From 18d98f6c04991dd3c12acf6f39cea40e9510640a Mon Sep 17 00:00:00 2001 From: Sachin Bhamare Date: Mon, 19 Mar 2012 20:47:58 -0700 Subject: pnfs-obj: autologin: Add support for protocol autologin The pnfs-objects protocol mandates that we autologin into devices not present in the system, according to information specified in the get_device_info returned from the server. The Protocol specifies two login hints. 1. An IP address:port combination 2. A string URI which is constructed as a URL with a protocol prefix followed by :// and a string as address. For each protocol prefix the string-address format might be different. We only support the second option. The first option is just redundant to the second one. NOTE: The Kernel part of autologin does not parse the URI string. It just channels it to a user-mode script. So any new login protocols should only update the user-mode script which is a part of the nfs-utils package, but the Kernel need not change. We implement the autologin by using the call_usermodehelper() API. (Thanks to Steve Dickson for pointing it out) So there is no running daemon needed, and/or special setup. We Add the osd_login_prog Kernel module parameters which defaults to: /sbin/osd_login Kernel try's to upcall the program specified in osd_login_prog. If the file is not found or the execution fails Kernel will disable any farther upcalls, by zeroing out osd_login_prog, Until Admin re-enables it by setting the osd_login_prog parameter to a proper program. Also add text about the osd_login program command line API to: Documentation/filesystems/nfs/pnfs.txt and documentation of the new osd_login_prog module parameter to: Documentation/kernel-parameters.txt TODO: Add timeout option in the case osd_login program gets stuck Signed-off-by: Sachin Bhamare Signed-off-by: Boaz Harrosh Signed-off-by: Trond Myklebust diff --git a/Documentation/filesystems/nfs/pnfs.txt b/Documentation/filesystems/nfs/pnfs.txt index 983e14a..c7919c6 100644 --- a/Documentation/filesystems/nfs/pnfs.txt +++ b/Documentation/filesystems/nfs/pnfs.txt @@ -53,3 +53,57 @@ lseg maintains an extra reference corresponding to the NFS_LSEG_VALID bit which holds it in the pnfs_layout_hdr's list. When the final lseg is removed from the pnfs_layout_hdr's list, the NFS_LAYOUT_DESTROYED bit is set, preventing any new lsegs from being added. + +layout drivers +-------------- + +PNFS utilizes what is called layout drivers. The STD defines 3 basic +layout types: "files" "objects" and "blocks". For each of these types +there is a layout-driver with a common function-vectors table which +are called by the nfs-client pnfs-core to implement the different layout +types. + +Files-layout-driver code is in: fs/nfs/nfs4filelayout.c && nfs4filelayoutdev.c +Objects-layout-deriver code is in: fs/nfs/objlayout/.. directory +Blocks-layout-deriver code is in: fs/nfs/blocklayout/.. directory + +objects-layout setup +-------------------- + +As part of the full STD implementation the objlayoutdriver.ko needs, at times, +to automatically login to yet undiscovered iscsi/osd devices. For this the +driver makes up-calles to a user-mode script called *osd_login* + +The path_name of the script to use is by default: + /sbin/osd_login. +This name can be overridden by the Kernel module parameter: + objlayoutdriver.osd_login_prog + +If Kernel does not find the osd_login_prog path it will zero it out +and will not attempt farther logins. An admin can then write new value +to the objlayoutdriver.osd_login_prog Kernel parameter to re-enable it. + +The /sbin/osd_login is part of the nfs-utils package, and should usually +be installed on distributions that support this Kernel version. + +The API to the login script is as follows: + Usage: $0 -u -o -s + Options: + -u target uri e.g. iscsi://: + (allways exists) + (More protocols can be defined in the future. + The client does not interpret this string it is + passed unchanged as recieved from the Server) + -o osdname of the requested target OSD + (Might be empty) + (A string which denotes the OSD name, there is a + limit of 64 chars on this string) + -s systemid of the requested target OSD + (Might be empty) + (This string, if not empty is always an hex + representation of the 20 bytes osd_system_id) + +blocks-layout setup +------------------- + +TODO: Document the setup needs of the blocks layout driver diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 7bae0fd..0d79a88 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1687,6 +1687,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. information. + objlayoutdriver.osd_login_prog= + [NFS] [OBJLAYOUT] sets the pathname to the program which + is used to automatically discover and login into new + osd-targets. Please see: + Documentation/filesystems/pnfs.txt for more explanations + nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take when a NMI is triggered. Format: [state][,regs][,debounce][,die] diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c index 3a621a2..4bff4a3 100644 --- a/fs/nfs/objlayout/objio_osd.c +++ b/fs/nfs/objlayout/objio_osd.c @@ -137,6 +137,7 @@ static int objio_devices_lookup(struct pnfs_layout_hdr *pnfslay, struct objio_dev_ent *ode; struct osd_dev *od; struct osd_dev_info odi; + bool retry_flag = true; int err; ode = _dev_list_find(NFS_SERVER(pnfslay->plh_inode), d_id); @@ -171,10 +172,18 @@ static int objio_devices_lookup(struct pnfs_layout_hdr *pnfslay, goto out; } +retry_lookup: od = osduld_info_lookup(&odi); if (unlikely(IS_ERR(od))) { err = PTR_ERR(od); dprintk("%s: osduld_info_lookup => %d\n", __func__, err); + if (err == -ENODEV && retry_flag) { + err = objlayout_autologin(deviceaddr); + if (likely(!err)) { + retry_flag = false; + goto retry_lookup; + } + } goto out; } diff --git a/fs/nfs/objlayout/objlayout.c b/fs/nfs/objlayout/objlayout.c index 157c47e..8d45f1c 100644 --- a/fs/nfs/objlayout/objlayout.c +++ b/fs/nfs/objlayout/objlayout.c @@ -37,6 +37,9 @@ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ +#include +#include +#include #include #include "objlayout.h" @@ -651,3 +654,134 @@ void objlayout_put_deviceinfo(struct pnfs_osd_deviceaddr *deviceaddr) __free_page(odi->page); kfree(odi); } + +enum { + OBJLAYOUT_MAX_URI_LEN = 256, OBJLAYOUT_MAX_OSDNAME_LEN = 64, + OBJLAYOUT_MAX_SYSID_HEX_LEN = OSD_SYSTEMID_LEN * 2 + 1, + OSD_LOGIN_UPCALL_PATHLEN = 256 +}; + +static char osd_login_prog[OSD_LOGIN_UPCALL_PATHLEN] = "/sbin/osd_login"; + +module_param_string(osd_login_prog, osd_login_prog, sizeof(osd_login_prog), + 0600); +MODULE_PARM_DESC(osd_login_prog, "Path to the osd_login upcall program"); + +struct __auto_login { + char uri[OBJLAYOUT_MAX_URI_LEN]; + char osdname[OBJLAYOUT_MAX_OSDNAME_LEN]; + char systemid_hex[OBJLAYOUT_MAX_SYSID_HEX_LEN]; +}; + +static int __objlayout_upcall(struct __auto_login *login) +{ + static char *envp[] = { "HOME=/", + "TERM=linux", + "PATH=/sbin:/usr/sbin:/bin:/usr/bin", + NULL + }; + char *argv[8]; + int ret; + + if (unlikely(!osd_login_prog[0])) { + dprintk("%s: osd_login_prog is disabled\n", __func__); + return -EACCES; + } + + dprintk("%s uri: %s\n", __func__, login->uri); + dprintk("%s osdname %s\n", __func__, login->osdname); + dprintk("%s systemid_hex %s\n", __func__, login->systemid_hex); + + argv[0] = (char *)osd_login_prog; + argv[1] = "-u"; + argv[2] = login->uri; + argv[3] = "-o"; + argv[4] = login->osdname; + argv[5] = "-s"; + argv[6] = login->systemid_hex; + argv[7] = NULL; + + ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC); + /* + * Disable the upcall mechanism if we're getting an ENOENT or + * EACCES error. The admin can re-enable it on the fly by using + * sysfs to set the objlayoutdriver.osd_login_prog module parameter once + * the problem has been fixed. + */ + if (ret == -ENOENT || ret == -EACCES) { + printk(KERN_ERR "PNFS-OBJ: %s was not found please set " + "objlayoutdriver.osd_login_prog kernel parameter!\n", + osd_login_prog); + osd_login_prog[0] = '\0'; + } + dprintk("%s %s return value: %d\n", __func__, osd_login_prog, ret); + + return ret; +} + +/* Assume dest is all zeros */ +static void __copy_nfsS_and_zero_terminate(struct nfs4_string s, + char *dest, int max_len, + const char *var_name) +{ + if (!s.len) + return; + + if (s.len >= max_len) { + pr_warn_ratelimited( + "objlayout_autologin: %s: s.len(%d) >= max_len(%d)", + var_name, s.len, max_len); + s.len = max_len - 1; /* space for null terminator */ + } + + memcpy(dest, s.data, s.len); +} + +/* Assume sysid is all zeros */ +static void _sysid_2_hex(struct nfs4_string s, + char sysid[OBJLAYOUT_MAX_SYSID_HEX_LEN]) +{ + int i; + char *cur; + + if (!s.len) + return; + + if (s.len != OSD_SYSTEMID_LEN) { + pr_warn_ratelimited( + "objlayout_autologin: systemid_len(%d) != OSD_SYSTEMID_LEN", + s.len); + if (s.len > OSD_SYSTEMID_LEN) + s.len = OSD_SYSTEMID_LEN; + } + + cur = sysid; + for (i = 0; i < s.len; i++) + cur = hex_byte_pack(cur, s.data[i]); +} + +int objlayout_autologin(struct pnfs_osd_deviceaddr *deviceaddr) +{ + int rc; + struct __auto_login login; + + if (!deviceaddr->oda_targetaddr.ota_netaddr.r_addr.len) + return -ENODEV; + + memset(&login, 0, sizeof(login)); + __copy_nfsS_and_zero_terminate( + deviceaddr->oda_targetaddr.ota_netaddr.r_addr, + login.uri, sizeof(login.uri), "URI"); + + __copy_nfsS_and_zero_terminate( + deviceaddr->oda_osdname, + login.osdname, sizeof(login.osdname), "OSDNAME"); + + _sysid_2_hex(deviceaddr->oda_systemid, login.systemid_hex); + + rc = __objlayout_upcall(&login); + if (rc > 0) /* script returns positive values */ + rc = -ENODEV; + + return rc; +} diff --git a/fs/nfs/objlayout/objlayout.h b/fs/nfs/objlayout/objlayout.h index 8ec3472..880ba08 100644 --- a/fs/nfs/objlayout/objlayout.h +++ b/fs/nfs/objlayout/objlayout.h @@ -184,4 +184,6 @@ extern void objlayout_encode_layoutreturn( struct xdr_stream *, const struct nfs4_layoutreturn_args *); +extern int objlayout_autologin(struct pnfs_osd_deviceaddr *deviceaddr); + #endif /* _OBJLAYOUT_H */ -- cgit v0.10.2