linux/fs/ext4/ext4_jbd2.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license 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 <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 14:07:57 +00:00
// SPDX-License-Identifier: GPL-2.0
/*
* Interface between ext4 and JBD
*/
#include "ext4_jbd2.h"
#include <trace/events/ext4.h>
/* Just increment the non-pointer handle value */
static handle_t *ext4_get_nojournal(void)
{
handle_t *handle = current->journal_info;
unsigned long ref_cnt = (unsigned long)handle;
BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
ref_cnt++;
handle = (handle_t *)ref_cnt;
current->journal_info = handle;
return handle;
}
/* Decrement the non-pointer handle value */
static void ext4_put_nojournal(handle_t *handle)
{
unsigned long ref_cnt = (unsigned long)handle;
BUG_ON(ref_cnt == 0);
ref_cnt--;
handle = (handle_t *)ref_cnt;
current->journal_info = handle;
}
/*
* Wrappers for jbd2_journal_start/end.
*/
static int ext4_journal_check_start(struct super_block *sb)
{
journal_t *journal;
might_sleep();
if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
return -EIO;
if (sb_rdonly(sb))
return -EROFS;
WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
journal = EXT4_SB(sb)->s_journal;
/*
* Special case here: if the journal has aborted behind our
* backs (eg. EIO in the commit thread), then we still need to
* take the FS itself readonly cleanly.
*/
if (journal && is_journal_aborted(journal)) {
ext4_abort(sb, "Detected aborted journal");
return -EROFS;
}
return 0;
}
handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
int type, int blocks, int rsv_blocks)
{
journal_t *journal;
int err;
trace_ext4_journal_start(sb, blocks, rsv_blocks, _RET_IP_);
err = ext4_journal_check_start(sb);
if (err < 0)
return ERR_PTR(err);
journal = EXT4_SB(sb)->s_journal;
if (!journal)
return ext4_get_nojournal();
return jbd2__journal_start(journal, blocks, rsv_blocks, GFP_NOFS,
type, line);
}
int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
{
struct super_block *sb;
int err;
int rc;
if (!ext4_handle_valid(handle)) {
ext4_put_nojournal(handle);
return 0;
}
ext4: fix NULL pointer dereference when journal restart fails 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 <lczerner@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2015-05-14 22:55:18 +00:00
err = handle->h_err;
ext4: fix NULL pointer dereference when journal restart fails 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 <lczerner@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2015-05-14 22:55:18 +00:00
if (!handle->h_transaction) {
rc = jbd2_journal_stop(handle);
return err ? err : rc;
ext4: fix NULL pointer dereference when journal restart fails 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 <lczerner@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2015-05-14 22:55:18 +00:00
}
sb = handle->h_transaction->t_journal->j_private;
rc = jbd2_journal_stop(handle);
if (!err)
err = rc;
if (err)
__ext4_std_error(sb, where, line, err);
return err;
}
handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
int type)
{
struct super_block *sb;
int err;
if (!ext4_handle_valid(handle))
return ext4_get_nojournal();
sb = handle->h_journal->j_private;
trace_ext4_journal_start_reserved(sb, handle->h_buffer_credits,
_RET_IP_);
err = ext4_journal_check_start(sb);
if (err < 0) {
jbd2_journal_free_reserved(handle);
return ERR_PTR(err);
}
err = jbd2_journal_start_reserved(handle, type, line);
if (err < 0)
return ERR_PTR(err);
return handle;
}
static void ext4_journal_abort_handle(const char *caller, unsigned int line,
const char *err_fn,
struct buffer_head *bh,
handle_t *handle, int err)
{
char nbuf[16];
const char *errstr = ext4_decode_error(NULL, err, nbuf);
BUG_ON(!ext4_handle_valid(handle));
if (bh)
BUFFER_TRACE(bh, "abort");
if (!handle->h_err)
handle->h_err = err;
if (is_handle_aborted(handle))
return;
printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
caller, line, errstr, err_fn);
jbd2_journal_abort_handle(handle);
}
int __ext4_journal_get_write_access(const char *where, unsigned int line,
handle_t *handle, struct buffer_head *bh)
{
int err = 0;
might_sleep();
if (ext4_handle_valid(handle)) {
struct super_block *sb;
sb = handle->h_transaction->t_journal->j_private;
if (unlikely(ext4_forced_shutdown(EXT4_SB(sb)))) {
jbd2_journal_abort_handle(handle);
return -EIO;
}
err = jbd2_journal_get_write_access(handle, bh);
if (err)
ext4_journal_abort_handle(where, line, __func__, bh,
handle, err);
}
return err;
}
/*
* The ext4 forget function must perform a revoke if we are freeing data
* which has been journaled. Metadata (eg. indirect blocks) must be
* revoked in all cases.
*
* "bh" may be NULL: a metadata block may have been freed from memory
* but there may still be a record of it in the journal, and that record
* still needs to be revoked.
*
* If the handle isn't valid we're not journaling, but we still need to
* call into ext4_journal_revoke() to put the buffer head.
*/
int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
int is_metadata, struct inode *inode,
struct buffer_head *bh, ext4_fsblk_t blocknr)
{
int err;
might_sleep();
trace_ext4_forget(inode, is_metadata, blocknr);
BUFFER_TRACE(bh, "enter");
jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
"data mode %x\n",
bh, is_metadata, inode->i_mode,
test_opt(inode->i_sb, DATA_FLAGS));
/* In the no journal case, we can just do a bforget and return */
if (!ext4_handle_valid(handle)) {
bforget(bh);
return 0;
}
/* Never use the revoke function if we are doing full data
* journaling: there is no need to, and a V1 superblock won't
* support it. Otherwise, only skip the revoke on un-journaled
* data blocks. */
if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
(!is_metadata && !ext4_should_journal_data(inode))) {
if (bh) {
BUFFER_TRACE(bh, "call jbd2_journal_forget");
err = jbd2_journal_forget(handle, bh);
if (err)
ext4_journal_abort_handle(where, line, __func__,
bh, handle, err);
return err;
}
return 0;
}
/*
* data!=journal && (is_metadata || should_journal_data(inode))
*/
BUFFER_TRACE(bh, "call jbd2_journal_revoke");
err = jbd2_journal_revoke(handle, blocknr, bh);
if (err) {
ext4_journal_abort_handle(where, line, __func__,
bh, handle, err);
__ext4_abort(inode->i_sb, where, line,
"error %d when attempting revoke", err);
}
BUFFER_TRACE(bh, "exit");
return err;
}
int __ext4_journal_get_create_access(const char *where, unsigned int line,
handle_t *handle, struct buffer_head *bh)
{
int err = 0;
if (ext4_handle_valid(handle)) {
err = jbd2_journal_get_create_access(handle, bh);
if (err)
ext4_journal_abort_handle(where, line, __func__,
bh, handle, err);
}
return err;
}
int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
handle_t *handle, struct inode *inode,
struct buffer_head *bh)
{
int err = 0;
might_sleep();
set_buffer_meta(bh);
set_buffer_prio(bh);
if (ext4_handle_valid(handle)) {
err = jbd2_journal_dirty_metadata(handle, bh);
/* Errors can only happen due to aborted journal or a nasty bug */
if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
ext4_journal_abort_handle(where, line, __func__, bh,
handle, err);
if (inode == NULL) {
pr_err("EXT4: jbd2_journal_dirty_metadata "
"failed: handle type %u started at "
"line %u, credits %u/%u, errcode %d",
handle->h_type,
handle->h_line_no,
handle->h_requested_credits,
handle->h_buffer_credits, err);
return err;
}
ext4_error_inode(inode, where, line,
bh->b_blocknr,
"journal_dirty_metadata failed: "
"handle type %u started at line %u, "
"credits %u/%u, errcode %d",
handle->h_type,
handle->h_line_no,
handle->h_requested_credits,
handle->h_buffer_credits, err);
}
} else {
if (inode)
mark_buffer_dirty_inode(bh, inode);
else
mark_buffer_dirty(bh);
if (inode && inode_needs_sync(inode)) {
sync_dirty_buffer(bh);
if (buffer_req(bh) && !buffer_uptodate(bh)) {
struct ext4_super_block *es;
es = EXT4_SB(inode->i_sb)->s_es;
es->s_last_error_block =
cpu_to_le64(bh->b_blocknr);
ext4_error_inode(inode, where, line,
bh->b_blocknr,
"IO error syncing itable block");
err = -EIO;
}
}
}
return err;
}
int __ext4_handle_dirty_super(const char *where, unsigned int line,
handle_t *handle, struct super_block *sb)
{
struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
int err = 0;
ext4_superblock_csum_set(sb);
if (ext4_handle_valid(handle)) {
err = jbd2_journal_dirty_metadata(handle, bh);
if (err)
ext4_journal_abort_handle(where, line, __func__,
bh, handle, err);
} else
mark_buffer_dirty(bh);
return err;
}