kernel/fs/ext4/ext4_jbd2.c, branch linux-5.1.y

ext4: shutdown should not prevent get_write_access

2018-02-19T03:07:36Z

The ext4 forced shutdown flag needs to prevent new handles from being started, but it needs to allow existing handles to complete. So the forced shutdown flag should not force ext4_journal_get_write_access to fail. Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)

2017-07-17T07:45:34Z

Firstly by applying the following with coccinelle's spatch: @@ expression SB; @@ -SB->s_flags & MS_RDONLY +sb_rdonly(SB) to effect the conversion to sb_rdonly(sb), then by applying: @@ expression A, SB; @@ ( -(!sb_rdonly(SB)) && A +!sb_rdonly(SB) && A | -A != (sb_rdonly(SB)) +A != sb_rdonly(SB) | -A == (sb_rdonly(SB)) +A == sb_rdonly(SB) | -!(sb_rdonly(SB)) +!sb_rdonly(SB) | -A && (sb_rdonly(SB)) +A && sb_rdonly(SB) | -A || (sb_rdonly(SB)) +A || sb_rdonly(SB) | -(sb_rdonly(SB)) != A +sb_rdonly(SB) != A | -(sb_rdonly(SB)) == A +sb_rdonly(SB) == A | -(sb_rdonly(SB)) && A +sb_rdonly(SB) && A | -(sb_rdonly(SB)) || A +sb_rdonly(SB) || A ) @@ expression A, B, SB; @@ ( -(sb_rdonly(SB)) ? 1 : 0 +sb_rdonly(SB) | -(sb_rdonly(SB)) ? A : B +sb_rdonly(SB) ? A : B ) to remove left over excess bracketage and finally by applying: @@ expression A, SB; @@ ( -(A & MS_RDONLY) != sb_rdonly(SB) +(bool)(A & MS_RDONLY) != sb_rdonly(SB) | -(A & MS_RDONLY) == sb_rdonly(SB) +(bool)(A & MS_RDONLY) == sb_rdonly(SB) ) to make comparisons against the result of sb_rdonly() (which is a bool) work correctly. Signed-off-by: David Howells

ext4: add shutdown bit and check for it

2017-02-05T06:28:48Z

Add a shutdown bit that will cause ext4 processing to fail immediately with EIO. Signed-off-by: Theodore Ts'o

ext4: fix potential use after free in __ext4_journal_stop

2015-10-18T02:57:06Z

There is a use-after-free possibility in __ext4_journal_stop() in the case that we free the handle in the first jbd2_journal_stop() because we're referencing handle->h_err afterwards. This was introduced in 9705acd63b125dee8b15c705216d7186daea4625 and it is wrong. Fix it by storing the handle->h_err value beforehand and avoid referencing potentially freed handle. Fixes: 9705acd63b125dee8b15c705216d7186daea4625 Signed-off-by: Lukas Czerner Reviewed-by: Andreas Dilger Cc: stable@vger.kernel.org

ext4: fix NULL pointer dereference when journal restart fails

2015-05-14T22:55:18Z

Currently when journal restart fails, we'll have the h_transaction of the handle set to NULL to indicate that the handle has been effectively aborted. We handle this situation quietly in the jbd2_journal_stop() and just free the handle and exit because everything else has been done before we attempted (and failed) to restart the journal. Unfortunately there are a number of problems with that approach introduced with commit 41a5b913197c "jbd2: invalidate handle if jbd2_journal_restart() fails" First of all in ext4 jbd2_journal_stop() will be called through __ext4_journal_stop() where we would try to get a hold of the superblock by dereferencing h_transaction which in this case would lead to NULL pointer dereference and crash. In addition we're going to free the handle regardless of the refcount which is bad as well, because others up the call chain will still reference the handle so we might potentially reference already freed memory. Moreover it's expected that we'll get aborted handle as well as detached handle in some of the journalling function as the error propagates up the stack, so it's unnecessary to call WARN_ON every time we get detached handle. And finally we might leak some memory by forgetting to free reserved handle in jbd2_journal_stop() in the case where handle was detached from the transaction (h_transaction is NULL). Fix the NULL pointer dereference in __ext4_journal_stop() by just calling jbd2_journal_stop() quietly as suggested by Jan Kara. Also fix the potential memory leak in jbd2_journal_stop() and use proper handle refcounting before we attempt to free it to avoid use-after-free issues. And finally remove all WARN_ON(!transaction) from the code so that we do not get random traces when something goes wrong because when journal restart fails we will get to some of those functions. Cc: stable@vger.kernel.org Signed-off-by: Lukas Czerner Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara

ext4: fix over-defensive complaint after journal abort

2014-10-02T02:23:15Z

Reviewed-by: Jan Kara Signed-off-by: Dmitry Monakhov Signed-off-by: Theodore Ts'o

ext4: make local functions static

2014-05-12T14:50:23Z

I have been running make namespacecheck to look for unneeded globals, and found these in ext4. Signed-off-by: Stephen Hemminger Signed-off-by: "Theodore Ts'o"

jbd2: improve error messages for inconsistent journal heads

2014-03-12T20:38:03Z

Fix up error messages printed when the transaction pointers in a journal head are inconsistent. This improves the error messages which are printed when running xfstests generic/068 in data=journal mode. See the bug report at: https://bugzilla.kernel.org/show_bug.cgi?id=60786 Signed-off-by: "Theodore Ts'o"

ext4: call ext4_error_inode() if jbd2_journal_dirty_metadata() fails

2013-12-02T14:31:36Z

While it's true that errors can only happen if there is a bug in jbd2_journal_dirty_metadata(), if a bug does happen, we need to halt the kernel or remount the file system read-only in order to avoid further data loss. The ext4_journal_abort_handle() function doesn't do any of this, and while it's likely that this call (since it doesn't adjust refcounts) will likely result in the file system eventually deadlocking since the current transaction will never be able to close, it's much cleaner to call let ext4's error handling system deal with this situation. There's a separate bug here which is that if certain jbd2 errors errors occur and file system is mounted errors=continue, the file system will probably eventually end grind to a halt as described above. But things have been this way in a long time, and usually when we have these sorts of errors it's pretty much a disaster --- and that's why the jbd2 layer aggressively retries memory allocations, which is the most likely cause of these jbd2 errors. Signed-off-by: "Theodore Ts'o" Reviewed-by: Jan Kara Cc: stable@vger.kernel.org