btrfs: report exact callsite where transaction abort occurs (1a9a8a71) · Commits · 戴 / test

WARN is called from a single location and all bugreports say that's in super.c __btrfs_abort_transaction. This is slightly confusing as we'd rather want to know the exact callsite. Whereas this information is printed in the syslog below the stacktrace, this requires further look and we usually see only the headline from WARNING. Moving the WARN into the macro has to inline some code and increases code by a few kilobytes: text data bss dec hex filename 835481 20305 14120 869906 d4612 btrfs.ko.before 842883 20305 14120 877308 d62fc btrfs.ko.after The delta is +7k (130+ calls), measured on 3.19 x86_64, distro config. The increase is not small and could lead to worse icache use. The code is on error/exit paths that can be recognized by compiler as cold and moved out of the way so the impact is speculated to be low, if measurable at all. Signed-off-by:

David Sterba <dsterba@suse.cz> Signed-off-by:

Chris Mason <clm@fb.com>

fs/btrfs/ctree.h

+9 −3

Original line number	Diff line number	Diff line
		@@ -4111,11 +4111,17 @@ static inline int __btrfs_fs_incompat(struct btrfs_fs_info *fs_info, u64 flag)
		* Call btrfs_abort_transaction as early as possible when an error condition is
		* detected, that way the exact line number is reported.
		*/

		#define btrfs_abort_transaction(trans, root, errno) \
		do { \
		__btrfs_abort_transaction(trans, root, __func__, \
		__LINE__, errno); \
		/* Report first abort since mount */ \
		if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED, \
		&((root)->fs_info->fs_state))) { \
		WARN(1, KERN_DEBUG \
		"BTRFS: Transaction aborted (error %d)\n", \
		(errno)); \
		} \
		__btrfs_abort_transaction((trans), (root), __func__, \
		__LINE__, (errno)); \
		} while (0)

		#define btrfs_std_error(fs_info, errno) \

fs/btrfs/super.c

+0 −8

Original line number	Diff line number	Diff line
		@@ -251,14 +251,6 @@ void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
		struct btrfs_root root, const char function,
		unsigned int line, int errno)
		{
		/*
		* Report first abort since mount
		*/
		if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED,
		&root->fs_info->fs_state)) {
		WARN(1, KERN_DEBUG "BTRFS: Transaction aborted (error %d)\n",
		errno);
		}
		trans->aborted = errno;
		/* Nothing used. The other threads that have joined this
		* transaction may be able to continue. */

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