fs/ext4/ext4_jbd2.c - arm/linux - Git at Google

 /*
  * 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;
 }
	/*
	* 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;
	}