From 804c83c37607efe415774c3a170ad72a789e5992 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 28 Aug 2007 13:59:03 +1000 Subject: [PATCH] [XFS] stop using uio in the readlink code Simplify the readlink code to get rid of the last user of uio. SGI-PV: 968563 SGI-Modid: xfs-linux-melb:xfs-kern:29479a Signed-off-by: Christoph Hellwig Signed-off-by: David Chinner Signed-off-by: Tim Shimmin --- fs/xfs/linux-2.6/xfs_ioctl.c | 63 +++++++++++++++------ fs/xfs/linux-2.6/xfs_iops.c | 50 +++++----------- fs/xfs/linux-2.6/xfs_vnode.h | 8 +-- fs/xfs/xfs_vnodeops.c | 132 ++++++++++++++++++++----------------------- 4 files changed, 121 insertions(+), 132 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c index 5917808..47cfde6 100644 --- a/fs/xfs/linux-2.6/xfs_ioctl.c +++ b/fs/xfs/linux-2.6/xfs_ioctl.c @@ -349,19 +349,44 @@ xfs_open_by_handle( return new_fd; } +/* + * This is a copy from fs/namei.c:vfs_readlink(), except for removing it's + * unused first argument. + */ +STATIC int +do_readlink( + char __user *buffer, + int buflen, + const char *link) +{ + int len; + + len = PTR_ERR(link); + if (IS_ERR(link)) + goto out; + + len = strlen(link); + if (len > (unsigned) buflen) + len = buflen; + if (copy_to_user(buffer, link, len)) + len = -EFAULT; + out: + return len; +} + + STATIC int xfs_readlink_by_handle( xfs_mount_t *mp, void __user *arg, struct inode *parinode) { - int error; - struct iovec aiov; - struct uio auio; struct inode *inode; xfs_fsop_handlereq_t hreq; bhv_vnode_t *vp; __u32 olen; + void *link; + int error; if (!capable(CAP_SYS_ADMIN)) return -XFS_ERROR(EPERM); @@ -374,29 +399,31 @@ xfs_readlink_by_handle( /* Restrict this handle operation to symlinks only. */ if (!S_ISLNK(inode->i_mode)) { - VN_RELE(vp); - return -XFS_ERROR(EINVAL); + error = -XFS_ERROR(EINVAL); + goto out_iput; } if (copy_from_user(&olen, hreq.ohandlen, sizeof(__u32))) { - VN_RELE(vp); - return -XFS_ERROR(EFAULT); + error = -XFS_ERROR(EFAULT); + goto out_iput; } - aiov.iov_len = olen; - aiov.iov_base = hreq.ohandle; - auio.uio_iov = (struct kvec *)&aiov; - auio.uio_iovcnt = 1; - auio.uio_offset = 0; - auio.uio_segflg = UIO_USERSPACE; - auio.uio_resid = olen; + link = kmalloc(MAXPATHLEN+1, GFP_KERNEL); + if (!link) + goto out_iput; - error = bhv_vop_readlink(vp, &auio, IO_INVIS, NULL); - VN_RELE(vp); + error = -bhv_vop_readlink(vp, link); if (error) - return -error; + goto out_kfree; + error = do_readlink(hreq.ohandle, olen, link); + if (error) + goto out_kfree; - return (olen - auio.uio_resid); + out_kfree: + kfree(link); + out_iput: + iput(inode); + return error; } STATIC int diff --git a/fs/xfs/linux-2.6/xfs_iops.c b/fs/xfs/linux-2.6/xfs_iops.c index 0b5fa12..ef941f9 100644 --- a/fs/xfs/linux-2.6/xfs_iops.c +++ b/fs/xfs/linux-2.6/xfs_iops.c @@ -542,50 +542,26 @@ xfs_vn_follow_link( struct dentry *dentry, struct nameidata *nd) { - bhv_vnode_t *vp; - uio_t *uio; - iovec_t iov; - int error; + bhv_vnode_t *vp = vn_from_inode(dentry->d_inode); char *link; - - ASSERT(dentry); - ASSERT(nd); + int error = -ENOMEM; link = kmalloc(MAXPATHLEN+1, GFP_KERNEL); - if (!link) { - nd_set_link(nd, ERR_PTR(-ENOMEM)); - return NULL; - } - - uio = kmalloc(sizeof(uio_t), GFP_KERNEL); - if (!uio) { - kfree(link); - nd_set_link(nd, ERR_PTR(-ENOMEM)); - return NULL; - } - - vp = vn_from_inode(dentry->d_inode); + if (!link) + goto out_err; - iov.iov_base = link; - iov.iov_len = MAXPATHLEN; - - uio->uio_iov = &iov; - uio->uio_offset = 0; - uio->uio_segflg = UIO_SYSSPACE; - uio->uio_resid = MAXPATHLEN; - uio->uio_iovcnt = 1; - - error = bhv_vop_readlink(vp, uio, 0, NULL); - if (unlikely(error)) { - kfree(link); - link = ERR_PTR(-error); - } else { - link[MAXPATHLEN - uio->uio_resid] = '\0'; - } - kfree(uio); + error = -bhv_vop_readlink(vp, link); + if (unlikely(error)) + goto out_kfree; nd_set_link(nd, link); return NULL; + + out_kfree: + kfree(link); + out_err: + nd_set_link(nd, ERR_PTR(error)); + return NULL; } STATIC void diff --git a/fs/xfs/linux-2.6/xfs_vnode.h b/fs/xfs/linux-2.6/xfs_vnode.h index 146c84b..bddbdb9 100644 --- a/fs/xfs/linux-2.6/xfs_vnode.h +++ b/fs/xfs/linux-2.6/xfs_vnode.h @@ -18,7 +18,6 @@ #ifndef __XFS_VNODE_H__ #define __XFS_VNODE_H__ -struct uio; struct file; struct bhv_vfs; struct bhv_vattr; @@ -165,8 +164,7 @@ typedef int (*vop_readdir_t)(bhv_desc_t *, void *dirent, size_t bufsize, xfs_off_t *offset, filldir_t filldir); typedef int (*vop_symlink_t)(bhv_desc_t *, bhv_vname_t *, struct bhv_vattr*, char *, bhv_vnode_t **, struct cred *); -typedef int (*vop_readlink_t)(bhv_desc_t *, struct uio *, int, - struct cred *); +typedef int (*vop_readlink_t)(bhv_desc_t *, char *); typedef int (*vop_fsync_t)(bhv_desc_t *, int, struct cred *, xfs_off_t, xfs_off_t); typedef int (*vop_inactive_t)(bhv_desc_t *, struct cred *); @@ -271,8 +269,8 @@ typedef struct bhv_vnodeops { VOP(vop_readdir, vp)(VNHEAD(vp),dirent,bufsize,offset,filldir) #define bhv_vop_symlink(dvp,d,vap,tnm,vpp,cr) \ VOP(vop_symlink, dvp)(VNHEAD(dvp),d,vap,tnm,vpp,cr) -#define bhv_vop_readlink(vp,uiop,fl,cr) \ - VOP(vop_readlink, vp)(VNHEAD(vp),uiop,fl,cr) +#define bhv_vop_readlink(vp,link) \ + VOP(vop_readlink, vp)(VNHEAD(vp), link) #define bhv_vop_fsync(vp,f,cr,b,e) VOP(vop_fsync, vp)(VNHEAD(vp),f,cr,b,e) #define bhv_vop_inactive(vp,cr) VOP(vop_inactive, vp)(VNHEAD(vp),cr) #define bhv_vop_release(vp) VOP(vop_release, vp)(VNHEAD(vp)) diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c index 36318c6..bde4a1a 100644 --- a/fs/xfs/xfs_vnodeops.c +++ b/fs/xfs/xfs_vnodeops.c @@ -951,6 +951,53 @@ xfs_access( */ #define SYMLINK_MAPS 2 +STATIC int +xfs_readlink_bmap( + xfs_inode_t *ip, + char *link) +{ + xfs_mount_t *mp = ip->i_mount; + int pathlen = ip->i_d.di_size; + int nmaps = SYMLINK_MAPS; + xfs_bmbt_irec_t mval[SYMLINK_MAPS]; + xfs_daddr_t d; + int byte_cnt; + int n; + xfs_buf_t *bp; + int error = 0; + + error = xfs_bmapi(NULL, ip, 0, XFS_B_TO_FSB(mp, pathlen), 0, NULL, 0, + mval, &nmaps, NULL, NULL); + if (error) + goto out; + + for (n = 0; n < nmaps; n++) { + d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock); + byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount); + + bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0); + error = XFS_BUF_GETERROR(bp); + if (error) { + xfs_ioerror_alert("xfs_readlink", + ip->i_mount, bp, XFS_BUF_ADDR(bp)); + xfs_buf_relse(bp); + goto out; + } + if (pathlen < byte_cnt) + byte_cnt = pathlen; + pathlen -= byte_cnt; + + memcpy(link, XFS_BUF_PTR(bp), byte_cnt); + xfs_buf_relse(bp); + } + + link[ip->i_d.di_size] = '\0'; + error = 0; + + out: + return error; +} + /* * xfs_readlink * @@ -958,29 +1005,14 @@ xfs_access( STATIC int xfs_readlink( bhv_desc_t *bdp, - uio_t *uiop, - int ioflags, - cred_t *credp) + char *link) { - xfs_inode_t *ip; - int count; - xfs_off_t offset; + xfs_inode_t *ip = XFS_BHVTOI(bdp); + xfs_mount_t *mp = ip->i_mount; int pathlen; - bhv_vnode_t *vp; int error = 0; - xfs_mount_t *mp; - int nmaps; - xfs_bmbt_irec_t mval[SYMLINK_MAPS]; - xfs_daddr_t d; - int byte_cnt; - int n; - xfs_buf_t *bp; - vp = BHV_TO_VNODE(bdp); - vn_trace_entry(vp, __FUNCTION__, (inst_t *)__return_address); - - ip = XFS_BHVTOI(bdp); - mp = ip->i_mount; + vn_trace_entry(XFS_ITOV(ip), __FUNCTION__, (inst_t *)__return_address); if (XFS_FORCED_SHUTDOWN(mp)) return XFS_ERROR(EIO); @@ -988,68 +1020,24 @@ xfs_readlink( xfs_ilock(ip, XFS_ILOCK_SHARED); ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFLNK); + ASSERT(ip->i_d.di_size <= MAXPATHLEN); - offset = uiop->uio_offset; - count = uiop->uio_resid; - - if (offset < 0) { - error = XFS_ERROR(EINVAL); - goto error_return; - } - if (count <= 0) { - error = 0; - goto error_return; - } - - /* - * See if the symlink is stored inline. - */ - pathlen = (int)ip->i_d.di_size; + pathlen = ip->i_d.di_size; + if (!pathlen) + goto out; if (ip->i_df.if_flags & XFS_IFINLINE) { - error = xfs_uio_read(ip->i_df.if_u1.if_data, pathlen, uiop); - } - else { - /* - * Symlink not inline. Call bmap to get it in. - */ - nmaps = SYMLINK_MAPS; - - error = xfs_bmapi(NULL, ip, 0, XFS_B_TO_FSB(mp, pathlen), - 0, NULL, 0, mval, &nmaps, NULL, NULL); - - if (error) { - goto error_return; - } - - for (n = 0; n < nmaps; n++) { - d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock); - byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount); - bp = xfs_buf_read(mp->m_ddev_targp, d, - BTOBB(byte_cnt), 0); - error = XFS_BUF_GETERROR(bp); - if (error) { - xfs_ioerror_alert("xfs_readlink", - ip->i_mount, bp, XFS_BUF_ADDR(bp)); - xfs_buf_relse(bp); - goto error_return; - } - if (pathlen < byte_cnt) - byte_cnt = pathlen; - pathlen -= byte_cnt; - - error = xfs_uio_read(XFS_BUF_PTR(bp), byte_cnt, uiop); - xfs_buf_relse (bp); - } - + memcpy(link, ip->i_df.if_u1.if_data, pathlen); + link[pathlen] = '\0'; + } else { + error = xfs_readlink_bmap(ip, link); } -error_return: + out: xfs_iunlock(ip, XFS_ILOCK_SHARED); return error; } - /* * xfs_fsync * -- 2.7.4