diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 5244400d5c23..6ee7252f51c0 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3070,6 +3070,13 @@ extern const struct iomap_ops btrfs_dio_iomap_ops; extern const struct iomap_dio_ops btrfs_dio_ops; extern const struct iomap_dio_ops btrfs_sync_dops; +/* Inode locking type flags, by default the exclusive lock is taken */ +#define BTRFS_ILOCK_SHARED (1U << 0) +#define BTRFS_ILOCK_TRY (1U << 1) + +int btrfs_inode_lock(struct inode *inode, unsigned int ilock_flags); +void btrfs_inode_unlock(struct inode *inode, unsigned int ilock_flags); + /* ioctl.c */ long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg); long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg); diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index b30ce769ae8b..fe1daa44f325 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1894,7 +1894,7 @@ static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) * is protected by inode lock. So we cannot unlock it here. */ if (pos + iov_iter_count(from) <= inode->i_size) { - inode_unlock(inode); + btrfs_inode_unlock(inode, 0); relock = true; } down_read(&BTRFS_I(inode)->dio_sem); @@ -1915,7 +1915,7 @@ static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) up_read(&BTRFS_I(inode)->dio_sem); if (relock) - inode_lock(inode); + btrfs_inode_lock(inode, 0); if (written < 0 || !iov_iter_count(from)) return written; @@ -1956,6 +1956,7 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, ssize_t num_written = 0; const bool sync = iocb->ki_flags & IOCB_DSYNC; ssize_t err; + unsigned int ilock_flags = 0; /* * If the fs flips readonly due to some impossible error, although we @@ -1969,22 +1970,22 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, (iocb->ki_flags & IOCB_NOWAIT)) return -EOPNOTSUPP; - if (iocb->ki_flags & IOCB_NOWAIT) { - if (!inode_trylock(inode)) - return -EAGAIN; - } else { - inode_lock(inode); - } + if (iocb->ki_flags & IOCB_NOWAIT) + ilock_flags |= BTRFS_ILOCK_TRY; + + err = btrfs_inode_lock(inode, ilock_flags); + if (err < 0) + return err; err = generic_write_checks(iocb, from); if (err <= 0) { - inode_unlock(inode); + btrfs_inode_unlock(inode, ilock_flags); return err; } err = btrfs_write_check(iocb, from, err); if (err < 0) { - inode_unlock(inode); + btrfs_inode_unlock(inode, ilock_flags); return err; } @@ -2030,7 +2031,7 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, num_written = btrfs_buffered_write(iocb, from); } - inode_unlock(inode); + btrfs_inode_unlock(inode, ilock_flags); /* * We also have to set last_sub_trans to the current log transid, @@ -3330,7 +3331,7 @@ static long btrfs_fallocate(struct file *file, int mode, return ret; } - inode_lock(inode); + btrfs_inode_lock(inode, 0); if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) { ret = inode_newsize_ok(inode, offset + len); @@ -3569,9 +3570,9 @@ static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence) return generic_file_llseek(file, offset, whence); case SEEK_DATA: case SEEK_HOLE: - inode_lock_shared(inode); + btrfs_inode_lock(inode, BTRFS_ILOCK_SHARED); offset = find_desired_extent(inode, offset, whence); - inode_unlock_shared(inode); + btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED); break; } @@ -3615,10 +3616,10 @@ static ssize_t btrfs_direct_read(struct kiocb *iocb, struct iov_iter *to) if (check_direct_read(btrfs_sb(inode->i_sb), to, iocb->ki_pos)) return 0; - inode_lock_shared(inode); + btrfs_inode_lock(inode, BTRFS_ILOCK_SHARED); ret = iomap_dio_rw(iocb, to, &btrfs_dio_iomap_ops, &btrfs_dio_ops, is_sync_kiocb(iocb)); - inode_unlock_shared(inode); + btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED); return ret; } diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 6fd561ac9866..3eea0d0be8a0 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -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.