diff options
Diffstat (limited to 'fs/ext4/file.c')
| -rw-r--r-- | fs/ext4/file.c | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 9facb4dc5c70..1f25c644cb12 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -31,6 +31,42 @@ #include "xattr.h" #include "acl.h" +#ifdef CONFIG_FS_DAX +static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct inode *inode = file_inode(iocb->ki_filp); + ssize_t ret; + + inode_lock_shared(inode); + /* + * Recheck under inode lock - at this point we are sure it cannot + * change anymore + */ + if (!IS_DAX(inode)) { + inode_unlock_shared(inode); + /* Fallback to buffered IO in case we cannot support DAX */ + return generic_file_read_iter(iocb, to); + } + ret = dax_iomap_rw(iocb, to, &ext4_iomap_ops); + inode_unlock_shared(inode); + + file_accessed(iocb->ki_filp); + return ret; +} +#endif + +static ssize_t ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + if (!iov_iter_count(to)) + return 0; /* skip atime */ + +#ifdef CONFIG_FS_DAX + if (IS_DAX(file_inode(iocb->ki_filp))) + return ext4_dax_read_iter(iocb, to); +#endif + return generic_file_read_iter(iocb, to); +} + /* * Called when an inode is released. Note that this is different * from ext4_file_open: open gets called at every open, but release @@ -690,7 +726,7 @@ loff_t ext4_llseek(struct file *file, loff_t offset, int whence) const struct file_operations ext4_file_operations = { .llseek = ext4_llseek, - .read_iter = generic_file_read_iter, + .read_iter = ext4_file_read_iter, .write_iter = ext4_file_write_iter, .unlocked_ioctl = ext4_ioctl, #ifdef CONFIG_COMPAT |