diff options
author | Ritesh Harjani (IBM) <ritesh.list@gmail.com> | 2023-04-21 15:16:15 +0530 |
---|---|---|
committer | Jan Kara <jack@suse.cz> | 2023-05-16 11:32:42 +0200 |
commit | fb5de4358e1aa4753dce73c4dc1aca73ff39cedd (patch) | |
tree | d647a3da6edfb7b8c8ec0d9c9982a897c0eec6c4 /fs/ext2/file.c | |
parent | d05307042500e3f2c06fc2f9e76e8db31d61c7c0 (diff) |
ext2: Move direct-io to use iomap
This patch converts ext2 direct-io path to iomap interface.
- This also takes care of DIO_SKIP_HOLES part in which we return -ENOTBLK
from ext2_iomap_begin(), in case if the write is done on a hole.
- This fallbacks to buffered-io in case of DIO_SKIP_HOLES or in case of
a partial write or if any error is detected in ext2_iomap_end().
We try to return -ENOTBLK in such cases.
- For any unaligned or extending DIO writes, we pass
IOMAP_DIO_FORCE_WAIT flag to ensure synchronous writes.
- For extending writes we set IOMAP_F_DIRTY in ext2_iomap_begin because
otherwise with dsync writes on devices that support FUA, generic_write_sync
won't be called and we might miss inode metadata updates.
- Since ext2 already now uses _nolock vartiant of sync write. Hence
there is no inode lock problem with iomap in this patch.
- ext2_iomap_ops are now being shared by DIO, DAX & fiemap path
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <610b672a52f2a7ff6dc550fd14d0f995806232a5.1682069716.git.ritesh.list@gmail.com>
Diffstat (limited to 'fs/ext2/file.c')
-rw-r--r-- | fs/ext2/file.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/fs/ext2/file.c b/fs/ext2/file.c index 749163787139..98add36c1a59 100644 --- a/fs/ext2/file.c +++ b/fs/ext2/file.c @@ -162,12 +162,124 @@ int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync) return ret; } +static ssize_t ext2_dio_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file->f_mapping->host; + ssize_t ret; + + inode_lock_shared(inode); + ret = iomap_dio_rw(iocb, to, &ext2_iomap_ops, NULL, 0, NULL, 0); + inode_unlock_shared(inode); + + return ret; +} + +static int ext2_dio_write_end_io(struct kiocb *iocb, ssize_t size, + int error, unsigned int flags) +{ + loff_t pos = iocb->ki_pos; + struct inode *inode = file_inode(iocb->ki_filp); + + if (error) + goto out; + + /* + * If we are extending the file, we have to update i_size here before + * page cache gets invalidated in iomap_dio_rw(). This prevents racing + * buffered reads from zeroing out too much from page cache pages. + * Note that all extending writes always happens synchronously with + * inode lock held by ext2_dio_write_iter(). So it is safe to update + * inode size here for extending file writes. + */ + pos += size; + if (pos > i_size_read(inode)) { + i_size_write(inode, pos); + mark_inode_dirty(inode); + } +out: + return error; +} + +static const struct iomap_dio_ops ext2_dio_write_ops = { + .end_io = ext2_dio_write_end_io, +}; + +static ssize_t ext2_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file->f_mapping->host; + ssize_t ret; + unsigned int flags = 0; + unsigned long blocksize = inode->i_sb->s_blocksize; + loff_t offset = iocb->ki_pos; + loff_t count = iov_iter_count(from); + + inode_lock(inode); + ret = generic_write_checks(iocb, from); + if (ret <= 0) + goto out_unlock; + + ret = kiocb_modified(iocb); + if (ret) + goto out_unlock; + + /* use IOMAP_DIO_FORCE_WAIT for unaligned or extending writes */ + if (iocb->ki_pos + iov_iter_count(from) > i_size_read(inode) || + (!IS_ALIGNED(iocb->ki_pos | iov_iter_alignment(from), blocksize))) + flags |= IOMAP_DIO_FORCE_WAIT; + + ret = iomap_dio_rw(iocb, from, &ext2_iomap_ops, &ext2_dio_write_ops, + flags, NULL, 0); + + /* ENOTBLK is magic return value for fallback to buffered-io */ + if (ret == -ENOTBLK) + ret = 0; + + if (ret < 0 && ret != -EIOCBQUEUED) + ext2_write_failed(inode->i_mapping, offset + count); + + /* handle case for partial write and for fallback to buffered write */ + if (ret >= 0 && iov_iter_count(from)) { + loff_t pos, endbyte; + ssize_t status; + int ret2; + + iocb->ki_flags &= ~IOCB_DIRECT; + pos = iocb->ki_pos; + status = generic_perform_write(iocb, from); + if (unlikely(status < 0)) { + ret = status; + goto out_unlock; + } + + iocb->ki_pos += status; + ret += status; + endbyte = pos + status - 1; + ret2 = filemap_write_and_wait_range(inode->i_mapping, pos, + endbyte); + if (!ret2) + invalidate_mapping_pages(inode->i_mapping, + pos >> PAGE_SHIFT, + endbyte >> PAGE_SHIFT); + if (ret > 0) + generic_write_sync(iocb, ret); + } + +out_unlock: + inode_unlock(inode); + return ret; +} + static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to) { #ifdef CONFIG_FS_DAX if (IS_DAX(iocb->ki_filp->f_mapping->host)) return ext2_dax_read_iter(iocb, to); #endif + if (iocb->ki_flags & IOCB_DIRECT) + return ext2_dio_read_iter(iocb, to); + return generic_file_read_iter(iocb, to); } @@ -177,6 +289,9 @@ static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from) if (IS_DAX(iocb->ki_filp->f_mapping->host)) return ext2_dax_write_iter(iocb, from); #endif + if (iocb->ki_flags & IOCB_DIRECT) + return ext2_dio_write_iter(iocb, from); + return generic_file_write_iter(iocb, from); } |