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: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo
David Sterba
parent
523929f1ca
commit
58f74b2203
|
|
@ -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,
|
||||
|
|
@ -354,31 +357,42 @@ 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.
|
||||
*
|
||||
* 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.
|
||||
* @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.
|
||||
*
|
||||
* 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,
|
||||
bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
|
||||
struct btrfs_ordered_extent **cached,
|
||||
u64 file_offset, u64 io_size, int uptodate)
|
||||
{
|
||||
|
|
@ -386,7 +400,7 @@ int btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
|
|||
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,
|
||||
bool 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_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,
|
||||
|
|
|
|||
Loading…
Reference in New Issue