X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=mm%2Ffilemap.c;h=dafb06f70a09dd97b1fa690969a638f596714091;hb=1a98c69af1ecd97bfd1f4e4539924a9192434e36;hp=7fadf1c6283844f07727a68fe12ce5f554f2fff6;hpb=e413a19a8ef49ae3b76310bb569dabe66b22f5a3;p=cascardo%2Flinux.git diff --git a/mm/filemap.c b/mm/filemap.c index 7fadf1c62838..dafb06f70a09 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1665,96 +1665,42 @@ out: return written ? written : error; } -/* - * Performs necessary checks before doing a write - * @iov: io vector request - * @nr_segs: number of segments in the iovec - * @count: number of bytes to write - * @access_flags: type of access: %VERIFY_READ or %VERIFY_WRITE - * - * Adjust number of segments and amount of bytes to write (nr_segs should be - * properly initialized first). Returns appropriate error code that caller - * should return or zero in case that write should be allowed. - */ -int generic_segment_checks(const struct iovec *iov, - unsigned long *nr_segs, size_t *count, int access_flags) -{ - unsigned long seg; - size_t cnt = 0; - for (seg = 0; seg < *nr_segs; seg++) { - const struct iovec *iv = &iov[seg]; - - /* - * If any segment has a negative length, or the cumulative - * length ever wraps negative then return -EINVAL. - */ - cnt += iv->iov_len; - if (unlikely((ssize_t)(cnt|iv->iov_len) < 0)) - return -EINVAL; - if (access_ok(access_flags, iv->iov_base, iv->iov_len)) - continue; - if (seg == 0) - return -EFAULT; - *nr_segs = seg; - cnt -= iv->iov_len; /* This segment is no good */ - break; - } - *count = cnt; - return 0; -} -EXPORT_SYMBOL(generic_segment_checks); - /** - * generic_file_aio_read - generic filesystem read routine + * generic_file_read_iter - generic filesystem read routine * @iocb: kernel I/O control block - * @iov: io vector request - * @nr_segs: number of segments in the iovec - * @pos: current file position + * @iter: destination for the data read * - * This is the "read()" routine for all filesystems + * This is the "read_iter()" routine for all filesystems * that can use the page cache directly. */ ssize_t -generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov, - unsigned long nr_segs, loff_t pos) +generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) { - struct file *filp = iocb->ki_filp; - ssize_t retval; - size_t count; + struct file *file = iocb->ki_filp; + ssize_t retval = 0; loff_t *ppos = &iocb->ki_pos; - struct iov_iter i; - - count = 0; - retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE); - if (retval) - return retval; - iov_iter_init(&i, iov, nr_segs, count, 0); + loff_t pos = *ppos; /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */ - if (filp->f_flags & O_DIRECT) { + if (file->f_flags & O_DIRECT) { + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; + size_t count = iov_iter_count(iter); loff_t size; - struct address_space *mapping; - struct inode *inode; - mapping = filp->f_mapping; - inode = mapping->host; if (!count) goto out; /* skip atime */ size = i_size_read(inode); retval = filemap_write_and_wait_range(mapping, pos, - pos + iov_length(iov, nr_segs) - 1); + pos + count - 1); if (!retval) { - retval = mapping->a_ops->direct_IO(READ, iocb, - iov, pos, nr_segs); + struct iov_iter data = *iter; + retval = mapping->a_ops->direct_IO(READ, iocb, &data, pos); } + if (retval > 0) { *ppos = pos + retval; - count -= retval; - /* - * If we did a short DIO read we need to skip the - * section of the iov that we've already read data into. - */ - iov_iter_advance(&i, retval); + iov_iter_advance(iter, retval); } /* @@ -1765,17 +1711,17 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov, * and return. Otherwise fallthrough to buffered io for * the rest of the read. */ - if (retval < 0 || !count || *ppos >= size) { - file_accessed(filp); + if (retval < 0 || !iov_iter_count(iter) || *ppos >= size) { + file_accessed(file); goto out; } } - retval = do_generic_file_read(filp, ppos, &i, retval); + retval = do_generic_file_read(file, ppos, iter, retval); out: return retval; } -EXPORT_SYMBOL(generic_file_aio_read); +EXPORT_SYMBOL(generic_file_read_iter); #ifdef CONFIG_MMU /** @@ -2386,9 +2332,7 @@ int pagecache_write_end(struct file *file, struct address_space *mapping, EXPORT_SYMBOL(pagecache_write_end); ssize_t -generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov, - unsigned long *nr_segs, loff_t pos, - size_t count, size_t ocount) +generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos) { struct file *file = iocb->ki_filp; struct address_space *mapping = file->f_mapping; @@ -2396,11 +2340,9 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov, ssize_t written; size_t write_len; pgoff_t end; + struct iov_iter data; - if (count != ocount) - *nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count); - - write_len = iov_length(iov, *nr_segs); + write_len = iov_iter_count(from); end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT; written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1); @@ -2427,7 +2369,8 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov, } } - written = mapping->a_ops->direct_IO(WRITE, iocb, iov, pos, *nr_segs); + data = *from; + written = mapping->a_ops->direct_IO(WRITE, iocb, &data, pos); /* * Finally, try again to invalidate clean pages which might have been @@ -2444,6 +2387,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov, if (written > 0) { pos += written; + iov_iter_advance(from, written); if (pos > i_size_read(inode) && !S_ISBLK(inode->i_mode)) { i_size_write(inode, pos); mark_inode_dirty(inode); @@ -2568,10 +2512,9 @@ again: EXPORT_SYMBOL(generic_perform_write); /** - * __generic_file_aio_write - write data to a file + * __generic_file_write_iter - write data to a file * @iocb: IO state structure (file, offset, etc.) - * @iov: vector with data to write - * @nr_segs: number of segments in the vector + * @from: iov_iter with data to write * * This function does all the work needed for actually writing data to a * file. It does all basic checks, removes SUID from the file, updates @@ -2585,26 +2528,16 @@ EXPORT_SYMBOL(generic_perform_write); * A caller has to handle it. This is mainly due to the fact that we want to * avoid syncing under i_mutex. */ -ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, - unsigned long nr_segs) +ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from) { struct file *file = iocb->ki_filp; struct address_space * mapping = file->f_mapping; - size_t ocount; /* original count */ - size_t count; /* after file limit checks */ struct inode *inode = mapping->host; loff_t pos = iocb->ki_pos; ssize_t written = 0; ssize_t err; ssize_t status; - struct iov_iter from; - - ocount = 0; - err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ); - if (err) - return err; - - count = ocount; + size_t count = iov_iter_count(from); /* We can write back this queue in page reclaim */ current->backing_dev_info = mapping->backing_dev_info; @@ -2615,6 +2548,8 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, if (count == 0) goto out; + iov_iter_truncate(from, count); + err = file_remove_suid(file); if (err) goto out; @@ -2623,17 +2558,13 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, if (err) goto out; - iov_iter_init(&from, iov, nr_segs, count, 0); - /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */ if (unlikely(file->f_flags & O_DIRECT)) { loff_t endbyte; - written = generic_file_direct_write(iocb, iov, &from.nr_segs, pos, - count, ocount); + written = generic_file_direct_write(iocb, from, pos); if (written < 0 || written == count) goto out; - iov_iter_advance(&from, written); /* * direct-io write to a hole: fall through to buffered I/O @@ -2642,7 +2573,7 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, pos += written; count -= written; - status = generic_perform_write(file, &from, pos); + status = generic_perform_write(file, from, pos); /* * If generic_perform_write() returned a synchronous error * then we want to return the number of bytes which were @@ -2674,7 +2605,7 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, */ } } else { - written = generic_perform_write(file, &from, pos); + written = generic_perform_write(file, from, pos); if (likely(written >= 0)) iocb->ki_pos = pos + written; } @@ -2682,30 +2613,25 @@ out: current->backing_dev_info = NULL; return written ? written : err; } -EXPORT_SYMBOL(__generic_file_aio_write); +EXPORT_SYMBOL(__generic_file_write_iter); /** - * generic_file_aio_write - write data to a file + * generic_file_write_iter - write data to a file * @iocb: IO state structure - * @iov: vector with data to write - * @nr_segs: number of segments in the vector - * @pos: position in file where to write + * @from: iov_iter with data to write * - * This is a wrapper around __generic_file_aio_write() to be used by most + * This is a wrapper around __generic_file_write_iter() to be used by most * filesystems. It takes care of syncing the file in case of O_SYNC file * and acquires i_mutex as needed. */ -ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, - unsigned long nr_segs, loff_t pos) +ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; ssize_t ret; - BUG_ON(iocb->ki_pos != pos); - mutex_lock(&inode->i_mutex); - ret = __generic_file_aio_write(iocb, iov, nr_segs); + ret = __generic_file_write_iter(iocb, from); mutex_unlock(&inode->i_mutex); if (ret > 0) { @@ -2717,7 +2643,7 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, } return ret; } -EXPORT_SYMBOL(generic_file_aio_write); +EXPORT_SYMBOL(generic_file_write_iter); /** * try_to_release_page() - release old fs-specific metadata on a page