ext4: remove /proc tuning knobs (b713a5ec) · Commits · EulixOS / Software / Kernel

Documentation/filesystems/proc.txt

+0 −21

Original line number	Diff line number	Diff line
		@@ -940,27 +940,6 @@ Table 1-10: Files in /proc/fs/ext4/<devname>
		File Content
		mb_groups details of multiblock allocator buddy cache of free blocks
		mb_history multiblock allocation history
		stats controls whether the multiblock allocator should start
		collecting statistics, which are shown during the unmount
		group_prealloc the multiblock allocator will round up allocation
		requests to a multiple of this tuning parameter if the
		stripe size is not set in the ext4 superblock
		max_to_scan The maximum number of extents the multiblock allocator
		will search to find the best extent
		min_to_scan The minimum number of extents the multiblock allocator
		will search to find the best extent
		order2_req Tuning parameter which controls the minimum size for
		requests (as a power of 2) where the buddy cache is
		used
		stream_req Files which have fewer blocks than this tunable
		parameter will have their blocks allocated out of a
		block group specific preallocation pool, so that small
		files are packed closely together. Each large file
		will have its blocks allocated out of its own unique
		preallocation pool.
		inode_readahead Tuning parameter which controls the maximum number of
		inode table blocks that ext4's inode table readahead
		algorithm will pre-read into the buffer cache
		..............................................................................

fs/ext4/ext4.h

+0 −16

Original line number	Diff line number	Diff line
		@@ -976,22 +976,6 @@ void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,

		extern struct proc_dir_entry *ext4_proc_root;

		#ifdef CONFIG_PROC_FS
		extern const struct file_operations ext4_ui_proc_fops;

		#define EXT4_PROC_HANDLER(name, var) \
		do { \
		proc = proc_create_data(name, mode, sbi->s_proc, \
		&ext4_ui_proc_fops, &sbi->s_##var); \
		if (proc == NULL) { \
		printk(KERN_ERR "EXT4-fs: can't create %s\n", name); \
		goto err_out; \
		} \
		} while (0)
		#else
		#define EXT4_PROC_HANDLER(name, var)
		#endif

		/*
		* Function prototypes
		*/

fs/ext4/inode.c

+1 −6

Original line number	Diff line number	Diff line
		@@ -4153,12 +4153,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
		unsigned num;

		table = ext4_inode_table(sb, gdp);
		/* Make sure s_inode_readahead_blks is a power of 2 */
		while (EXT4_SB(sb)->s_inode_readahead_blks &
		(EXT4_SB(sb)->s_inode_readahead_blks-1))
		EXT4_SB(sb)->s_inode_readahead_blks =
		(EXT4_SB(sb)->s_inode_readahead_blks &
		(EXT4_SB(sb)->s_inode_readahead_blks-1));
		/* s_inode_readahead_blks is always a power of 2 */
		b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
		if (table > b)
		b = table;

fs/ext4/mballoc.c

+29 −88

Original line number	Diff line number	Diff line
		@@ -46,22 +46,23 @@
		* The allocation request involve request for multiple number of blocks
		* near to the goal(block) value specified.
		*
		* During initialization phase of the allocator we decide to use the group
		* preallocation or inode preallocation depending on the size file. The
		* size of the file could be the resulting file size we would have after
		* allocation or the current file size which ever is larger. If the size is
		* less that sbi->s_mb_stream_request we select the group
		* preallocation. The default value of s_mb_stream_request is 16
		* blocks. This can also be tuned via
		* /proc/fs/ext4/<partition>/stream_req. The value is represented in terms
		* of number of blocks.
		* During initialization phase of the allocator we decide to use the
		* group preallocation or inode preallocation depending on the size of
		* the file. The size of the file could be the resulting file size we
		* would have after allocation, or the current file size, which ever
		* is larger. If the size is less than sbi->s_mb_stream_request we
		* select to use the group preallocation. The default value of
		* s_mb_stream_request is 16 blocks. This can also be tuned via
		* /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in
		* terms of number of blocks.
		*
		* The main motivation for having small file use group preallocation is to
		* ensure that we have small file closer in the disk.
		* ensure that we have small files closer together on the disk.
		*
		* First stage the allocator looks at the inode prealloc list
		* ext4_inode_info->i_prealloc_list contain list of prealloc spaces for
		* this particular inode. The inode prealloc space is represented as:
		* First stage the allocator looks at the inode prealloc list,
		* ext4_inode_info->i_prealloc_list, which contains list of prealloc
		* spaces for this particular inode. The inode prealloc space is
		* represented as:
		*
		* pa_lstart -> the logical start block for this prealloc space
		* pa_pstart -> the physical start block for this prealloc space
		@@ -121,29 +122,29 @@
		* list. In case of inode preallocation we follow a list of heuristics
		* based on file size. This can be found in ext4_mb_normalize_request. If
		* we are doing a group prealloc we try to normalize the request to
		* sbi->s_mb_group_prealloc. Default value of s_mb_group_prealloc is set to
		* sbi->s_mb_group_prealloc. Default value of s_mb_group_prealloc is
		* 512 blocks. This can be tuned via
		* /proc/fs/ext4/<partition/group_prealloc. The value is represented in
		* /sys/fs/ext4/<partition/mb_group_prealloc. The value is represented in
		* terms of number of blocks. If we have mounted the file system with -O
		* stripe=<value> option the group prealloc request is normalized to the
		* stripe value (sbi->s_stripe)
		*
		* The regular allocator(using the buddy cache) support few tunables.
		* The regular allocator(using the buddy cache) supports few tunables.
		*
		* /proc/fs/ext4/<partition>/min_to_scan
		* /proc/fs/ext4/<partition>/max_to_scan
		* /proc/fs/ext4/<partition>/order2_req
		* /sys/fs/ext4/<partition>/mb_min_to_scan
		* /sys/fs/ext4/<partition>/mb_max_to_scan
		* /sys/fs/ext4/<partition>/mb_order2_req
		*
		* The regular allocator use buddy scan only if the request len is power of
		* The regular allocator uses buddy scan only if the request len is power of
		* 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
		* value of s_mb_order2_reqs can be tuned via
		* /proc/fs/ext4/<partition>/order2_req. If the request len is equal to
		* /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
		* stripe size (sbi->s_stripe), we try to search for contigous block in
		* stripe size. This should result in better allocation on RAID setup. If
		* not we search in the specific group using bitmap for best extents. The
		* tunable min_to_scan and max_to_scan controll the behaviour here.
		* stripe size. This should result in better allocation on RAID setups. If
		* not, we search in the specific group using bitmap for best extents. The
		* tunable min_to_scan and max_to_scan control the behaviour here.
		* min_to_scan indicate how long the mballoc __must__ look for a best
		* extent and max_to_scanindicate how long the mballoc __can__ look for a
		* extent and max_to_scan indicates how long the mballoc __can__ look for a
		* best extent in the found extents. Searching for the blocks starts with
		* the group specified as the goal value in allocation context via
		* ac_g_ex. Each group is first checked based on the criteria whether it
		@@ -337,8 +338,6 @@ static void ext4_mb_generate_from_pa(struct super_block sb, void bitmap,
		ext4_group_t group);
		static void ext4_mb_generate_from_freelist(struct super_block sb, void bitmap,
		ext4_group_t group);
		static int ext4_mb_init_per_dev_proc(struct super_block *sb);
		static int ext4_mb_destroy_per_dev_proc(struct super_block *sb);
		static void release_blocks_on_commit(journal_t journal, transaction_t txn);


		@@ -1978,7 +1977,7 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
		/*
		* We search using buddy data only if the order of the request
		* is greater than equal to the sbi_s_mb_order2_reqs
		* You can tune it via /proc/fs/ext4/<partition>/order2_req
		* You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
		*/
		if (i >= sbi->s_mb_order2_reqs) {
		/*
		@@ -2753,7 +2752,6 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
		spin_lock_init(&lg->lg_prealloc_lock);
		}

		ext4_mb_init_per_dev_proc(sb);
		ext4_mb_history_init(sb);

		if (sbi->s_journal)
		@@ -2836,7 +2834,6 @@ int ext4_mb_release(struct super_block *sb)

		free_percpu(sbi->s_locality_groups);
		ext4_mb_history_release(sb);
		ext4_mb_destroy_per_dev_proc(sb);

		return 0;
		}
		@@ -2897,62 +2894,6 @@ static void release_blocks_on_commit(journal_t journal, transaction_t txn)
		mb_debug("freed %u blocks in %u structures\n", count, count2);
		}

		#define EXT4_MB_STATS_NAME "stats"
		#define EXT4_MB_MAX_TO_SCAN_NAME "max_to_scan"
		#define EXT4_MB_MIN_TO_SCAN_NAME "min_to_scan"
		#define EXT4_MB_ORDER2_REQ "order2_req"
		#define EXT4_MB_STREAM_REQ "stream_req"
		#define EXT4_MB_GROUP_PREALLOC "group_prealloc"

		static int ext4_mb_init_per_dev_proc(struct super_block *sb)
		{
		#ifdef CONFIG_PROC_FS
		mode_t mode = S_IFREG \| S_IRUGO \| S_IWUSR;
		struct ext4_sb_info *sbi = EXT4_SB(sb);
		struct proc_dir_entry *proc;

		if (sbi->s_proc == NULL)
		return -EINVAL;

		EXT4_PROC_HANDLER(EXT4_MB_STATS_NAME, mb_stats);
		EXT4_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME, mb_max_to_scan);
		EXT4_PROC_HANDLER(EXT4_MB_MIN_TO_SCAN_NAME, mb_min_to_scan);
		EXT4_PROC_HANDLER(EXT4_MB_ORDER2_REQ, mb_order2_reqs);
		EXT4_PROC_HANDLER(EXT4_MB_STREAM_REQ, mb_stream_request);
		EXT4_PROC_HANDLER(EXT4_MB_GROUP_PREALLOC, mb_group_prealloc);
		return 0;

		err_out:
		remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_proc);
		remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_proc);
		remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_proc);
		remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_proc);
		remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_proc);
		remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_proc);
		return -ENOMEM;
		#else
		return 0;
		#endif
		}

		static int ext4_mb_destroy_per_dev_proc(struct super_block *sb)
		{
		#ifdef CONFIG_PROC_FS
		struct ext4_sb_info *sbi = EXT4_SB(sb);

		if (sbi->s_proc == NULL)
		return -EINVAL;

		remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_proc);
		remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_proc);
		remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_proc);
		remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_proc);
		remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_proc);
		remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_proc);
		#endif
		return 0;
		}

		int __init init_ext4_mballoc(void)
		{
		ext4_pspace_cachep =
		@@ -3123,7 +3064,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
		* here we normalize request for locality group
		* Group request are normalized to s_strip size if we set the same via mount
		* option. If not we set it to s_mb_group_prealloc which can be configured via
		* /proc/fs/ext4/<partition>/group_prealloc
		* /sys/fs/ext4/<partition>/mb_group_prealloc
		*
		* XXX: should we try to preallocate more than the group has now?
		*/
		@@ -4239,7 +4180,7 @@ static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
		* file is determined by the current size or the resulting size after
		* allocation which ever is larger
		*
		* One can tune this size via /proc/fs/ext4/<partition>/stream_req
		* One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
		*/
		static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
		{

fs/ext4/super.c

+0 −46

Original line number	Diff line number	Diff line
		@@ -579,7 +579,6 @@ static void ext4_put_super(struct super_block *sb)
		ext4_commit_super(sb, es, 1);
		}
		if (sbi->s_proc) {
		remove_proc_entry("inode_readahead_blks", sbi->s_proc);
		remove_proc_entry(sb->s_id, ext4_proc_root);
		}
		kobject_del(&sbi->s_kobj);
		@@ -2529,11 +2528,6 @@ static int ext4_fill_super(struct super_block sb, void data, int silent)
		#ifdef CONFIG_PROC_FS
		if (ext4_proc_root)
		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);

		if (sbi->s_proc)
		proc_create_data("inode_readahead_blks", 0644, sbi->s_proc,
		&ext4_ui_proc_fops,
		&sbi->s_inode_readahead_blks);
		#endif

		bgl_lock_init(sbi->s_blockgroup_lock);
		@@ -2832,7 +2826,6 @@ static int ext4_fill_super(struct super_block sb, void data, int silent)
		kfree(sbi->s_group_desc);
		failed_mount:
		if (sbi->s_proc) {
		remove_proc_entry("inode_readahead_blks", sbi->s_proc);
		remove_proc_entry(sb->s_id, ext4_proc_root);
		}
		#ifdef CONFIG_QUOTA
		@@ -3865,45 +3858,6 @@ static int ext4_get_sb(struct file_system_type *fs_type,
		return get_sb_bdev(fs_type, flags, dev_name, data, ext4_fill_super, mnt);
		}

		#ifdef CONFIG_PROC_FS
		static int ext4_ui_proc_show(struct seq_file m, void v)
		{
		unsigned int *p = m->private;

		seq_printf(m, "%u\n", *p);
		return 0;
		}

		static int ext4_ui_proc_open(struct inode inode, struct file file)
		{
		return single_open(file, ext4_ui_proc_show, PDE(inode)->data);
		}

		static ssize_t ext4_ui_proc_write(struct file file, const char __user buf,
		size_t cnt, loff_t *ppos)
		{
		unsigned long *p = PDE(file->f_path.dentry->d_inode)->data;
		char str[32];

		if (cnt >= sizeof(str))
		return -EINVAL;
		if (copy_from_user(str, buf, cnt))
		return -EFAULT;

		*p = simple_strtoul(str, NULL, 0);
		return cnt;
		}

		const struct file_operations ext4_ui_proc_fops = {
		.owner = THIS_MODULE,
		.open = ext4_ui_proc_open,
		.read = seq_read,
		.llseek = seq_lseek,
		.release = single_release,
		.write = ext4_ui_proc_write,
		};
		#endif

		static struct file_system_type ext4_fs_type = {
		.owner = THIS_MODULE,
		.name = "ext4",