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Commit 4e9e63a6 authored by Ryusuke Konishi's avatar Ryusuke Konishi Committed by Linus Torvalds
Browse files

nilfs2: do not call nilfs_mdt_bgl_lock() needlessly 



In the bitmap based allocator implementation, nilfs_mdt_bgl_lock() helper
is frequently used to get a spinlock protecting a target block group.
This reduces its usage and simplifies arguments of some related functions
by directly passing a pointer to the spinlock.

Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b7bed712

fs/nilfs2/alloc.c

+40 −44
Original line number Diff line number Diff line
@@ -133,38 +133,34 @@ nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group) 


/**

 * nilfs_palloc_group_desc_nfrees - get the number of free entries in a group

 * @inode: inode of metadata file using this allocator

 * @group: group number

 * @desc: pointer to descriptor structure for the group

 * @lock: spin lock protecting @desc

 */

static unsigned long

nilfs_palloc_group_desc_nfrees(struct inode *inode, unsigned long group,

			       const struct nilfs_palloc_group_desc *desc)

nilfs_palloc_group_desc_nfrees(const struct nilfs_palloc_group_desc *desc,

			       spinlock_t *lock)

{

	unsigned long nfree;



	spin_lock(nilfs_mdt_bgl_lock(inode, group));

	spin_lock(lock);

	nfree = le32_to_cpu(desc->pg_nfrees);

	spin_unlock(nilfs_mdt_bgl_lock(inode, group));

	spin_unlock(lock);

	return nfree;

}



/**

 * nilfs_palloc_group_desc_add_entries - adjust count of free entries

 * @inode: inode of metadata file using this allocator

 * @group: group number

 * @desc: pointer to descriptor structure for the group

 * @lock: spin lock protecting @desc

 * @n: delta to be added

 */

static void

nilfs_palloc_group_desc_add_entries(struct inode *inode,

				    unsigned long group,

				    struct nilfs_palloc_group_desc *desc,

				    u32 n)

nilfs_palloc_group_desc_add_entries(struct nilfs_palloc_group_desc *desc,

				    spinlock_t *lock, u32 n)

{

	spin_lock(nilfs_mdt_bgl_lock(inode, group));

	spin_lock(lock);

	le32_add_cpu(&desc->pg_nfrees, n);

	spin_unlock(nilfs_mdt_bgl_lock(inode, group));

	spin_unlock(lock);

}



/**
@@ -332,17 +328,15 @@ void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr, 


/**

 * nilfs_palloc_find_available_slot - find available slot in a group

 * @inode: inode of metadata file using this allocator

 * @group: group number

 * @target: offset number of an entry in the group (start point)

 * @bitmap: bitmap of the group

 * @target: offset number of an entry in the group (start point)

 * @bsize: size in bits

 * @lock: spin lock protecting @bitmap

 */

static int nilfs_palloc_find_available_slot(struct inode *inode,

					    unsigned long group,

static int nilfs_palloc_find_available_slot(unsigned char *bitmap,

					    unsigned long target,

					    unsigned char *bitmap,

					    int bsize)

					    int bsize,

					    spinlock_t *lock)

{

	int curr, pos, end, i;
@@ -351,12 +345,11 @@ static int nilfs_palloc_find_available_slot(struct inode *inode, 
		if (end > bsize)

			end = bsize;

		pos = nilfs_find_next_zero_bit(bitmap, end, target);

		if (pos < end &&

		    !nilfs_set_bit_atomic(

			    nilfs_mdt_bgl_lock(inode, group), pos, bitmap))

		if (pos < end && !nilfs_set_bit_atomic(lock, pos, bitmap))

			return pos;

	} else

	} else {

		end = 0;

	}



	for (i = 0, curr = end;

	     i < bsize;
@@ -370,10 +363,8 @@ static int nilfs_palloc_find_available_slot(struct inode *inode, 
			if (end > bsize)

				end = bsize;

			pos = nilfs_find_next_zero_bit(bitmap, end, curr);

			if ((pos < end) &&

			    !nilfs_set_bit_atomic(

				    nilfs_mdt_bgl_lock(inode, group), pos,

				    bitmap))

			if (pos < end &&

			    !nilfs_set_bit_atomic(lock, pos, bitmap))

				return pos;

		}

	}
@@ -477,6 +468,7 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode, 
	unsigned long group_offset, maxgroup_offset;

	unsigned long n, entries_per_group, groups_per_desc_block;

	unsigned long i, j;

	spinlock_t *lock;

	int pos, ret;



	ngroups = nilfs_palloc_groups_count(inode);
@@ -501,8 +493,8 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode, 
		n = nilfs_palloc_rest_groups_in_desc_block(inode, group,

							   maxgroup);

		for (j = 0; j < n; j++, desc++, group++) {

			if (nilfs_palloc_group_desc_nfrees(inode, group, desc)

			    > 0) {

			lock = nilfs_mdt_bgl_lock(inode, group);

			if (nilfs_palloc_group_desc_nfrees(desc, lock) > 0) {

				ret = nilfs_palloc_get_bitmap_block(

					inode, group, 1, &bitmap_bh);

				if (ret < 0)
@@ -510,12 +502,12 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode, 
				bitmap_kaddr = kmap(bitmap_bh->b_page);

				bitmap = bitmap_kaddr + bh_offset(bitmap_bh);

				pos = nilfs_palloc_find_available_slot(

					inode, group, group_offset, bitmap,

					entries_per_group);

					bitmap, group_offset,

					entries_per_group, lock);

				if (pos >= 0) {

					/* found a free entry */

					nilfs_palloc_group_desc_add_entries(

						inode, group, desc, -1);

						desc, lock, -1);

					req->pr_entry_nr =

						entries_per_group * group + pos;

					kunmap(desc_bh->b_page);
@@ -573,6 +565,7 @@ void nilfs_palloc_commit_free_entry(struct inode *inode, 
	unsigned long group, group_offset;

	unsigned char *bitmap;

	void *desc_kaddr, *bitmap_kaddr;

	spinlock_t *lock;



	group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);

	desc_kaddr = kmap(req->pr_desc_bh->b_page);
@@ -580,15 +573,15 @@ void nilfs_palloc_commit_free_entry(struct inode *inode, 
						 req->pr_desc_bh, desc_kaddr);

	bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);

	bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);

	lock = nilfs_mdt_bgl_lock(inode, group);



	if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),

				    group_offset, bitmap))

	if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))

		nilfs_warning(inode->i_sb, __func__,

			      "entry number %llu already freed: ino=%lu\n",

			      (unsigned long long)req->pr_entry_nr,

			      (unsigned long)inode->i_ino);

	else

		nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);

		nilfs_palloc_group_desc_add_entries(desc, lock, 1);



	kunmap(req->pr_bitmap_bh->b_page);

	kunmap(req->pr_desc_bh->b_page);
@@ -613,6 +606,7 @@ void nilfs_palloc_abort_alloc_entry(struct inode *inode, 
	void *desc_kaddr, *bitmap_kaddr;

	unsigned char *bitmap;

	unsigned long group, group_offset;

	spinlock_t *lock;



	group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);

	desc_kaddr = kmap(req->pr_desc_bh->b_page);
@@ -620,14 +614,15 @@ void nilfs_palloc_abort_alloc_entry(struct inode *inode, 
						 req->pr_desc_bh, desc_kaddr);

	bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);

	bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);

	if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),

				    group_offset, bitmap))

	lock = nilfs_mdt_bgl_lock(inode, group);



	if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))

		nilfs_warning(inode->i_sb, __func__,

			      "entry number %llu already freed: ino=%lu\n",

			      (unsigned long long)req->pr_entry_nr,

			      (unsigned long)inode->i_ino);

	else

		nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);

		nilfs_palloc_group_desc_add_entries(desc, lock, 1);



	kunmap(req->pr_bitmap_bh->b_page);

	kunmap(req->pr_desc_bh->b_page);
@@ -712,6 +707,7 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems) 
	unsigned char *bitmap;

	void *desc_kaddr, *bitmap_kaddr;

	unsigned long group, group_offset;

	spinlock_t *lock;

	int i, j, n, ret;



	for (i = 0; i < nitems; i = j) {
@@ -730,14 +726,14 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems) 
			inode, group, desc_bh, desc_kaddr);

		bitmap_kaddr = kmap(bitmap_bh->b_page);

		bitmap = bitmap_kaddr + bh_offset(bitmap_bh);

		lock = nilfs_mdt_bgl_lock(inode, group);

		for (j = i, n = 0;

		     (j < nitems) && nilfs_palloc_group_is_in(inode, group,

							      entry_nrs[j]);

		     j++) {

			nilfs_palloc_group(inode, entry_nrs[j], &group_offset);

			if (!nilfs_clear_bit_atomic(

				    nilfs_mdt_bgl_lock(inode, group),

				    group_offset, bitmap)) {

			if (!nilfs_clear_bit_atomic(lock, group_offset,

						    bitmap)) {

				nilfs_warning(inode->i_sb, __func__,

					      "entry number %llu already freed: ino=%lu\n",

					      (unsigned long long)entry_nrs[j],
@@ -746,7 +742,7 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems) 
				n++;

			}

		}

		nilfs_palloc_group_desc_add_entries(inode, group, desc, n);

		nilfs_palloc_group_desc_add_entries(desc, lock, n);



		kunmap(bitmap_bh->b_page);

		kunmap(desc_bh->b_page);