android_kernel_xiaomi_sm8350/drivers/infiniband/hw/ipath/ipath_fs.c
David Howells 454e2398be [PATCH] VFS: Permit filesystem to override root dentry on mount
Extend the get_sb() filesystem operation to take an extra argument that
permits the VFS to pass in the target vfsmount that defines the mountpoint.

The filesystem is then required to manually set the superblock and root dentry
pointers.  For most filesystems, this should be done with simple_set_mnt()
which will set the superblock pointer and then set the root dentry to the
superblock's s_root (as per the old default behaviour).

The get_sb() op now returns an integer as there's now no need to return the
superblock pointer.

This patch permits a superblock to be implicitly shared amongst several mount
points, such as can be done with NFS to avoid potential inode aliasing.  In
such a case, simple_set_mnt() would not be called, and instead the mnt_root
and mnt_sb would be set directly.

The patch also makes the following changes:

 (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount
     pointer argument and return an integer, so most filesystems have to change
     very little.

 (*) If one of the convenience function is not used, then get_sb() should
     normally call simple_set_mnt() to instantiate the vfsmount. This will
     always return 0, and so can be tail-called from get_sb().

 (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the
     dcache upon superblock destruction rather than shrink_dcache_anon().

     This is required because the superblock may now have multiple trees that
     aren't actually bound to s_root, but that still need to be cleaned up. The
     currently called functions assume that the whole tree is rooted at s_root,
     and that anonymous dentries are not the roots of trees which results in
     dentries being left unculled.

     However, with the way NFS superblock sharing are currently set to be
     implemented, these assumptions are violated: the root of the filesystem is
     simply a dummy dentry and inode (the real inode for '/' may well be
     inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries
     with child trees.

     [*] Anonymous until discovered from another tree.

 (*) The documentation has been adjusted, including the additional bit of
     changing ext2_* into foo_* in the documentation.

[akpm@osdl.org: convert ipath_fs, do other stuff]
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:42:45 -07:00

607 lines
14 KiB
C

/*
* Copyright (c) 2006 PathScale, Inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <linux/version.h>
#include <linux/config.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/namei.h>
#include <linux/pci.h>
#include "ipath_kernel.h"
#define IPATHFS_MAGIC 0x726a77
static struct super_block *ipath_super;
static int ipathfs_mknod(struct inode *dir, struct dentry *dentry,
int mode, struct file_operations *fops,
void *data)
{
int error;
struct inode *inode = new_inode(dir->i_sb);
if (!inode) {
error = -EPERM;
goto bail;
}
inode->i_mode = mode;
inode->i_uid = 0;
inode->i_gid = 0;
inode->i_blksize = PAGE_CACHE_SIZE;
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
inode->u.generic_ip = data;
if ((mode & S_IFMT) == S_IFDIR) {
inode->i_op = &simple_dir_inode_operations;
inode->i_nlink++;
dir->i_nlink++;
}
inode->i_fop = fops;
d_instantiate(dentry, inode);
error = 0;
bail:
return error;
}
static int create_file(const char *name, mode_t mode,
struct dentry *parent, struct dentry **dentry,
struct file_operations *fops, void *data)
{
int error;
*dentry = NULL;
mutex_lock(&parent->d_inode->i_mutex);
*dentry = lookup_one_len(name, parent, strlen(name));
if (!IS_ERR(dentry))
error = ipathfs_mknod(parent->d_inode, *dentry,
mode, fops, data);
else
error = PTR_ERR(dentry);
mutex_unlock(&parent->d_inode->i_mutex);
return error;
}
static ssize_t atomic_stats_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
return simple_read_from_buffer(buf, count, ppos, &ipath_stats,
sizeof ipath_stats);
}
static struct file_operations atomic_stats_ops = {
.read = atomic_stats_read,
};
#define NUM_COUNTERS sizeof(struct infinipath_counters) / sizeof(u64)
static ssize_t atomic_counters_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
u64 counters[NUM_COUNTERS];
u16 i;
struct ipath_devdata *dd;
dd = file->f_dentry->d_inode->u.generic_ip;
for (i = 0; i < NUM_COUNTERS; i++)
counters[i] = ipath_snap_cntr(dd, i);
return simple_read_from_buffer(buf, count, ppos, counters,
sizeof counters);
}
static struct file_operations atomic_counters_ops = {
.read = atomic_counters_read,
};
static ssize_t atomic_node_info_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
u32 nodeinfo[10];
struct ipath_devdata *dd;
u64 guid;
dd = file->f_dentry->d_inode->u.generic_ip;
guid = be64_to_cpu(dd->ipath_guid);
nodeinfo[0] = /* BaseVersion is SMA */
/* ClassVersion is SMA */
(1 << 8) /* NodeType */
| (1 << 0); /* NumPorts */
nodeinfo[1] = (u32) (guid >> 32);
nodeinfo[2] = (u32) (guid & 0xffffffff);
/* PortGUID == SystemImageGUID for us */
nodeinfo[3] = nodeinfo[1];
/* PortGUID == SystemImageGUID for us */
nodeinfo[4] = nodeinfo[2];
/* PortGUID == NodeGUID for us */
nodeinfo[5] = nodeinfo[3];
/* PortGUID == NodeGUID for us */
nodeinfo[6] = nodeinfo[4];
nodeinfo[7] = (4 << 16) /* we support 4 pkeys */
| (dd->ipath_deviceid << 0);
/* our chip version as 16 bits major, 16 bits minor */
nodeinfo[8] = dd->ipath_minrev | (dd->ipath_majrev << 16);
nodeinfo[9] = (dd->ipath_unit << 24) | (dd->ipath_vendorid << 0);
return simple_read_from_buffer(buf, count, ppos, nodeinfo,
sizeof nodeinfo);
}
static struct file_operations atomic_node_info_ops = {
.read = atomic_node_info_read,
};
static ssize_t atomic_port_info_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
u32 portinfo[13];
u32 tmp, tmp2;
struct ipath_devdata *dd;
dd = file->f_dentry->d_inode->u.generic_ip;
/* so we only initialize non-zero fields. */
memset(portinfo, 0, sizeof portinfo);
/*
* Notimpl yet M_Key (64)
* Notimpl yet GID (64)
*/
portinfo[4] = (dd->ipath_lid << 16);
/*
* Notimpl yet SMLID (should we store this in the driver, in case
* SMA dies?) CapabilityMask is 0, we don't support any of these
* DiagCode is 0; we don't store any diag info for now Notimpl yet
* M_KeyLeasePeriod (we don't support M_Key)
*/
/* LocalPortNum is whichever port number they ask for */
portinfo[7] = (dd->ipath_unit << 24)
/* LinkWidthEnabled */
| (2 << 16)
/* LinkWidthSupported (really 2, but not IB valid) */
| (3 << 8)
/* LinkWidthActive */
| (2 << 0);
tmp = dd->ipath_lastibcstat & IPATH_IBSTATE_MASK;
tmp2 = 5;
if (tmp == IPATH_IBSTATE_INIT)
tmp = 2;
else if (tmp == IPATH_IBSTATE_ARM)
tmp = 3;
else if (tmp == IPATH_IBSTATE_ACTIVE)
tmp = 4;
else {
tmp = 0; /* down */
tmp2 = tmp & 0xf;
}
portinfo[8] = (1 << 28) /* LinkSpeedSupported */
| (tmp << 24) /* PortState */
| (tmp2 << 20) /* PortPhysicalState */
| (2 << 16)
/* LinkDownDefaultState */
/* M_KeyProtectBits == 0 */
/* NotImpl yet LMC == 0 (we can support all values) */
| (1 << 4) /* LinkSpeedActive */
| (1 << 0); /* LinkSpeedEnabled */
switch (dd->ipath_ibmtu) {
case 4096:
tmp = 5;
break;
case 2048:
tmp = 4;
break;
case 1024:
tmp = 3;
break;
case 512:
tmp = 2;
break;
case 256:
tmp = 1;
break;
default: /* oops, something is wrong */
ipath_dbg("Problem, ipath_ibmtu 0x%x not a valid IB MTU, "
"treat as 2048\n", dd->ipath_ibmtu);
tmp = 4;
break;
}
portinfo[9] = (tmp << 28)
/* NeighborMTU */
/* Notimpl MasterSMSL */
| (1 << 20)
/* VLCap */
/* Notimpl InitType (actually, an SMA decision) */
/* VLHighLimit is 0 (only one VL) */
; /* VLArbitrationHighCap is 0 (only one VL) */
portinfo[10] = /* VLArbitrationLowCap is 0 (only one VL) */
/* InitTypeReply is SMA decision */
(5 << 16) /* MTUCap 4096 */
| (7 << 13) /* VLStallCount */
| (0x1f << 8) /* HOQLife */
| (1 << 4)
/* OperationalVLs 0 */
/* PartitionEnforcementInbound */
/* PartitionEnforcementOutbound not enforced */
/* FilterRawinbound not enforced */
; /* FilterRawOutbound not enforced */
/* M_KeyViolations are not counted by hardware, SMA can count */
tmp = ipath_read_creg32(dd, dd->ipath_cregs->cr_errpkey);
/* P_KeyViolations are counted by hardware. */
portinfo[11] = ((tmp & 0xffff) << 0);
portinfo[12] =
/* Q_KeyViolations are not counted by hardware */
(1 << 8)
/* GUIDCap */
/* SubnetTimeOut handled by SMA */
/* RespTimeValue handled by SMA */
;
/* LocalPhyErrors are programmed to max */
portinfo[12] |= (0xf << 20)
| (0xf << 16) /* OverRunErrors are programmed to max */
;
return simple_read_from_buffer(buf, count, ppos, portinfo,
sizeof portinfo);
}
static struct file_operations atomic_port_info_ops = {
.read = atomic_port_info_read,
};
static ssize_t flash_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct ipath_devdata *dd;
ssize_t ret;
loff_t pos;
char *tmp;
pos = *ppos;
if ( pos < 0) {
ret = -EINVAL;
goto bail;
}
if (pos >= sizeof(struct ipath_flash)) {
ret = 0;
goto bail;
}
if (count > sizeof(struct ipath_flash) - pos)
count = sizeof(struct ipath_flash) - pos;
tmp = kmalloc(count, GFP_KERNEL);
if (!tmp) {
ret = -ENOMEM;
goto bail;
}
dd = file->f_dentry->d_inode->u.generic_ip;
if (ipath_eeprom_read(dd, pos, tmp, count)) {
ipath_dev_err(dd, "failed to read from flash\n");
ret = -ENXIO;
goto bail_tmp;
}
if (copy_to_user(buf, tmp, count)) {
ret = -EFAULT;
goto bail_tmp;
}
*ppos = pos + count;
ret = count;
bail_tmp:
kfree(tmp);
bail:
return ret;
}
static ssize_t flash_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct ipath_devdata *dd;
ssize_t ret;
loff_t pos;
char *tmp;
pos = *ppos;
if ( pos < 0) {
ret = -EINVAL;
goto bail;
}
if (pos >= sizeof(struct ipath_flash)) {
ret = 0;
goto bail;
}
if (count > sizeof(struct ipath_flash) - pos)
count = sizeof(struct ipath_flash) - pos;
tmp = kmalloc(count, GFP_KERNEL);
if (!tmp) {
ret = -ENOMEM;
goto bail;
}
if (copy_from_user(tmp, buf, count)) {
ret = -EFAULT;
goto bail_tmp;
}
dd = file->f_dentry->d_inode->u.generic_ip;
if (ipath_eeprom_write(dd, pos, tmp, count)) {
ret = -ENXIO;
ipath_dev_err(dd, "failed to write to flash\n");
goto bail_tmp;
}
*ppos = pos + count;
ret = count;
bail_tmp:
kfree(tmp);
bail:
return ret;
}
static struct file_operations flash_ops = {
.read = flash_read,
.write = flash_write,
};
static int create_device_files(struct super_block *sb,
struct ipath_devdata *dd)
{
struct dentry *dir, *tmp;
char unit[10];
int ret;
snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
ret = create_file(unit, S_IFDIR|S_IRUGO|S_IXUGO, sb->s_root, &dir,
(struct file_operations *) &simple_dir_operations,
dd);
if (ret) {
printk(KERN_ERR "create_file(%s) failed: %d\n", unit, ret);
goto bail;
}
ret = create_file("atomic_counters", S_IFREG|S_IRUGO, dir, &tmp,
&atomic_counters_ops, dd);
if (ret) {
printk(KERN_ERR "create_file(%s/atomic_counters) "
"failed: %d\n", unit, ret);
goto bail;
}
ret = create_file("node_info", S_IFREG|S_IRUGO, dir, &tmp,
&atomic_node_info_ops, dd);
if (ret) {
printk(KERN_ERR "create_file(%s/node_info) "
"failed: %d\n", unit, ret);
goto bail;
}
ret = create_file("port_info", S_IFREG|S_IRUGO, dir, &tmp,
&atomic_port_info_ops, dd);
if (ret) {
printk(KERN_ERR "create_file(%s/port_info) "
"failed: %d\n", unit, ret);
goto bail;
}
ret = create_file("flash", S_IFREG|S_IWUSR|S_IRUGO, dir, &tmp,
&flash_ops, dd);
if (ret) {
printk(KERN_ERR "create_file(%s/flash) "
"failed: %d\n", unit, ret);
goto bail;
}
bail:
return ret;
}
static void remove_file(struct dentry *parent, char *name)
{
struct dentry *tmp;
tmp = lookup_one_len(name, parent, strlen(name));
spin_lock(&dcache_lock);
spin_lock(&tmp->d_lock);
if (!(d_unhashed(tmp) && tmp->d_inode)) {
dget_locked(tmp);
__d_drop(tmp);
spin_unlock(&tmp->d_lock);
spin_unlock(&dcache_lock);
simple_unlink(parent->d_inode, tmp);
} else {
spin_unlock(&tmp->d_lock);
spin_unlock(&dcache_lock);
}
}
static int remove_device_files(struct super_block *sb,
struct ipath_devdata *dd)
{
struct dentry *dir, *root;
char unit[10];
int ret;
root = dget(sb->s_root);
mutex_lock(&root->d_inode->i_mutex);
snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
dir = lookup_one_len(unit, root, strlen(unit));
if (IS_ERR(dir)) {
ret = PTR_ERR(dir);
printk(KERN_ERR "Lookup of %s failed\n", unit);
goto bail;
}
remove_file(dir, "flash");
remove_file(dir, "port_info");
remove_file(dir, "node_info");
remove_file(dir, "atomic_counters");
d_delete(dir);
ret = simple_rmdir(root->d_inode, dir);
bail:
mutex_unlock(&root->d_inode->i_mutex);
dput(root);
return ret;
}
static int ipathfs_fill_super(struct super_block *sb, void *data,
int silent)
{
struct ipath_devdata *dd, *tmp;
unsigned long flags;
int ret;
static struct tree_descr files[] = {
[1] = {"atomic_stats", &atomic_stats_ops, S_IRUGO},
{""},
};
ret = simple_fill_super(sb, IPATHFS_MAGIC, files);
if (ret) {
printk(KERN_ERR "simple_fill_super failed: %d\n", ret);
goto bail;
}
spin_lock_irqsave(&ipath_devs_lock, flags);
list_for_each_entry_safe(dd, tmp, &ipath_dev_list, ipath_list) {
spin_unlock_irqrestore(&ipath_devs_lock, flags);
ret = create_device_files(sb, dd);
if (ret) {
deactivate_super(sb);
goto bail;
}
spin_lock_irqsave(&ipath_devs_lock, flags);
}
spin_unlock_irqrestore(&ipath_devs_lock, flags);
bail:
return ret;
}
static int ipathfs_get_sb(struct file_system_type *fs_type, int flags,
const char *dev_name, void *data, struct vfsmount *mnt)
{
int ret = get_sb_single(fs_type, flags, data,
ipathfs_fill_super, mnt);
if (ret >= 0)
ipath_super = mnt->mnt_sb;
return ret;
}
static void ipathfs_kill_super(struct super_block *s)
{
kill_litter_super(s);
ipath_super = NULL;
}
int ipathfs_add_device(struct ipath_devdata *dd)
{
int ret;
if (ipath_super == NULL) {
ret = 0;
goto bail;
}
ret = create_device_files(ipath_super, dd);
bail:
return ret;
}
int ipathfs_remove_device(struct ipath_devdata *dd)
{
int ret;
if (ipath_super == NULL) {
ret = 0;
goto bail;
}
ret = remove_device_files(ipath_super, dd);
bail:
return ret;
}
static struct file_system_type ipathfs_fs_type = {
.owner = THIS_MODULE,
.name = "ipathfs",
.get_sb = ipathfs_get_sb,
.kill_sb = ipathfs_kill_super,
};
int __init ipath_init_ipathfs(void)
{
return register_filesystem(&ipathfs_fs_type);
}
void __exit ipath_exit_ipathfs(void)
{
unregister_filesystem(&ipathfs_fs_type);
}