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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-17 18:44:00 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-17 18:44:00 -0800 |
commit | 0110c350c86d511be2130cb2a30dcbb76c4af750 (patch) | |
tree | d343a9e0fcb586a7110b13d411b314d33d404c08 /fs/read_write.c | |
parent | d9cb5bfcc3339f1a63df8fe0af8cece33c83c3af (diff) | |
parent | 9763f7a4a5f7b1a7c480fa06d01b2bad25163c0a (diff) | |
download | linux-0110c350c86d511be2130cb2a30dcbb76c4af750.tar.gz linux-0110c350c86d511be2130cb2a30dcbb76c4af750.tar.bz2 linux-0110c350c86d511be2130cb2a30dcbb76c4af750.zip |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
"In this pile:
- autofs-namespace series
- dedupe stuff
- more struct path constification"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
ocfs2: implement the VFS clone_range, copy_range, and dedupe_range features
ocfs2: charge quota for reflinked blocks
ocfs2: fix bad pointer cast
ocfs2: always unlock when completing dio writes
ocfs2: don't eat io errors during _dio_end_io_write
ocfs2: budget for extent tree splits when adding refcount flag
ocfs2: prohibit refcounted swapfiles
ocfs2: add newlines to some error messages
ocfs2: convert inode refcount test to a helper
simple_write_end(): don't zero in short copy into uptodate
exofs: don't mess with simple_write_{begin,end}
9p: saner ->write_end() on failing copy into non-uptodate page
fix gfs2_stuffed_write_end() on short copies
fix ceph_write_end()
nfs_write_end(): fix handling of short copies
vfs: refactor clone/dedupe_file_range common functions
fs: try to clone files first in vfs_copy_file_range
vfs: misc struct path constification
namespace.c: constify struct path passed to a bunch of primitives
quota: constify struct path in quota_on
...
Diffstat (limited to 'fs/read_write.c')
-rw-r--r-- | fs/read_write.c | 231 |
1 files changed, 226 insertions, 5 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index 53bccd1c786e..da6de12b5c46 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1540,20 +1540,37 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, sb_start_write(inode_out->i_sb); - ret = -EOPNOTSUPP; - if (file_out->f_op->copy_file_range) + /* + * Try cloning first, this is supported by more file systems, and + * more efficient if both clone and copy are supported (e.g. NFS). + */ + if (file_in->f_op->clone_file_range) { + ret = file_in->f_op->clone_file_range(file_in, pos_in, + file_out, pos_out, len); + if (ret == 0) { + ret = len; + goto done; + } + } + + if (file_out->f_op->copy_file_range) { ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out, pos_out, len, flags); - if (ret == -EOPNOTSUPP) - ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, - len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); + if (ret != -EOPNOTSUPP) + goto done; + } + + ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, + len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0); +done: if (ret > 0) { fsnotify_access(file_in); add_rchar(current, ret); fsnotify_modify(file_out); add_wchar(current, ret); } + inc_syscr(current); inc_syscw(current); @@ -1648,6 +1665,114 @@ static int clone_verify_area(struct file *file, loff_t pos, u64 len, bool write) return security_file_permission(file, write ? MAY_WRITE : MAY_READ); } +/* + * Check that the two inodes are eligible for cloning, the ranges make + * sense, and then flush all dirty data. Caller must ensure that the + * inodes have been locked against any other modifications. + */ +int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in, + struct inode *inode_out, loff_t pos_out, + u64 *len, bool is_dedupe) +{ + loff_t bs = inode_out->i_sb->s_blocksize; + loff_t blen; + loff_t isize; + bool same_inode = (inode_in == inode_out); + int ret; + + /* Don't touch certain kinds of inodes */ + if (IS_IMMUTABLE(inode_out)) + return -EPERM; + + if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) + return -ETXTBSY; + + /* Don't reflink dirs, pipes, sockets... */ + if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) + return -EISDIR; + if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) + return -EINVAL; + + /* Are we going all the way to the end? */ + isize = i_size_read(inode_in); + if (isize == 0) { + *len = 0; + return 0; + } + + /* Zero length dedupe exits immediately; reflink goes to EOF. */ + if (*len == 0) { + if (is_dedupe) { + *len = 0; + return 0; + } + *len = isize - pos_in; + } + + /* Ensure offsets don't wrap and the input is inside i_size */ + if (pos_in + *len < pos_in || pos_out + *len < pos_out || + 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; + else + blen = *len; + + /* Only reflink if we're aligned to block boundaries */ + if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_in + blen, bs) || + !IS_ALIGNED(pos_out, bs) || !IS_ALIGNED(pos_out + blen, bs)) + return -EINVAL; + + /* Don't allow overlapped reflink within the same file */ + if (same_inode) { + if (pos_out + blen > pos_in && pos_out < pos_in + blen) + return -EINVAL; + } + + /* Wait for the completion of any pending IOs on both files */ + inode_dio_wait(inode_in); + if (!same_inode) + inode_dio_wait(inode_out); + + ret = filemap_write_and_wait_range(inode_in->i_mapping, + pos_in, pos_in + *len - 1); + if (ret) + return ret; + + ret = filemap_write_and_wait_range(inode_out->i_mapping, + pos_out, pos_out + *len - 1); + if (ret) + return ret; + + /* + * Check that the extents are the same. + */ + if (is_dedupe) { + bool is_same = false; + + ret = vfs_dedupe_file_range_compare(inode_in, pos_in, + inode_out, pos_out, *len, &is_same); + if (ret) + return ret; + if (!is_same) + return -EBADE; + } + + return 0; +} +EXPORT_SYMBOL(vfs_clone_file_prep_inodes); + int vfs_clone_file_range(struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, u64 len) { @@ -1698,6 +1823,102 @@ int vfs_clone_file_range(struct file *file_in, loff_t pos_in, } EXPORT_SYMBOL(vfs_clone_file_range); +/* + * Read a page's worth of file data into the page cache. Return the page + * locked. + */ +static struct page *vfs_dedupe_get_page(struct inode *inode, loff_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. + * Caller must have locked both inodes to prevent write races. + */ +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; + void *src_addr; + void *dest_addr; + struct page *src_page; + struct page *dest_page; + loff_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); + if (cmp_len <= 0) + goto out_error; + + src_page = vfs_dedupe_get_page(src, srcoff); + if (IS_ERR(src_page)) { + error = PTR_ERR(src_page); + goto out_error; + } + dest_page = vfs_dedupe_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: + return error; +} +EXPORT_SYMBOL(vfs_dedupe_file_range_compare); + int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same) { struct file_dedupe_range_info *info; |