diff options
| -rw-r--r-- | fs/aio.c | 171 | ||||
| -rw-r--r-- | fs/read_write.c | 129 | ||||
| -rw-r--r-- | include/linux/aio.h | 4 | ||||
| -rw-r--r-- | include/linux/aio_abi.h | 2 | ||||
| -rw-r--r-- | include/linux/fs.h | 5 |
5 files changed, 203 insertions, 108 deletions
@@ -415,6 +415,7 @@ static struct kiocb fastcall *__aio_get_req(struct kioctx *ctx) req->ki_retry = NULL; req->ki_dtor = NULL; req->private = NULL; + req->ki_iovec = NULL; INIT_LIST_HEAD(&req->ki_run_list); /* Check if the completion queue has enough free space to @@ -460,6 +461,8 @@ static inline void really_put_req(struct kioctx *ctx, struct kiocb *req) if (req->ki_dtor) req->ki_dtor(req); + if (req->ki_iovec != &req->ki_inline_vec) + kfree(req->ki_iovec); kmem_cache_free(kiocb_cachep, req); ctx->reqs_active--; @@ -1301,69 +1304,63 @@ asmlinkage long sys_io_destroy(aio_context_t ctx) return -EINVAL; } -/* - * aio_p{read,write} are the default ki_retry methods for - * IO_CMD_P{READ,WRITE}. They maintains kiocb retry state around potentially - * multiple calls to f_op->aio_read(). They loop around partial progress - * instead of returning -EIOCBRETRY because they don't have the means to call - * kick_iocb(). - */ -static ssize_t aio_pread(struct kiocb *iocb) +static void aio_advance_iovec(struct kiocb *iocb, ssize_t ret) { - struct file *file = iocb->ki_filp; - struct address_space *mapping = file->f_mapping; - struct inode *inode = mapping->host; - ssize_t ret = 0; - - do { - iocb->ki_inline_vec.iov_base = iocb->ki_buf; - iocb->ki_inline_vec.iov_len = iocb->ki_left; - - ret = file->f_op->aio_read(iocb, &iocb->ki_inline_vec, - 1, iocb->ki_pos); - /* - * Can't just depend on iocb->ki_left to determine - * whether we are done. This may have been a short read. - */ - if (ret > 0) { - iocb->ki_buf += ret; - iocb->ki_left -= ret; + struct iovec *iov = &iocb->ki_iovec[iocb->ki_cur_seg]; + + BUG_ON(ret <= 0); + + while (iocb->ki_cur_seg < iocb->ki_nr_segs && ret > 0) { + ssize_t this = min((ssize_t)iov->iov_len, ret); + iov->iov_base += this; + iov->iov_len -= this; + iocb->ki_left -= this; + ret -= this; + if (iov->iov_len == 0) { + iocb->ki_cur_seg++; + iov++; } + } - /* - * For pipes and sockets we return once we have some data; for - * regular files we retry till we complete the entire read or - * find that we can't read any more data (e.g short reads). - */ - } while (ret > 0 && iocb->ki_left > 0 && - !S_ISFIFO(inode->i_mode) && !S_ISSOCK(inode->i_mode)); - - /* This means we must have transferred all that we could */ - /* No need to retry anymore */ - if ((ret == 0) || (iocb->ki_left == 0)) - ret = iocb->ki_nbytes - iocb->ki_left; - - return ret; + /* the caller should not have done more io than what fit in + * the remaining iovecs */ + BUG_ON(ret > 0 && iocb->ki_left == 0); } -/* see aio_pread() */ -static ssize_t aio_pwrite(struct kiocb *iocb) +static ssize_t aio_rw_vect_retry(struct kiocb *iocb) { struct file *file = iocb->ki_filp; + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; + ssize_t (*rw_op)(struct kiocb *, const struct iovec *, + unsigned long, loff_t); ssize_t ret = 0; + unsigned short opcode; + + if ((iocb->ki_opcode == IOCB_CMD_PREADV) || + (iocb->ki_opcode == IOCB_CMD_PREAD)) { + rw_op = file->f_op->aio_read; + opcode = IOCB_CMD_PREADV; + } else { + rw_op = file->f_op->aio_write; + opcode = IOCB_CMD_PWRITEV; + } do { - iocb->ki_inline_vec.iov_base = iocb->ki_buf; - iocb->ki_inline_vec.iov_len = iocb->ki_left; - - ret = file->f_op->aio_write(iocb, &iocb->ki_inline_vec, - 1, iocb->ki_pos); - if (ret > 0) { - iocb->ki_buf += ret; - iocb->ki_left -= ret; - } - } while (ret > 0 && iocb->ki_left > 0); + ret = rw_op(iocb, &iocb->ki_iovec[iocb->ki_cur_seg], + iocb->ki_nr_segs - iocb->ki_cur_seg, + iocb->ki_pos); + if (ret > 0) + aio_advance_iovec(iocb, ret); + + /* retry all partial writes. retry partial reads as long as its a + * regular file. */ + } while (ret > 0 && iocb->ki_left > 0 && + (opcode == IOCB_CMD_PWRITEV || + (!S_ISFIFO(inode->i_mode) && !S_ISSOCK(inode->i_mode)))); + /* This means we must have transferred all that we could */ + /* No need to retry anymore */ if ((ret == 0) || (iocb->ki_left == 0)) ret = iocb->ki_nbytes - iocb->ki_left; @@ -1390,6 +1387,38 @@ static ssize_t aio_fsync(struct kiocb *iocb) return ret; } +static ssize_t aio_setup_vectored_rw(int type, struct kiocb *kiocb) +{ + ssize_t ret; + + ret = rw_copy_check_uvector(type, (struct iovec __user *)kiocb->ki_buf, + kiocb->ki_nbytes, 1, + &kiocb->ki_inline_vec, &kiocb->ki_iovec); + if (ret < 0) + goto out; + + kiocb->ki_nr_segs = kiocb->ki_nbytes; + kiocb->ki_cur_seg = 0; + /* ki_nbytes/left now reflect bytes instead of segs */ + kiocb->ki_nbytes = ret; + kiocb->ki_left = ret; + + ret = 0; +out: + return ret; +} + +static ssize_t aio_setup_single_vector(struct kiocb *kiocb) +{ + kiocb->ki_iovec = &kiocb->ki_inline_vec; + kiocb->ki_iovec->iov_base = kiocb->ki_buf; + kiocb->ki_iovec->iov_len = kiocb->ki_left; + kiocb->ki_nr_segs = 1; + kiocb->ki_cur_seg = 0; + kiocb->ki_nbytes = kiocb->ki_left; + return 0; +} + /* * aio_setup_iocb: * Performs the initial checks and aio retry method @@ -1412,9 +1441,12 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb) ret = security_file_permission(file, MAY_READ); if (unlikely(ret)) break; + ret = aio_setup_single_vector(kiocb); + if (ret) + break; ret = -EINVAL; if (file->f_op->aio_read) - kiocb->ki_retry = aio_pread; + kiocb->ki_retry = aio_rw_vect_retry; break; case IOCB_CMD_PWRITE: ret = -EBADF; @@ -1427,9 +1459,40 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb) ret = security_file_permission(file, MAY_WRITE); if (unlikely(ret)) break; + ret = aio_setup_single_vector(kiocb); + if (ret) + break; + ret = -EINVAL; + if (file->f_op->aio_write) + kiocb->ki_retry = aio_rw_vect_retry; + break; + case IOCB_CMD_PREADV: + ret = -EBADF; + if (unlikely(!(file->f_mode & FMODE_READ))) + break; + ret = security_file_permission(file, MAY_READ); + if (unlikely(ret)) + break; + ret = aio_setup_vectored_rw(READ, kiocb); + if (ret) + break; + ret = -EINVAL; + if (file->f_op->aio_read) + kiocb->ki_retry = aio_rw_vect_retry; + break; + case IOCB_CMD_PWRITEV: + ret = -EBADF; + if (unlikely(!(file->f_mode & FMODE_WRITE))) + break; + ret = security_file_permission(file, MAY_WRITE); + if (unlikely(ret)) + break; + ret = aio_setup_vectored_rw(WRITE, kiocb); + if (ret) + break; ret = -EINVAL; if (file->f_op->aio_write) - kiocb->ki_retry = aio_pwrite; + kiocb->ki_retry = aio_rw_vect_retry; break; case IOCB_CMD_FDSYNC: ret = -EINVAL; diff --git a/fs/read_write.c b/fs/read_write.c index 4ed839b..f792000 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -511,6 +511,74 @@ ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, /* A write operation does a read from user space and vice versa */ #define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ) +ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, + unsigned long nr_segs, unsigned long fast_segs, + struct iovec *fast_pointer, + struct iovec **ret_pointer) + { + unsigned long seg; + ssize_t ret; + struct iovec *iov = fast_pointer; + + /* + * SuS says "The readv() function *may* fail if the iovcnt argument + * was less than or equal to 0, or greater than {IOV_MAX}. Linux has + * traditionally returned zero for zero segments, so... + */ + if (nr_segs == 0) { + ret = 0; + goto out; + } + + /* + * First get the "struct iovec" from user memory and + * verify all the pointers + */ + if (nr_segs > UIO_MAXIOV) { + ret = -EINVAL; + goto out; + } + if (nr_segs > fast_segs) { + iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); + if (iov == NULL) { + ret = -ENOMEM; + goto out; + } + } + if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) { + ret = -EFAULT; + goto out; + } + + /* + * According to the Single Unix Specification we should return EINVAL + * if an element length is < 0 when cast to ssize_t or if the + * total length would overflow the ssize_t return value of the + * system call. + */ + ret = 0; + for (seg = 0; seg < nr_segs; seg++) { + void __user *buf = iov[seg].iov_base; + ssize_t len = (ssize_t)iov[seg].iov_len; + + /* see if we we're about to use an invalid len or if + * it's about to overflow ssize_t */ + if (len < 0 || (ret + len < ret)) { + ret = -EINVAL; + goto out; + } + if (unlikely(!access_ok(vrfy_dir(type), buf, len))) { + ret = -EFAULT; + goto out; + } + + ret += len; + } +out: + *ret_pointer = iov; + return ret; +} + static ssize_t do_readv_writev(int type, struct file *file, const struct iovec __user * uvector, unsigned long nr_segs, loff_t *pos) @@ -519,64 +587,20 @@ static ssize_t do_readv_writev(int type, struct file *file, struct iovec iovstack[UIO_FASTIOV]; struct iovec *iov = iovstack; ssize_t ret; - int seg; io_fn_t fn; iov_fn_t fnv; - /* - * SuS says "The readv() function *may* fail if the iovcnt argument - * was less than or equal to 0, or greater than {IOV_MAX}. Linux has - * traditionally returned zero for zero segments, so... - */ - ret = 0; - if (nr_segs == 0) - goto out; - - /* - * First get the "struct iovec" from user memory and - * verify all the pointers - */ - ret = -EINVAL; - if (nr_segs > UIO_MAXIOV) - goto out; - if (!file->f_op) - goto out; - if (nr_segs > UIO_FASTIOV) { - ret = -ENOMEM; - iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); - if (!iov) - goto out; - } - ret = -EFAULT; - if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) + if (!file->f_op) { + ret = -EINVAL; goto out; + } - /* - * Single unix specification: - * We should -EINVAL if an element length is not >= 0 and fitting an - * ssize_t. The total length is fitting an ssize_t - * - * Be careful here because iov_len is a size_t not an ssize_t - */ - tot_len = 0; - ret = -EINVAL; - for (seg = 0; seg < nr_segs; seg++) { - void __user *buf = iov[seg].iov_base; - ssize_t len = (ssize_t)iov[seg].iov_len; - - if (len < 0) /* size_t not fitting an ssize_t .. */ - goto out; - if (unlikely(!access_ok(vrfy_dir(type), buf, len))) - goto Efault; - tot_len += len; - if ((ssize_t)tot_len < 0) /* maths overflow on the ssize_t */ - goto out; - } - if (tot_len == 0) { - ret = 0; + ret = rw_copy_check_uvector(type, uvector, nr_segs, + ARRAY_SIZE(iovstack), iovstack, &iov); + if (ret <= 0) goto out; - } + tot_len = ret; ret = rw_verify_area(type, file, pos, tot_len); if (ret < 0) goto out; @@ -609,9 +633,6 @@ out: fsnotify_modify(file->f_dentry); } return ret; -Efault: - ret = -EFAULT; - goto out; } ssize_t vfs_readv(struct file *file, const struct iovec __user *vec, diff --git a/include/linux/aio.h b/include/linux/aio.h index 58349e5..5722568 100644 --- a/include/linux/aio.h +++ b/include/linux/aio.h @@ -7,6 +7,7 @@ #include <linux/uio.h> #include <asm/atomic.h> +#include <linux/uio.h> #define AIO_MAXSEGS 4 #define AIO_KIOGRP_NR_ATOMIC 8 @@ -114,6 +115,9 @@ struct kiocb { long ki_kicked; /* just for testing */ long ki_queued; /* just for testing */ struct iovec ki_inline_vec; /* inline vector */ + struct iovec *ki_iovec; + unsigned long ki_nr_segs; + unsigned long ki_cur_seg; struct list_head ki_list; /* the aio core uses this * for cancellation */ diff --git a/include/linux/aio_abi.h b/include/linux/aio_abi.h index 30fdcc8..3466b1d 100644 --- a/include/linux/aio_abi.h +++ b/include/linux/aio_abi.h @@ -41,6 +41,8 @@ enum { * IOCB_CMD_POLL = 5, */ IOCB_CMD_NOOP = 6, + IOCB_CMD_PREADV = 7, + IOCB_CMD_PWRITEV = 8, }; /* read() from /dev/aio returns these structures. */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 011129f..4bb7087 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1150,6 +1150,11 @@ struct inode_operations { struct seq_file; +ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, + unsigned long nr_segs, unsigned long fast_segs, + struct iovec *fast_pointer, + struct iovec **ret_pointer); + extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *); extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *); extern ssize_t vfs_readv(struct file *, const struct iovec __user *, |
