From c99c2171fc61476afac0dfb59fb2c447a01fb1e0 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 1 Nov 2018 23:07:27 +0000 Subject: afs: Use fs_context to pass parameters over automount Alter the AFS automounting code to create and modify an fs_context struct when parameterising a new mount triggered by an AFS mountpoint rather than constructing device name and option strings. Also remove the cell=, vol= and rwpath options as they are then redundant. The reason they existed is because the 'device name' may be derived literally from a mountpoint object in the filesystem, so default cell and parent-type information needed to be passed in by some other method from the automount routines. The vol= option didn't end up being used. Signed-off-by: David Howells cc: Eric W. Biederman Signed-off-by: Al Viro --- fs/afs/mntpt.c | 148 ++++++++++++++++++++++++++++++--------------------------- 1 file changed, 77 insertions(+), 71 deletions(-) (limited to 'fs/afs/mntpt.c') diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c index b3f41d27590b..eecd8b699186 100644 --- a/fs/afs/mntpt.c +++ b/fs/afs/mntpt.c @@ -48,6 +48,8 @@ static DECLARE_DELAYED_WORK(afs_mntpt_expiry_timer, afs_mntpt_expiry_timed_out); static unsigned long afs_mntpt_expiry_timeout = 10 * 60; +static const char afs_root_volume[] = "root.cell"; + /* * no valid lookup procedure on this sort of dir */ @@ -69,108 +71,112 @@ static int afs_mntpt_open(struct inode *inode, struct file *file) } /* - * create a vfsmount to be automounted + * Set the parameters for the proposed superblock. */ -static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt) +static int afs_mntpt_set_params(struct fs_context *fc, struct dentry *mntpt) { - struct afs_super_info *as; - struct vfsmount *mnt; - struct afs_vnode *vnode; - struct page *page; - char *devname, *options; - bool rwpath = false; + struct afs_fs_context *ctx = fc->fs_private; + struct afs_super_info *src_as = AFS_FS_S(mntpt->d_sb); + struct afs_vnode *vnode = AFS_FS_I(d_inode(mntpt)); + struct afs_cell *cell; + const char *p; int ret; - _enter("{%pd}", mntpt); - - BUG_ON(!d_inode(mntpt)); - - ret = -ENOMEM; - devname = (char *) get_zeroed_page(GFP_KERNEL); - if (!devname) - goto error_no_devname; - - options = (char *) get_zeroed_page(GFP_KERNEL); - if (!options) - goto error_no_options; + if (fc->net_ns != src_as->net_ns) { + put_net(fc->net_ns); + fc->net_ns = get_net(src_as->net_ns); + } - vnode = AFS_FS_I(d_inode(mntpt)); + if (src_as->volume && src_as->volume->type == AFSVL_RWVOL) { + ctx->type = AFSVL_RWVOL; + ctx->force = true; + } + if (ctx->cell) { + afs_put_cell(ctx->net, ctx->cell); + ctx->cell = NULL; + } if (test_bit(AFS_VNODE_PSEUDODIR, &vnode->flags)) { /* if the directory is a pseudo directory, use the d_name */ - static const char afs_root_cell[] = ":root.cell."; unsigned size = mntpt->d_name.len; - ret = -ENOENT; - if (size < 2 || size > AFS_MAXCELLNAME) - goto error_no_page; + if (size < 2) + return -ENOENT; + p = mntpt->d_name.name; if (mntpt->d_name.name[0] == '.') { - devname[0] = '%'; - memcpy(devname + 1, mntpt->d_name.name + 1, size - 1); - memcpy(devname + size, afs_root_cell, - sizeof(afs_root_cell)); - rwpath = true; - } else { - devname[0] = '#'; - memcpy(devname + 1, mntpt->d_name.name, size); - memcpy(devname + size + 1, afs_root_cell, - sizeof(afs_root_cell)); + size--; + p++; + ctx->type = AFSVL_RWVOL; + ctx->force = true; } + if (size > AFS_MAXCELLNAME) + return -ENAMETOOLONG; + + cell = afs_lookup_cell(ctx->net, p, size, NULL, false); + if (IS_ERR(cell)) { + pr_err("kAFS: unable to lookup cell '%pd'\n", mntpt); + return PTR_ERR(cell); + } + ctx->cell = cell; + + ctx->volname = afs_root_volume; + ctx->volnamesz = sizeof(afs_root_volume) - 1; } else { /* read the contents of the AFS special symlink */ + struct page *page; loff_t size = i_size_read(d_inode(mntpt)); char *buf; - ret = -EINVAL; + if (src_as->cell) + ctx->cell = afs_get_cell(src_as->cell); + if (size > PAGE_SIZE - 1) - goto error_no_page; + return -EINVAL; page = read_mapping_page(d_inode(mntpt)->i_mapping, 0, NULL); - if (IS_ERR(page)) { - ret = PTR_ERR(page); - goto error_no_page; - } + if (IS_ERR(page)) + return PTR_ERR(page); if (PageError(page)) { ret = afs_bad(AFS_FS_I(d_inode(mntpt)), afs_file_error_mntpt); - goto error; + put_page(page); + return ret; } - buf = kmap_atomic(page); - memcpy(devname, buf, size); - kunmap_atomic(buf); + buf = kmap(page); + ret = vfs_parse_fs_string(fc, "source", buf, size); + kunmap(page); put_page(page); - page = NULL; + if (ret < 0) + return ret; } - /* work out what options we want */ - as = AFS_FS_S(mntpt->d_sb); - if (as->cell) { - memcpy(options, "cell=", 5); - strcpy(options + 5, as->cell->name); - if ((as->volume && as->volume->type == AFSVL_RWVOL) || rwpath) - strcat(options, ",rwpath"); - } + return 0; +} - /* try and do the mount */ - _debug("--- attempting mount %s -o %s ---", devname, options); - mnt = vfs_submount(mntpt, &afs_fs_type, devname, options); - _debug("--- mount result %p ---", mnt); +/* + * create a vfsmount to be automounted + */ +static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt) +{ + struct fs_context *fc; + struct vfsmount *mnt; + int ret; - free_page((unsigned long) devname); - free_page((unsigned long) options); - _leave(" = %p", mnt); - return mnt; + BUG_ON(!d_inode(mntpt)); -error: - put_page(page); -error_no_page: - free_page((unsigned long) options); -error_no_options: - free_page((unsigned long) devname); -error_no_devname: - _leave(" = %d", ret); - return ERR_PTR(ret); + fc = fs_context_for_submount(&afs_fs_type, mntpt); + if (IS_ERR(fc)) + return ERR_CAST(fc); + + ret = afs_mntpt_set_params(fc, mntpt); + if (!ret) + mnt = fc_mount(fc); + else + mnt = ERR_PTR(ret); + + put_fs_context(fc); + return mnt; } /* -- cgit v1.2.3