[mirror_ubuntu-artful-kernel.git] / fs / ext4 / ext4_jbd2.c

/*
 * 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->s_flags & MS_RDONLY)
		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;
	}

	err = handle->h_err;
	if (!handle->h_transaction) {
		rc = jbd2_journal_stop(handle);
		return err ? err : rc;
	}

	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;
}
Commit	Line	Data
8984d137 AM	1	/*
	2	* Interface between ext4 and JBD
	3	*/
	4
3dcf5451	5	#include "ext4_jbd2.h"
8984d137	6
d6797d14 TT	7	#include <trace/events/ext4.h>
d6797d14 TT	8
722887dd TT	9	/* Just increment the non-pointer handle value */
	10	static handle_t *ext4_get_nojournal(void)
	11	{
	12	handle_t *handle = current->journal_info;
	13	unsigned long ref_cnt = (unsigned long)handle;
	14
	15	BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
	16
	17	ref_cnt++;
	18	handle = (handle_t *)ref_cnt;
	19
	20	current->journal_info = handle;
	21	return handle;
	22	}
	23
	24
	25	/* Decrement the non-pointer handle value */
	26	static void ext4_put_nojournal(handle_t *handle)
	27	{
	28	unsigned long ref_cnt = (unsigned long)handle;
	29
	30	BUG_ON(ref_cnt == 0);
	31
	32	ref_cnt--;
	33	handle = (handle_t *)ref_cnt;
	34
	35	current->journal_info = handle;
	36	}
	37
	38	/*
	39	* Wrappers for jbd2_journal_start/end.
	40	*/
5fe2fe89	41	static int ext4_journal_check_start(struct super_block *sb)
722887dd TT	42	{
	43	journal_t *journal;
	44
b10a44c3	45	might_sleep();
0db1ff22 TT	46
	47	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
	48	return -EIO;
	49
722887dd	50	if (sb->s_flags & MS_RDONLY)
5fe2fe89	51	return -EROFS;
722887dd TT	52	WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
722887dd TT	53	journal = EXT4_SB(sb)->s_journal;
722887dd TT	54	/*
	55	* Special case here: if the journal has aborted behind our
	56	* backs (eg. EIO in the commit thread), then we still need to
	57	* take the FS itself readonly cleanly.
	58	*/
5fe2fe89	59	if (journal && is_journal_aborted(journal)) {
722887dd	60	ext4_abort(sb, "Detected aborted journal");
5fe2fe89	61	return -EROFS;
722887dd	62	}
5fe2fe89 JK	63	return 0;
	64	}
	65
	66	handle_t __ext4_journal_start_sb(struct super_block sb, unsigned int line,
	67	int type, int blocks, int rsv_blocks)
	68	{
	69	journal_t *journal;
	70	int err;
	71
	72	trace_ext4_journal_start(sb, blocks, rsv_blocks, _RET_IP_);
	73	err = ext4_journal_check_start(sb);
	74	if (err < 0)
	75	return ERR_PTR(err);
	76
	77	journal = EXT4_SB(sb)->s_journal;
	78	if (!journal)
	79	return ext4_get_nojournal();
	80	return jbd2__journal_start(journal, blocks, rsv_blocks, GFP_NOFS,
	81	type, line);
722887dd TT	82	}
	83
	84	int __ext4_journal_stop(const char where, unsigned int line, handle_t handle)
	85	{
	86	struct super_block *sb;
	87	int err;
	88	int rc;
	89
	90	if (!ext4_handle_valid(handle)) {
	91	ext4_put_nojournal(handle);
	92	return 0;
	93	}
9d506594	94
6934da92	95	err = handle->h_err;
9d506594	96	if (!handle->h_transaction) {
6934da92 LC	97	rc = jbd2_journal_stop(handle);
6934da92 LC	98	return err ? err : rc;
9d506594 LC	99	}
9d506594 LC	100
722887dd	101	sb = handle->h_transaction->t_journal->j_private;
722887dd TT	102	rc = jbd2_journal_stop(handle);
	103
	104	if (!err)
	105	err = rc;
	106	if (err)
	107	__ext4_std_error(sb, where, line, err);
	108	return err;
	109	}
	110
5fe2fe89 JK	111	handle_t __ext4_journal_start_reserved(handle_t handle, unsigned int line,
	112	int type)
	113	{
	114	struct super_block *sb;
	115	int err;
	116
	117	if (!ext4_handle_valid(handle))
	118	return ext4_get_nojournal();
	119
	120	sb = handle->h_journal->j_private;
	121	trace_ext4_journal_start_reserved(sb, handle->h_buffer_credits,
	122	_RET_IP_);
	123	err = ext4_journal_check_start(sb);
	124	if (err < 0) {
	125	jbd2_journal_free_reserved(handle);
	126	return ERR_PTR(err);
	127	}
	128
	129	err = jbd2_journal_start_reserved(handle, type, line);
	130	if (err < 0)
	131	return ERR_PTR(err);
	132	return handle;
	133	}
	134
c197855e SH	135	static void ext4_journal_abort_handle(const char *caller, unsigned int line,
	136	const char *err_fn,
	137	struct buffer_head *bh,
	138	handle_t *handle, int err)
722887dd TT	139	{
	140	char nbuf[16];
	141	const char *errstr = ext4_decode_error(NULL, err, nbuf);
	142
	143	BUG_ON(!ext4_handle_valid(handle));
	144
	145	if (bh)
	146	BUFFER_TRACE(bh, "abort");
	147
	148	if (!handle->h_err)
	149	handle->h_err = err;
	150
	151	if (is_handle_aborted(handle))
	152	return;
	153
	154	printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
	155	caller, line, errstr, err_fn);
	156
	157	jbd2_journal_abort_handle(handle);
	158	}
	159
90c7201b TT	160	int __ext4_journal_get_write_access(const char *where, unsigned int line,
90c7201b TT	161	handle_t handle, struct buffer_head bh)
8984d137	162	{
0390131b FM	163	int err = 0;
0390131b FM	164
b10a44c3 TT	165	might_sleep();
b10a44c3 TT	166
0390131b	167	if (ext4_handle_valid(handle)) {
0db1ff22 TT	168	struct super_block *sb;
	169
	170	sb = handle->h_transaction->t_journal->j_private;
	171	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb)))) {
	172	jbd2_journal_abort_handle(handle);
	173	return -EIO;
	174	}
0390131b FM	175	err = jbd2_journal_get_write_access(handle, bh);
0390131b FM	176	if (err)
90c7201b	177	ext4_journal_abort_handle(where, line, __func__, bh,
0390131b FM	178	handle, err);
0390131b FM	179	}
8984d137 AM	180	return err;
	181	}
	182
d6797d14 TT	183	/*
	184	* The ext4 forget function must perform a revoke if we are freeing data
	185	* which has been journaled. Metadata (eg. indirect blocks) must be
	186	* revoked in all cases.
	187	*
	188	* "bh" may be NULL: a metadata block may have been freed from memory
	189	* but there may still be a record of it in the journal, and that record
	190	* still needs to be revoked.
	191	*
	192	* If the handle isn't valid we're not journaling, but we still need to
	193	* call into ext4_journal_revoke() to put the buffer head.
	194	*/
90c7201b TT	195	int __ext4_forget(const char where, unsigned int line, handle_t handle,
	196	int is_metadata, struct inode *inode,
	197	struct buffer_head *bh, ext4_fsblk_t blocknr)
d6797d14 TT	198	{
	199	int err;
	200
	201	might_sleep();
	202
	203	trace_ext4_forget(inode, is_metadata, blocknr);
	204	BUFFER_TRACE(bh, "enter");
	205
	206	jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
	207	"data mode %x\n",
	208	bh, is_metadata, inode->i_mode,
	209	test_opt(inode->i_sb, DATA_FLAGS));
	210
e4684b3f TT	211	/* In the no journal case, we can just do a bforget and return */
	212	if (!ext4_handle_valid(handle)) {
	213	bforget(bh);
	214	return 0;
	215	}
	216
d6797d14 TT	217	/* Never use the revoke function if we are doing full data
	218	* journaling: there is no need to, and a V1 superblock won't
	219	* support it. Otherwise, only skip the revoke on un-journaled
	220	* data blocks. */
	221
	222	if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA \|\|
	223	(!is_metadata && !ext4_should_journal_data(inode))) {
	224	if (bh) {
	225	BUFFER_TRACE(bh, "call jbd2_journal_forget");
b7e57e7c TT	226	err = jbd2_journal_forget(handle, bh);
b7e57e7c TT	227	if (err)
90c7201b TT	228	ext4_journal_abort_handle(where, line, __func__,
90c7201b TT	229	bh, handle, err);
b7e57e7c	230	return err;
d6797d14 TT	231	}
	232	return 0;
	233	}
	234
	235	/*
	236	* data!=journal && (is_metadata \|\| should_journal_data(inode))
	237	*/
e4684b3f TT	238	BUFFER_TRACE(bh, "call jbd2_journal_revoke");
	239	err = jbd2_journal_revoke(handle, blocknr, bh);
	240	if (err) {
90c7201b TT	241	ext4_journal_abort_handle(where, line, __func__,
90c7201b TT	242	bh, handle, err);
c398eda0 TT	243	__ext4_abort(inode->i_sb, where, line,
c398eda0 TT	244	"error %d when attempting revoke", err);
e4684b3f	245	}
d6797d14 TT	246	BUFFER_TRACE(bh, "exit");
	247	return err;
	248	}
	249
90c7201b	250	int __ext4_journal_get_create_access(const char *where, unsigned int line,
8984d137 AM	251	handle_t handle, struct buffer_head bh)
8984d137 AM	252	{
0390131b FM	253	int err = 0;
	254
	255	if (ext4_handle_valid(handle)) {
	256	err = jbd2_journal_get_create_access(handle, bh);
	257	if (err)
90c7201b TT	258	ext4_journal_abort_handle(where, line, __func__,
90c7201b TT	259	bh, handle, err);
0390131b	260	}
8984d137 AM	261	return err;
	262	}
	263
90c7201b TT	264	int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
	265	handle_t handle, struct inode inode,
	266	struct buffer_head *bh)
8984d137	267	{
0390131b FM	268	int err = 0;
0390131b FM	269
b10a44c3 TT	270	might_sleep();
b10a44c3 TT	271
13fca323 TT	272	set_buffer_meta(bh);
13fca323 TT	273	set_buffer_prio(bh);
0390131b FM	274	if (ext4_handle_valid(handle)) {
0390131b FM	275	err = jbd2_journal_dirty_metadata(handle, bh);
c5d31192 DM	276	/* Errors can only happen due to aborted journal or a nasty bug */
c5d31192 DM	277	if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
91aa11fa JK	278	ext4_journal_abort_handle(where, line, __func__, bh,
91aa11fa JK	279	handle, err);
66a4cb18 TT	280	if (inode == NULL) {
	281	pr_err("EXT4: jbd2_journal_dirty_metadata "
	282	"failed: handle type %u started at "
	283	"line %u, credits %u/%u, errcode %d",
	284	handle->h_type,
	285	handle->h_line_no,
	286	handle->h_requested_credits,
	287	handle->h_buffer_credits, err);
	288	return err;
	289	}
ae1495b1 TT	290	ext4_error_inode(inode, where, line,
	291	bh->b_blocknr,
	292	"journal_dirty_metadata failed: "
	293	"handle type %u started at line %u, "
	294	"credits %u/%u, errcode %d",
	295	handle->h_type,
	296	handle->h_line_no,
	297	handle->h_requested_credits,
	298	handle->h_buffer_credits, err);
9ea7a0df	299	}
0390131b	300	} else {
73b50c1c	301	if (inode)
fe188c0e TT	302	mark_buffer_dirty_inode(bh, inode);
	303	else
	304	mark_buffer_dirty(bh);
0390131b FM	305	if (inode && inode_needs_sync(inode)) {
	306	sync_dirty_buffer(bh);
	307	if (buffer_req(bh) && !buffer_uptodate(bh)) {
1c13d5c0 TT	308	struct ext4_super_block *es;
	309
	310	es = EXT4_SB(inode->i_sb)->s_es;
	311	es->s_last_error_block =
	312	cpu_to_le64(bh->b_blocknr);
c398eda0 TT	313	ext4_error_inode(inode, where, line,
	314	bh->b_blocknr,
	315	"IO error syncing itable block");
0390131b FM	316	err = -EIO;
	317	}
	318	}
	319	}
8984d137 AM	320	return err;
8984d137 AM	321	}
a0375156	322
90c7201b	323	int __ext4_handle_dirty_super(const char *where, unsigned int line,
b50924c2	324	handle_t handle, struct super_block sb)
a0375156 TT	325	{
	326	struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
	327	int err = 0;
	328
06db49e6	329	ext4_superblock_csum_set(sb);
a0375156 TT	330	if (ext4_handle_valid(handle)) {
	331	err = jbd2_journal_dirty_metadata(handle, bh);
	332	if (err)
90c7201b TT	333	ext4_journal_abort_handle(where, line, __func__,
90c7201b TT	334	bh, handle, err);
06db49e6	335	} else
a9c47317	336	mark_buffer_dirty(bh);
a0375156 TT	337	return err;
a0375156 TT	338	}