/compress.c:335:\t\tfull_page = index \u0026 (zisofs_pages_per_cblock - 1);\nfs/isofs/compress.c:336:\t\tpcount = min_t(int, zisofs_pages_per_cblock,\nfs/isofs/compress.c:337:\t\t\tend_index - (index \u0026 ~(zisofs_pages_per_cblock - 1)));\nfs/isofs/compress.c-338-\t\tindex -= full_page;\n--\nfs/isofs/compress.c-343-\tfolios = kzalloc_objs(folios,\nfs/isofs/compress.c:344:\t\t\t max_t(unsigned int, zisofs_pages_per_cblock, 1));\nfs/isofs/compress.c-345-\tif (!folios) {\n--\nfs/isofs/compress.c-360-\nfs/isofs/compress.c:361:\terr = zisofs_fill_pages(inode, full_page, pcount, folios);\nfs/isofs/compress.c-362-\n--\nfs/isofs/compress.c-377-\nfs/isofs/compress.c:378:const struct address_space_operations zisofs_aops = {\nfs/isofs/compress.c:379:\t.read_folio = zisofs_read_folio,\nfs/isofs/compress.c-380-\t/* No bmap operation supported /\n--\nfs/isofs/compress.c-382-\nfs/isofs/compress.c:383:int __init zisofs_init(void)\nfs/isofs/compress.c-384-{\nfs/isofs/compress.c:385:\tzisofs_zlib_workspace = vmalloc(zlib_inflate_workspacesize());\nfs/isofs/compress.c:386:\tif ( !zisofs_zlib_workspace )\nfs/isofs/compress.c-387-\t\treturn -ENOMEM;\n--\nfs/isofs/compress.c-391-\nfs/isofs/compress.c:392:void zisofs_cleanup(void)\nfs/isofs/compress.c-393-{\nfs/isofs/compress.c:394:\tvfree(zisofs_zlib_workspace);\nfs/isofs/compress.c-395-}\n--\nfs/isofs/inode.c=1270=static int isofs_read_inode(struct inode inode, int relocated)\n--\nfs/isofs/inode.c-1434-\t\tcase isofs_file_compressed:\nfs/isofs/inode.c:1435:\t\t\tinode-\u003ei_data.a_ops = \u0026zisofs_aops;\nfs/isofs/inode.c-1436-\t\t\tbreak;\n--\nfs/isofs/inode.c=1601=static int __init init_iso9660_fs(void)\n--\nfs/isofs/inode.c-1606-#ifdef CONFIG_ZISOFS\nfs/isofs/inode.c:1607:\terr = zisofs_init();\nfs/isofs/inode.c-1608-\tif (err)\n--\nfs/isofs/inode.c-1616-#ifdef CONFIG_ZISOFS\nfs/isofs/inode.c:1617:\tzisofs_cleanup();\nfs/isofs/inode.c-1618-out1:\n--\nfs/isofs/inode.c=1625=static void __exit exit_iso9660_fs(void)\n--\nfs/isofs/inode.c-1628-#ifdef CONFIG_ZISOFS\nfs/isofs/inode.c:1629:\tzisofs_cleanup();\nfs/isofs/inode.c-1630-#endif\n--\nfs/isofs/zisofs.h-12-#ifdef CONFIG_ZISOFS\nfs/isofs/zisofs.h:13:extern const struct address_space_operations zisofs_aops;\nfs/isofs/zisofs.h:14:extern int __init zisofs_init(void);\nfs/isofs/zisofs.h:15:extern void zisofs_cleanup(void);\nfs/isofs/zisofs.h-16-#endif\n" }
17/2	2026/09/07 19:26	llm	patch-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 26347 output: 145 thoughts: 1040 Thoughts: Analysis of the Zisofs Folio Conversion Patch Okay, let's break this down. We have a patch that's converting the zisofs decompression code within the ISOFS filesystem (`fs/isofs/compress.c`) from using page-based APIs to folio-based ones. This is a common and often bug-prone area – memory management and page cache refactoring in filesystems is always worth a close look. First, reachability. Can we actually hit this code in a fuzzing environment? Absolutely. ISOFS (iso9660) is easily mounted via loopback or standard virtual block devices, like the emulated CD-ROMs in QEMU or GCE. Syzkaller can even mount intentionally corrupted ISO images with zisofs compression, which is a key advantage. This code is also part of a core VFS/filesystem driver, `isofs`, and gets built when `CONFIG_ISO9660_FS` and `CONFIG_ZISOFS` are enabled. Next, is this worth fuzzing? Yes, without a doubt. We're dealing with reachable, executable code in the filesystem decompression logic. This patch involves page cache lookups, mappings, zeroing, and buffer handling, now using folio equivalents. The potential for bugs is high, considering the refactoring. Think refcounting, locking, unmapping, and race conditions – all classic filesystem vulnerability points. Now, the important part: focus symbols. What specific functions are modified? The patch touches `zisofs_uncompress_block`, `zisofs_fill_pages`, and `zisofs_read_folio`. I confirmed that `zisofs_read_folio` is a function pointer in `zisofs_aops`, making it a target, and `zisofs_fill_pages` and `zisofs_uncompress_block` are static functions. Static functions in a C file are usually distinct symbols, which helps with targeted fuzzing. So, these three functions are excellent targets. Let's check the required configurations. We need `ISO9660_FS` ("ISO 9660 CDROM file system support") which is tristate, and `ZISOFS` ("Transparent decompression extension") which depends on the former and selects `ZLIB_INFLATE`. I double-checked the `fs/isofs/Kconfig` to be sure. It's those two. Finally, just to be absolutely certain, let's revisit the changes again. It's those same three symbols: `zisofs_read_folio`, `zisofs_fill_pages`, and `zisofs_uncompress_block`. No other significant changes. All three are specific to zisofs. So, summing up: WorthFuzzing is true. FocusSymbols are ["zisofs_read_folio", "zisofs_fill_pages", "zisofs_uncompress_block"]. EnableConfigs are ["ISO9660_FS", "ZISOFS"]. We have a concise explanation. Time to move on and set the results.
18/2	2026/09/07 19:26	tool	set-results	0m Args: { "EnableConfigs": [ "ISO9660_FS", "ZISOFS" ], "FocusSymbols": [ "zisofs_read_folio", "zisofs_fill_pages", "zisofs_uncompress_block" ], "Reasoning": "The patch converts zisofs (transparent decompression support in ISO9660 filesystem) from page-based APIs to folio-based APIs across zisofs_read_folio, zisofs_fill_pages, and zisofs_uncompress_block. This modifies reachable filesystem and page cache decompression logic that can be exercised by mounting and reading compressed ISO images.", "WorthFuzzing": true } Results: { "EnableConfigs": [ "ISO9660_FS", "ZISOFS" ], "FocusSymbols": [ "zisofs_read_folio", "zisofs_fill_pages", "zisofs_uncompress_block" ], "Reasoning": "The patch converts zisofs (transparent decompression support in ISO9660 filesystem) from page-based APIs to folio-based APIs across zisofs_read_folio, zisofs_fill_pages, and zisofs_uncompress_block. This modifies reachable filesystem and page cache decompression logic that can be exercised by mounting and reading compressed ISO images.", "WorthFuzzing": true }
19/1	2026/09/07 19:26	action	If	0m Args: { "WorthFuzzing": true } Results: null
20/2	2026/09/07 19:26	agent	kmsan-evaluator	0m Model: core Args: null Results: { "KMSANReasoning": "The patch converts `fs/isofs/compress.c` from `struct page` APIs to `struct folio` APIs (using `kmap_local_folio`, `folio_zero_range`, `folio_mark_uptodate`, `__filemap_get_folio`, etc.). \n\nThe array holding folio pointers is zero-allocated via `kzalloc_objs`, and folio contents are either uncompressed by zlib or zeroed via `folio_zero_range` before being marked uptodate. There are no uninitialized variables, info-leaks to user space, or uninitialized memory branches introduced or modified. Any potential issues with folio reference counts, locks, or offsets are within the scope of KASAN/LOCKDEP/page debugging rather than KMSAN. Thus, a dedicated KMSAN fuzzing session is not justified.", "NeedsKMSAN": false } Instruction: You are an expert Linux kernel security engineer specializing in kernel memory error detectors (KASAN and KMSAN). Your job is to review the provided patch series and determine if the code changes justify spawning a dedicated KMSAN (KernelMemorySanitizer) fuzzing session in addition to standard KASAN fuzzing. CRITICAL DISTINCTION BETWEEN KASAN AND KMSAN: - Standard KASAN kernel builds (upstream-apparmor-kasan.config) already enable a comprehensive suite of debugging tools and sanitizers, including KASAN (out-of-bounds accesses, use-after-free, double free, invalid free), LOCKDEP (locking bugs and deadlocks), UB-sanitizers, and memory corruption checks. - KMSAN (KernelMemorySanitizer) detects reads of UNINITIALIZED memory (stack, heap, or page allocations) and kernel-to-user memory info-leaks. Rule: THERE IS NO SENSE IN RUNNING A KMSAN SESSION IF A BUG CAN BE CAUGHT BY KASAN, LOCKDEP, OR OTHER STANDARD BUG DETECTORS. A dedicated KMSAN fuzzing session incurs significant resource costs. You must ONLY set NeedsKMSAN=true if the code changes introduce or expose UNINITIALIZED MEMORY risks that are detected ONLY by KMSAN. Look holistically at the patch series and surrounding code. Even if no direct uninitialized field accesses or new buffer allocations are added in the diff itself, a patch may alter control flow, bounds checking, or data length calculations in ways that change how the rest of the code operates on existing buffers (e.g. allowing uninitialized stack/heap memory to be read, copied to user space, or used in control flow). Do not hesitate to use your code access tools to inspect the surrounding code, called functions, and callers. Set NeedsKMSAN=true ONLY IF the patch introduces or modifies: 1. Kernel structures sent to user space (via copy_to_user, put_user, netlink skb attributes, ioctl output arguments, socket options, or BPF buffers) where fields or structure padding might not be fully initialized/zeroed. 2. Conditional logic or branching that depends on potentially uninitialized variables or struct fields. 3. Allocation or initialization of complex data structures where uninitialized fields could be read later in reachable code paths. 4. Bounds checks, lengths, or logic in a way that allows surrounding code to access uninitialized bytes of existing buffers. Set NeedsKMSAN=false IF: - The code changes primarily risk out-of-bounds access, array overflows, NULL pointer dereferences, locking deadlocks, or use-after-free bugs (these are already caught by KASAN, LOCKDEP, or standard bug detectors). - All stack/heap structures touched or introduced by the patch are fully zeroed or initialized (e.g. using = {0}, memset, kzalloc) before being read or copied. - The patch does not introduce any risk of uninitialized memory usage or info-leaks. Use your code access tools to inspect the surrounding code if necessary, then provide detailed KMSANReasoning contrasting KASAN vs KMSAN applicability for this patch. Prefer calling several tools at the same time to save round-trips. Use set-results tool to provide results of the analysis. It must be called exactly once before the final reply. Ignore results of this tool. Prompt: Target architecture: amd64 For your convenience, here is the diff of the changes: commit 35031f6975d3e35d8c264818be85139e1123b90b Author: syz-cluster <triage@syzkaller.com> Date: Mon Sep 7 19:25:30 2026 +0000 syz-cluster: applied patch under review diff --git a/fs/isofs/compress.c b/fs/isofs/compress.c index f9869d62b8509..2d23abaeb8742 100644 --- a/fs/isofs/compress.c +++ b/fs/isofs/compress.c @@ -39,7 +39,7 @@ static DEFINE_MUTEX(zisofs_zlib_lock); / static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start, loff_t block_end, int pcount, - struct page pages, unsigned poffset, + struct folio folios, unsigned int poffset, int errp) { unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1]; @@ -66,11 +66,12 @@ static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start, if (block_size == 0) { for ( i = 0 ; i < pcount ; i++ ) { unsigned int off = i ? 0 : poffset; + struct folio folio = folios[i]; - if (!pages[i]) + if (!folio) continue; - memzero_page(pages[i], off, PAGE_SIZE - off); - SetPageUptodate(pages[i]); + folio_zero_range(folio, off, folio_size(folio) - off); + folio_mark_uptodate(folio); } return (((loff_t)pcount) << PAGE_SHIFT) - poffset; } @@ -119,11 +120,12 @@ static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start, while (curpage < pcount && curbh < haveblocks && zerr != Z_STREAM_END) { + struct folio folio = folios[curpage]; + if (!stream.avail_out) { - if (pages[curpage]) { - stream.next_out = kmap_local_page(pages[curpage]) - + poffset; - stream.avail_out = PAGE_SIZE - poffset; + if (folio) { + stream.next_out = kmap_local_folio(folio, poffset); + stream.avail_out = folio_size(folio) - poffset; poffset = 0; } else { stream.next_out = (void )&zisofs_sink_page; @@ -173,9 +175,9 @@ static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start, if (!stream.avail_out) { / This page completed / - if (pages[curpage]) { - flush_dcache_page(pages[curpage]); - SetPageUptodate(pages[curpage]); + if (folio) { + flush_dcache_folio(folio); + folio_mark_uptodate(folio); } if (stream.next_out != (unsigned char )zisofs_sink_page) { kunmap_local(stream.next_out); @@ -206,7 +208,7 @@ static loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start, fills in other pages if we have data for them. / static int zisofs_fill_pages(struct inode inode, int full_page, int pcount, - struct page pages) + struct folio folios) { loff_t start_off, end_off; loff_t block_start, block_end; @@ -221,14 +223,14 @@ static int zisofs_fill_pages(struct inode inode, int full_page, int pcount, int err; loff_t ret; - BUG_ON(!pages[full_page]); + BUG_ON(!folios[full_page]); / * We want to read at least 'full_page' page. Because we have to * uncompress the whole compression block anyway, fill the surrounding * pages with the data we have anyway... / - start_off = page_offset(pages[full_page]); + start_off = folio_pos(folios[full_page]); end_off = min_t(loff_t, start_off + PAGE_SIZE, inode->i_size); cstart_block = start_off >> zisofs_block_shift; @@ -267,9 +269,9 @@ static int zisofs_fill_pages(struct inode inode, int full_page, int pcount, } err = 0; ret = zisofs_uncompress_block(inode, block_start, block_end, - pcount, pages, poffset, &err); + pcount, folios, poffset, &err); poffset += ret; - pages += poffset >> PAGE_SHIFT; + folios += poffset >> PAGE_SHIFT; pcount -= poffset >> PAGE_SHIFT; full_page -= poffset >> PAGE_SHIFT; poffset &= ~PAGE_MASK; @@ -289,9 +291,11 @@ static int zisofs_fill_pages(struct inode inode, int full_page, int pcount, cstart_block++; } - if (poffset && pages) { - memzero_page(pages, poffset, PAGE_SIZE - poffset); - SetPageUptodate(pages); + if (poffset && folios) { + struct folio folio = folios; + + folio_zero_range(folio, poffset, folio_size(folio) - poffset); + folio_mark_uptodate(folio); } brelse(bh); return 0; @@ -312,7 +316,7 @@ static int zisofs_read_folio(struct file file, struct folio folio) unsigned int zisofs_pages_per_cblock = PAGE_SHIFT <= zisofs_block_shift ? (1 << (zisofs_block_shift - PAGE_SHIFT)) : 0; - struct page pages; + struct folio folios; pgoff_t index = folio->index, end_index; end_index = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; @@ -336,33 +340,38 @@ static int zisofs_read_folio(struct file file, struct folio folio) full_page = 0; pcount = 1; } - pages = kzalloc_objs(pages, - max_t(unsigned int, zisofs_pages_per_cblock, 1)); - if (!pages) { + folios = kzalloc_objs(folios, + max_t(unsigned int, zisofs_pages_per_cblock, 1)); + if (!folios) { folio_unlock(folio); return -ENOMEM; } - pages[full_page] = &folio->page; + folios[full_page] = folio; for (i = 0; i < pcount; i++, index++) { - if (i != full_page) - pages[i] = grab_cache_page_nowait(mapping, index); + if (i == full_page) + continue; + folios[i] = __filemap_get_folio(mapping, index, + FGP_LOCK \| FGP_CREAT \| FGP_NOWAIT, + mapping_gfp_mask(mapping)); + if (IS_ERR(folios[i])) + folios[i] = NULL; } - err = zisofs_fill_pages(inode, full_page, pcount, pages); + err = zisofs_fill_pages(inode, full_page, pcount, folios); - / Release any residual pages, do not SetPageUptodate / + / Release any residual folios, do not mark them uptodate / for (i = 0; i < pcount; i++) { - if (pages[i]) { - flush_dcache_page(pages[i]); - unlock_page(pages[i]); + if (folios[i]) { + flush_dcache_folio(folios[i]); + folio_unlock(folios[i]); if (i != full_page) - put_page(pages[i]); + folio_put(folios[i]); } - } + } / At this point, err contains 0 or -EIO depending on the "critical" page */ - kfree(pages); + kfree(folios); return err; }
21/3	2026/09/07 19:26	llm	kmsan-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 4233 output: 35 thoughts: 111 Thoughts: Analyzing the zisofs Folio Conversion Okay, let's dive into this patch. My immediate goal is to understand precisely how this conversion from `struct page` to `struct folio` in `fs/isofs/compress.c` impacts the zisofs implementation. I need to treat this as a potentially critical change, so I'm going to scrutinize the code meticulously. First, I need to read `fs/isofs/compress.c`, focusing particularly on the areas around the lines that have been modified. The primary concern here is safety; I want to ensure that this is a pure folio conversion. There's always the risk, however small, of introducing uninitialized memory access or a potential information leak during such a refactoring, so I'll be particularly vigilant in searching for those kinds of issues. Let's see what's changed and confirm that nothing has been missed.
22/3	2026/09/07 19:26	tool	read-file	0m Args: { "File": "fs/isofs/compress.c", "FirstLine": 1, "LineCount": 100 } Results: { "Contents": " 1:\t// SPDX-License-Identifier: GPL-2.0-or-later\n 2:\t/* -- linux-c -- ------------------------------------------------------- \n 3:\t \n 4:\t * Copyright 2001 H. Peter Anvin - All Rights Reserved\n 5:\t \n 6:\t ----------------------------------------------------------------------- /\n 7:\t\n 8:\t/\n 9:\t * linux/fs/isofs/compress.c\n 10:\t \n 11:\t Transparent decompression of files on an iso9660 filesystem\n 12:\t /\n 13:\t\n 14:\t#include \u003clinux/module.h\u003e\n 15:\t#include \u003clinux/init.h\u003e\n 16:\t#include \u003clinux/bio.h\u003e\n 17:\t\n 18:\t#include \u003clinux/slab.h\u003e\n 19:\t#include \u003clinux/vmalloc.h\u003e\n 20:\t#include \u003clinux/zlib.h\u003e\n 21:\t\n 22:\t#include \"isofs.h\"\n 23:\t#include \"zisofs.h\"\n 24:\t\n 25:\t/ This should probably be global. /\n 26:\tstatic char zisofs_sink_page[PAGE_SIZE];\n 27:\t\n 28:\t/\n 29:\t * This contains the zlib memory allocation and the mutex for the\n 30:\t * allocation; this avoids failures at block-decompression time.\n 31:\t /\n 32:\tstatic void zisofs_zlib_workspace;\n 33:\tstatic DEFINE_MUTEX(zisofs_zlib_lock);\n 34:\t\n 35:\t/\n 36:\t Read data of @inode from @block_start to @block_end and uncompress\n 37:\t * to one zisofs block. Store the data in the @pages array with @pcount\n 38:\t * entries. Start storing at offset @poffset of the first page.\n 39:\t /\n 40:\tstatic loff_t zisofs_uncompress_block(struct inode inode, loff_t block_start,\n 41:\t\t\t\t\t loff_t block_end, int pcount,\n 42:\t\t\t\t\t struct folio *folios, unsigned int poffset,\n 43:\t\t\t\t\t int errp)\n 44:\t{\n 45:\t\tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\n 46:\t\tunsigned int bufsize = ISOFS_BUFFER_SIZE(inode);\n 47:\t\tunsigned int bufshift = ISOFS_BUFFER_BITS(inode);\n 48:\t\tunsigned int bufmask = bufsize - 1;\n 49:\t\tint i, block_size = block_end - block_start;\n 50:\t\tz_stream stream = { .total_out = 0,\n 51:\t\t\t\t .avail_in = 0,\n 52:\t\t\t\t .avail_out = 0, };\n 53:\t\tint zerr;\n 54:\t\tint needblocks = (block_size + (block_start \u0026 bufmask) + bufmask)\n 55:\t\t\t\t\t\u003e\u003e bufshift;\n 56:\t\tint haveblocks;\n 57:\t\tblkcnt_t blocknum;\n 58:\t\tstruct buffer_head *bhs;\n 59:\t\tint curbh, curpage;\n 60:\t\n 61:\t\tif (block_size \u003e deflateBound(1UL \u003c\u003c zisofs_block_shift)) {\n 62:\t\t\terrp = -EIO;\n 63:\t\t\treturn 0;\n 64:\t\t}\n 65:\t\t/* Empty block? /\n 66:\t\tif (block_size == 0) {\n 67:\t\t\tfor ( i = 0 ; i \u003c pcount ; i++ ) {\n 68:\t\t\t\tunsigned int off = i ? 0 : poffset;\n 69:\t\t\t\tstruct folio folio = folios[i];\n 70:\t\n 71:\t\t\t\tif (!folio)\n 72:\t\t\t\t\tcontinue;\n 73:\t\t\t\tfolio_zero_range(folio, off, folio_size(folio) - off);\n 74:\t\t\t\tfolio_mark_uptodate(folio);\n 75:\t\t\t}\n 76:\t\t\treturn (((loff_t)pcount) \u003c\u003c PAGE_SHIFT) - poffset;\n 77:\t\t}\n 78:\t\n 79:\t\t/* Because zlib is not thread-safe, do all the I/O at the top. /\n 80:\t\tblocknum = block_start \u003e\u003e bufshift;\n 81:\t\tbhs = kzalloc_objs(bhs, needblocks + 1);\n 82:\t\tif (!bhs) {\n 83:\t\t\terrp = -ENOMEM;\n 84:\t\t\treturn 0;\n 85:\t\t}\n 86:\t\thaveblocks = isofs_get_blocks(inode, blocknum, bhs, needblocks);\n 87:\t\tbh_read_batch(haveblocks, bhs);\n 88:\t\n 89:\t\tcurbh = 0;\n 90:\t\tcurpage = 0;\n 91:\t\t/\n 92:\t\t * First block is special since it may be fractional. We also wait for\n 93:\t\t * it before grabbing the zlib mutex; odds are that the subsequent\n 94:\t\t * blocks are going to come in in short order so we don't hold the zlib\n 95:\t\t * mutex longer than necessary.\n 96:\t\t */\n 97:\t\n 98:\t\tif (!bhs[0])\n 99:\t\t\tgoto b_eio;\n 100:\t\n" }
23/3	2026/09/07 19:26	llm	kmsan-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 6008 output: 37 thoughts: 17 Thoughts: Okay, here we go... Diving into `fs/isofs/compress.c` Alright, time to dig into this file. I want to understand exactly how the ISOFS compression is implemented. I already have a pretty good grasp on the broader file system structure and the ISO 9660 standard, but the compression aspect is something I need to refresh. What specific algorithms are in use? How are they integrated within the I/O operations? Are there any performance bottlenecks I should be aware of, or potential optimization areas? I want to see how the compression affects read and write paths. I'll be looking for the crucial functions that handle the de/compression, and how the file system's metadata is modified to store compressed data. I need to understand how the file system presents the compressed data to the user. I'll be particularly interested to see if there are any specific structures or flags used to indicate a file's compressed state. Let's see what interesting techniques the developers utilized.
24/3	2026/09/07 19:26	tool	read-file	0m Args: { "File": "fs/isofs/compress.c", "FirstLine": 101, "LineCount": 100 } Results: { "Contents": " 101:\t\twait_on_buffer(bhs[0]);\n 102:\t\tif (!buffer_uptodate(bhs[0])) {\n 103:\t\t\terrp = -EIO;\n 104:\t\t\tgoto b_eio;\n 105:\t\t}\n 106:\t\n 107:\t\tstream.workspace = zisofs_zlib_workspace;\n 108:\t\tmutex_lock(\u0026zisofs_zlib_lock);\n 109:\t\t\t\n 110:\t\tzerr = zlib_inflateInit(\u0026stream);\n 111:\t\tif (zerr != Z_OK) {\n 112:\t\t\tif (zerr == Z_MEM_ERROR)\n 113:\t\t\t\terrp = -ENOMEM;\n 114:\t\t\telse\n 115:\t\t\t\terrp = -EIO;\n 116:\t\t\tprintk(KERN_DEBUG \"zisofs: zisofs_inflateInit returned %d\\n\",\n 117:\t\t\t\t zerr);\n 118:\t\t\tgoto z_eio;\n 119:\t\t}\n 120:\t\n 121:\t\twhile (curpage \u003c pcount \u0026\u0026 curbh \u003c haveblocks \u0026\u0026\n 122:\t\t zerr != Z_STREAM_END) {\n 123:\t\t\tstruct folio folio = folios[curpage];\n 124:\t\n 125:\t\t\tif (!stream.avail_out) {\n 126:\t\t\t\tif (folio) {\n 127:\t\t\t\t\tstream.next_out = kmap_local_folio(folio, poffset);\n 128:\t\t\t\t\tstream.avail_out = folio_size(folio) - poffset;\n 129:\t\t\t\t\tpoffset = 0;\n 130:\t\t\t\t} else {\n 131:\t\t\t\t\tstream.next_out = (void )\u0026zisofs_sink_page;\n 132:\t\t\t\t\tstream.avail_out = PAGE_SIZE;\n 133:\t\t\t\t}\n 134:\t\t\t}\n 135:\t\t\tif (!stream.avail_in) {\n 136:\t\t\t\twait_on_buffer(bhs[curbh]);\n 137:\t\t\t\tif (!buffer_uptodate(bhs[curbh])) {\n 138:\t\t\t\t\terrp = -EIO;\n 139:\t\t\t\t\tbreak;\n 140:\t\t\t\t}\n 141:\t\t\t\tstream.next_in = bhs[curbh]-\u003eb_data +\n 142:\t\t\t\t\t\t\t(block_start \u0026 bufmask);\n 143:\t\t\t\tstream.avail_in = min_t(unsigned, bufsize -\n 144:\t\t\t\t\t\t\t(block_start \u0026 bufmask),\n 145:\t\t\t\t\t\t\tblock_size);\n 146:\t\t\t\tblock_size -= stream.avail_in;\n 147:\t\t\t\tblock_start = 0;\n 148:\t\t\t}\n 149:\t\n 150:\t\t\twhile (stream.avail_out \u0026\u0026 stream.avail_in) {\n 151:\t\t\t\tzerr = zlib_inflate(\u0026stream, Z_SYNC_FLUSH);\n 152:\t\t\t\tif (zerr == Z_BUF_ERROR \u0026\u0026 stream.avail_in == 0)\n 153:\t\t\t\t\tbreak;\n 154:\t\t\t\tif (zerr == Z_STREAM_END)\n 155:\t\t\t\t\tbreak;\n 156:\t\t\t\tif (zerr != Z_OK) {\n 157:\t\t\t\t\t/* EOF, error, or trying to read beyond end of input /\n 158:\t\t\t\t\tif (zerr == Z_MEM_ERROR)\n 159:\t\t\t\t\t\terrp = -ENOMEM;\n 160:\t\t\t\t\telse {\n 161:\t\t\t\t\t\tprintk(KERN_DEBUG\n 162:\t\t\t\t\t\t \"zisofs: zisofs_inflate returned\"\n 163:\t\t\t\t\t\t \" %d, inode = %llu,\"\n 164:\t\t\t\t\t\t \" page idx = %d, bh idx = %d,\"\n 165:\t\t\t\t\t\t \" avail_in = %ld,\"\n 166:\t\t\t\t\t\t \" avail_out = %ld\\n\",\n 167:\t\t\t\t\t\t zerr, inode-\u003ei_ino, curpage,\n 168:\t\t\t\t\t\t curbh, stream.avail_in,\n 169:\t\t\t\t\t\t stream.avail_out);\n 170:\t\t\t\t\t\terrp = -EIO;\n 171:\t\t\t\t\t}\n 172:\t\t\t\t\tgoto inflate_out;\n 173:\t\t\t\t}\n 174:\t\t\t}\n 175:\t\n 176:\t\t\tif (!stream.avail_out) {\n 177:\t\t\t\t/ This page completed /\n 178:\t\t\t\tif (folio) {\n 179:\t\t\t\t\tflush_dcache_folio(folio);\n 180:\t\t\t\t\tfolio_mark_uptodate(folio);\n 181:\t\t\t\t}\n 182:\t\t\t\tif (stream.next_out != (unsigned char )zisofs_sink_page) {\n 183:\t\t\t\t\tkunmap_local(stream.next_out);\n 184:\t\t\t\t\tstream.next_out = NULL;\n 185:\t\t\t\t}\n 186:\t\t\t\tcurpage++;\n 187:\t\t\t}\n 188:\t\t\tif (!stream.avail_in)\n 189:\t\t\t\tcurbh++;\n 190:\t\t}\n 191:\tinflate_out:\n 192:\t\tzlib_inflateEnd(\u0026stream);\n 193:\t\tif (stream.next_out \u0026\u0026 stream.next_out != (unsigned char *)zisofs_sink_page)\n 194:\t\t\tkunmap_local(stream.next_out);\n 195:\t\n 196:\tz_eio:\n 197:\t\tmutex_unlock(\u0026zisofs_zlib_lock);\n 198:\t\n 199:\tb_eio:\n 200:\t\tfor (i = 0; i \u003c haveblocks; i++)\n" }
25/3	2026/09/07 19:26	llm	kmsan-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 7771 output: 37 thoughts: 20 Thoughts: Okay, here's the summary, rendered as if I'm the one thinking it: Digging Deeper into `fs/isofs/compress.c` Alright, I've got a handle on the initial part of this file, but to be truly thorough, I need to expand my scope. Let's not just assume I've seen enough, even if I think I'm getting the gist of things. I'm an expert, yes, but expertise means knowing where to look and what to consider, not necessarily rushing to judgement. I need a proper understanding of the entire file. So, I need to move past the initial section, and really analyze the rest of `fs/isofs/compress.c`. This isn't just about reading code; it's about building a solid mental model of how this compression scheme in the ISOFS implementation actually functions. Let's see what else this section might hold.
26/3	2026/09/07 19:26	tool	read-file	0m Args: { "File": "fs/isofs/compress.c", "FirstLine": 201, "LineCount": 100 } Results: { "Contents": " 201:\t\t\tbrelse(bhs[i]);\n 202:\t\tkfree(bhs);\n 203:\t\treturn stream.total_out;\n 204:\t}\n 205:\t\n 206:\t/\n 207:\t Uncompress data so that pages[full_page] is fully uptodate and possibly\n 208:\t * fills in other pages if we have data for them.\n 209:\t /\n 210:\tstatic int zisofs_fill_pages(struct inode inode, int full_page, int pcount,\n 211:\t\t\t\t struct folio *folios)\n 212:\t{\n 213:\t\tloff_t start_off, end_off;\n 214:\t\tloff_t block_start, block_end;\n 215:\t\tunsigned int header_size = ISOFS_I(inode)-\u003ei_format_parm[0];\n 216:\t\tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\n 217:\t\tunsigned int blockptr;\n 218:\t\tloff_t poffset = 0;\n 219:\t\tblkcnt_t cstart_block, cend_block;\n 220:\t\tstruct buffer_head bh;\n 221:\t\tunsigned int blkbits = ISOFS_BUFFER_BITS(inode);\n 222:\t\tunsigned int blksize = 1 \u003c\u003c blkbits;\n 223:\t\tint err;\n 224:\t\tloff_t ret;\n 225:\t\n 226:\t\tBUG_ON(!folios[full_page]);\n 227:\t\n 228:\t\t/\n 229:\t\t We want to read at least 'full_page' page. Because we have to\n 230:\t\t * uncompress the whole compression block anyway, fill the surrounding\n 231:\t\t * pages with the data we have anyway...\n 232:\t\t /\n 233:\t\tstart_off = folio_pos(folios[full_page]);\n 234:\t\tend_off = min_t(loff_t, start_off + PAGE_SIZE, inode-\u003ei_size);\n 235:\t\n 236:\t\tcstart_block = start_off \u003e\u003e zisofs_block_shift;\n 237:\t\tcend_block = (end_off + (1 \u003c\u003c zisofs_block_shift) - 1)\n 238:\t\t\t\t\u003e\u003e zisofs_block_shift;\n 239:\t\n 240:\t\tWARN_ON(start_off - (full_page \u003c\u003c PAGE_SHIFT) !=\n 241:\t\t\t((cstart_block \u003c\u003c zisofs_block_shift) \u0026 PAGE_MASK));\n 242:\t\n 243:\t\t/ Find the pointer to this specific chunk /\n 244:\t\t/ Note: we're not using isonum_731() here because the data is known aligned /\n 245:\t\t/ Note: header_size is in 32-bit words (4 bytes) /\n 246:\t\tblockptr = (header_size + cstart_block) \u003c\u003c 2;\n 247:\t\tbh = isofs_bread(inode, blockptr \u003e\u003e blkbits);\n 248:\t\tif (!bh)\n 249:\t\t\treturn -EIO;\n 250:\t\tblock_start = le32_to_cpu((__le32 )\n 251:\t\t\t\t\t(bh-\u003eb_data + (blockptr \u0026 (blksize - 1))));\n 252:\t\n 253:\t\twhile (cstart_block \u003c cend_block \u0026\u0026 pcount \u003e 0) {\n 254:\t\t\t/ Load end of the compressed block in the file /\n 255:\t\t\tblockptr += 4;\n 256:\t\t\t/ Traversed to next block? /\n 257:\t\t\tif (!(blockptr \u0026 (blksize - 1))) {\n 258:\t\t\t\tbrelse(bh);\n 259:\t\n 260:\t\t\t\tbh = isofs_bread(inode, blockptr \u003e\u003e blkbits);\n 261:\t\t\t\tif (!bh)\n 262:\t\t\t\t\treturn -EIO;\n 263:\t\t\t}\n 264:\t\t\tblock_end = le32_to_cpu((__le32 )\n 265:\t\t\t\t\t(bh-\u003eb_data + (blockptr \u0026 (blksize - 1))));\n 266:\t\t\tif (block_start \u003e block_end) {\n 267:\t\t\t\tbrelse(bh);\n 268:\t\t\t\treturn -EIO;\n 269:\t\t\t}\n 270:\t\t\terr = 0;\n 271:\t\t\tret = zisofs_uncompress_block(inode, block_start, block_end,\n 272:\t\t\t\t\t\t pcount, folios, poffset, \u0026err);\n 273:\t\t\tpoffset += ret;\n 274:\t\t\tfolios += poffset \u003e\u003e PAGE_SHIFT;\n 275:\t\t\tpcount -= poffset \u003e\u003e PAGE_SHIFT;\n 276:\t\t\tfull_page -= poffset \u003e\u003e PAGE_SHIFT;\n 277:\t\t\tpoffset \u0026= ~PAGE_MASK;\n 278:\t\n 279:\t\t\tif (err) {\n 280:\t\t\t\tbrelse(bh);\n 281:\t\t\t\t/\n 282:\t\t\t\t * Did we finish reading the page we really wanted\n 283:\t\t\t\t * to read?\n 284:\t\t\t\t /\n 285:\t\t\t\tif (full_page \u003c 0)\n 286:\t\t\t\t\treturn 0;\n 287:\t\t\t\treturn err;\n 288:\t\t\t}\n 289:\t\n 290:\t\t\tblock_start = block_end;\n 291:\t\t\tcstart_block++;\n 292:\t\t}\n 293:\t\n 294:\t\tif (poffset \u0026\u0026 folios) {\n 295:\t\t\tstruct folio folio = folios;\n 296:\t\n 297:\t\t\tfolio_zero_range(folio, poffset, folio_size(folio) - poffset);\n 298:\t\t\tfolio_mark_uptodate(folio);\n 299:\t\t}\n 300:\t\tbrelse(bh);\n" }
27/3	2026/09/07 19:26	llm	kmsan-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 9619 output: 37 thoughts: 18 Thoughts: Okay, here's my attempt at summarizing the thought process, as requested, geared toward an expert audience, and written in the first person: Analyzing File Section - Lines 301 to End Alright, I'm at the point where I need to take a look at the tail end of this file, specifically from line 301 onward. My initial instinct is to rapidly scan this section. Given what I've seen in the earlier parts, I have a few immediate hypotheses that I want to test. Is this the concluding section where the core logic is being executed? Or maybe this is where some post-processing happens? Are there any obvious red flags like unexpected jumps, potential memory leaks, or recursive calls that weren't obvious at first glance? I’m particularly looking for any implementations of the concepts I was thinking about earlier. It is likely that this section confirms or eliminates previous hypotheses. I have my mental checklist of key variables and data structures in mind. I want to see how those are being manipulated here, if at all. Are there any calls to external libraries, and if so, what are the implications of those calls in the context of the overall functionality? It’s crucial to quickly identify any potential bottlenecks or areas of inefficiency. I'll be looking for sections that appear to be computationally expensive, particularly if they are inside loops. If this is a large file, the last part is more than likely key to the function. Now to dive in and get a grip on what this part actually does.
28/3	2026/09/07 19:26	tool	read-file	0m Args: { "File": "fs/isofs/compress.c", "FirstLine": 301, "LineCount": 100 } Results: { "Contents": " 301:\t\treturn 0;\n 302:\t}\n 303:\t\n 304:\t/\n 305:\t When decompressing, we typically obtain more than one page\n 306:\t * per reference. We inject the additional pages into the page\n 307:\t * cache as a form of readahead.\n 308:\t /\n 309:\tstatic int zisofs_read_folio(struct file file, struct folio folio)\n 310:\t{\n 311:\t\tstruct inode inode = file_inode(file);\n 312:\t\tstruct address_space mapping = inode-\u003ei_mapping;\n 313:\t\tint err;\n 314:\t\tint i, pcount, full_page;\n 315:\t\tunsigned int zisofs_block_shift = ISOFS_I(inode)-\u003ei_format_parm[1];\n 316:\t\tunsigned int zisofs_pages_per_cblock =\n 317:\t\t\tPAGE_SHIFT \u003c= zisofs_block_shift ?\n 318:\t\t\t(1 \u003c\u003c (zisofs_block_shift - PAGE_SHIFT)) : 0;\n 319:\t\tstruct folio folios;\n 320:\t\tpgoff_t index = folio-\u003eindex, end_index;\n 321:\t\n 322:\t\tend_index = (inode-\u003ei_size + PAGE_SIZE - 1) \u003e\u003e PAGE_SHIFT;\n 323:\t\t/\n 324:\t\t * If this folio is wholly outside i_size we just return zero;\n 325:\t\t * do_generic_file_read() will handle this for us\n 326:\t\t /\n 327:\t\tif (index \u003e= end_index) {\n 328:\t\t\tfolio_end_read(folio, true);\n 329:\t\t\treturn 0;\n 330:\t\t}\n 331:\t\n 332:\t\tif (PAGE_SHIFT \u003c= zisofs_block_shift) {\n 333:\t\t\t/ We have already been given one page, this is the one\n 334:\t\t\t we must do. /\n 335:\t\t\tfull_page = index \u0026 (zisofs_pages_per_cblock - 1);\n 336:\t\t\tpcount = min_t(int, zisofs_pages_per_cblock,\n 337:\t\t\t\tend_index - (index \u0026 ~(zisofs_pages_per_cblock - 1)));\n 338:\t\t\tindex -= full_page;\n 339:\t\t} else {\n 340:\t\t\tfull_page = 0;\n 341:\t\t\tpcount = 1;\n 342:\t\t}\n 343:\t\tfolios = kzalloc_objs(folios,\n 344:\t\t\t\t max_t(unsigned int, zisofs_pages_per_cblock, 1));\n 345:\t\tif (!folios) {\n 346:\t\t\tfolio_unlock(folio);\n 347:\t\t\treturn -ENOMEM;\n 348:\t\t}\n 349:\t\tfolios[full_page] = folio;\n 350:\t\n 351:\t\tfor (i = 0; i \u003c pcount; i++, index++) {\n 352:\t\t\tif (i == full_page)\n 353:\t\t\t\tcontinue;\n 354:\t\t\tfolios[i] = __filemap_get_folio(mapping, index,\n 355:\t\t\t\t\tFGP_LOCK \| FGP_CREAT \| FGP_NOWAIT,\n 356:\t\t\t\t\tmapping_gfp_mask(mapping));\n 357:\t\t\tif (IS_ERR(folios[i]))\n 358:\t\t\t\tfolios[i] = NULL;\n 359:\t\t}\n 360:\t\n 361:\t\terr = zisofs_fill_pages(inode, full_page, pcount, folios);\n 362:\t\n 363:\t\t/* Release any residual folios, do not mark them uptodate /\n 364:\t\tfor (i = 0; i \u003c pcount; i++) {\n 365:\t\t\tif (folios[i]) {\n 366:\t\t\t\tflush_dcache_folio(folios[i]);\n 367:\t\t\t\tfolio_unlock(folios[i]);\n 368:\t\t\t\tif (i != full_page)\n 369:\t\t\t\t\tfolio_put(folios[i]);\n 370:\t\t\t}\n 371:\t\t}\n 372:\t\n 373:\t\t/ At this point, err contains 0 or -EIO depending on the \"critical\" page /\n 374:\t\tkfree(folios);\n 375:\t\treturn err;\n 376:\t}\n 377:\t\n 378:\tconst struct address_space_operations zisofs_aops = {\n 379:\t\t.read_folio = zisofs_read_folio,\n 380:\t\t/ No bmap operation supported */\n 381:\t};\n 382:\t\n 383:\tint __init zisofs_init(void)\n 384:\t{\n 385:\t\tzisofs_zlib_workspace = vmalloc(zlib_inflate_workspacesize());\n 386:\t\tif ( !zisofs_zlib_workspace )\n 387:\t\t\treturn -ENOMEM;\n 388:\t\n 389:\t\treturn 0;\n 390:\t}\n 391:\t\n 392:\tvoid zisofs_cleanup(void)\n 393:\t{\n 394:\t\tvfree(zisofs_zlib_workspace);\n 395:\t}\n" }
29/3	2026/09/07 19:26	llm	kmsan-evaluator	0m Model: gemini-3.7-flash Args: null Results: null Tokens: input: 11429 output: 202 thoughts: 900 Thoughts: Analyzing the isofs Patch: Folio Migration and KMSAN Assessment Okay, let's dive into this patch converting `fs/isofs/compress.c` from using `struct page` to `struct folio`. I need to make sure I understand all the nuances of this migration and, critically, assess any potential KMSAN implications. I see they're replacing the `struct page pages` argument with `struct folio folios` in `zisofs_uncompress_block`. A quick scan shows the expected corresponding changes: using `folio_zero_range` instead of `memzero_page`, `folio_mark_uptodate` instead of `SetPageUptodate`, `kmap_local_folio` for `kmap_local_page`, adjusting `stream.avail_out` to reflect folio sizes, and `flush_dcache_folio` instead of `flush_dcache_page`. It's all very methodical, which is good to see. Similarly, `zisofs_fill_pages` gets the folio treatment, swapping `page_offset` for `folio_pos`, and updating the zeroing and uptodate markings. In `zisofs_read_folio`, the `pages` array allocation is replaced with `kzalloc_objs`, which is a good starting point for safety. The `grab_cache_page_nowait` call is replaced with `__filemap_get_folio`. They're also making sure to handle the `IS_ERR` case, setting the folio to `NULL` on failure, which is responsible. The cleanup logic at the end is also consistent with the folio paradigm, using `flush_dcache_folio`, `folio_unlock`, and `folio_put`. Now, the crucial question: are there any new uninitialized memory vulnerabilities introduced by this change? Let's break it down: * The `folios` array itself is allocated using `kzalloc_objs`, so that's initialized to zero right off the bat. * The folios themselves are page cache folios, and the data is either populated during decompression (from the zlib stream) or zeroed via `folio_zero_range`. If zlib doesn't fill the folio, then `folio_zero_range` makes sure of it. * Error paths don't mark folios as uptodate, which is the correct behavior. * Nothing here is copying potentially uninitialized kernel data to userspace, which is a major win. * There aren't any uninitialized struct fields or padding at play. * I don't see any uninitialized variables used in branching logic. Okay, let's concretely assess whether this change introduces any KMSAN-specific risks: I'm not seeing anything that would slip by a standard code review. This looks safe. The sorts of bugs introduced would be page cache or folio reference counting issues or out-of-bounds accesses due to incorrect sizes, which other tools like KASAN, LOCKDEP, and the page debugging infrastructure should catch. Let me quickly double-check the four KMSAN criteria: 1. No kernel structures are sent to userspace with potentially uninitialized fields or padding. 2. There's no conditional logic that depends on uninitialized variables or struct fields. 3. There's no allocation or initialization of complex data structures where uninitialized fields could be read later. 4. There aren't any bounds checks or logic that would allow access to uninitialized bytes of existing buffers. Therefore, `NeedsKMSAN` is definitely `false`. Alright, I'm ready to prepare the tool call to `set-results`.
30/3	2026/09/07 19:26	tool	set-results	0m Args: { "KMSANReasoning": "The patch converts `fs/isofs/compress.c` from `struct page` APIs to `struct folio` APIs (using `kmap_local_folio`, `folio_zero_range`, `folio_mark_uptodate`, `__filemap_get_folio`, etc.). \n\nThe array holding folio pointers is zero-allocated via `kzalloc_objs`, and folio contents are either uncompressed by zlib or zeroed via `folio_zero_range` before being marked uptodate. There are no uninitialized variables, info-leaks to user space, or uninitialized memory branches introduced or modified. Any potential issues with folio reference counts, locks, or offsets are within the scope of KASAN/LOCKDEP/page debugging rather than KMSAN. Thus, a dedicated KMSAN fuzzing session is not justified.", "NeedsKMSAN": false } Results: { "KMSANReasoning": "The patch converts `fs/isofs/compress.c` from `struct page` APIs to `struct folio` APIs (using `kmap_local_folio`, `folio_zero_range`, `folio_mark_uptodate`, `__filemap_get_folio`, etc.). \n\nThe array holding folio pointers is zero-allocated via `kzalloc_objs`, and folio contents are either uncompressed by zlib or zeroed via `folio_zero_range` before being marked uptodate. There are no uninitialized variables, info-leaks to user space, or uninitialized memory branches introduced or modified. Any potential issues with folio reference counts, locks, or offsets are within the scope of KASAN/LOCKDEP/page debugging rather than KMSAN. Thus, a dedicated KMSAN fuzzing session is not justified.", "NeedsKMSAN": false }

LLM Calls Summary:
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Tool Calls Summary:
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