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btrfs: introduce btrfs_inode_lock()/unlock()

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btrfs_inode_lock/unlock() are wrappers around inode locks, separating
the type of lock and actual locking.

- 0 - default, exclusive lock
- BTRFS_ILOCK_SHARED - for shared locks, for possible parallel DIO
- BTRFS_ILOCK_TRY - for the RWF_NOWAIT sequence

The bits SHARED and TRY can be combined together.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Goldwyn Rodrigues
2020-09-24 11:39:16 -05:00
committed by David Sterba
parent b8d8e1fd57
commit a14b78ad06
3 changed files with 69 additions and 16 deletions
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45
fs/btrfs/inode.c
View File

@@ -95,6 +95,51 @@ static void __endio_write_update_ordered(struct btrfs_inode *inode,
const u64 offset, const u64 bytes,
const bool uptodate);
/*
* btrfs_inode_lock - lock inode i_rwsem based on arguments passed
*
* ilock_flags can have the following bit set:
*
* BTRFS_ILOCK_SHARED - acquire a shared lock on the inode
* BTRFS_ILOCK_TRY - try to acquire the lock, if fails on first attempt
* return -EAGAIN
*/
int btrfs_inode_lock(struct inode *inode, unsigned int ilock_flags)
{
if (ilock_flags & BTRFS_ILOCK_SHARED) {
if (ilock_flags & BTRFS_ILOCK_TRY) {
if (!inode_trylock_shared(inode))
return -EAGAIN;
else
return 0;
}
inode_lock_shared(inode);
} else {
if (ilock_flags & BTRFS_ILOCK_TRY) {
if (!inode_trylock(inode))
return -EAGAIN;
else
return 0;
}
inode_lock(inode);
}
return 0;
}
/*
* btrfs_inode_unlock - unock inode i_rwsem
*
* ilock_flags should contain the same bits set as passed to btrfs_inode_lock()
* to decide whether the lock acquired is shared or exclusive.
*/
void btrfs_inode_unlock(struct inode *inode, unsigned int ilock_flags)
{
if (ilock_flags & BTRFS_ILOCK_SHARED)
inode_unlock_shared(inode);
else
inode_unlock(inode);
}
/*
* Cleanup all submitted ordered extents in specified range to handle errors
* from the btrfs_run_delalloc_range() callback.