diff options
Diffstat (limited to 'fs/xfs')
| -rw-r--r-- | fs/xfs/xfs_file.c | 48 | ||||
| -rw-r--r-- | fs/xfs/xfs_reflink.c | 127 | ||||
| -rw-r--r-- | fs/xfs/xfs_reflink.h | 5 |
3 files changed, 174 insertions, 6 deletions
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index cf24b61951e3..39fde9f51303 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -1010,7 +1010,8 @@ xfs_file_share_range( loff_t pos_in, struct file *file_out, loff_t pos_out, - u64 len) + u64 len, + bool is_dedupe) { struct inode *inode_in; struct inode *inode_out; @@ -1019,6 +1020,7 @@ xfs_file_share_range( loff_t isize; int same_inode; loff_t blen; + unsigned int flags = 0; inode_in = file_inode(file_in); inode_out = file_inode(file_out); @@ -1056,6 +1058,15 @@ xfs_file_share_range( pos_in + len > isize) return -EINVAL; + /* Don't allow dedupe past EOF in the dest file */ + if (is_dedupe) { + loff_t disize; + + disize = i_size_read(inode_out); + if (pos_out >= disize || pos_out + len > disize) + return -EINVAL; + } + /* If we're linking to EOF, continue to the block boundary. */ if (pos_in + len == isize) blen = ALIGN(isize, bs) - pos_in; @@ -1079,8 +1090,10 @@ xfs_file_share_range( if (ret) goto out_unlock; + if (is_dedupe) + flags |= XFS_REFLINK_DEDUPE; ret = xfs_reflink_remap_range(XFS_I(inode_in), pos_in, XFS_I(inode_out), - pos_out, len); + pos_out, len, flags); if (ret < 0) goto out_unlock; @@ -1100,7 +1113,7 @@ xfs_file_copy_range( int error; error = xfs_file_share_range(file_in, pos_in, file_out, pos_out, - len); + len, false); if (error) return error; return len; @@ -1115,7 +1128,33 @@ xfs_file_clone_range( u64 len) { return xfs_file_share_range(file_in, pos_in, file_out, pos_out, - len); + len, false); +} + +#define XFS_MAX_DEDUPE_LEN (16 * 1024 * 1024) +STATIC ssize_t +xfs_file_dedupe_range( + struct file *src_file, + u64 loff, + u64 len, + struct file *dst_file, + u64 dst_loff) +{ + int error; + + /* + * Limit the total length we will dedupe for each operation. + * This is intended to bound the total time spent in this + * ioctl to something sane. + */ + if (len > XFS_MAX_DEDUPE_LEN) + len = XFS_MAX_DEDUPE_LEN; + + error = xfs_file_share_range(src_file, loff, dst_file, dst_loff, + len, true); + if (error) + return error; + return len; } STATIC int @@ -1779,6 +1818,7 @@ const struct file_operations xfs_file_operations = { .fallocate = xfs_file_fallocate, .copy_file_range = xfs_file_copy_range, .clone_file_range = xfs_file_clone_range, + .dedupe_file_range = xfs_file_dedupe_range, }; const struct file_operations xfs_dir_file_operations = { diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index c1e98a43a937..6b22669421b2 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -1150,6 +1150,111 @@ err: } /* + * Read a page's worth of file data into the page cache. Return the page + * locked. + */ +static struct page * +xfs_get_page( + struct inode *inode, + xfs_off_t offset) +{ + struct address_space *mapping; + struct page *page; + pgoff_t n; + + n = offset >> PAGE_SHIFT; + mapping = inode->i_mapping; + page = read_mapping_page(mapping, n, NULL); + if (IS_ERR(page)) + return page; + if (!PageUptodate(page)) { + put_page(page); + return ERR_PTR(-EIO); + } + lock_page(page); + return page; +} + +/* + * Compare extents of two files to see if they are the same. + */ +static int +xfs_compare_extents( + struct inode *src, + xfs_off_t srcoff, + struct inode *dest, + xfs_off_t destoff, + xfs_off_t len, + bool *is_same) +{ + xfs_off_t src_poff; + xfs_off_t dest_poff; + void *src_addr; + void *dest_addr; + struct page *src_page; + struct page *dest_page; + xfs_off_t cmp_len; + bool same; + int error; + + error = -EINVAL; + same = true; + while (len) { + src_poff = srcoff & (PAGE_SIZE - 1); + dest_poff = destoff & (PAGE_SIZE - 1); + cmp_len = min(PAGE_SIZE - src_poff, + PAGE_SIZE - dest_poff); + cmp_len = min(cmp_len, len); + ASSERT(cmp_len > 0); + + trace_xfs_reflink_compare_extents(XFS_I(src), srcoff, cmp_len, + XFS_I(dest), destoff); + + src_page = xfs_get_page(src, srcoff); + if (IS_ERR(src_page)) { + error = PTR_ERR(src_page); + goto out_error; + } + dest_page = xfs_get_page(dest, destoff); + if (IS_ERR(dest_page)) { + error = PTR_ERR(dest_page); + unlock_page(src_page); + put_page(src_page); + goto out_error; + } + src_addr = kmap_atomic(src_page); + dest_addr = kmap_atomic(dest_page); + + flush_dcache_page(src_page); + flush_dcache_page(dest_page); + + if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len)) + same = false; + + kunmap_atomic(dest_addr); + kunmap_atomic(src_addr); + unlock_page(dest_page); + unlock_page(src_page); + put_page(dest_page); + put_page(src_page); + + if (!same) + break; + + srcoff += cmp_len; + destoff += cmp_len; + len -= cmp_len; + } + + *is_same = same; + return 0; + +out_error: + trace_xfs_reflink_compare_extents_error(XFS_I(dest), error, _RET_IP_); + return error; +} + +/* * Link a range of blocks from one file to another. */ int @@ -1158,12 +1263,14 @@ xfs_reflink_remap_range( xfs_off_t srcoff, struct xfs_inode *dest, xfs_off_t destoff, - xfs_off_t len) + xfs_off_t len, + unsigned int flags) { struct xfs_mount *mp = src->i_mount; xfs_fileoff_t sfsbno, dfsbno; xfs_filblks_t fsblen; int error; + bool is_same; if (!xfs_sb_version_hasreflink(&mp->m_sb)) return -EOPNOTSUPP; @@ -1175,6 +1282,9 @@ xfs_reflink_remap_range( if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest)) return -EINVAL; + if (flags & ~XFS_REFLINK_ALL) + return -EINVAL; + trace_xfs_reflink_remap_range(src, srcoff, len, dest, destoff); /* Lock both files against IO */ @@ -1186,6 +1296,21 @@ xfs_reflink_remap_range( xfs_lock_two_inodes(src, dest, XFS_MMAPLOCK_EXCL); } + /* + * Check that the extents are the same. + */ + if (flags & XFS_REFLINK_DEDUPE) { + is_same = false; + error = xfs_compare_extents(VFS_I(src), srcoff, VFS_I(dest), + destoff, len, &is_same); + if (error) + goto out_error; + if (!is_same) { + error = -EBADE; + goto out_error; + } + } + error = xfs_reflink_set_inode_flag(src, dest); if (error) goto out_error; diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h index c35ce299281b..df82b2049187 100644 --- a/fs/xfs/xfs_reflink.h +++ b/fs/xfs/xfs_reflink.h @@ -43,7 +43,10 @@ extern int xfs_reflink_cancel_cow_range(struct xfs_inode *ip, xfs_off_t offset, extern int xfs_reflink_end_cow(struct xfs_inode *ip, xfs_off_t offset, xfs_off_t count); extern int xfs_reflink_recover_cow(struct xfs_mount *mp); +#define XFS_REFLINK_DEDUPE 1 /* only reflink if contents match */ +#define XFS_REFLINK_ALL (XFS_REFLINK_DEDUPE) extern int xfs_reflink_remap_range(struct xfs_inode *src, xfs_off_t srcoff, - struct xfs_inode *dest, xfs_off_t destoff, xfs_off_t len); + struct xfs_inode *dest, xfs_off_t destoff, xfs_off_t len, + unsigned int flags); #endif /* __XFS_REFLINK_H */ |