From 25f4e70291a309749a93b30ffa58d2eac9f200f8 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 19 Sep 2016 11:30:29 +1000 Subject: [PATCH] ext2: use iomap to implement DAX Signed-off-by: Christoph Hellwig Reviewed-by: Ross Zwisler Signed-off-by: Dave Chinner --- fs/ext2/Kconfig | 1 + fs/ext2/ext2.h | 1 + fs/ext2/file.c | 76 ++++++++++++++++++++++++++++++++++++++++++++----- fs/ext2/inode.c | 63 ++++++++++++++++++++++++++++++++++++---- 4 files changed, 129 insertions(+), 12 deletions(-) diff --git a/fs/ext2/Kconfig b/fs/ext2/Kconfig index c634874e12d9..36bea5adcaba 100644 --- a/fs/ext2/Kconfig +++ b/fs/ext2/Kconfig @@ -1,5 +1,6 @@ config EXT2_FS tristate "Second extended fs support" + select FS_IOMAP if FS_DAX help Ext2 is a standard Linux file system for hard disks. diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h index 06af2f92226c..37e2be784ac7 100644 --- a/fs/ext2/ext2.h +++ b/fs/ext2/ext2.h @@ -814,6 +814,7 @@ extern const struct file_operations ext2_file_operations; /* inode.c */ extern const struct address_space_operations ext2_aops; extern const struct address_space_operations ext2_nobh_aops; +extern struct iomap_ops ext2_iomap_ops; /* namei.c */ extern const struct inode_operations ext2_dir_inode_operations; diff --git a/fs/ext2/file.c b/fs/ext2/file.c index 5efeefe17abb..423cc01c9d41 100644 --- a/fs/ext2/file.c +++ b/fs/ext2/file.c @@ -22,11 +22,59 @@ #include #include #include +#include +#include #include "ext2.h" #include "xattr.h" #include "acl.h" #ifdef CONFIG_FS_DAX +static ssize_t ext2_dax_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct inode *inode = iocb->ki_filp->f_mapping->host; + ssize_t ret; + + if (!iov_iter_count(to)) + return 0; /* skip atime */ + + inode_lock_shared(inode); + ret = iomap_dax_rw(iocb, to, &ext2_iomap_ops); + inode_unlock_shared(inode); + + file_accessed(iocb->ki_filp); + return ret; +} + +static ssize_t ext2_dax_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; + + inode_lock(inode); + ret = generic_write_checks(iocb, from); + if (ret <= 0) + goto out_unlock; + ret = file_remove_privs(file); + if (ret) + goto out_unlock; + ret = file_update_time(file); + if (ret) + goto out_unlock; + + ret = iomap_dax_rw(iocb, from, &ext2_iomap_ops); + if (ret > 0 && iocb->ki_pos > i_size_read(inode)) { + i_size_write(inode, iocb->ki_pos); + mark_inode_dirty(inode); + } + +out_unlock: + inode_unlock(inode); + if (ret > 0) + ret = generic_write_sync(iocb, ret); + return ret; +} + /* * The lock ordering for ext2 DAX fault paths is: * @@ -51,7 +99,7 @@ static int ext2_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf) } down_read(&ei->dax_sem); - ret = dax_fault(vma, vmf, ext2_get_block); + ret = iomap_dax_fault(vma, vmf, &ext2_iomap_ops); up_read(&ei->dax_sem); if (vmf->flags & FAULT_FLAG_WRITE) @@ -156,14 +204,28 @@ int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync) return ret; } -/* - * We have mostly NULL's here: the current defaults are ok for - * the ext2 filesystem. - */ +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 + return generic_file_read_iter(iocb, to); +} + +static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ +#ifdef CONFIG_FS_DAX + if (IS_DAX(iocb->ki_filp->f_mapping->host)) + return ext2_dax_write_iter(iocb, from); +#endif + return generic_file_write_iter(iocb, from); +} + const struct file_operations ext2_file_operations = { .llseek = generic_file_llseek, - .read_iter = generic_file_read_iter, - .write_iter = generic_file_write_iter, + .read_iter = ext2_file_read_iter, + .write_iter = ext2_file_write_iter, .unlocked_ioctl = ext2_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = ext2_compat_ioctl, diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 2a69ab2e7bb0..aae5f61f980b 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include "ext2.h" @@ -787,6 +788,59 @@ int ext2_get_block(struct inode *inode, sector_t iblock, } +#ifdef CONFIG_FS_DAX +static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length, + unsigned flags, struct iomap *iomap) +{ + unsigned int blkbits = inode->i_blkbits; + unsigned long first_block = offset >> blkbits; + unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits; + bool new = false, boundary = false; + u32 bno; + int ret; + + ret = ext2_get_blocks(inode, first_block, max_blocks, + &bno, &new, &boundary, flags & IOMAP_WRITE); + if (ret < 0) + return ret; + + iomap->flags = 0; + iomap->bdev = inode->i_sb->s_bdev; + iomap->offset = first_block << blkbits; + + if (ret == 0) { + iomap->type = IOMAP_HOLE; + iomap->blkno = IOMAP_NULL_BLOCK; + iomap->length = 1 << blkbits; + } else { + iomap->type = IOMAP_MAPPED; + iomap->blkno = (sector_t)bno << (blkbits - 9); + iomap->length = (u64)ret << blkbits; + iomap->flags |= IOMAP_F_MERGED; + } + + if (new) + iomap->flags |= IOMAP_F_NEW; + return 0; +} + +static int +ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length, + ssize_t written, unsigned flags, struct iomap *iomap) +{ + if (iomap->type == IOMAP_MAPPED && + written < length && + (flags & IOMAP_WRITE)) + ext2_write_failed(inode->i_mapping, offset + length); + return 0; +} + +struct iomap_ops ext2_iomap_ops = { + .iomap_begin = ext2_iomap_begin, + .iomap_end = ext2_iomap_end, +}; +#endif /* CONFIG_FS_DAX */ + int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len) { @@ -872,11 +926,10 @@ ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter) loff_t offset = iocb->ki_pos; ssize_t ret; - if (IS_DAX(inode)) - ret = dax_do_io(iocb, inode, iter, ext2_get_block, NULL, - DIO_LOCKING); - else - ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block); + if (WARN_ON_ONCE(IS_DAX(inode))) + return -EIO; + + ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block); if (ret < 0 && iov_iter_rw(iter) == WRITE) ext2_write_failed(mapping, offset + count); return ret; -- 2.20.1