| Message ID | 20190429172649.8288-4-rgoldwyn@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs dax support | expand |
On Mon, Apr 29, 2019 at 12:26:34PM -0500, Goldwyn Rodrigues wrote: > From: Goldwyn Rodrigues <rgoldwyn@suse.com> > > Perform a basic read using iomap support. The btrfs_iomap_begin() > finds the extent at the position and fills the iomap data > structure with the values. > > Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> > --- > fs/btrfs/Makefile | 1 + > fs/btrfs/ctree.h | 5 +++++ > fs/btrfs/dax.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ > fs/btrfs/file.c | 11 ++++++++++- > 4 files changed, 65 insertions(+), 1 deletion(-) > create mode 100644 fs/btrfs/dax.c > > diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile > index ca693dd554e9..1fa77b875ae9 100644 > --- a/fs/btrfs/Makefile > +++ b/fs/btrfs/Makefile > @@ -12,6 +12,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \ > reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \ > uuid-tree.o props.o free-space-tree.o tree-checker.o > > +btrfs-$(CONFIG_FS_DAX) += dax.o > btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o > btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o > btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h > index 9512f49262dd..b7bbe5130a3b 100644 > --- a/fs/btrfs/ctree.h > +++ b/fs/btrfs/ctree.h > @@ -3795,6 +3795,11 @@ int btrfs_reada_wait(void *handle); > void btrfs_reada_detach(void *handle); > int btree_readahead_hook(struct extent_buffer *eb, int err); > > +#ifdef CONFIG_FS_DAX > +/* dax.c */ > +ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to); > +#endif /* CONFIG_FS_DAX */ > + > static inline int is_fstree(u64 rootid) > { > if (rootid == BTRFS_FS_TREE_OBJECTID || > diff --git a/fs/btrfs/dax.c b/fs/btrfs/dax.c > new file mode 100644 > index 000000000000..bf3d46b0acb6 > --- /dev/null > +++ b/fs/btrfs/dax.c > @@ -0,0 +1,49 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * DAX support for BTRFS > + * > + * Copyright (c) 2019 SUSE Linux > + * Author: Goldwyn Rodrigues <rgoldwyn@suse.com> > + */ > + > +#ifdef CONFIG_FS_DAX > +#include <linux/dax.h> > +#include <linux/iomap.h> > +#include "ctree.h" > +#include "btrfs_inode.h" > + > +static int btrfs_iomap_begin(struct inode *inode, loff_t pos, > + loff_t length, unsigned flags, struct iomap *iomap) > +{ > + struct extent_map *em; > + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); > + em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, pos, length, 0); > + if (em->block_start == EXTENT_MAP_HOLE) { > + iomap->type = IOMAP_HOLE; > + return 0; I'm not doing a rigorous review of the btrfs-specific pieces, but you're required to fill out the other iomap fields for a read hole. --D > + } > + iomap->type = IOMAP_MAPPED; > + iomap->bdev = em->bdev; > + iomap->dax_dev = fs_info->dax_dev; > + iomap->offset = em->start; > + iomap->length = em->len; > + iomap->addr = em->block_start; > + return 0; > +} > + > +static const struct iomap_ops btrfs_iomap_ops = { > + .iomap_begin = btrfs_iomap_begin, > +}; > + > +ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to) > +{ > + ssize_t ret; > + struct inode *inode = file_inode(iocb->ki_filp); > + > + inode_lock_shared(inode); > + ret = dax_iomap_rw(iocb, to, &btrfs_iomap_ops); > + inode_unlock_shared(inode); > + > + return ret; > +} > +#endif /* CONFIG_FS_DAX */ > diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c > index 34fe8a58b0e9..9194591f9eea 100644 > --- a/fs/btrfs/file.c > +++ b/fs/btrfs/file.c > @@ -3288,9 +3288,18 @@ static int btrfs_file_open(struct inode *inode, struct file *filp) > return generic_file_open(inode, filp); > } > > +static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) > +{ > +#ifdef CONFIG_FS_DAX > + if (IS_DAX(file_inode(iocb->ki_filp))) > + return btrfs_file_dax_read(iocb, to); > +#endif > + return generic_file_read_iter(iocb, to); > +} > + > const struct file_operations btrfs_file_operations = { > .llseek = btrfs_file_llseek, > - .read_iter = generic_file_read_iter, > + .read_iter = btrfs_file_read_iter, > .splice_read = generic_file_splice_read, > .write_iter = btrfs_file_write_iter, > .mmap = btrfs_file_mmap, > -- > 2.16.4 >
On 8:14 21/05, Darrick J. Wong wrote: > On Mon, Apr 29, 2019 at 12:26:34PM -0500, Goldwyn Rodrigues wrote: > > From: Goldwyn Rodrigues <rgoldwyn@suse.com> > > > > Perform a basic read using iomap support. The btrfs_iomap_begin() > > finds the extent at the position and fills the iomap data > > structure with the values. > > > > Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> > > --- > > fs/btrfs/Makefile | 1 + > > fs/btrfs/ctree.h | 5 +++++ > > fs/btrfs/dax.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ > > fs/btrfs/file.c | 11 ++++++++++- > > 4 files changed, 65 insertions(+), 1 deletion(-) > > create mode 100644 fs/btrfs/dax.c > > > > diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile > > index ca693dd554e9..1fa77b875ae9 100644 > > --- a/fs/btrfs/Makefile > > +++ b/fs/btrfs/Makefile > > @@ -12,6 +12,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \ > > reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \ > > uuid-tree.o props.o free-space-tree.o tree-checker.o > > > > +btrfs-$(CONFIG_FS_DAX) += dax.o > > btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o > > btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o > > btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o > > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h > > index 9512f49262dd..b7bbe5130a3b 100644 > > --- a/fs/btrfs/ctree.h > > +++ b/fs/btrfs/ctree.h > > @@ -3795,6 +3795,11 @@ int btrfs_reada_wait(void *handle); > > void btrfs_reada_detach(void *handle); > > int btree_readahead_hook(struct extent_buffer *eb, int err); > > > > +#ifdef CONFIG_FS_DAX > > +/* dax.c */ > > +ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to); > > +#endif /* CONFIG_FS_DAX */ > > + > > static inline int is_fstree(u64 rootid) > > { > > if (rootid == BTRFS_FS_TREE_OBJECTID || > > diff --git a/fs/btrfs/dax.c b/fs/btrfs/dax.c > > new file mode 100644 > > index 000000000000..bf3d46b0acb6 > > --- /dev/null > > +++ b/fs/btrfs/dax.c > > @@ -0,0 +1,49 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * DAX support for BTRFS > > + * > > + * Copyright (c) 2019 SUSE Linux > > + * Author: Goldwyn Rodrigues <rgoldwyn@suse.com> > > + */ > > + > > +#ifdef CONFIG_FS_DAX > > +#include <linux/dax.h> > > +#include <linux/iomap.h> > > +#include "ctree.h" > > +#include "btrfs_inode.h" > > + > > +static int btrfs_iomap_begin(struct inode *inode, loff_t pos, > > + loff_t length, unsigned flags, struct iomap *iomap) > > +{ > > + struct extent_map *em; > > + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); > > + em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, pos, length, 0); > > + if (em->block_start == EXTENT_MAP_HOLE) { > > + iomap->type = IOMAP_HOLE; > > + return 0; > > I'm not doing a rigorous review of the btrfs-specific pieces, but you're > required to fill out the other iomap fields for a read hole. I fixed this in the patch adding write support. However, this looks wrong as a patch. I will fix this.
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index ca693dd554e9..1fa77b875ae9 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -12,6 +12,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \ reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \ uuid-tree.o props.o free-space-tree.o tree-checker.o +btrfs-$(CONFIG_FS_DAX) += dax.o btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o btrfs-$(CONFIG_BTRFS_FS_REF_VERIFY) += ref-verify.o diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 9512f49262dd..b7bbe5130a3b 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3795,6 +3795,11 @@ int btrfs_reada_wait(void *handle); void btrfs_reada_detach(void *handle); int btree_readahead_hook(struct extent_buffer *eb, int err); +#ifdef CONFIG_FS_DAX +/* dax.c */ +ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to); +#endif /* CONFIG_FS_DAX */ + static inline int is_fstree(u64 rootid) { if (rootid == BTRFS_FS_TREE_OBJECTID || diff --git a/fs/btrfs/dax.c b/fs/btrfs/dax.c new file mode 100644 index 000000000000..bf3d46b0acb6 --- /dev/null +++ b/fs/btrfs/dax.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DAX support for BTRFS + * + * Copyright (c) 2019 SUSE Linux + * Author: Goldwyn Rodrigues <rgoldwyn@suse.com> + */ + +#ifdef CONFIG_FS_DAX +#include <linux/dax.h> +#include <linux/iomap.h> +#include "ctree.h" +#include "btrfs_inode.h" + +static int btrfs_iomap_begin(struct inode *inode, loff_t pos, + loff_t length, unsigned flags, struct iomap *iomap) +{ + struct extent_map *em; + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, pos, length, 0); + if (em->block_start == EXTENT_MAP_HOLE) { + iomap->type = IOMAP_HOLE; + return 0; + } + iomap->type = IOMAP_MAPPED; + iomap->bdev = em->bdev; + iomap->dax_dev = fs_info->dax_dev; + iomap->offset = em->start; + iomap->length = em->len; + iomap->addr = em->block_start; + return 0; +} + +static const struct iomap_ops btrfs_iomap_ops = { + .iomap_begin = btrfs_iomap_begin, +}; + +ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to) +{ + ssize_t ret; + struct inode *inode = file_inode(iocb->ki_filp); + + inode_lock_shared(inode); + ret = dax_iomap_rw(iocb, to, &btrfs_iomap_ops); + inode_unlock_shared(inode); + + return ret; +} +#endif /* CONFIG_FS_DAX */ diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 34fe8a58b0e9..9194591f9eea 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -3288,9 +3288,18 @@ static int btrfs_file_open(struct inode *inode, struct file *filp) return generic_file_open(inode, filp); } +static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ +#ifdef CONFIG_FS_DAX + if (IS_DAX(file_inode(iocb->ki_filp))) + return btrfs_file_dax_read(iocb, to); +#endif + return generic_file_read_iter(iocb, to); +} + const struct file_operations btrfs_file_operations = { .llseek = btrfs_file_llseek, - .read_iter = generic_file_read_iter, + .read_iter = btrfs_file_read_iter, .splice_read = generic_file_splice_read, .write_iter = btrfs_file_write_iter, .mmap = btrfs_file_mmap,