From 9cb20f94afcd2964944f9468e38da736ee855b19 Mon Sep 17 00:00:00 2001 From: Ira Weiny Date: Thu, 28 May 2020 08:00:00 -0700 Subject: fs/ext4: Make DAX mount option a tri-state 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. Reviewed-by: Jan Kara Signed-off-by: Ira Weiny Link: https://lore.kernel.org/r/20200528150003.828793-7-ira.weiny@intel.com Signed-off-by: Theodore Ts'o --- 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 f5291693ce6e..65ffb831b2b9 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 01636cf5f322..68fac9289109 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4402,6 +4402,8 @@ static bool ext4_should_enable_dax(struct inode *inode) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + 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 80eb814c47eb..5e056aa20ce9 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1512,7 +1512,8 @@ 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, @@ -1579,6 +1580,9 @@ 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"}, @@ -1726,6 +1730,7 @@ 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; @@ -1775,7 +1780,13 @@ 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}, @@ -2084,13 +2095,32 @@ 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) { @@ -2254,7 +2284,7 @@ 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 */ @@ -2314,6 +2344,17 @@ 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; } @@ -5436,10 +5477,16 @@ 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) -- cgit