In subpagesize-blocksize scenario, if i_size occurs in a block which is not
the last block in the page, then the space to be reserved should be calculated
appropriately.
Signed-off-by: Chandan Rajendra <chan...@linux.vnet.ibm.com>
---
fs/btrfs/inode.c | 33 ++++++++++++++++++++++-----------
1 file changed, 22 insertions(+), 11 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index a9c7bc8..3255568 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7690,26 +7690,23 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma,
struct vm_fault *vmf)
loff_t size;
int ret;
int reserved = 0;
+ u64 delalloc_size;
u64 page_start;
u64 page_end;
sb_start_pagefault(inode->i_sb);
- ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
- if (!ret) {
- ret = file_update_time(vma->vm_file);
- reserved = 1;
- }
+
+ ret = file_update_time(vma->vm_file);
if (ret) {
if (ret == -ENOMEM)
ret = VM_FAULT_OOM;
else /* -ENOSPC, -EIO, etc */
ret = VM_FAULT_SIGBUS;
- if (reserved)
- goto out;
- goto out_noreserve;
+ goto out;
}
ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
+
again:
lock_page(page);
size = i_size_read(inode);
@@ -7740,6 +7737,19 @@ again:
goto again;
}
+ if (page->index == ((size - 1) >> PAGE_CACHE_SHIFT))
+ delalloc_size = round_up(size - page_start, root->sectorsize);
+ else
+ delalloc_size = PAGE_CACHE_SIZE;
+
+ ret = btrfs_delalloc_reserve_space(inode, delalloc_size);
+ if (ret) {
+ /* -ENOSPC */
+ ret = VM_FAULT_SIGBUS;
+ goto out_unlock;
+ }
+ reserved = 1;
+
/*
* XXX - page_mkwrite gets called every time the page is dirtied, even
* if it was already dirty, so for space accounting reasons we need to
@@ -7752,7 +7762,8 @@ again:
EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
0, 0, &cached_state, GFP_NOFS);
- ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
+ ret = btrfs_set_extent_delalloc(inode, page_start,
+ page_start + delalloc_size - 1,
&cached_state);
if (ret) {
unlock_extent_cached(io_tree, page_start, page_end,
@@ -7791,8 +7802,8 @@ out_unlock:
}
unlock_page(page);
out:
- btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
-out_noreserve:
+ if (reserved)
+ btrfs_delalloc_release_space(inode, delalloc_size);
sb_end_pagefault(inode->i_sb);
return ret;
}
--
1.8.3.1
--
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