diff options
| -rw-r--r-- | fs/ntfs/file.c | 21 | ||||
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_lrw.c | 22 | ||||
| -rw-r--r-- | include/linux/fs.h | 2 | ||||
| -rw-r--r-- | mm/filemap.c | 82 |
4 files changed, 53 insertions, 74 deletions
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c index dbbac5593106..621de369e6f8 100644 --- a/fs/ntfs/file.c +++ b/fs/ntfs/file.c @@ -2129,28 +2129,13 @@ static ssize_t ntfs_file_aio_write_nolock(struct kiocb *iocb, struct address_space *mapping = file->f_mapping; struct inode *inode = mapping->host; loff_t pos; - unsigned long seg; size_t count; /* after file limit checks */ ssize_t written, err; count = 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. - */ - count += iv->iov_len; - if (unlikely((ssize_t)(count|iv->iov_len) < 0)) - return -EINVAL; - if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len)) - continue; - if (!seg) - return -EFAULT; - nr_segs = seg; - count -= iv->iov_len; /* This segment is no good */ - break; - } + err = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ); + if (err) + return err; pos = *ppos; vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); /* We can write back this queue in page reclaim. */ diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c index ff8d64eba9f8..558076dd0752 100644 --- a/fs/xfs/linux-2.6/xfs_lrw.c +++ b/fs/xfs/linux-2.6/xfs_lrw.c @@ -639,7 +639,6 @@ xfs_write( xfs_fsize_t isize, new_size; xfs_iocore_t *io; bhv_vnode_t *vp; - unsigned long seg; int iolock; int eventsent = 0; bhv_vrwlock_t locktype; @@ -652,24 +651,9 @@ xfs_write( vp = BHV_TO_VNODE(bdp); xip = XFS_BHVTOI(bdp); - for (seg = 0; seg < segs; seg++) { - const struct iovec *iv = &iovp[seg]; - - /* - * If any segment has a negative length, or the cumulative - * length ever wraps negative then return -EINVAL. - */ - ocount += iv->iov_len; - if (unlikely((ssize_t)(ocount|iv->iov_len) < 0)) - return -EINVAL; - if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len)) - continue; - if (seg == 0) - return -EFAULT; - segs = seg; - ocount -= iv->iov_len; /* This segment is no good */ - break; - } + error = generic_segment_checks(iovp, &segs, &ocount, VERIFY_READ); + if (error) + return error; count = ocount; pos = *offset; diff --git a/include/linux/fs.h b/include/linux/fs.h index bc6d27cecaac..020a8426e10a 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1735,6 +1735,8 @@ extern ssize_t generic_file_sendfile(struct file *, loff_t *, size_t, read_actor extern void do_generic_mapping_read(struct address_space *mapping, struct file_ra_state *, struct file *, loff_t *, read_descriptor_t *, read_actor_t); +extern int generic_segment_checks(const struct iovec *iov, + unsigned long *nr_segs, size_t *count, int access_flags); /* fs/splice.c */ extern ssize_t generic_file_splice_read(struct file *, loff_t *, diff --git a/mm/filemap.c b/mm/filemap.c index 5631d6b2a62d..3e49fe13d6ac 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1110,6 +1110,45 @@ success: return size; } +/* + * 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 * @iocb: kernel I/O control block @@ -1131,24 +1170,9 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov, loff_t *ppos = &iocb->ki_pos; count = 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. - */ - count += iv->iov_len; - if (unlikely((ssize_t)(count|iv->iov_len) < 0)) - return -EINVAL; - if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len)) - continue; - if (seg == 0) - return -EFAULT; - nr_segs = seg; - count -= iv->iov_len; /* This segment is no good */ - break; - } + retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE); + if (retval) + return retval; /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */ if (filp->f_flags & O_DIRECT) { @@ -2218,30 +2242,14 @@ __generic_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov, size_t ocount; /* original count */ size_t count; /* after file limit checks */ struct inode *inode = mapping->host; - unsigned long seg; loff_t pos; ssize_t written; ssize_t err; ocount = 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. - */ - ocount += iv->iov_len; - if (unlikely((ssize_t)(ocount|iv->iov_len) < 0)) - return -EINVAL; - if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len)) - continue; - if (seg == 0) - return -EFAULT; - nr_segs = seg; - ocount -= iv->iov_len; /* This segment is no good */ - break; - } + err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ); + if (err) + return err; count = ocount; pos = *ppos; |