diff options
Diffstat (limited to 'fs/ext4/file.c')
| -rw-r--r-- | fs/ext4/file.c | 51 |
1 files changed, 37 insertions, 14 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 8cc11715518a..a7a597c727e6 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -36,17 +36,34 @@ #include "acl.h" #include "truncate.h" -static bool ext4_dio_supported(struct inode *inode) +/* + * Returns %true if the given DIO request should be attempted with DIO, or + * %false if it should fall back to buffered I/O. + * + * DIO isn't well specified; when it's unsupported (either due to the request + * being misaligned, or due to the file not supporting DIO at all), filesystems + * either fall back to buffered I/O or return EINVAL. For files that don't use + * any special features like encryption or verity, ext4 has traditionally + * returned EINVAL for misaligned DIO. iomap_dio_rw() uses this convention too. + * In this case, we should attempt the DIO, *not* fall back to buffered I/O. + * + * In contrast, in cases where DIO is unsupported due to ext4 features, ext4 + * traditionally falls back to buffered I/O. + * + * This function implements the traditional ext4 behavior in all these cases. + */ +static bool ext4_should_use_dio(struct kiocb *iocb, struct iov_iter *iter) { - if (IS_ENABLED(CONFIG_FS_ENCRYPTION) && IS_ENCRYPTED(inode)) - return false; - if (fsverity_active(inode)) - return false; - if (ext4_should_journal_data(inode)) - return false; - if (ext4_has_inline_data(inode)) + struct inode *inode = file_inode(iocb->ki_filp); + u32 dio_align = ext4_dio_alignment(inode); + + if (dio_align == 0) return false; - return true; + + if (dio_align == 1) + return true; + + return IS_ALIGNED(iocb->ki_pos | iov_iter_alignment(iter), dio_align); } static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to) @@ -61,7 +78,7 @@ static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to) inode_lock_shared(inode); } - if (!ext4_dio_supported(inode)) { + if (!ext4_should_use_dio(iocb, to)) { inode_unlock_shared(inode); /* * Fallback to buffered I/O if the operation being performed on @@ -74,7 +91,7 @@ static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to) return generic_file_read_iter(iocb, to); } - ret = iomap_dio_rw(iocb, to, &ext4_iomap_ops, NULL, 0, 0); + ret = iomap_dio_rw(iocb, to, &ext4_iomap_ops, NULL, 0, NULL, 0); inode_unlock_shared(inode); file_accessed(iocb->ki_filp); @@ -265,7 +282,7 @@ static ssize_t ext4_buffered_write_iter(struct kiocb *iocb, goto out; current->backing_dev_info = inode_to_bdi(inode); - ret = generic_perform_write(iocb->ki_filp, from, iocb->ki_pos); + ret = generic_perform_write(iocb, from); current->backing_dev_info = NULL; out: @@ -509,7 +526,7 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) } /* Fallback to buffered I/O if the inode does not support direct I/O. */ - if (!ext4_dio_supported(inode)) { + if (!ext4_should_use_dio(iocb, from)) { if (ilock_shared) inode_unlock_shared(inode); else @@ -526,6 +543,12 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) ret = -EAGAIN; goto out; } + /* + * Make sure inline data cannot be created anymore since we are going + * to allocate blocks for DIO. We know the inode does not have any + * inline data now because ext4_dio_supported() checked for that. + */ + ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); offset = iocb->ki_pos; count = ret; @@ -563,7 +586,7 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) iomap_ops = &ext4_iomap_overwrite_ops; ret = iomap_dio_rw(iocb, from, iomap_ops, &ext4_dio_write_ops, (unaligned_io || extend) ? IOMAP_DIO_FORCE_WAIT : 0, - 0); + NULL, 0); if (ret == -ENOTBLK) ret = 0; |