From b3881f74b31b7d47d0f1c4d89ac3e7f0b9c05e3e Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 5 Jan 2009 22:46:26 -0500 Subject: [PATCH] ext4: Add mount option to set kjournald's I/O priority Signed-off-by: "Theodore Ts'o" Cc: Jens Axboe --- Documentation/filesystems/ext4.txt | 7 +++++++ fs/ext4/super.c | 29 +++++++++++++++++++++++++---- fs/ioprio.c | 3 ++- include/linux/ioprio.h | 2 ++ 4 files changed, 36 insertions(+), 5 deletions(-) diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt index 9ec29d86ff8..8938949b201 100644 --- a/Documentation/filesystems/ext4.txt +++ b/Documentation/filesystems/ext4.txt @@ -308,6 +308,13 @@ min_batch_time=usec This parameter sets the commit time (as multi-threaded, synchronous workloads on very fast disks, at the cost of increasing latency. +journal_ioprio=prio The I/O priority (from 0 to 7, where 0 is the + highest priorty) which should be used for I/O + operations submitted by kjournald2 during a + commit operation. This defaults to 3, which is + a slightly higher priority than the default I/O + priority. + Data Mode ========= There are 3 different data modes: diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 8036392b212..8ff8709828f 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1013,7 +1013,7 @@ enum { Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota, Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version, Opt_stripe, Opt_delalloc, Opt_nodelalloc, - Opt_inode_readahead_blks + Opt_inode_readahead_blks, Opt_journal_ioprio }; static const match_table_t tokens = { @@ -1074,6 +1074,7 @@ static const match_table_t tokens = { {Opt_delalloc, "delalloc"}, {Opt_nodelalloc, "nodelalloc"}, {Opt_inode_readahead_blks, "inode_readahead_blks=%u"}, + {Opt_journal_ioprio, "journal_ioprio=%u"}, {Opt_err, NULL}, }; @@ -1098,8 +1099,11 @@ static ext4_fsblk_t get_sb_block(void **data) return sb_block; } +#define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3)) + static int parse_options(char *options, struct super_block *sb, unsigned long *journal_devnum, + unsigned int *journal_ioprio, ext4_fsblk_t *n_blocks_count, int is_remount) { struct ext4_sb_info *sbi = EXT4_SB(sb); @@ -1492,6 +1496,14 @@ set_qf_format: return 0; sbi->s_inode_readahead_blks = option; break; + case Opt_journal_ioprio: + if (match_int(&args[0], &option)) + return 0; + if (option < 0 || option > 7) + break; + *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, + option); + break; default: printk(KERN_ERR "EXT4-fs: Unrecognized mount option \"%s\" " @@ -2035,6 +2047,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) int features; __u64 blocks_count; int err; + unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO; sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); if (!sbi) @@ -2141,7 +2154,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) set_opt(sbi->s_mount_opt, DELALLOC); - if (!parse_options((char *) data, sb, &journal_devnum, NULL, 0)) + if (!parse_options((char *) data, sb, &journal_devnum, + &journal_ioprio, NULL, 0)) goto failed_mount; sb->s_flags = (sb->s_flags & ~MS_POSIXACL) | @@ -2506,6 +2520,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) default: break; } + set_task_ioprio(sbi->s_journal->j_task, journal_ioprio); no_journal: @@ -3127,6 +3142,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) unsigned long old_sb_flags; struct ext4_mount_options old_opts; ext4_group_t g; + unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO; int err; #ifdef CONFIG_QUOTA int i; @@ -3145,11 +3161,14 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) for (i = 0; i < MAXQUOTAS; i++) old_opts.s_qf_names[i] = sbi->s_qf_names[i]; #endif + if (sbi->s_journal && sbi->s_journal->j_task->io_context) + journal_ioprio = sbi->s_journal->j_task->io_context->ioprio; /* * Allow the "check" option to be passed as a remount option. */ - if (!parse_options(data, sb, NULL, &n_blocks_count, 1)) { + if (!parse_options(data, sb, NULL, &journal_ioprio, + &n_blocks_count, 1)) { err = -EINVAL; goto restore_opts; } @@ -3162,8 +3181,10 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) es = sbi->s_es; - if (sbi->s_journal) + if (sbi->s_journal) { ext4_init_journal_params(sb, sbi->s_journal); + set_task_ioprio(sbi->s_journal->j_task, journal_ioprio); + } if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) || n_blocks_count > ext4_blocks_count(es)) { diff --git a/fs/ioprio.c b/fs/ioprio.c index 3569e0ad86a..1a39ac37094 100644 --- a/fs/ioprio.c +++ b/fs/ioprio.c @@ -27,7 +27,7 @@ #include #include -static int set_task_ioprio(struct task_struct *task, int ioprio) +int set_task_ioprio(struct task_struct *task, int ioprio) { int err; struct io_context *ioc; @@ -70,6 +70,7 @@ static int set_task_ioprio(struct task_struct *task, int ioprio) task_unlock(task); return err; } +EXPORT_SYMBOL_GPL(set_task_ioprio); asmlinkage long sys_ioprio_set(int which, int who, int ioprio) { diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h index f98a656b17e..76dad480884 100644 --- a/include/linux/ioprio.h +++ b/include/linux/ioprio.h @@ -86,4 +86,6 @@ static inline int task_nice_ioclass(struct task_struct *task) */ extern int ioprio_best(unsigned short aprio, unsigned short bprio); +extern int set_task_ioprio(struct task_struct *task, int ioprio); + #endif -- 2.41.1