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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>
This commit is contained in:
Yan, Zheng
2010-05-16 10:49:59 -04:00
committed by Chris Mason
parent 4a500fd178
commit efa5646456
3 changed files with 94 additions and 47 deletions
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94
fs/btrfs/relocation.c
View File

@ -2545,6 +2545,50 @@ out:
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)
@ -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;
@ -2601,21 +2644,24 @@ 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;
mutex_lock(&inode->i_mutex);
i_size_write(inode, cluster->end + 1 - offset);
ret = setup_extent_mapping(inode, cluster->start - offset,
cluster->end - offset, cluster->start);
ret = prealloc_file_extent_cluster(inode, cluster);
if (ret)
goto out_unlock;
goto out;
file_ra_state_init(ra, inode->i_mapping);
WARN_ON(cluster->start != cluster->boundary[0]);
ret = setup_extent_mapping(inode, cluster->start - offset,
cluster->end - offset, cluster->start);
if (ret)
goto out;
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,
@ -2623,8 +2669,10 @@ static int relocate_file_extent_cluster(struct inode *inode,
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;
}
}
@ -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;
}
}
@ -2660,10 +2710,9 @@ 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);
@ -2671,20 +2720,11 @@ static int relocate_file_extent_cluster(struct inode *inode,
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;
}