Revision e8129c642155616d9e2160a75f103e127c8c3708 authored by Heiko Carstens on 25 November 2010, 08:52:45 UTC, committed by Martin Schwidefsky on 25 November 2010, 08:52:59 UTC
On each machine check all registers are revalidated. The save area for the clock comparator however only contains the upper most seven bytes of the former contents, if valid. Therefore the machine check handler uses a store clock instruction to get the current time and writes that to the clock comparator register which in turn will generate an immediate timer interrupt. However within the lowcore the expected time of the next timer interrupt is stored. If the interrupt happens before that time the handler won't be called. In turn the clock comparator won't be reprogrammed and therefore the interrupt condition stays pending which causes an interrupt loop until the expected time is reached. On NOHZ machines this can result in unresponsive machines since the time of the next expected interrupted can be a couple of days in the future. To fix this just revalidate the clock comparator register with the expected value. In addition the special handling for udelay must be changed as well. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
1 parent 698fd6a
dir.c
/*
* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
*/
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/reiserfs_fs.h>
#include <linux/stat.h>
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <asm/uaccess.h>
extern const struct reiserfs_key MIN_KEY;
static int reiserfs_readdir(struct file *, void *, filldir_t);
static int reiserfs_dir_fsync(struct file *filp, int datasync);
const struct file_operations reiserfs_dir_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.readdir = reiserfs_readdir,
.fsync = reiserfs_dir_fsync,
.unlocked_ioctl = reiserfs_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = reiserfs_compat_ioctl,
#endif
};
static int reiserfs_dir_fsync(struct file *filp, int datasync)
{
struct inode *inode = filp->f_mapping->host;
int err;
reiserfs_write_lock(inode->i_sb);
err = reiserfs_commit_for_inode(inode);
reiserfs_write_unlock(inode->i_sb);
if (err < 0)
return err;
return 0;
}
#define store_ih(where,what) copy_item_head (where, what)
static inline bool is_privroot_deh(struct dentry *dir,
struct reiserfs_de_head *deh)
{
struct dentry *privroot = REISERFS_SB(dir->d_sb)->priv_root;
return (dir == dir->d_parent && privroot->d_inode &&
deh->deh_objectid == INODE_PKEY(privroot->d_inode)->k_objectid);
}
int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent,
filldir_t filldir, loff_t *pos)
{
struct inode *inode = dentry->d_inode;
struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
INITIALIZE_PATH(path_to_entry);
struct buffer_head *bh;
int item_num, entry_num;
const struct reiserfs_key *rkey;
struct item_head *ih, tmp_ih;
int search_res;
char *local_buf;
loff_t next_pos;
char small_buf[32]; /* avoid kmalloc if we can */
struct reiserfs_dir_entry de;
int ret = 0;
reiserfs_write_lock(inode->i_sb);
reiserfs_check_lock_depth(inode->i_sb, "readdir");
/* form key for search the next directory entry using f_pos field of
file structure */
make_cpu_key(&pos_key, inode, *pos ?: DOT_OFFSET, TYPE_DIRENTRY, 3);
next_pos = cpu_key_k_offset(&pos_key);
path_to_entry.reada = PATH_READA;
while (1) {
research:
/* search the directory item, containing entry with specified key */
search_res =
search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
&de);
if (search_res == IO_ERROR) {
// FIXME: we could just skip part of directory which could
// not be read
ret = -EIO;
goto out;
}
entry_num = de.de_entry_num;
bh = de.de_bh;
item_num = de.de_item_num;
ih = de.de_ih;
store_ih(&tmp_ih, ih);
/* we must have found item, that is item of this directory, */
RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
"vs-9000: found item %h does not match to dir we readdir %K",
ih, &pos_key);
RFALSE(item_num > B_NR_ITEMS(bh) - 1,
"vs-9005 item_num == %d, item amount == %d",
item_num, B_NR_ITEMS(bh));
/* and entry must be not more than number of entries in the item */
RFALSE(I_ENTRY_COUNT(ih) < entry_num,
"vs-9010: entry number is too big %d (%d)",
entry_num, I_ENTRY_COUNT(ih));
if (search_res == POSITION_FOUND
|| entry_num < I_ENTRY_COUNT(ih)) {
/* go through all entries in the directory item beginning from the entry, that has been found */
struct reiserfs_de_head *deh =
B_I_DEH(bh, ih) + entry_num;
for (; entry_num < I_ENTRY_COUNT(ih);
entry_num++, deh++) {
int d_reclen;
char *d_name;
off_t d_off;
ino_t d_ino;
if (!de_visible(deh))
/* it is hidden entry */
continue;
d_reclen = entry_length(bh, ih, entry_num);
d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
if (d_reclen <= 0 ||
d_name + d_reclen > bh->b_data + bh->b_size) {
/* There is corrupted data in entry,
* We'd better stop here */
pathrelse(&path_to_entry);
ret = -EIO;
goto out;
}
if (!d_name[d_reclen - 1])
d_reclen = strlen(d_name);
if (d_reclen >
REISERFS_MAX_NAME(inode->i_sb->
s_blocksize)) {
/* too big to send back to VFS */
continue;
}
/* Ignore the .reiserfs_priv entry */
if (is_privroot_deh(dentry, deh))
continue;
d_off = deh_offset(deh);
*pos = d_off;
d_ino = deh_objectid(deh);
if (d_reclen <= 32) {
local_buf = small_buf;
} else {
local_buf = kmalloc(d_reclen,
GFP_NOFS);
if (!local_buf) {
pathrelse(&path_to_entry);
ret = -ENOMEM;
goto out;
}
if (item_moved(&tmp_ih, &path_to_entry)) {
kfree(local_buf);
goto research;
}
}
// Note, that we copy name to user space via temporary
// buffer (local_buf) because filldir will block if
// user space buffer is swapped out. At that time
// entry can move to somewhere else
memcpy(local_buf, d_name, d_reclen);
/*
* Since filldir might sleep, we can release
* the write lock here for other waiters
*/
reiserfs_write_unlock(inode->i_sb);
if (filldir
(dirent, local_buf, d_reclen, d_off, d_ino,
DT_UNKNOWN) < 0) {
reiserfs_write_lock(inode->i_sb);
if (local_buf != small_buf) {
kfree(local_buf);
}
goto end;
}
reiserfs_write_lock(inode->i_sb);
if (local_buf != small_buf) {
kfree(local_buf);
}
// next entry should be looked for with such offset
next_pos = deh_offset(deh) + 1;
if (item_moved(&tmp_ih, &path_to_entry)) {
goto research;
}
} /* for */
}
if (item_num != B_NR_ITEMS(bh) - 1)
// end of directory has been reached
goto end;
/* item we went through is last item of node. Using right
delimiting key check is it directory end */
rkey = get_rkey(&path_to_entry, inode->i_sb);
if (!comp_le_keys(rkey, &MIN_KEY)) {
/* set pos_key to key, that is the smallest and greater
that key of the last entry in the item */
set_cpu_key_k_offset(&pos_key, next_pos);
continue;
}
if (COMP_SHORT_KEYS(rkey, &pos_key)) {
// end of directory has been reached
goto end;
}
/* directory continues in the right neighboring block */
set_cpu_key_k_offset(&pos_key,
le_key_k_offset(KEY_FORMAT_3_5, rkey));
} /* while */
end:
*pos = next_pos;
pathrelse(&path_to_entry);
reiserfs_check_path(&path_to_entry);
out:
reiserfs_write_unlock(inode->i_sb);
return ret;
}
static int reiserfs_readdir(struct file *file, void *dirent, filldir_t filldir)
{
struct dentry *dentry = file->f_path.dentry;
return reiserfs_readdir_dentry(dentry, dirent, filldir, &file->f_pos);
}
/* compose directory item containing "." and ".." entries (entries are
not aligned to 4 byte boundary) */
/* the last four params are LE */
void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
__le32 par_dirid, __le32 par_objid)
{
struct reiserfs_de_head *deh;
memset(body, 0, EMPTY_DIR_SIZE_V1);
deh = (struct reiserfs_de_head *)body;
/* direntry header of "." */
put_deh_offset(&(deh[0]), DOT_OFFSET);
/* these two are from make_le_item_head, and are are LE */
deh[0].deh_dir_id = dirid;
deh[0].deh_objectid = objid;
deh[0].deh_state = 0; /* Endian safe if 0 */
put_deh_location(&(deh[0]), EMPTY_DIR_SIZE_V1 - strlen("."));
mark_de_visible(&(deh[0]));
/* direntry header of ".." */
put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
/* key of ".." for the root directory */
/* these two are from the inode, and are are LE */
deh[1].deh_dir_id = par_dirid;
deh[1].deh_objectid = par_objid;
deh[1].deh_state = 0; /* Endian safe if 0 */
put_deh_location(&(deh[1]), deh_location(&(deh[0])) - strlen(".."));
mark_de_visible(&(deh[1]));
/* copy ".." and "." */
memcpy(body + deh_location(&(deh[0])), ".", 1);
memcpy(body + deh_location(&(deh[1])), "..", 2);
}
/* compose directory item containing "." and ".." entries */
void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
__le32 par_dirid, __le32 par_objid)
{
struct reiserfs_de_head *deh;
memset(body, 0, EMPTY_DIR_SIZE);
deh = (struct reiserfs_de_head *)body;
/* direntry header of "." */
put_deh_offset(&(deh[0]), DOT_OFFSET);
/* these two are from make_le_item_head, and are are LE */
deh[0].deh_dir_id = dirid;
deh[0].deh_objectid = objid;
deh[0].deh_state = 0; /* Endian safe if 0 */
put_deh_location(&(deh[0]), EMPTY_DIR_SIZE - ROUND_UP(strlen(".")));
mark_de_visible(&(deh[0]));
/* direntry header of ".." */
put_deh_offset(&(deh[1]), DOT_DOT_OFFSET);
/* key of ".." for the root directory */
/* these two are from the inode, and are are LE */
deh[1].deh_dir_id = par_dirid;
deh[1].deh_objectid = par_objid;
deh[1].deh_state = 0; /* Endian safe if 0 */
put_deh_location(&(deh[1]),
deh_location(&(deh[0])) - ROUND_UP(strlen("..")));
mark_de_visible(&(deh[1]));
/* copy ".." and "." */
memcpy(body + deh_location(&(deh[0])), ".", 1);
memcpy(body + deh_location(&(deh[1])), "..", 2);
}
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