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Btrfs: Pre-allocate space for data relocation
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Pre-allocate space for data relocation. This can detect ENOPSC
condition caused by fragmentation of free space.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
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Yan, Zheng authored and Chris Mason committed May 25, 2010
1 parent 4a500fd commit efa5646
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Showing 3 changed files with 92 additions and 45 deletions.
3 changes: 3 additions & 0 deletions fs/btrfs/ctree.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2420,6 +2420,9 @@ int btrfs_cont_expand(struct inode *inode, loff_t size);
int btrfs_invalidate_inodes(struct btrfs_root *root);
void btrfs_add_delayed_iput(struct inode *inode);
void btrfs_run_delayed_iputs(struct btrfs_root *root);
int btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint);
extern const struct dentry_operations btrfs_dentry_operations;

/* ioctl.c */
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44 changes: 24 additions & 20 deletions fs/btrfs/inode.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1175,6 +1175,13 @@ static noinline int run_delalloc_nocow(struct inode *inode,
num_bytes, num_bytes, type);
BUG_ON(ret);

if (root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID) {
ret = btrfs_reloc_clone_csums(inode, cur_offset,
num_bytes);
BUG_ON(ret);
}

extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
cur_offset, cur_offset + num_bytes - 1,
locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
Expand Down Expand Up @@ -6080,16 +6087,15 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
return err;
}

static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
u64 alloc_hint, int mode, loff_t actual_len)
int btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key ins;
u64 cur_offset = start;
u64 num_bytes = end - start;
int ret = 0;
u64 i_size;

while (num_bytes > 0) {
trans = btrfs_start_transaction(root, 3);
Expand All @@ -6098,9 +6104,8 @@ static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
break;
}

ret = btrfs_reserve_extent(trans, root, num_bytes,
root->sectorsize, 0, alloc_hint,
(u64)-1, &ins, 1);
ret = btrfs_reserve_extent(trans, root, num_bytes, min_size,
0, *alloc_hint, (u64)-1, &ins, 1);
if (ret) {
btrfs_end_transaction(trans, root);
break;
Expand All @@ -6117,20 +6122,19 @@ static int prealloc_file_range(struct inode *inode, u64 start, u64 end,

num_bytes -= ins.offset;
cur_offset += ins.offset;
alloc_hint = ins.objectid + ins.offset;
*alloc_hint = ins.objectid + ins.offset;

inode->i_ctime = CURRENT_TIME;
BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
if (!(mode & FALLOC_FL_KEEP_SIZE) &&
(actual_len > inode->i_size) &&
(cur_offset > inode->i_size)) {

(actual_len > inode->i_size) &&
(cur_offset > inode->i_size)) {
if (cur_offset > actual_len)
i_size = actual_len;
i_size_write(inode, actual_len);
else
i_size = cur_offset;
i_size_write(inode, i_size);
btrfs_ordered_update_i_size(inode, i_size, NULL);
i_size_write(inode, cur_offset);
i_size_write(inode, cur_offset);
btrfs_ordered_update_i_size(inode, cur_offset, NULL);
}

ret = btrfs_update_inode(trans, root, inode);
Expand Down Expand Up @@ -6216,16 +6220,16 @@ static long btrfs_fallocate(struct inode *inode, int mode,
if (em->block_start == EXTENT_MAP_HOLE ||
(cur_offset >= inode->i_size &&
!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
ret = prealloc_file_range(inode,
cur_offset, last_byte,
alloc_hint, mode, offset+len);
ret = btrfs_prealloc_file_range(inode, 0, cur_offset,
last_byte - cur_offset,
1 << inode->i_blkbits,
offset + len,
&alloc_hint);
if (ret < 0) {
free_extent_map(em);
break;
}
}
if (em->block_start <= EXTENT_MAP_LAST_BYTE)
alloc_hint = em->block_start;
free_extent_map(em);

cur_offset = last_byte;
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90 changes: 65 additions & 25 deletions fs/btrfs/relocation.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2545,6 +2545,50 @@ int relocate_tree_blocks(struct btrfs_trans_handle *trans,
return err;
}

static noinline_for_stack
int prealloc_file_extent_cluster(struct inode *inode,
struct file_extent_cluster *cluster)
{
u64 alloc_hint = 0;
u64 start;
u64 end;
u64 offset = BTRFS_I(inode)->index_cnt;
u64 num_bytes;
int nr = 0;
int ret = 0;

BUG_ON(cluster->start != cluster->boundary[0]);
mutex_lock(&inode->i_mutex);

ret = btrfs_check_data_free_space(inode, cluster->end +
1 - cluster->start);
if (ret)
goto out;

while (nr < cluster->nr) {
start = cluster->boundary[nr] - offset;
if (nr + 1 < cluster->nr)
end = cluster->boundary[nr + 1] - 1 - offset;
else
end = cluster->end - offset;

lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
num_bytes = end + 1 - start;
ret = btrfs_prealloc_file_range(inode, 0, start,
num_bytes, num_bytes,
end + 1, &alloc_hint);
unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
if (ret)
break;
nr++;
}
btrfs_free_reserved_data_space(inode, cluster->end +
1 - cluster->start);
out:
mutex_unlock(&inode->i_mutex);
return ret;
}

static noinline_for_stack
int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
u64 block_start)
Expand Down Expand Up @@ -2588,7 +2632,6 @@ static int relocate_file_extent_cluster(struct inode *inode,
u64 offset = BTRFS_I(inode)->index_cnt;
unsigned long index;
unsigned long last_index;
unsigned int dirty_page = 0;
struct page *page;
struct file_ra_state *ra;
int nr = 0;
Expand All @@ -2601,30 +2644,35 @@ static int relocate_file_extent_cluster(struct inode *inode,
if (!ra)
return -ENOMEM;

index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
ret = prealloc_file_extent_cluster(inode, cluster);
if (ret)
goto out;

mutex_lock(&inode->i_mutex);
file_ra_state_init(ra, inode->i_mapping);

i_size_write(inode, cluster->end + 1 - offset);
ret = setup_extent_mapping(inode, cluster->start - offset,
cluster->end - offset, cluster->start);
if (ret)
goto out_unlock;

file_ra_state_init(ra, inode->i_mapping);
goto out;

WARN_ON(cluster->start != cluster->boundary[0]);
index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
while (index <= last_index) {
ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
if (ret)
goto out;

page = find_lock_page(inode->i_mapping, index);
if (!page) {
page_cache_sync_readahead(inode->i_mapping,
ra, NULL, index,
last_index + 1 - index);
page = grab_cache_page(inode->i_mapping, index);
if (!page) {
btrfs_delalloc_release_metadata(inode,
PAGE_CACHE_SIZE);
ret = -ENOMEM;
goto out_unlock;
goto out;
}
}

Expand All @@ -2640,8 +2688,10 @@ static int relocate_file_extent_cluster(struct inode *inode,
if (!PageUptodate(page)) {
unlock_page(page);
page_cache_release(page);
btrfs_delalloc_release_metadata(inode,
PAGE_CACHE_SIZE);
ret = -EIO;
goto out_unlock;
goto out;
}
}

Expand All @@ -2660,31 +2710,21 @@ static int relocate_file_extent_cluster(struct inode *inode,
EXTENT_BOUNDARY, GFP_NOFS);
nr++;
}
btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);

btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
set_page_dirty(page);
dirty_page++;

unlock_extent(&BTRFS_I(inode)->io_tree,
page_start, page_end, GFP_NOFS);
unlock_page(page);
page_cache_release(page);

index++;
if (nr < cluster->nr &&
page_end + 1 + offset == cluster->boundary[nr]) {
balance_dirty_pages_ratelimited_nr(inode->i_mapping,
dirty_page);
dirty_page = 0;
}
}
if (dirty_page) {
balance_dirty_pages_ratelimited_nr(inode->i_mapping,
dirty_page);
balance_dirty_pages_ratelimited(inode->i_mapping);
btrfs_throttle(BTRFS_I(inode)->root);
}
WARN_ON(nr != cluster->nr);
out_unlock:
mutex_unlock(&inode->i_mutex);
out:
kfree(ra);
return ret;
}
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