diff options
| -rw-r--r-- | mm/filemap.c | 84 |
1 files changed, 52 insertions, 32 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 47e6bfd45a91..84b7301e41a0 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2916,6 +2916,42 @@ 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. + */ +static int generic_access_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; + + 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; +} + +static int generic_write_check_limits(struct file *file, loff_t pos, + loff_t *count) +{ + 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); + } + + return generic_access_check_limits(file, pos, count); +} + +/* * Performs necessary checks before doing a write * * Can adjust writing position or amount of bytes to write. @@ -2926,8 +2962,8 @@ 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; - unsigned long limit = rlimit(RLIMIT_FSIZE); - loff_t pos; + loff_t count; + int ret; if (!iov_iter_count(from)) return 0; @@ -2936,40 +2972,15 @@ inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) if (iocb->ki_flags & IOCB_APPEND) iocb->ki_pos = i_size_read(inode); - pos = iocb->ki_pos; - if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)) return -EINVAL; - if (limit != RLIM_INFINITY) { - if (iocb->ki_pos >= limit) { - send_sig(SIGXFSZ, current, 0); - return -EFBIG; - } - iov_iter_truncate(from, limit - (unsigned long)pos); - } - - /* - * LFS rule - */ - if (unlikely(pos + iov_iter_count(from) > MAX_NON_LFS && - !(file->f_flags & O_LARGEFILE))) { - if (pos >= MAX_NON_LFS) - return -EFBIG; - iov_iter_truncate(from, MAX_NON_LFS - (unsigned long)pos); - } - - /* - * Are we about to exceed the fs block limit ? - * - * If we have written data it becomes a short write. If we have - * exceeded without writing data we send a signal and return EFBIG. - * Linus frestrict idea will clean these up nicely.. - */ - if (unlikely(pos >= inode->i_sb->s_maxbytes)) - return -EFBIG; + count = iov_iter_count(from); + ret = generic_write_check_limits(file, iocb->ki_pos, &count); + if (ret) + return ret; - iov_iter_truncate(from, inode->i_sb->s_maxbytes - pos); + iov_iter_truncate(from, count); return iov_iter_count(from); } EXPORT_SYMBOL(generic_write_checks); @@ -2991,6 +3002,7 @@ int generic_remap_checks(struct file *file_in, loff_t pos_in, 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)) @@ -3014,6 +3026,14 @@ int generic_remap_checks(struct file *file_in, loff_t pos_in, return -EINVAL; count = min(count, size_in - (uint64_t)pos_in); + ret = generic_access_check_limits(file_in, pos_in, &count); + if (ret) + return ret; + + 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. |