From 1383a7ed67490fb00d793e36c7a4d599ff88a64d Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Tue, 30 Oct 2018 10:40:31 +1100 Subject: vfs: check file ranges before cloning files Move the file range checks from vfs_clone_file_prep into a separate generic_remap_checks function so that all the checks are collected in a central location. This forms the basis for adding more checks from generic_write_checks that will make cloning's input checking more consistent with write input checking. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Reviewed-by: Amir Goldstein Signed-off-by: Dave Chinner --- fs/read_write.c | 55 +++++++++++++------------------------------------------ 1 file changed, 13 insertions(+), 42 deletions(-) (limited to 'fs/read_write.c') diff --git a/fs/read_write.c b/fs/read_write.c index 260797b01851..d6e8e242a15f 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1717,13 +1717,12 @@ static int clone_verify_area(struct file *file, loff_t pos, u64 len, bool write) * Returns: 0 for "nothing to clone", 1 for "something to clone", or * the usual negative error code. */ -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) +int vfs_clone_file_prep(struct file *file_in, loff_t pos_in, + struct file *file_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; + struct inode *inode_in = file_inode(file_in); + struct inode *inode_out = file_inode(file_out); bool same_inode = (inode_in == inode_out); int ret; @@ -1740,10 +1739,10 @@ int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in, if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) return -EINVAL; - isize = i_size_read(inode_in); - /* Zero length dedupe exits immediately; reflink goes to EOF. */ if (*len == 0) { + loff_t isize = i_size_read(inode_in); + if (is_dedupe || pos_in == isize) return 0; if (pos_in > isize) @@ -1751,36 +1750,11 @@ int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in, *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; - } + /* Check that we don't violate system file offset limits. */ + ret = generic_remap_checks(file_in, pos_in, file_out, pos_out, len, + is_dedupe); + if (ret) + return ret; /* Wait for the completion of any pending IOs on both files */ inode_dio_wait(inode_in); @@ -1813,7 +1787,7 @@ int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in, return 1; } -EXPORT_SYMBOL(vfs_clone_file_prep_inodes); +EXPORT_SYMBOL(vfs_clone_file_prep); int do_clone_file_range(struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, u64 len) @@ -1851,9 +1825,6 @@ int do_clone_file_range(struct file *file_in, loff_t pos_in, if (ret) return ret; - if (pos_in + len > i_size_read(inode_in)) - return -EINVAL; - ret = file_in->f_op->clone_file_range(file_in, pos_in, file_out, pos_out, len); if (!ret) { -- cgit