diff mbox series

[v2,7/9] fs/ext4: Make DAX mount option a tri-state

Message ID 20200515044121.2987940-8-ira.weiny@intel.com
State Superseded
Headers show
Series Enable ext4 support for per-file/directory DAX operations | expand

Commit Message

Ira Weiny May 15, 2020, 4:41 a.m. UTC 
From: Ira Weiny <ira.weiny@intel.com>

We add 'always', 'never', and 'inode' (default).  '-o dax' continues to
operate the same which is equivalent to 'always'.  This new
functionality is limited to ext4 only.

Specifically we introduce a 2nd DAX mount flag EXT4_MOUNT2_DAX_NEVER and set
it and EXT4_MOUNT_DAX_ALWAYS appropriately for the mode.

We also force EXT4_MOUNT2_DAX_NEVER if !CONFIG_FS_DAX.

Finally, EXT4_MOUNT2_DAX_INODE is used solely to detect if the user
specified that option for printing.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Changes from V1:
	Fix up mounting options to only show an option if specified
	Fix remount to prevent dax changes
	Isolate behavior to ext4 only

Changes from RFC:
	Combine remount check for DAX_NEVER with DAX_ALWAYS
	Update ext4_should_enable_dax()
---
 fs/ext4/ext4.h  |  2 ++
 fs/ext4/inode.c |  2 ++
 fs/ext4/super.c | 67 +++++++++++++++++++++++++++++++++++++++++--------
 3 files changed, 61 insertions(+), 10 deletions(-)

Comments

Jan Kara May 15, 2020, 9:32 a.m. UTC | #1 
On Thu 14-05-20 21:41:19, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
> 
> We add 'always', 'never', and 'inode' (default).  '-o dax' continues to
> operate the same which is equivalent to 'always'.  This new
> functionality is limited to ext4 only.
> 
> Specifically we introduce a 2nd DAX mount flag EXT4_MOUNT2_DAX_NEVER and set
> it and EXT4_MOUNT_DAX_ALWAYS appropriately for the mode.
> 
> We also force EXT4_MOUNT2_DAX_NEVER if !CONFIG_FS_DAX.
> 
> Finally, EXT4_MOUNT2_DAX_INODE is used solely to detect if the user
> specified that option for printing.
> 
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Thanks. The patch looks good to me now. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> 
> ---
> Changes from V1:
> 	Fix up mounting options to only show an option if specified
> 	Fix remount to prevent dax changes
> 	Isolate behavior to ext4 only
> 
> Changes from RFC:
> 	Combine remount check for DAX_NEVER with DAX_ALWAYS
> 	Update ext4_should_enable_dax()
> ---
>  fs/ext4/ext4.h  |  2 ++
>  fs/ext4/inode.c |  2 ++
>  fs/ext4/super.c | 67 +++++++++++++++++++++++++++++++++++++++++--------
>  3 files changed, 61 insertions(+), 10 deletions(-)
> 
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 86a0994332ce..6235440e4c39 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -1168,6 +1168,8 @@ struct ext4_inode_info {
>  						      blocks */
>  #define EXT4_MOUNT2_HURD_COMPAT		0x00000004 /* Support HURD-castrated
>  						      file systems */
> +#define EXT4_MOUNT2_DAX_NEVER		0x00000008 /* Do not allow Direct Access */
> +#define EXT4_MOUNT2_DAX_INODE		0x00000010 /* For printing options only */
>  
>  #define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM	0x00000008 /* User explicitly
>  						specified journal checksum */
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 23e42a223235..140b1930e2f4 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -4400,6 +4400,8 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
>  
>  static bool ext4_should_enable_dax(struct inode *inode)
>  {
> +	if (test_opt2(inode->i_sb, DAX_NEVER))
> +		return false;
>  	if (!S_ISREG(inode->i_mode))
>  		return false;
>  	if (ext4_should_journal_data(inode))
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 5ec900fdf73c..4753de53b186 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -1504,7 +1504,8 @@ enum {
>  	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
>  	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
>  	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
> -	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
> +	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
> +	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
>  	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
>  	Opt_nowarn_on_error, Opt_mblk_io_submit,
>  	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
> @@ -1571,6 +1572,9 @@ static const match_table_t tokens = {
>  	{Opt_nobarrier, "nobarrier"},
>  	{Opt_i_version, "i_version"},
>  	{Opt_dax, "dax"},
> +	{Opt_dax_always, "dax=always"},
> +	{Opt_dax_inode, "dax=inode"},
> +	{Opt_dax_never, "dax=never"},
>  	{Opt_stripe, "stripe=%u"},
>  	{Opt_delalloc, "delalloc"},
>  	{Opt_warn_on_error, "warn_on_error"},
> @@ -1718,6 +1722,7 @@ static int clear_qf_name(struct super_block *sb, int qtype)
>  #define MOPT_NO_EXT3	0x0200
>  #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
>  #define MOPT_STRING	0x0400
> +#define MOPT_SKIP	0x0800
>  
>  static const struct mount_opts {
>  	int	token;
> @@ -1767,7 +1772,13 @@ static const struct mount_opts {
>  	{Opt_min_batch_time, 0, MOPT_GTE0},
>  	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
>  	{Opt_init_itable, 0, MOPT_GTE0},
> -	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET},
> +	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
> +	{Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
> +		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
> +	{Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
> +		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
> +	{Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
> +		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
>  	{Opt_stripe, 0, MOPT_GTE0},
>  	{Opt_resuid, 0, MOPT_GTE0},
>  	{Opt_resgid, 0, MOPT_GTE0},
> @@ -2076,13 +2087,32 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
>  		}
>  		sbi->s_jquota_fmt = m->mount_opt;
>  #endif
> -	} else if (token == Opt_dax) {
> +	} else if (token == Opt_dax || token == Opt_dax_always ||
> +		   token == Opt_dax_inode || token == Opt_dax_never) {
>  #ifdef CONFIG_FS_DAX
> -		ext4_msg(sb, KERN_WARNING,
> -		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
> -		sbi->s_mount_opt |= m->mount_opt;
> +		switch (token) {
> +		case Opt_dax:
> +		case Opt_dax_always:
> +			ext4_msg(sb, KERN_WARNING,
> +				"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
> +			sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
> +			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
> +			break;
> +		case Opt_dax_never:
> +			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
> +			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
> +			break;
> +		case Opt_dax_inode:
> +			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
> +			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
> +			/* Strictly for printing options */
> +			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_INODE;
> +			break;
> +		}
>  #else
>  		ext4_msg(sb, KERN_INFO, "dax option not supported");
> +		sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
> +		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
>  		return -1;
>  #endif
>  	} else if (token == Opt_data_err_abort) {
> @@ -2246,7 +2276,7 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
>  	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
>  		int want_set = m->flags & MOPT_SET;
>  		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
> -		    (m->flags & MOPT_CLEAR_ERR))
> +		    (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
>  			continue;
>  		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
>  			continue; /* skip if same as the default */
> @@ -2306,6 +2336,17 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
>  	if (DUMMY_ENCRYPTION_ENABLED(sbi))
>  		SEQ_OPTS_PUTS("test_dummy_encryption");
>  
> +	if (test_opt(sb, DAX_ALWAYS)) {
> +		if (IS_EXT2_SB(sb))
> +			SEQ_OPTS_PUTS("dax");
> +		else
> +			SEQ_OPTS_PUTS("dax=always");
> +	} else if (test_opt2(sb, DAX_NEVER)) {
> +		SEQ_OPTS_PUTS("dax=never");
> +	} else if (test_opt2(sb, DAX_INODE)) {
> +		SEQ_OPTS_PUTS("dax=inode");
> +	}
> +
>  	ext4_show_quota_options(seq, sb);
>  	return 0;
>  }
> @@ -5425,10 +5466,16 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
>  		goto restore_opts;
>  	}
>  
> -	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX_ALWAYS) {
> +	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX_ALWAYS ||
> +	    (sbi->s_mount_opt2 ^ old_opts.s_mount_opt2) & EXT4_MOUNT2_DAX_NEVER ||
> +	    (sbi->s_mount_opt2 ^ old_opts.s_mount_opt2) & EXT4_MOUNT2_DAX_INODE) {
>  		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
> -			"dax flag with busy inodes while remounting");
> -		sbi->s_mount_opt ^= EXT4_MOUNT_DAX_ALWAYS;
> +			"dax mount option with busy inodes while remounting");
> +		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
> +		sbi->s_mount_opt |= old_opts.s_mount_opt & EXT4_MOUNT_DAX_ALWAYS;
> +		sbi->s_mount_opt2 &= ~(EXT4_MOUNT2_DAX_NEVER | EXT4_MOUNT2_DAX_INODE);
> +		sbi->s_mount_opt2 |= old_opts.s_mount_opt2 &
> +				     (EXT4_MOUNT2_DAX_NEVER | EXT4_MOUNT2_DAX_INODE);
>  	}
>  
>  	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
> -- 
> 2.25.1
>
diff mbox series

Patch

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 86a0994332ce..6235440e4c39 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1168,6 +1168,8 @@  struct ext4_inode_info {
 						      blocks */
 #define EXT4_MOUNT2_HURD_COMPAT		0x00000004 /* Support HURD-castrated
 						      file systems */
+#define EXT4_MOUNT2_DAX_NEVER		0x00000008 /* Do not allow Direct Access */
+#define EXT4_MOUNT2_DAX_INODE		0x00000010 /* For printing options only */
 
 #define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM	0x00000008 /* User explicitly
 						specified journal checksum */
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 23e42a223235..140b1930e2f4 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4400,6 +4400,8 @@  int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
 
 static bool ext4_should_enable_dax(struct inode *inode)
 {
+	if (test_opt2(inode->i_sb, DAX_NEVER))
+		return false;
 	if (!S_ISREG(inode->i_mode))
 		return false;
 	if (ext4_should_journal_data(inode))
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 5ec900fdf73c..4753de53b186 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1504,7 +1504,8 @@  enum {
 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
-	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
+	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
+	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
 	Opt_nowarn_on_error, Opt_mblk_io_submit,
 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
@@ -1571,6 +1572,9 @@  static const match_table_t tokens = {
 	{Opt_nobarrier, "nobarrier"},
 	{Opt_i_version, "i_version"},
 	{Opt_dax, "dax"},
+	{Opt_dax_always, "dax=always"},
+	{Opt_dax_inode, "dax=inode"},
+	{Opt_dax_never, "dax=never"},
 	{Opt_stripe, "stripe=%u"},
 	{Opt_delalloc, "delalloc"},
 	{Opt_warn_on_error, "warn_on_error"},
@@ -1718,6 +1722,7 @@  static int clear_qf_name(struct super_block *sb, int qtype)
 #define MOPT_NO_EXT3	0x0200
 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
 #define MOPT_STRING	0x0400
+#define MOPT_SKIP	0x0800
 
 static const struct mount_opts {
 	int	token;
@@ -1767,7 +1772,13 @@  static const struct mount_opts {
 	{Opt_min_batch_time, 0, MOPT_GTE0},
 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
 	{Opt_init_itable, 0, MOPT_GTE0},
-	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET},
+	{Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP},
+	{Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS,
+		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
+	{Opt_dax_inode, EXT4_MOUNT2_DAX_INODE,
+		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
+	{Opt_dax_never, EXT4_MOUNT2_DAX_NEVER,
+		MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP},
 	{Opt_stripe, 0, MOPT_GTE0},
 	{Opt_resuid, 0, MOPT_GTE0},
 	{Opt_resgid, 0, MOPT_GTE0},
@@ -2076,13 +2087,32 @@  static int handle_mount_opt(struct super_block *sb, char *opt, int token,
 		}
 		sbi->s_jquota_fmt = m->mount_opt;
 #endif
-	} else if (token == Opt_dax) {
+	} else if (token == Opt_dax || token == Opt_dax_always ||
+		   token == Opt_dax_inode || token == Opt_dax_never) {
 #ifdef CONFIG_FS_DAX
-		ext4_msg(sb, KERN_WARNING,
-		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
-		sbi->s_mount_opt |= m->mount_opt;
+		switch (token) {
+		case Opt_dax:
+		case Opt_dax_always:
+			ext4_msg(sb, KERN_WARNING,
+				"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
+			sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS;
+			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
+			break;
+		case Opt_dax_never:
+			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
+			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
+			break;
+		case Opt_dax_inode:
+			sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
+			sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER;
+			/* Strictly for printing options */
+			sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_INODE;
+			break;
+		}
 #else
 		ext4_msg(sb, KERN_INFO, "dax option not supported");
+		sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER;
+		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
 		return -1;
 #endif
 	} else if (token == Opt_data_err_abort) {
@@ -2246,7 +2276,7 @@  static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
 		int want_set = m->flags & MOPT_SET;
 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
-		    (m->flags & MOPT_CLEAR_ERR))
+		    (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP)
 			continue;
 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
 			continue; /* skip if same as the default */
@@ -2306,6 +2336,17 @@  static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
 		SEQ_OPTS_PUTS("test_dummy_encryption");
 
+	if (test_opt(sb, DAX_ALWAYS)) {
+		if (IS_EXT2_SB(sb))
+			SEQ_OPTS_PUTS("dax");
+		else
+			SEQ_OPTS_PUTS("dax=always");
+	} else if (test_opt2(sb, DAX_NEVER)) {
+		SEQ_OPTS_PUTS("dax=never");
+	} else if (test_opt2(sb, DAX_INODE)) {
+		SEQ_OPTS_PUTS("dax=inode");
+	}
+
 	ext4_show_quota_options(seq, sb);
 	return 0;
 }
@@ -5425,10 +5466,16 @@  static int ext4_remount(struct super_block *sb, int *flags, char *data)
 		goto restore_opts;
 	}
 
-	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX_ALWAYS) {
+	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX_ALWAYS ||
+	    (sbi->s_mount_opt2 ^ old_opts.s_mount_opt2) & EXT4_MOUNT2_DAX_NEVER ||
+	    (sbi->s_mount_opt2 ^ old_opts.s_mount_opt2) & EXT4_MOUNT2_DAX_INODE) {
 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
-			"dax flag with busy inodes while remounting");
-		sbi->s_mount_opt ^= EXT4_MOUNT_DAX_ALWAYS;
+			"dax mount option with busy inodes while remounting");
+		sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS;
+		sbi->s_mount_opt |= old_opts.s_mount_opt & EXT4_MOUNT_DAX_ALWAYS;
+		sbi->s_mount_opt2 &= ~(EXT4_MOUNT2_DAX_NEVER | EXT4_MOUNT2_DAX_INODE);
+		sbi->s_mount_opt2 |= old_opts.s_mount_opt2 &
+				     (EXT4_MOUNT2_DAX_NEVER | EXT4_MOUNT2_DAX_INODE);
 	}
 
 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)