From 02e83f46ebfaf9405881e290794c913d457541f0 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Wed, 14 Oct 2020 16:47:08 -0700 Subject: vfs: move generic_remap_checks out of mm I would like to move all the generic helpers for the vfs remap range functionality (aka clonerange and dedupe) into a separate file so that they won't be scattered across the vfs and the mm subsystems. The eventual goal is to be able to deselect remap_range.c if none of the filesystems need that code, but the tricky part here is picking a stable(ish) part of the merge window to rearrange code. Signed-off-by: Darrick J. Wong --- mm/filemap.c | 81 +----------------------------------------------------------- 1 file changed, 1 insertion(+), 80 deletions(-) (limited to 'mm') diff --git a/mm/filemap.c b/mm/filemap.c index 99c49eeae71b..cf20e5aeb11b 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3098,8 +3098,7 @@ EXPORT_SYMBOL(read_cache_page_gfp); * LFS limits. If pos is under the limit it becomes a short access. If it * exceeds the limit we return -EFBIG. */ -static int generic_write_check_limits(struct file *file, loff_t pos, - loff_t *count) +int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count) { struct inode *inode = file->f_mapping->host; loff_t max_size = inode->i_sb->s_maxbytes; @@ -3161,84 +3160,6 @@ inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) } EXPORT_SYMBOL(generic_write_checks); -/* - * Performs necessary checks before doing a clone. - * - * Can adjust amount of bytes to clone via @req_count argument. - * Returns appropriate error code that caller should return or - * zero in case the clone should be allowed. - */ -int generic_remap_checks(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - loff_t *req_count, unsigned int remap_flags) -{ - struct inode *inode_in = file_in->f_mapping->host; - struct inode *inode_out = file_out->f_mapping->host; - uint64_t count = *req_count; - uint64_t bcount; - loff_t size_in, size_out; - loff_t bs = inode_out->i_sb->s_blocksize; - int ret; - - /* The start of both ranges must be aligned to an fs block. */ - if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_out, bs)) - return -EINVAL; - - /* Ensure offsets don't wrap. */ - if (pos_in + count < pos_in || pos_out + count < pos_out) - return -EINVAL; - - size_in = i_size_read(inode_in); - size_out = i_size_read(inode_out); - - /* Dedupe requires both ranges to be within EOF. */ - if ((remap_flags & REMAP_FILE_DEDUP) && - (pos_in >= size_in || pos_in + count > size_in || - pos_out >= size_out || pos_out + count > size_out)) - return -EINVAL; - - /* Ensure the infile range is within the infile. */ - if (pos_in >= size_in) - return -EINVAL; - count = min(count, size_in - (uint64_t)pos_in); - - ret = generic_write_check_limits(file_out, pos_out, &count); - if (ret) - return ret; - - /* - * If the user wanted us to link to the infile's EOF, round up to the - * next block boundary for this check. - * - * Otherwise, make sure the count is also block-aligned, having - * already confirmed the starting offsets' block alignment. - */ - if (pos_in + count == size_in) { - bcount = ALIGN(size_in, bs) - pos_in; - } else { - if (!IS_ALIGNED(count, bs)) - count = ALIGN_DOWN(count, bs); - bcount = count; - } - - /* Don't allow overlapped cloning within the same file. */ - if (inode_in == inode_out && - pos_out + bcount > pos_in && - pos_out < pos_in + bcount) - return -EINVAL; - - /* - * We shortened the request but the caller can't deal with that, so - * bounce the request back to userspace. - */ - if (*req_count != count && !(remap_flags & REMAP_FILE_CAN_SHORTEN)) - return -EINVAL; - - *req_count = count; - return 0; -} - - /* * Performs common checks before doing a file copy/clone * from @file_in to @file_out. -- cgit From 407e9c63ee571f44a2dfb0828fc30daa02abb6dc Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 15 Oct 2020 09:21:17 -0700 Subject: vfs: move the generic write and copy checks out of mm The generic write check helpers also don't have much to do with the page cache, so move them to the vfs. Signed-off-by: Darrick J. Wong --- mm/filemap.c | 143 ----------------------------------------------------------- 1 file changed, 143 deletions(-) (limited to 'mm') diff --git a/mm/filemap.c b/mm/filemap.c index cf20e5aeb11b..9962fd682f20 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3093,149 +3093,6 @@ struct page *read_cache_page_gfp(struct address_space *mapping, } EXPORT_SYMBOL(read_cache_page_gfp); -/* - * Don't operate on ranges the page cache doesn't support, and don't exceed the - * LFS limits. If pos is under the limit it becomes a short access. If it - * exceeds the limit we return -EFBIG. - */ -int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count) -{ - struct inode *inode = file->f_mapping->host; - loff_t max_size = inode->i_sb->s_maxbytes; - loff_t limit = rlimit(RLIMIT_FSIZE); - - if (limit != RLIM_INFINITY) { - if (pos >= limit) { - send_sig(SIGXFSZ, current, 0); - return -EFBIG; - } - *count = min(*count, limit - pos); - } - - if (!(file->f_flags & O_LARGEFILE)) - max_size = MAX_NON_LFS; - - if (unlikely(pos >= max_size)) - return -EFBIG; - - *count = min(*count, max_size - pos); - - return 0; -} - -/* - * Performs necessary checks before doing a write - * - * Can adjust writing position or amount of bytes to write. - * Returns appropriate error code that caller should return or - * zero in case that write should be allowed. - */ -inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) -{ - struct file *file = iocb->ki_filp; - struct inode *inode = file->f_mapping->host; - loff_t count; - int ret; - - if (IS_SWAPFILE(inode)) - return -ETXTBSY; - - if (!iov_iter_count(from)) - return 0; - - /* FIXME: this is for backwards compatibility with 2.4 */ - if (iocb->ki_flags & IOCB_APPEND) - iocb->ki_pos = i_size_read(inode); - - if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)) - return -EINVAL; - - count = iov_iter_count(from); - ret = generic_write_check_limits(file, iocb->ki_pos, &count); - if (ret) - return ret; - - iov_iter_truncate(from, count); - return iov_iter_count(from); -} -EXPORT_SYMBOL(generic_write_checks); - -/* - * Performs common checks before doing a file copy/clone - * from @file_in to @file_out. - */ -int generic_file_rw_checks(struct file *file_in, struct file *file_out) -{ - struct inode *inode_in = file_inode(file_in); - struct inode *inode_out = file_inode(file_out); - - /* Don't copy 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; - - if (!(file_in->f_mode & FMODE_READ) || - !(file_out->f_mode & FMODE_WRITE) || - (file_out->f_flags & O_APPEND)) - return -EBADF; - - return 0; -} - -/* - * Performs necessary checks before doing a file copy - * - * Can adjust amount of bytes to copy via @req_count argument. - * Returns appropriate error code that caller should return or - * zero in case the copy should be allowed. - */ -int generic_copy_file_checks(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - size_t *req_count, unsigned int flags) -{ - struct inode *inode_in = file_inode(file_in); - struct inode *inode_out = file_inode(file_out); - uint64_t count = *req_count; - loff_t size_in; - int ret; - - ret = generic_file_rw_checks(file_in, file_out); - if (ret) - return 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; - - /* Ensure offsets don't wrap. */ - if (pos_in + count < pos_in || pos_out + count < pos_out) - return -EOVERFLOW; - - /* Shorten the copy to EOF */ - size_in = i_size_read(inode_in); - if (pos_in >= size_in) - count = 0; - else - count = min(count, size_in - (uint64_t)pos_in); - - ret = generic_write_check_limits(file_out, pos_out, &count); - if (ret) - return ret; - - /* Don't allow overlapped copying within the same file. */ - if (inode_in == inode_out && - pos_out + count > pos_in && - pos_out < pos_in + count) - return -EINVAL; - - *req_count = count; - return 0; -} - int pagecache_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata) -- cgit