Commit 58f74b22 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba

btrfs: refactor btrfs_dec_test_* functions for ordered extents

The refactoring involves the following modifications:

- Return bool instead of int

- Parameter update for @cached of btrfs_dec_test_first_ordered_pending()
  For btrfs_dec_test_first_ordered_pending(), @cached is only used to
  return the finished ordered extent.
  Rename it to @finished_ret.

- Comment updates

  * Change one stale comment
    Which still refers to btrfs_dec_test_ordered_pending(), but the
    context is calling  btrfs_dec_test_first_ordered_pending().
  * Follow the common comment style for both functions
    Add more detailed descriptions for parameters and the return value
  * Move the reason why test_and_set_bit() is used into the call sites

- Change how the return value is calculated
  The most anti-human part of the return value is:

    if (...)
	ret = 1;
    ...
    return ret == 0;

  This means, when we set ret to 1, the function returns 0.
  Change the local variable name to @finished, and directly return the
  value of it.
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 523929f1
......@@ -7797,10 +7797,8 @@ static void __endio_write_update_ordered(struct btrfs_inode *inode,
NULL);
btrfs_queue_work(wq, &ordered->work);
}
/*
* If btrfs_dec_test_ordered_pending does not find any ordered
* extent in the range, we can exit.
*/
/* No ordered extent found in the range, exit */
if (ordered_offset == last_offset)
return;
/*
......
......@@ -297,26 +297,33 @@ void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
}
/*
* this is used to account for finished IO across a given range
* of the file. The IO may span ordered extents. If
* a given ordered_extent is completely done, 1 is returned, otherwise
* 0.
* Finish IO for one ordered extent across a given range. The range can
* contain several ordered extents.
*
* test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
* to make sure this function only returns 1 once for a given ordered extent.
* @found_ret: Return the finished ordered extent
* @file_offset: File offset for the finished IO
* Will also be updated to one byte past the range that is
* recordered as finished. This allows caller to walk forward.
* @io_size: Length of the finish IO range
* @uptodate: If the IO finished without problem
*
* file_offset is updated to one byte past the range that is recorded as
* complete. This allows you to walk forward in the file.
* Return true if any ordered extent is finished in the range, and update
* @found_ret and @file_offset.
* Return false otherwise.
*
* NOTE: Although The range can cross multiple ordered extents, only one
* ordered extent will be updated during one call. The caller is responsible to
* iterate all ordered extents in the range.
*/
int btrfs_dec_test_first_ordered_pending(struct btrfs_inode *inode,
struct btrfs_ordered_extent **cached,
bool btrfs_dec_test_first_ordered_pending(struct btrfs_inode *inode,
struct btrfs_ordered_extent **finished_ret,
u64 *file_offset, u64 io_size, int uptodate)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
struct rb_node *node;
struct btrfs_ordered_extent *entry = NULL;
int ret;
bool finished = false;
unsigned long flags;
u64 dec_end;
u64 dec_start;
......@@ -324,16 +331,12 @@ int btrfs_dec_test_first_ordered_pending(struct btrfs_inode *inode,
spin_lock_irqsave(&tree->lock, flags);
node = tree_search(tree, *file_offset);
if (!node) {
ret = 1;
if (!node)
goto out;
}
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
if (!offset_in_entry(entry, *file_offset)) {
ret = 1;
if (!offset_in_entry(entry, *file_offset))
goto out;
}
dec_start = max(*file_offset, entry->file_offset);
dec_end = min(*file_offset + io_size,
......@@ -354,39 +357,50 @@ int btrfs_dec_test_first_ordered_pending(struct btrfs_inode *inode,
set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
if (entry->bytes_left == 0) {
ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
/*
* Ensure only one caller can set the flag and finished_ret
* accordingly
*/
finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
/* test_and_set_bit implies a barrier */
cond_wake_up_nomb(&entry->wait);
} else {
ret = 1;
}
out:
if (!ret && cached && entry) {
*cached = entry;
if (finished && finished_ret && entry) {
*finished_ret = entry;
refcount_inc(&entry->refs);
}
spin_unlock_irqrestore(&tree->lock, flags);
return ret == 0;
return finished;
}
/*
* this is used to account for finished IO across a given range
* of the file. The IO should not span ordered extents. If
* a given ordered_extent is completely done, 1 is returned, otherwise
* 0.
* Finish IO for one ordered extent across a given range. The range can only
* contain one ordered extent.
*
* @cached: The cached ordered extent. If not NULL, we can skip the tree
* search and use the ordered extent directly.
* Will be also used to store the finished ordered extent.
* @file_offset: File offset for the finished IO
* @io_size: Length of the finish IO range
* @uptodate: If the IO finishes without problem
*
* Return true if the ordered extent is finished in the range, and update
* @cached.
* Return false otherwise.
*
* test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
* to make sure this function only returns 1 once for a given ordered extent.
* NOTE: The range can NOT cross multiple ordered extents.
* Thus caller should ensure the range doesn't cross ordered extents.
*/
int btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
struct btrfs_ordered_extent **cached,
u64 file_offset, u64 io_size, int uptodate)
bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
struct btrfs_ordered_extent **cached,
u64 file_offset, u64 io_size, int uptodate)
{
struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
struct rb_node *node;
struct btrfs_ordered_extent *entry = NULL;
unsigned long flags;
int ret;
bool finished = false;
spin_lock_irqsave(&tree->lock, flags);
if (cached && *cached) {
......@@ -395,41 +409,39 @@ int btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
}
node = tree_search(tree, file_offset);
if (!node) {
ret = 1;
if (!node)
goto out;
}
entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
have_entry:
if (!offset_in_entry(entry, file_offset)) {
ret = 1;
if (!offset_in_entry(entry, file_offset))
goto out;
}
if (io_size > entry->bytes_left) {
if (io_size > entry->bytes_left)
btrfs_crit(inode->root->fs_info,
"bad ordered accounting left %llu size %llu",
entry->bytes_left, io_size);
}
entry->bytes_left -= io_size;
if (!uptodate)
set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
if (entry->bytes_left == 0) {
ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
/*
* Ensure only one caller can set the flag and finished_ret
* accordingly
*/
finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
/* test_and_set_bit implies a barrier */
cond_wake_up_nomb(&entry->wait);
} else {
ret = 1;
}
out:
if (!ret && cached && entry) {
if (finished && cached && entry) {
*cached = entry;
refcount_inc(&entry->refs);
}
spin_unlock_irqrestore(&tree->lock, flags);
return ret == 0;
return finished;
}
/*
......
......@@ -152,11 +152,11 @@ btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
struct btrfs_ordered_extent *entry);
int btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
struct btrfs_ordered_extent **cached,
u64 file_offset, u64 io_size, int uptodate);
int btrfs_dec_test_first_ordered_pending(struct btrfs_inode *inode,
struct btrfs_ordered_extent **cached,
bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
struct btrfs_ordered_extent **cached,
u64 file_offset, u64 io_size, int uptodate);
bool btrfs_dec_test_first_ordered_pending(struct btrfs_inode *inode,
struct btrfs_ordered_extent **finished_ret,
u64 *file_offset, u64 io_size,
int uptodate);
int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment