> -----Original Message----- > From: Ritesh Harjani <ritesh.l...@gmail.com> > Subject: Re: [PATCH v3 08/10] fsdax: Dedup file range to use a compare > function > > On 21/03/19 09:52AM, Shiyang Ruan wrote: > > With dax we cannot deal with readpage() etc. So, we create a dax > > comparison funciton which is similar with > > vfs_dedupe_file_range_compare(). > > And introduce dax_remap_file_range_prep() for filesystem use. > > > > Signed-off-by: Goldwyn Rodrigues <rgold...@suse.com> > > Signed-off-by: Shiyang Ruan <ruansy.f...@fujitsu.com> > > --- > > fs/dax.c | 56 > ++++++++++++++++++++++++++++++++++++++++++++ > > fs/remap_range.c | 45 ++++++++++++++++++++++++++++------- > > fs/xfs/xfs_reflink.c | 9 +++++-- > > include/linux/dax.h | 4 ++++ > > include/linux/fs.h | 15 ++++++++---- > > 5 files changed, 115 insertions(+), 14 deletions(-) > > > > diff --git a/fs/dax.c b/fs/dax.c > > index 348297b38f76..76f81f1d76ec 100644 > > --- a/fs/dax.c > > +++ b/fs/dax.c > > @@ -1833,3 +1833,59 @@ vm_fault_t dax_finish_sync_fault(struct vm_fault > *vmf, > > return dax_insert_pfn_mkwrite(vmf, pfn, order); } > > EXPORT_SYMBOL_GPL(dax_finish_sync_fault); > > + > > +static loff_t dax_range_compare_actor(struct inode *ino1, loff_t pos1, > > + struct inode *ino2, loff_t pos2, loff_t len, void *data, > > + struct iomap *smap, struct iomap *dmap) { > > + void *saddr, *daddr; > > + bool *same = data; > > + int ret; > > + > > + if (smap->type == IOMAP_HOLE && dmap->type == IOMAP_HOLE) { > > + *same = true; > > + return len; > > + } > > + > > + if (smap->type == IOMAP_HOLE || dmap->type == IOMAP_HOLE) { > > + *same = false; > > + return 0; > > + } > > + > > + ret = dax_iomap_direct_access(smap, pos1, ALIGN(pos1 + len, PAGE_SIZE), > > + &saddr, NULL); > > shouldn't it take len as the second argument?
The second argument of dax_iomap_direct_access() means offset, and the third one means length. So, I think this is right. > > > + if (ret < 0) > > + return -EIO; > > + > > + ret = dax_iomap_direct_access(dmap, pos2, ALIGN(pos2 + len, PAGE_SIZE), > > + &daddr, NULL); > > ditto. > > + if (ret < 0) > > + return -EIO; > > + > > + *same = !memcmp(saddr, daddr, len); > > + return len; > > +} > > + > > +int dax_dedupe_file_range_compare(struct inode *src, loff_t srcoff, > > + struct inode *dest, loff_t destoff, loff_t len, bool *is_same, > > + const struct iomap_ops *ops) > > +{ > > + int id, ret = 0; > > + > > + id = dax_read_lock(); > > + while (len) { > > + ret = iomap_apply2(src, srcoff, dest, destoff, len, 0, ops, > > + is_same, dax_range_compare_actor); > > + if (ret < 0 || !*is_same) > > + goto out; > > + > > + len -= ret; > > + srcoff += ret; > > + destoff += ret; > > + } > > + ret = 0; > > +out: > > + dax_read_unlock(id); > > + return ret; > > +} > > +EXPORT_SYMBOL_GPL(dax_dedupe_file_range_compare); > > diff --git a/fs/remap_range.c b/fs/remap_range.c index > > 77dba3a49e65..9079390edaf3 100644 > > --- a/fs/remap_range.c > > +++ b/fs/remap_range.c > > @@ -14,6 +14,7 @@ > > #include <linux/compat.h> > > #include <linux/mount.h> > > #include <linux/fs.h> > > +#include <linux/dax.h> > > #include "internal.h" > > > > #include <linux/uaccess.h> > > @@ -199,9 +200,9 @@ static void vfs_unlock_two_pages(struct page *page1, > struct page *page2) > > * Compare extents of two files to see if they are the same. > > * Caller must have locked both inodes to prevent write races. > > */ > > -static int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff, > > - struct inode *dest, loff_t destoff, > > - loff_t len, bool *is_same) > > +int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff, > > + struct inode *dest, loff_t destoff, > > + loff_t len, bool *is_same) > > { > > loff_t src_poff; > > loff_t dest_poff; > > @@ -280,6 +281,7 @@ static int vfs_dedupe_file_range_compare(struct > > inode *src, loff_t srcoff, > > out_error: > > return error; > > } > > +EXPORT_SYMBOL(vfs_dedupe_file_range_compare); > > > > /* > > * Check that the two inodes are eligible for cloning, the ranges > > make @@ -289,9 +291,11 @@ static int > vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff, > > * If there's an error, then the usual negative error code is returned. > > * Otherwise returns 0 with *len set to the request length. > > */ > > -int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, > > - struct file *file_out, loff_t pos_out, > > - loff_t *len, unsigned int remap_flags) > > +static int > > +__generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, > > + struct file *file_out, loff_t pos_out, > > + loff_t *len, unsigned int remap_flags, > > + const struct iomap_ops *ops) > > { > > struct inode *inode_in = file_inode(file_in); > > struct inode *inode_out = file_inode(file_out); @@ -351,8 +355,15 @@ > > int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, > > if (remap_flags & REMAP_FILE_DEDUP) { > > bool is_same = false; > > > > - ret = vfs_dedupe_file_range_compare(inode_in, pos_in, > > - inode_out, pos_out, *len, &is_same); > > + if (!IS_DAX(inode_in) && !IS_DAX(inode_out)) > > + ret = vfs_dedupe_file_range_compare(inode_in, pos_in, > > + inode_out, pos_out, *len, &is_same); > > + else if (IS_DAX(inode_in) && IS_DAX(inode_out) && ops) > > + ret = dax_dedupe_file_range_compare(inode_in, pos_in, > > + inode_out, pos_out, *len, &is_same, > > + ops); > > + else > > + return -EINVAL; > > if (ret) > > return ret; > > if (!is_same) > > should we consider to check !is_same check b4? > you should maybe relook at this error handling side of code. > we still return len from actor function but is_same is set to false. > So we are essentially returning ret (positive value), instead should be > returning > -EBADE because of !memcmp The ret from compare function will not be positive, it will always be 0 or negative. In addition, if something wrong happens, is_same will always be false. The caller could not get correct errno if check !is_same firstly. > > > @@ -370,6 +381,24 @@ int generic_remap_file_range_prep(struct file > > *file_in, loff_t pos_in, > > > > return ret; > > } > > + > > +int dax_remap_file_range_prep(struct file *file_in, loff_t pos_in, > > + struct file *file_out, loff_t pos_out, > > + loff_t *len, unsigned int remap_flags, > > + const struct iomap_ops *ops) { > > + return __generic_remap_file_range_prep(file_in, pos_in, file_out, > > + pos_out, len, remap_flags, ops); > > } > > +EXPORT_SYMBOL(dax_remap_file_range_prep); > > + > > +int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, > > + struct file *file_out, loff_t pos_out, > > + loff_t *len, unsigned int remap_flags) { > > + return __generic_remap_file_range_prep(file_in, pos_in, file_out, > > + pos_out, len, remap_flags, > > NULL); } > > EXPORT_SYMBOL(generic_remap_file_range_prep); > > > > loff_t do_clone_file_range(struct file *file_in, loff_t pos_in, diff > > --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index > > 6fa05fb78189..f5b3a3da36b7 100644 > > --- a/fs/xfs/xfs_reflink.c > > +++ b/fs/xfs/xfs_reflink.c > > @@ -1308,8 +1308,13 @@ xfs_reflink_remap_prep( > > if (IS_DAX(inode_in) || IS_DAX(inode_out)) > > goto out_unlock; > > > > - ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out, > > - len, remap_flags); > > + if (IS_DAX(inode_in)) > > if (!IS_DAX(inode_in)) no? My mistake... > > > + ret = generic_remap_file_range_prep(file_in, pos_in, file_out, > > + pos_out, len, remap_flags); > > + else > > + ret = dax_remap_file_range_prep(file_in, pos_in, file_out, > > + pos_out, len, remap_flags, > > + &xfs_read_iomap_ops); > > if (ret || *len == 0) > > goto out_unlock; > > > > diff --git a/include/linux/dax.h b/include/linux/dax.h index > > 3275e01ed33d..32e1c34349f2 100644 > > --- a/include/linux/dax.h > > +++ b/include/linux/dax.h > > @@ -239,6 +239,10 @@ int dax_invalidate_mapping_entry_sync(struct > address_space *mapping, > > pgoff_t index); > > s64 dax_iomap_zero(loff_t pos, u64 length, struct iomap *iomap, > > struct iomap *srcmap); > > +int dax_dedupe_file_range_compare(struct inode *src, loff_t srcoff, > > + struct inode *dest, loff_t destoff, > > + loff_t len, bool *is_same, > > + const struct iomap_ops *ops); > > static inline bool dax_mapping(struct address_space *mapping) { > > return mapping->host && IS_DAX(mapping->host); diff --git > > a/include/linux/fs.h b/include/linux/fs.h index > > fd47deea7c17..2e6ec5bdf82a 100644 > > --- a/include/linux/fs.h > > +++ b/include/linux/fs.h > > @@ -68,6 +68,7 @@ struct fsverity_info; struct fsverity_operations; > > struct fs_context; struct fs_parameter_spec; > > +struct iomap_ops; > > > > extern void __init inode_init(void); > > extern void __init inode_init_early(void); @@ -1910,13 +1911,19 @@ > > extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t > > *); extern ssize_t vfs_write(struct file *, const char __user *, > > size_t, loff_t *); extern ssize_t vfs_copy_file_range(struct file *, > > loff_t , struct > file *, > > loff_t, size_t, unsigned int); > > +typedef int (*compare_range_t)(struct inode *src, loff_t srcpos, > > + struct inode *dest, loff_t destpos, > > + loff_t len, bool *is_same); > > Is this used anywhere? No, I forgot to remove it... -- Thanks, Ruan Shiyang. > > > extern ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in, > > struct file *file_out, loff_t pos_out, > > size_t len, unsigned int flags); -extern > > int > > generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, > > - struct file *file_out, loff_t pos_out, > > - loff_t *count, > > - unsigned int remap_flags); > > +int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, > > + struct file *file_out, loff_t pos_out, > > + loff_t *count, unsigned int remap_flags); int > > +dax_remap_file_range_prep(struct file *file_in, loff_t pos_in, > > + struct file *file_out, loff_t pos_out, > > + loff_t *len, unsigned int remap_flags, > > + const struct iomap_ops *ops); > > extern loff_t do_clone_file_range(struct file *file_in, loff_t pos_in, > > struct file *file_out, loff_t pos_out, > > loff_t len, unsigned int remap_flags); > > -- > > 2.30.1 > > > > > > _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-le...@lists.01.org