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ext4: Fix bigalloc quota accounting and i_blocks value

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With bigalloc changes, the i_blocks value was not correctly set (it was still
set to number of blocks being used, but in case of bigalloc, we want i_blocks
to represent the number of clusters being used). Since the quota subsystem sets
the i_blocks value, this patch fixes the quota accounting and makes sure that
the i_blocks value is set correctly.

Signed-off-by: Aditya Kali <adityakali@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Aditya Kali
2011-09-09 19:04:51 -04:00
committed by Theodore Ts'o
parent 27baebb849
commit 7b415bf60f
7 changed files with 366 additions and 25 deletions
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306
fs/ext4/extents.c
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@@ -2686,6 +2686,21 @@ again:
}
}
/* If we still have something in the partial cluster and we have removed
* even the first extent, then we should free the blocks in the partial
* cluster as well. */
if (partial_cluster && path->p_hdr->eh_entries == 0) {
int flags = EXT4_FREE_BLOCKS_FORGET;
if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
flags |= EXT4_FREE_BLOCKS_METADATA;
ext4_free_blocks(handle, inode, NULL,
EXT4_C2B(EXT4_SB(sb), partial_cluster),
EXT4_SB(sb)->s_cluster_ratio, flags);
partial_cluster = 0;
}
/* TODO: flexible tree reduction should be here */
if (path->p_hdr->eh_entries == 0) {
/*
@@ -3233,6 +3248,195 @@ static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
return ext4_mark_inode_dirty(handle, inode);
}
/**
* ext4_find_delalloc_range: find delayed allocated block in the given range.
*
* Goes through the buffer heads in the range [lblk_start, lblk_end] and returns
* whether there are any buffers marked for delayed allocation. It returns '1'
* on the first delalloc'ed buffer head found. If no buffer head in the given
* range is marked for delalloc, it returns 0.
* lblk_start should always be <= lblk_end.
* search_hint_reverse is to indicate that searching in reverse from lblk_end to
* lblk_start might be more efficient (i.e., we will likely hit the delalloc'ed
* block sooner). This is useful when blocks are truncated sequentially from
* lblk_start towards lblk_end.
*/
static int ext4_find_delalloc_range(struct inode *inode,
ext4_lblk_t lblk_start,
ext4_lblk_t lblk_end,
int search_hint_reverse)
{
struct address_space *mapping = inode->i_mapping;
struct buffer_head *head, *bh = NULL;
struct page *page;
ext4_lblk_t i, pg_lblk;
pgoff_t index;
/* reverse search wont work if fs block size is less than page size */
if (inode->i_blkbits < PAGE_CACHE_SHIFT)
search_hint_reverse = 0;
if (search_hint_reverse)
i = lblk_end;
else
i = lblk_start;
index = i >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
while ((i >= lblk_start) && (i <= lblk_end)) {
page = find_get_page(mapping, index);
if (!page || !PageDirty(page))
goto nextpage;
if (PageWriteback(page)) {
/*
* This might be a race with allocation and writeout. In
* this case we just assume that the rest of the range
* will eventually be written and there wont be any
* delalloc blocks left.
* TODO: the above assumption is troublesome, but might
* work better in practice. other option could be note
* somewhere that the cluster is getting written out and
* detect that here.
*/
page_cache_release(page);
return 0;
}
if (!page_has_buffers(page))
goto nextpage;
head = page_buffers(page);
if (!head)
goto nextpage;
bh = head;
pg_lblk = index << (PAGE_CACHE_SHIFT -
inode->i_blkbits);
do {
if (unlikely(pg_lblk < lblk_start)) {
/*
* This is possible when fs block size is less
* than page size and our cluster starts/ends in
* middle of the page. So we need to skip the
* initial few blocks till we reach the 'lblk'
*/
pg_lblk++;
continue;
}
if (buffer_delay(bh)) {
page_cache_release(page);
return 1;
}
if (search_hint_reverse)
i--;
else
i++;
} while ((i >= lblk_start) && (i <= lblk_end) &&
((bh = bh->b_this_page) != head));
nextpage:
if (page)
page_cache_release(page);
/*
* Move to next page. 'i' will be the first lblk in the next
* page.
*/
if (search_hint_reverse)
index--;
else
index++;
i = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
}
return 0;
}
int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk,
int search_hint_reverse)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
ext4_lblk_t lblk_start, lblk_end;
lblk_start = lblk & (~(sbi->s_cluster_ratio - 1));
lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
return ext4_find_delalloc_range(inode, lblk_start, lblk_end,
search_hint_reverse);
}
/**
* Determines how many complete clusters (out of those specified by the 'map')
* are under delalloc and were reserved quota for.
* This function is called when we are writing out the blocks that were
* originally written with their allocation delayed, but then the space was
* allocated using fallocate() before the delayed allocation could be resolved.
* The cases to look for are:
* ('=' indicated delayed allocated blocks
* '-' indicates non-delayed allocated blocks)
* (a) partial clusters towards beginning and/or end outside of allocated range
* are not delalloc'ed.
* Ex:
* |----c---=|====c====|====c====|===-c----|
* |++++++ allocated ++++++|
* ==> 4 complete clusters in above example
*
* (b) partial cluster (outside of allocated range) towards either end is
* marked for delayed allocation. In this case, we will exclude that
* cluster.
* Ex:
* |----====c========|========c========|
* |++++++ allocated ++++++|
* ==> 1 complete clusters in above example
*
* Ex:
* |================c================|
* |++++++ allocated ++++++|
* ==> 0 complete clusters in above example
*
* The ext4_da_update_reserve_space will be called only if we
* determine here that there were some "entire" clusters that span
* this 'allocated' range.
* In the non-bigalloc case, this function will just end up returning num_blks
* without ever calling ext4_find_delalloc_range.
*/
static unsigned int
get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
unsigned int num_blks)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
ext4_lblk_t lblk_from, lblk_to, c_offset;
unsigned int allocated_clusters = 0;
alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
/* max possible clusters for this allocation */
allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
/* Check towards left side */
c_offset = lblk_start & (sbi->s_cluster_ratio - 1);
if (c_offset) {
lblk_from = lblk_start & (~(sbi->s_cluster_ratio - 1));
lblk_to = lblk_from + c_offset - 1;
if (ext4_find_delalloc_range(inode, lblk_from, lblk_to, 0))
allocated_clusters--;
}
/* Now check towards right. */
c_offset = (lblk_start + num_blks) & (sbi->s_cluster_ratio - 1);
if (allocated_clusters && c_offset) {
lblk_from = lblk_start + num_blks;
lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
if (ext4_find_delalloc_range(inode, lblk_from, lblk_to, 0))
allocated_clusters--;
}
return allocated_clusters;
}
static int
ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
struct ext4_map_blocks *map,
@@ -3338,8 +3542,15 @@ out:
* But fallocate would have already updated quota and block
* count for this offset. So cancel these reservation
*/
if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
ext4_da_update_reserve_space(inode, allocated, 0);
if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
unsigned int reserved_clusters;
reserved_clusters = get_reserved_cluster_alloc(inode,
map->m_lblk, map->m_len);
if (reserved_clusters)
ext4_da_update_reserve_space(inode,
reserved_clusters,
0);
}
map_out:
map->m_flags |= EXT4_MAP_MAPPED;
@@ -3484,6 +3695,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
ext4_fsblk_t newblock = 0;
int free_on_err = 0, err = 0, depth, ret;
unsigned int allocated = 0, offset = 0;
unsigned int allocated_clusters = 0, reserved_clusters = 0;
unsigned int punched_out = 0;
unsigned int result = 0;
struct ext4_allocation_request ar;
@@ -3499,6 +3711,10 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
if (!(flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) &&
ext4_ext_in_cache(inode, map->m_lblk, &newex)) {
if (!newex.ee_start_lo && !newex.ee_start_hi) {
if ((sbi->s_cluster_ratio > 1) &&
ext4_find_delalloc_cluster(inode, map->m_lblk, 0))
map->m_flags |= EXT4_MAP_FROM_CLUSTER;
if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
/*
* block isn't allocated yet and
@@ -3509,6 +3725,8 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
/* we should allocate requested block */
} else {
/* block is already allocated */
if (sbi->s_cluster_ratio > 1)
map->m_flags |= EXT4_MAP_FROM_CLUSTER;
newblock = map->m_lblk
- le32_to_cpu(newex.ee_block)
+ ext4_ext_pblock(&newex);
@@ -3665,6 +3883,10 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
}
}
if ((sbi->s_cluster_ratio > 1) &&
ext4_find_delalloc_cluster(inode, map->m_lblk, 0))
map->m_flags |= EXT4_MAP_FROM_CLUSTER;
/*
* requested block isn't allocated yet;
* we couldn't try to create block if create flag is zero
@@ -3681,6 +3903,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
/*
* Okay, we need to do block allocation.
*/
map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
newex.ee_block = cpu_to_le32(map->m_lblk);
cluster_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
@@ -3692,6 +3915,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
get_implied_cluster_alloc(sbi, map, ex, path)) {
ar.len = allocated = map->m_len;
newblock = map->m_pblk;
map->m_flags |= EXT4_MAP_FROM_CLUSTER;
goto got_allocated_blocks;
}
@@ -3712,6 +3936,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
get_implied_cluster_alloc(sbi, map, ex2, path)) {
ar.len = allocated = map->m_len;
newblock = map->m_pblk;
map->m_flags |= EXT4_MAP_FROM_CLUSTER;
goto got_allocated_blocks;
}
@@ -3765,6 +3990,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
ext_debug("allocate new block: goal %llu, found %llu/%u\n",
ar.goal, newblock, allocated);
free_on_err = 1;
allocated_clusters = ar.len;
ar.len = EXT4_C2B(sbi, ar.len) - offset;
if (ar.len > allocated)
ar.len = allocated;
@@ -3822,8 +4048,80 @@ got_allocated_blocks:
* Update reserved blocks/metadata blocks after successful
* block allocation which had been deferred till now.
*/
if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
ext4_da_update_reserve_space(inode, allocated, 1);
if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
/*
* Check how many clusters we had reserved this allocted range.
*/
reserved_clusters = get_reserved_cluster_alloc(inode,
map->m_lblk, allocated);
if (map->m_flags & EXT4_MAP_FROM_CLUSTER) {
if (reserved_clusters) {
/*
* We have clusters reserved for this range.
* But since we are not doing actual allocation
* and are simply using blocks from previously
* allocated cluster, we should release the
* reservation and not claim quota.
*/
ext4_da_update_reserve_space(inode,
reserved_clusters, 0);
}
} else {
BUG_ON(allocated_clusters < reserved_clusters);
/* We will claim quota for all newly allocated blocks.*/
ext4_da_update_reserve_space(inode, allocated_clusters,
1);
if (reserved_clusters < allocated_clusters) {
int reservation = allocated_clusters -
reserved_clusters;
/*
* It seems we claimed few clusters outside of
* the range of this allocation. We should give
* it back to the reservation pool. This can
* happen in the following case:
*
* * Suppose s_cluster_ratio is 4 (i.e., each
* cluster has 4 blocks. Thus, the clusters
* are [0-3],[4-7],[8-11]...
* * First comes delayed allocation write for
* logical blocks 10 & 11. Since there were no
* previous delayed allocated blocks in the
* range [8-11], we would reserve 1 cluster
* for this write.
* * Next comes write for logical blocks 3 to 8.
* In this case, we will reserve 2 clusters
* (for [0-3] and [4-7]; and not for [8-11] as
* that range has a delayed allocated blocks.
* Thus total reserved clusters now becomes 3.
* * Now, during the delayed allocation writeout
* time, we will first write blocks [3-8] and
* allocate 3 clusters for writing these
* blocks. Also, we would claim all these
* three clusters above.
* * Now when we come here to writeout the
* blocks [10-11], we would expect to claim
* the reservation of 1 cluster we had made
* (and we would claim it since there are no
* more delayed allocated blocks in the range
* [8-11]. But our reserved cluster count had
* already gone to 0.
*
* Thus, at the step 4 above when we determine
* that there are still some unwritten delayed
* allocated blocks outside of our current
* block range, we should increment the
* reserved clusters count so that when the
* remaining blocks finally gets written, we
* could claim them.
*/
while (reservation) {
ext4_da_reserve_space(inode,
map->m_lblk);
reservation--;
}
}
}
}
/*
* Cache the extent and update transaction to commit on fdatasync only