ext4: Regularize mount options (06705bff) · Commits · 戴 / test

Documentation/filesystems/ext4.txt

+23 −2

Original line number	Diff line number	Diff line
		@@ -183,8 +183,8 @@ commit=nrsec (*) Ext4 can be told to sync all its data and metadata
		performance.

		barrier=<0\|1(*)> This enables/disables the use of write barriers in
		the jbd code. barrier=0 disables, barrier=1 enables.
		This also requires an IO stack which can support
		barrier(*) the jbd code. barrier=0 disables, barrier=1 enables.
		nobarrier This also requires an IO stack which can support
		barriers, and if jbd gets an error on a barrier
		write, it will disable again with a warning.
		Write barriers enforce proper on-disk ordering
		@@ -192,6 +192,9 @@ barrier=<0\|1(*)> This enables/disables the use of write barriers in
		safe to use, at some performance penalty. If
		your disks are battery-backed in one way or another,
		disabling barriers may safely improve performance.
		The mount options "barrier" and "nobarrier" can
		also be used to enable or disable barriers, for
		consistency with other ext4 mount options.

		inode_readahead=n This tuning parameter controls the maximum
		number of inode table blocks that ext4's inode
		@@ -313,6 +316,24 @@ journal_ioprio=prio The I/O priority (from 0 to 7, where 0 is the
		a slightly higher priority than the default I/O
		priority.

		auto_da_alloc(*) Many broken applications don't use fsync() when
		noauto_da_alloc replacing existing files via patterns such as
		fd = open("foo.new")/write(fd,..)/close(fd)/
		rename("foo.new", "foo"), or worse yet,
		fd = open("foo", O_TRUNC)/write(fd,..)/close(fd).
		If auto_da_alloc is enabled, ext4 will detect
		the replace-via-rename and replace-via-truncate
		patterns and force that any delayed allocation
		blocks are allocated such that at the next
		journal commit, in the default data=ordered
		mode, the data blocks of the new file are forced
		to disk before the rename() operation is
		commited. This provides roughly the same level
		of guarantees as ext3, and avoids the
		"zero-length" problem that can happen when a
		system crashes before the delayed allocation
		blocks are forced to disk.

		Data Mode
		=========
		There are 3 different data modes:

fs/ext4/super.c

+22 −8

Original line number	Diff line number	Diff line
		@@ -867,7 +867,7 @@ static int ext4_show_options(struct seq_file seq, struct vfsmount vfs)
		seq_puts(seq, ",data_err=abort");

		if (test_opt(sb, NO_AUTO_DA_ALLOC))
		seq_puts(seq, ",auto_da_alloc=0");
		seq_puts(seq, ",noauto_da_alloc");

		ext4_show_quota_options(seq, sb);
		return 0;
		@@ -1018,7 +1018,7 @@ enum {
		Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
		Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
		Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
		Opt_auto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
		Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
		Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
		Opt_journal_update, Opt_journal_dev,
		Opt_journal_checksum, Opt_journal_async_commit,
		@@ -1026,8 +1026,8 @@ enum {
		Opt_data_err_abort, Opt_data_err_ignore,
		Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
		Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
		Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
		Opt_grpquota, Opt_i_version,
		Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err, Opt_resize,
		Opt_usrquota, Opt_grpquota, Opt_i_version,
		Opt_stripe, Opt_delalloc, Opt_nodelalloc,
		Opt_inode_readahead_blks, Opt_journal_ioprio
		};
		@@ -1080,6 +1080,8 @@ static const match_table_t tokens = {
		{Opt_quota, "quota"},
		{Opt_usrquota, "usrquota"},
		{Opt_barrier, "barrier=%u"},
		{Opt_barrier, "barrier"},
		{Opt_nobarrier, "nobarrier"},
		{Opt_i_version, "i_version"},
		{Opt_stripe, "stripe=%u"},
		{Opt_resize, "resize"},
		@@ -1088,6 +1090,8 @@ static const match_table_t tokens = {
		{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
		{Opt_journal_ioprio, "journal_ioprio=%u"},
		{Opt_auto_da_alloc, "auto_da_alloc=%u"},
		{Opt_auto_da_alloc, "auto_da_alloc"},
		{Opt_noauto_da_alloc, "noauto_da_alloc"},
		{Opt_err, NULL},
		};

		@@ -1422,9 +1426,14 @@ set_qf_format:
		case Opt_abort:
		set_opt(sbi->s_mount_opt, ABORT);
		break;
		case Opt_nobarrier:
		clear_opt(sbi->s_mount_opt, BARRIER);
		break;
		case Opt_barrier:
		if (match_int(&args[0], &option))
		return 0;
		if (match_int(&args[0], &option)) {
		set_opt(sbi->s_mount_opt, BARRIER);
		break;
		}
		if (option)
		set_opt(sbi->s_mount_opt, BARRIER);
		else
		@@ -1485,9 +1494,14 @@ set_qf_format:
		*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
		option);
		break;
		case Opt_noauto_da_alloc:
		set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC);
		break;
		case Opt_auto_da_alloc:
		if (match_int(&args[0], &option))
		return 0;
		if (match_int(&args[0], &option)) {
		clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
		break;
		}
		if (option)
		clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC);
		else

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