ext4: grow the s_group_info array as needed (28623c2f) · Commits · 戴 / test

fs/ext4/ext4.h

+3 −0

Original line number	Original line	Diff line number	Diff line
	@@ -1233,6 +1233,7 @@ struct ext4_sb_info {
	spinlock_t s_md_lock;		spinlock_t s_md_lock;
	unsigned short *s_mb_offsets;		unsigned short *s_mb_offsets;
	unsigned int *s_mb_maxs;		unsigned int *s_mb_maxs;
			unsigned int s_group_info_size;

	/* tunables */		/* tunables */
	unsigned long s_stripe;		unsigned long s_stripe;
	@@ -1971,6 +1972,8 @@ extern void ext4_exit_mballoc(void);
	extern void ext4_free_blocks(handle_t handle, struct inode inode,		extern void ext4_free_blocks(handle_t handle, struct inode inode,
	struct buffer_head *bh, ext4_fsblk_t block,		struct buffer_head *bh, ext4_fsblk_t block,
	unsigned long count, int flags);		unsigned long count, int flags);
			extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
			ext4_group_t ngroups);
	extern int ext4_mb_add_groupinfo(struct super_block *sb,		extern int ext4_mb_add_groupinfo(struct super_block *sb,
	ext4_group_t i, struct ext4_group_desc *desc);		ext4_group_t i, struct ext4_group_desc *desc);
	extern int ext4_group_add_blocks(handle_t handle, struct super_block sb,		extern int ext4_group_add_blocks(handle_t handle, struct super_block sb,

fs/ext4/mballoc.c

+39 −40

Original line number	Original line	Diff line number	Diff line
	@@ -24,6 +24,7 @@
	#include "ext4_jbd2.h"		#include "ext4_jbd2.h"
	#include "mballoc.h"		#include "mballoc.h"
	#include <linux/debugfs.h>		#include <linux/debugfs.h>
			#include <linux/log2.h>
	#include <linux/slab.h>		#include <linux/slab.h>
	#include <trace/events/ext4.h>		#include <trace/events/ext4.h>

	@@ -2163,6 +2164,39 @@ static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
	return cachep;		return cachep;
	}		}

			/*
			* Allocate the top-level s_group_info array for the specified number
			* of groups
			*/
			int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups)
			{
			struct ext4_sb_info *sbi = EXT4_SB(sb);
			unsigned size;
			struct ext4_group_info ***new_groupinfo;

			size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >>
			EXT4_DESC_PER_BLOCK_BITS(sb);
			if (size <= sbi->s_group_info_size)
			return 0;

			size = roundup_pow_of_two(sizeof(sbi->s_group_info) size);
			new_groupinfo = ext4_kvzalloc(size, GFP_KERNEL);
			if (!new_groupinfo) {
			ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group");
			return -ENOMEM;
			}
			if (sbi->s_group_info) {
			memcpy(new_groupinfo, sbi->s_group_info,
			sbi->s_group_info_size * sizeof(*sbi->s_group_info));
			ext4_kvfree(sbi->s_group_info);
			}
			sbi->s_group_info = new_groupinfo;
			sbi->s_group_info_size = size / sizeof(*sbi->s_group_info);
			ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
			sbi->s_group_info_size);
			return 0;
			}

	/* Create and initialize ext4_group_info data for the given group. */		/* Create and initialize ext4_group_info data for the given group. */
	int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,		int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
	struct ext4_group_desc *desc)		struct ext4_group_desc *desc)
	@@ -2252,49 +2286,14 @@ static int ext4_mb_init_backend(struct super_block *sb)
	ext4_group_t ngroups = ext4_get_groups_count(sb);		ext4_group_t ngroups = ext4_get_groups_count(sb);
	ext4_group_t i;		ext4_group_t i;
	struct ext4_sb_info *sbi = EXT4_SB(sb);		struct ext4_sb_info *sbi = EXT4_SB(sb);
	struct ext4_super_block *es = sbi->s_es;		int err;
	int num_meta_group_infos;
	int num_meta_group_infos_max;
	int array_size;
	struct ext4_group_desc *desc;		struct ext4_group_desc *desc;
	struct kmem_cache *cachep;		struct kmem_cache *cachep;

	/* This is the number of blocks used by GDT */		err = ext4_mb_alloc_groupinfo(sb, ngroups);
	num_meta_group_infos = (ngroups + EXT4_DESC_PER_BLOCK(sb) -		if (err)
	1) >> EXT4_DESC_PER_BLOCK_BITS(sb);		return err;

	/*
	* This is the total number of blocks used by GDT including
	* the number of reserved blocks for GDT.
	* The s_group_info array is allocated with this value
	* to allow a clean online resize without a complex
	* manipulation of pointer.
	* The drawback is the unused memory when no resize
	* occurs but it's very low in terms of pages
	* (see comments below)
	* Need to handle this properly when META_BG resizing is allowed
	*/
	num_meta_group_infos_max = num_meta_group_infos +
	le16_to_cpu(es->s_reserved_gdt_blocks);

	/*
	* array_size is the size of s_group_info array. We round it
	* to the next power of two because this approximation is done
	* internally by kmalloc so we can have some more memory
	* for free here (e.g. may be used for META_BG resize).
	*/
	array_size = 1;
	while (array_size < sizeof(sbi->s_group_info)
	num_meta_group_infos_max)
	array_size = array_size << 1;
	/* An 8TB filesystem with 64-bit pointers requires a 4096 byte
	* kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
	* So a two level scheme suffices for now. */
	sbi->s_group_info = ext4_kvzalloc(array_size, GFP_KERNEL);
	if (sbi->s_group_info == NULL) {
	ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group");
	return -ENOMEM;
	}
	sbi->s_buddy_cache = new_inode(sb);		sbi->s_buddy_cache = new_inode(sb);
	if (sbi->s_buddy_cache == NULL) {		if (sbi->s_buddy_cache == NULL) {
	ext4_msg(sb, KERN_ERR, "can't get new inode");		ext4_msg(sb, KERN_ERR, "can't get new inode");
	@@ -2322,7 +2321,7 @@ err_freebuddy:
	cachep = get_groupinfo_cache(sb->s_blocksize_bits);		cachep = get_groupinfo_cache(sb->s_blocksize_bits);
	while (i-- > 0)		while (i-- > 0)
	kmem_cache_free(cachep, ext4_get_group_info(sb, i));		kmem_cache_free(cachep, ext4_get_group_info(sb, i));
	i = num_meta_group_infos;		i = sbi->s_group_info_size;
	while (i-- > 0)		while (i-- > 0)
	kfree(sbi->s_group_info[i]);		kfree(sbi->s_group_info[i]);
	iput(sbi->s_buddy_cache);		iput(sbi->s_buddy_cache);

fs/ext4/resize.c

+8 −0

Original line number	Original line	Diff line number	Diff line
	@@ -1507,6 +1507,10 @@ int ext4_group_add(struct super_block sb, struct ext4_new_group_data input)
	if (err)		if (err)
	return err;		return err;

			err = ext4_mb_alloc_groupinfo(sb, input->group + 1);
			if (err)
			goto out;

	flex_gd.count = 1;		flex_gd.count = 1;
	flex_gd.groups = input;		flex_gd.groups = input;
	flex_gd.bg_flags = &bg_flags;		flex_gd.bg_flags = &bg_flags;
	@@ -1732,6 +1736,10 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
	if (err)		if (err)
	return err;		return err;

			err = ext4_mb_alloc_groupinfo(sb, n_group + 1);
			if (err)
			goto out;

	flex_gd = alloc_flex_gd(flexbg_size);		flex_gd = alloc_flex_gd(flexbg_size);
	if (flex_gd == NULL) {		if (flex_gd == NULL) {
	err = -ENOMEM;		err = -ENOMEM;

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