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Asides of the avalanche of LLM-driven fixes, there are a couple of

Browse Source 
big changes this cycle:
 
 - negative dentry and symlink cache
 - a way out of the unkillable "io_wait_event_killable" (because it
   looped around waiting for the request flush to come back from
   server; this has been bugging syzcaller folks since forever):
   I'm still not 100% sure about this patch, but I think it's as
   good as we'll ever get, and will keep testing a bit further in the
   coming weeks
 
 The rest is more noisy than usual, but shouldn't cause any trouble.
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Merge tag '9p-for-7.2-rc1' of https://github.com/martinetd/linux

Pull 9p updates from Dominique Martinet:
 "Asides of the avalanche of LLM-driven fixes, there are a couple of big
  changes this cycle:

   - negative dentry and symlink cache

   - a way out of the unkillable "io_wait_event_killable" (because it
     looped around waiting for the request flush to come back from
     server; this has been bugging syzcaller folks since forever): I'm
     still not 100% sure about this patch, but I think it's as good as
     we'll ever get, and will keep testing a bit further in the coming
     weeks

  The rest is more noisy than usual, but shouldn't cause any trouble"

* tag '9p-for-7.2-rc1' of https://github.com/martinetd/linux:
  9p: Add missing read barrier in virtio zero-copy path
  net/9p: Replace strlen() strcpy() pair with strscpy()
  9p: skip nlink update in cacheless mode to fix WARN_ON
  net/9p: fix race condition on rdma->state in trans_rdma.c
  9p: v9fs_file_do_lock: replace WARN_ONCE with p9_debug
  9p: Enable symlink caching in page cache
  9p: Set default negative dentry retention time for cache=loose
  9p: Add mount option for negative dentry cache retention
  9p: Cache negative dentries for lookup performance
  9p: avoid returning ERR_PTR(0) from mkdir operations
  9p: avoid putting oldfid in p9_client_walk() error path
  net/9p: fix infinite loop in p9_client_rpc on fatal signal
  docs/filesystems/9p: fix broken external links
  9p: invalidate readdir buffer on seek
  9p: use kvzalloc for readdir buffer
  net/9p/usbg: Constify struct configfs_item_operations
This commit is contained in:
Linus Torvalds 2026-06-21 10:26:31 -07:00
commit 1bc1885835
18 changed files with 320 additions and 74 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
Documentation/filesystems/9p.rst
View File

@ -23,13 +23,10 @@ the 9p client is available in the form of a USENIX paper:
Other applications are described in the following papers:
* XCPU & Clustering
http://xcpu.org/papers/xcpu-talk.pdf
* KVMFS: control file system for KVM
http://xcpu.org/papers/kvmfs.pdf
* CellFS: A New Programming Model for the Cell BE
http://xcpu.org/papers/cellfs-talk.pdf
* PROSE I/O: Using 9p to enable Application Partitions
http://plan9.escet.urjc.es/iwp9/cready/PROSE_iwp9_2006.pdf
http://web.archive.org/web/20110101152020/http://plan9.escet.urjc.es/iwp9/cready/PROSE_iwp9_2006.pdf
* VirtFS: A Virtualization Aware File System pass-through
https://kernel.org/doc/ols/2010/ols2010-pages-109-120.pdf
@ -238,6 +235,11 @@ Options
cachetag cache tag to use the specified persistent cache.
cache tags for existing cache sessions can be listed at
/sys/fs/9p/caches. (applies only to cache=fscache)
negtimeout the duration (in milliseconds) that negative dentries (paths
that do not actually exist) are retained in the cache. If
set to a negative value, those entries are kept indefinitely
until evicted by the buffer cache management system
============= ===============================================================
Behavior

11
fs/9p/fid.c
View File

@ -20,7 +20,9 @@
static inline void __add_fid(struct dentry *dentry, struct p9_fid *fid)
{
hlist_add_head(&fid->dlist, (struct hlist_head *)&dentry->d_fsdata);
struct v9fs_dentry *v9fs_dentry = to_v9fs_dentry(dentry);
hlist_add_head(&fid->dlist, &v9fs_dentry->head);
}
@ -112,6 +114,7 @@ void v9fs_open_fid_add(struct inode *inode, struct p9_fid **pfid)
static struct p9_fid *v9fs_fid_find(struct dentry *dentry, kuid_t uid, int any)
{
struct v9fs_dentry *v9fs_dentry = to_v9fs_dentry(dentry);
struct p9_fid *fid, *ret;
p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p) uid %d any %d\n",
@ -119,11 +122,9 @@ static struct p9_fid *v9fs_fid_find(struct dentry *dentry, kuid_t uid, int any)
any);
ret = NULL;
/* we'll recheck under lock if there's anything to look in */
if (dentry->d_fsdata) {
struct hlist_head *h = (struct hlist_head *)&dentry->d_fsdata;
if (!hlist_empty(&v9fs_dentry->head)) {
spin_lock(&dentry->d_lock);
hlist_for_each_entry(fid, h, dlist) {
hlist_for_each_entry(fid, &v9fs_dentry->head, dlist) {
if (any || uid_eq(fid->uid, uid)) {
ret = fid;
p9_fid_get(ret);

27
fs/9p/v9fs.c
View File

@ -24,6 +24,9 @@
#include "v9fs_vfs.h"
#include "cache.h"
/* cache=loose default negative dentry retention time is 24hours */
#define CACHE_LOOSE_NDENTRY_TIMEOUT_DEFAULT (24 * 60 * 60 * 1000)
static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
static LIST_HEAD(v9fs_sessionlist);
struct kmem_cache *v9fs_inode_cache;
@ -39,7 +42,7 @@ enum {
* source if we rejected it as EINVAL */
Opt_source,
/* Options that take integer arguments */
Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid, Opt_negtimeout,
/* String options */
Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
/* Options that take no arguments */
@ -93,6 +96,7 @@ const struct fs_parameter_spec v9fs_param_spec[] = {
fsparam_string ("access", Opt_access),
fsparam_flag ("posixacl", Opt_posixacl),
fsparam_u32 ("locktimeout", Opt_locktimeout),
fsparam_s32 ("negtimeout", Opt_negtimeout),
/* client options */
fsparam_u32 ("msize", Opt_msize),
@ -159,6 +163,9 @@ int v9fs_show_options(struct seq_file *m, struct dentry *root)
from_kgid_munged(&init_user_ns, v9ses->dfltgid));
if (v9ses->afid != ~0)
seq_printf(m, ",afid=%u", v9ses->afid);
if (v9ses->flags & V9FS_NDENTRY_TIMEOUT_SET)
seq_printf(m, ",negtimeout=%d",
(int)v9ses->ndentry_timeout_ms);
if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)
seq_printf(m, ",uname=%s", v9ses->uname);
if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)
@ -337,6 +344,16 @@ int v9fs_parse_param(struct fs_context *fc, struct fs_parameter *param)
session_opts->session_lock_timeout = (long)result.uint_32 * HZ;
break;
case Opt_negtimeout:
session_opts->flags |= V9FS_NDENTRY_TIMEOUT_SET;
if (result.int_32 < 0) {
session_opts->ndentry_timeout_ms =
NDENTRY_TIMEOUT_NEVER;
} else {
session_opts->ndentry_timeout_ms = result.int_32;
}
break;
/* Options for client */
case Opt_msize:
if (result.uint_32 < 4096) {
@ -426,6 +443,14 @@ static void v9fs_apply_options(struct v9fs_session_info *v9ses,
v9ses->cache = ctx->session_opts.cache;
v9ses->uid = ctx->session_opts.uid;
v9ses->session_lock_timeout = ctx->session_opts.session_lock_timeout;
v9ses->ndentry_timeout_ms = ctx->session_opts.ndentry_timeout_ms;
/* If negative dentry timeout has not been overridden set default for
* cache=loose
*/
if (!(v9ses->flags & V9FS_NDENTRY_TIMEOUT_SET) &&
(v9ses->cache & CACHE_LOOSE))
v9ses->ndentry_timeout_ms = CACHE_LOOSE_NDENTRY_TIMEOUT_DEFAULT;
}
/**

28
fs/9p/v9fs.h
View File

@ -24,6 +24,8 @@
* @V9FS_ACCESS_ANY: use a single attach for all users
* @V9FS_ACCESS_MASK: bit mask of different ACCESS options
* @V9FS_POSIX_ACL: POSIX ACLs are enforced
* @V9FS_NDENTRY_TIMEOUT_SET: Has negative dentry timeout retention time been
* overridden by negtimeout mount option
*
* Session flags reflect options selected by users at mount time
*/
@ -34,16 +36,17 @@
#define V9FS_ACL_MASK V9FS_POSIX_ACL
enum p9_session_flags {
V9FS_PROTO_2000U = 0x01,
V9FS_PROTO_2000L = 0x02,
V9FS_ACCESS_SINGLE = 0x04,
V9FS_ACCESS_USER = 0x08,
V9FS_ACCESS_CLIENT = 0x10,
V9FS_POSIX_ACL = 0x20,
V9FS_NO_XATTR = 0x40,
V9FS_IGNORE_QV = 0x80, /* ignore qid.version for cache hints */
V9FS_DIRECT_IO = 0x100,
V9FS_SYNC = 0x200
V9FS_PROTO_2000U = 0x01,
V9FS_PROTO_2000L = 0x02,
V9FS_ACCESS_SINGLE = 0x04,
V9FS_ACCESS_USER = 0x08,
V9FS_ACCESS_CLIENT = 0x10,
V9FS_POSIX_ACL = 0x20,
V9FS_NO_XATTR = 0x40,
V9FS_IGNORE_QV = 0x80, /* ignore qid.version for cache hints */
V9FS_DIRECT_IO = 0x100,
V9FS_SYNC = 0x200,
V9FS_NDENTRY_TIMEOUT_SET = 0x400,
};
/**
@ -91,6 +94,7 @@ enum p9_cache_bits {
* @debug: debug level
* @afid: authentication handle
* @cache: cache mode of type &p9_cache_bits
* @ndentry_timeout: Negative dentry lookup cache retention time in ms
* @cachetag: the tag of the cache associated with this session
* @fscache: session cookie associated with FS-Cache
* @uname: string user name to mount hierarchy as
@ -101,6 +105,7 @@ enum p9_cache_bits {
* @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
* @clnt: reference to 9P network client instantiated for this session
* @slist: reference to list of registered 9p sessions
* @ndentry_timeout_ms: Negative dentry caching retention time
*
* This structure holds state for each session instance established during
* a sys_mount() .
@ -116,6 +121,7 @@ struct v9fs_session_info {
unsigned short debug;
unsigned int afid;
unsigned int cache;
unsigned int ndentry_timeout_ms;
#ifdef CONFIG_9P_FSCACHE
char *cachetag;
struct fscache_volume *fscache;
@ -133,6 +139,8 @@ struct v9fs_session_info {
long session_lock_timeout; /* retry interval for blocking locks */
};
#define NDENTRY_TIMEOUT_NEVER (-1U)
/* cache_validity flags */
#define V9FS_INO_INVALID_ATTR 0x01

15
fs/9p/v9fs_vfs.h
View File

@ -28,6 +28,19 @@
/* flags for v9fs_stat2inode() & v9fs_stat2inode_dotl() */
#define V9FS_STAT2INODE_KEEP_ISIZE 1
/**
* struct v9fs_dentry - v9fs specific dentry data
* @head: List of fid associated with this dentry
* @expire_time: Lookup cache expiration time for negative dentries
* @rcu: used by kfree_rcu to schedule clean up job
*/
struct v9fs_dentry {
struct hlist_head head;
u64 expire_time;
struct rcu_head rcu;
};
#define to_v9fs_dentry(d) ((struct v9fs_dentry *)((d)->d_fsdata))
extern struct file_system_type v9fs_fs_type;
extern const struct address_space_operations v9fs_addr_operations;
extern const struct file_operations v9fs_file_operations;
@ -35,6 +48,8 @@ extern const struct file_operations v9fs_file_operations_dotl;
extern const struct file_operations v9fs_dir_operations;
extern const struct file_operations v9fs_dir_operations_dotl;
extern const struct dentry_operations v9fs_dentry_operations;
extern void v9fs_ndentry_refresh_timeout(struct dentry *dentry);
extern void v9fs_dentry_fid_remove(struct dentry *dentry);
extern const struct dentry_operations v9fs_cached_dentry_operations;
extern struct kmem_cache *v9fs_inode_cache;

36
fs/9p/vfs_addr.c
View File

@ -70,11 +70,34 @@ static void v9fs_issue_read(struct netfs_io_subrequest *subreq)
{
struct netfs_io_request *rreq = subreq->rreq;
struct p9_fid *fid = rreq->netfs_priv;
char *target;
unsigned long long pos = subreq->start + subreq->transferred;
int total, err;
int total = 0, err, len, n;
total = p9_client_read(fid, pos, &subreq->io_iter, &err);
if (S_ISLNK(rreq->inode->i_mode)) {
/* p9_client_readlink() must not be called for legacy protocols
* 9p2000 or 9p2000.u.
*/
BUG_ON(!p9_is_proto_dotl(fid->clnt));
if (WARN_ON_ONCE(pos)) {
/* reading a link at a non null offset should
* not happen
*/
err = -EIO;
goto fill_subreq;
}
err = p9_client_readlink(fid, &target);
if (err != 0)
goto fill_subreq;
len = strlen(target);
n = copy_to_iter(target, len, &subreq->io_iter);
kfree(target);
total = n;
} else {
total = p9_client_read(fid, pos, &subreq->io_iter, &err);
}
fill_subreq:
/* if we just extended the file size, any portion not in
* cache won't be on server and is zeroes */
if (subreq->rreq->origin != NETFS_UNBUFFERED_READ &&
@ -99,6 +122,7 @@ static void v9fs_issue_read(struct netfs_io_subrequest *subreq)
static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
{
struct p9_fid *fid;
struct dentry *dentry;
bool writing = (rreq->origin == NETFS_READ_FOR_WRITE ||
rreq->origin == NETFS_WRITETHROUGH ||
rreq->origin == NETFS_UNBUFFERED_WRITE ||
@ -115,6 +139,14 @@ static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
if (!fid)
goto no_fid;
p9_fid_get(fid);
} else if (S_ISLNK(rreq->inode->i_mode)) {
dentry = d_find_any_alias(rreq->inode);
if (!dentry)
goto no_fid;
fid = v9fs_fid_lookup(dentry);
dput(dentry);
if (IS_ERR(fid))
goto no_fid;
} else {
fid = v9fs_fid_find_inode(rreq->inode, writing, INVALID_UID, true);
if (!fid)

105
fs/9p/vfs_dentry.c
View File

@ -23,6 +23,46 @@
#include "v9fs_vfs.h"
#include "fid.h"
/**
* v9fs_ndentry_is_expired - Check if negative dentry lookup has expired
*
* This should be called to know if a negative dentry should be removed from
* cache.
*
* @dentry: dentry in question
*
*/
static bool v9fs_ndentry_is_expired(struct dentry const *dentry)
{
struct v9fs_session_info *v9ses = v9fs_dentry2v9ses(dentry);
struct v9fs_dentry *v9fs_dentry = to_v9fs_dentry(dentry);
if (v9ses->ndentry_timeout_ms == NDENTRY_TIMEOUT_NEVER)
return false;
return time_before_eq64(v9fs_dentry->expire_time, get_jiffies_64());
}
/**
* v9fs_ndentry_refresh_timeout - Refresh negative dentry lookup cache timeout
*
* This should be called when a look up yields a negative entry.
*
* @dentry: dentry in question
*
*/
void v9fs_ndentry_refresh_timeout(struct dentry *dentry)
{
struct v9fs_session_info *v9ses = v9fs_dentry2v9ses(dentry);
struct v9fs_dentry *v9fs_dentry = to_v9fs_dentry(dentry);
if (v9ses->ndentry_timeout_ms == NDENTRY_TIMEOUT_NEVER)
return;
v9fs_dentry->expire_time = get_jiffies_64() +
msecs_to_jiffies(v9ses->ndentry_timeout_ms);
}
/**
* v9fs_cached_dentry_delete - called when dentry refcount equals 0
* @dentry: dentry in question
@ -33,20 +73,15 @@ static int v9fs_cached_dentry_delete(const struct dentry *dentry)
p9_debug(P9_DEBUG_VFS, " dentry: %pd (%p)\n",
dentry, dentry);
/* Don't cache negative dentries */
if (d_really_is_negative(dentry))
return 1;
return 0;
if (!d_really_is_negative(dentry))
return 0;
return v9fs_ndentry_is_expired(dentry);
}
/**
* v9fs_dentry_release - called when dentry is going to be freed
* @dentry: dentry that is being release
*
*/
static void v9fs_dentry_release(struct dentry *dentry)
static void __v9fs_dentry_fid_remove(struct dentry *dentry)
{
struct v9fs_dentry *v9fs_dentry = to_v9fs_dentry(dentry);
struct hlist_node *p, *n;
struct hlist_head head;
@ -54,13 +89,54 @@ static void v9fs_dentry_release(struct dentry *dentry)
dentry, dentry);
spin_lock(&dentry->d_lock);
hlist_move_list((struct hlist_head *)&dentry->d_fsdata, &head);
hlist_move_list(&v9fs_dentry->head, &head);
spin_unlock(&dentry->d_lock);
hlist_for_each_safe(p, n, &head)
p9_fid_put(hlist_entry(p, struct p9_fid, dlist));
}
/**
* v9fs_dentry_fid_remove - Release all dentry's fids
* @dentry: dentry in question
*
*/
void v9fs_dentry_fid_remove(struct dentry *dentry)
{
__v9fs_dentry_fid_remove(dentry);
}
/**
* v9fs_dentry_init - Initialize v9fs dentry data
* @dentry: dentry in question
*
*/
static int v9fs_dentry_init(struct dentry *dentry)
{
struct v9fs_dentry *v9fs_dentry = kzalloc(sizeof(*v9fs_dentry),
GFP_KERNEL);
if (!v9fs_dentry)
return -ENOMEM;
INIT_HLIST_HEAD(&v9fs_dentry->head);
dentry->d_fsdata = (void *)v9fs_dentry;
return 0;
}
/**
* v9fs_dentry_release - called when dentry is going to be freed
* @dentry: dentry that is being released
*
*/
static void v9fs_dentry_release(struct dentry *dentry)
{
struct v9fs_dentry *v9fs_dentry = to_v9fs_dentry(dentry);
__v9fs_dentry_fid_remove(dentry);
kfree_rcu(v9fs_dentry, rcu);
}
static int __v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
{
struct p9_fid *fid;
@ -72,7 +148,7 @@ static int __v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
inode = d_inode(dentry);
if (!inode)
goto out_valid;
return !v9fs_ndentry_is_expired(dentry);
v9inode = V9FS_I(inode);
if (v9inode->cache_validity & V9FS_INO_INVALID_ATTR) {
@ -112,7 +188,6 @@ static int __v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
return retval;
}
}
out_valid:
p9_debug(P9_DEBUG_VFS, "dentry: %pd (%p) is valid\n", dentry, dentry);
return 1;
}
@ -139,12 +214,14 @@ const struct dentry_operations v9fs_cached_dentry_operations = {
.d_revalidate = v9fs_lookup_revalidate,
.d_weak_revalidate = __v9fs_lookup_revalidate,
.d_delete = v9fs_cached_dentry_delete,
.d_init = v9fs_dentry_init,
.d_release = v9fs_dentry_release,
.d_unalias_trylock = v9fs_dentry_unalias_trylock,
.d_unalias_unlock = v9fs_dentry_unalias_unlock,
};
const struct dentry_operations v9fs_dentry_operations = {
.d_init = v9fs_dentry_init,
.d_release = v9fs_dentry_release,
.d_unalias_trylock = v9fs_dentry_unalias_trylock,
.d_unalias_unlock = v9fs_dentry_unalias_unlock,

14
fs/9p/vfs_dir.c
View File

@ -27,6 +27,7 @@
* struct p9_rdir - readdir accounting
* @head: start offset of current dirread buffer
* @tail: end offset of current dirread buffer
* @offset: file position the data at @head corresponds to
* @buf: dirread buffer
*
* private structure for keeping track of readdir
@ -36,6 +37,7 @@
struct p9_rdir {
int head;
int tail;
loff_t offset;
uint8_t buf[];
};
@ -70,7 +72,7 @@ static struct p9_rdir *v9fs_alloc_rdir_buf(struct file *filp, int buflen)
struct p9_fid *fid = filp->private_data;
if (!fid->rdir)
fid->rdir = kzalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
fid->rdir = kvzalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
return fid->rdir;
}
@ -102,6 +104,9 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
kvec.iov_base = rdir->buf;
kvec.iov_len = buflen;
if (rdir->head < rdir->tail && rdir->offset != ctx->pos)
rdir->head = rdir->tail = 0;
while (1) {
if (rdir->tail == rdir->head) {
struct iov_iter to;
@ -117,6 +122,7 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
rdir->head = 0;
rdir->tail = n;
rdir->offset = ctx->pos;
}
while (rdir->head < rdir->tail) {
err = p9stat_read(fid->clnt, rdir->buf + rdir->head,
@ -134,6 +140,7 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
rdir->head += err;
ctx->pos += err;
rdir->offset = ctx->pos;
}
}
}
@ -161,6 +168,9 @@ static int v9fs_dir_readdir_dotl(struct file *file, struct dir_context *ctx)
if (!rdir)
return -ENOMEM;
if (rdir->head < rdir->tail && rdir->offset != ctx->pos)
rdir->head = rdir->tail = 0;
while (1) {
if (rdir->tail == rdir->head) {
err = p9_client_readdir(fid, rdir->buf, buflen,
@ -170,6 +180,7 @@ static int v9fs_dir_readdir_dotl(struct file *file, struct dir_context *ctx)
rdir->head = 0;
rdir->tail = err;
rdir->offset = ctx->pos;
}
while (rdir->head < rdir->tail) {
@ -190,6 +201,7 @@ static int v9fs_dir_readdir_dotl(struct file *file, struct dir_context *ctx)
ctx->pos = curdirent.d_off;
rdir->head += err;
rdir->offset = ctx->pos;
}
}
}

2
fs/9p/vfs_file.c
View File

@ -198,7 +198,7 @@ static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl)
res = -EAGAIN;
break;
default:
WARN_ONCE(1, "unknown lock status code: %d\n", status);
p9_debug(P9_DEBUG_ERROR, "unknown lock status code: %d\n", status);
fallthrough;
case P9_LOCK_ERROR:
case P9_LOCK_GRACE:

46
fs/9p/vfs_inode.c
View File

@ -302,10 +302,12 @@ int v9fs_init_inode(struct v9fs_session_info *v9ses,
goto error;
}
if (v9fs_proto_dotl(v9ses))
if (v9fs_proto_dotl(v9ses)) {
inode->i_op = &v9fs_symlink_inode_operations_dotl;
else
inode_nohighmem(inode);
} else {
inode->i_op = &v9fs_symlink_inode_operations;
}
break;
case S_IFDIR:
@ -488,10 +490,19 @@ static int v9fs_at_to_dotl_flags(int flags)
* - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
* than EXT4_LINK_MAX (65000) links.
*
* In cacheless mode the server is the source of truth for nlink and the
* inode is going away immediately, so locally adjusting i_nlink buys
* nothing and races with concurrent metadata fetches that may already
* have observed the post-unlink value (nlink == 0).
*
* @inode: inode whose nlink is being dropped
*/
static void v9fs_dec_count(struct inode *inode)
{
struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
if (!(v9ses->cache & (CACHE_META | CACHE_LOOSE)))
return;
if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)
drop_nlink(inode);
}
@ -549,7 +560,7 @@ static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
/* invalidate all fids associated with dentry */
/* NOTE: This will not include open fids */
dentry->d_op->d_release(dentry);
v9fs_dentry_fid_remove(dentry);
}
return retval;
}
@ -672,27 +683,20 @@ v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir,
static struct dentry *v9fs_vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
int err;
u32 perm;
struct p9_fid *fid;
struct v9fs_session_info *v9ses;
p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
err = 0;
v9ses = v9fs_inode2v9ses(dir);
perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
if (IS_ERR(fid)) {
err = PTR_ERR(fid);
fid = NULL;
} else {
inc_nlink(dir);
v9fs_invalidate_inode_attr(dir);
}
if (fid)
p9_fid_put(fid);
return ERR_PTR(err);
if (IS_ERR(fid))
return ERR_CAST(fid);
inc_nlink(dir);
v9fs_invalidate_inode_attr(dir);
p9_fid_put(fid);
return NULL;
}
/**
@ -732,14 +736,16 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
name = dentry->d_name.name;
fid = p9_client_walk(dfid, 1, &name, 1);
p9_fid_put(dfid);
if (fid == ERR_PTR(-ENOENT))
if (fid == ERR_PTR(-ENOENT)) {
inode = NULL;
else if (IS_ERR(fid))
v9fs_ndentry_refresh_timeout(dentry);
} else if (IS_ERR(fid)) {
inode = ERR_CAST(fid);
else if (v9ses->cache & (CACHE_META|CACHE_LOOSE))
} else if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
else
} else {
inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
}
/*
* If we had a rename on the server and a parallel lookup
* for the new name, then make sure we instantiate with

58
fs/9p/vfs_inode_dotl.c
View File

@ -349,7 +349,7 @@ static struct dentry *v9fs_vfs_mkdir_dotl(struct mnt_idmap *idmap,
struct inode *dir, struct dentry *dentry,
umode_t omode)
{
int err;
int err = 0;
struct v9fs_session_info *v9ses;
struct p9_fid *fid = NULL, *dfid = NULL;
kgid_t gid;
@ -412,7 +412,7 @@ static struct dentry *v9fs_vfs_mkdir_dotl(struct mnt_idmap *idmap,
p9_fid_put(fid);
v9fs_put_acl(dacl, pacl);
p9_fid_put(dfid);
return ERR_PTR(err);
return err ? ERR_PTR(err) : NULL;
}
static int
@ -690,9 +690,11 @@ v9fs_vfs_symlink_dotl(struct mnt_idmap *idmap, struct inode *dir,
int err;
kgid_t gid;
const unsigned char *name;
struct v9fs_session_info *v9ses;
struct p9_qid qid;
struct p9_fid *dfid;
struct p9_fid *fid = NULL;
struct inode *inode;
name = dentry->d_name.name;
p9_debug(P9_DEBUG_VFS, "%llu,%s,%s\n", dir->i_ino, name, symname);
@ -716,6 +718,26 @@ v9fs_vfs_symlink_dotl(struct mnt_idmap *idmap, struct inode *dir,
v9fs_invalidate_inode_attr(dir);
/* instantiate inode and assign the unopened fid to the dentry */
fid = p9_client_walk(dfid, 1, &name, 1);
if (IS_ERR(fid)) {
err = PTR_ERR(fid);
p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n",
err);
goto error;
}
v9ses = v9fs_inode2v9ses(dir);
inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
err);
goto error;
}
v9fs_fid_add(dentry, &fid);
d_instantiate(dentry, inode);
err = 0;
error:
p9_fid_put(fid);
p9_fid_put(dfid);
@ -857,16 +879,18 @@ v9fs_vfs_mknod_dotl(struct mnt_idmap *idmap, struct inode *dir,
}
/**
* v9fs_vfs_get_link_dotl - follow a symlink path
* v9fs_vfs_get_link_nocache_dotl - Resolve a symlink directly.
*
* To be used when symlink caching is not enabled.
*
* @dentry: dentry for symlink
* @inode: inode for symlink
* @done: destructor for return value
*/
static const char *
v9fs_vfs_get_link_dotl(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
v9fs_vfs_get_link_nocache_dotl(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
{
struct p9_fid *fid;
char *target;
@ -888,6 +912,26 @@ v9fs_vfs_get_link_dotl(struct dentry *dentry,
return target;
}
/**
* v9fs_vfs_get_link_dotl - follow a symlink path
* @dentry: dentry for symlink
* @inode: inode for symlink
* @done: destructor for return value
*/
static const char *
v9fs_vfs_get_link_dotl(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
{
struct v9fs_session_info *v9ses;
v9ses = v9fs_inode2v9ses(inode);
if (v9ses->cache & (CACHE_META|CACHE_LOOSE))
return page_get_link(dentry, inode, done);
return v9fs_vfs_get_link_nocache_dotl(dentry, inode, done);
}
int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
{
struct p9_stat_dotl *st;

1
fs/9p/vfs_super.c
View File

@ -330,6 +330,7 @@ static int v9fs_init_fs_context(struct fs_context *fc)
ctx->session_opts.uid = INVALID_UID;
ctx->session_opts.dfltuid = V9FS_DEFUID;
ctx->session_opts.dfltgid = V9FS_DEFGID;
ctx->session_opts.ndentry_timeout_ms = 0;
/* initialize client options */
ctx->client_opts.proto_version = p9_proto_2000L;

2
include/net/9p/client.h
View File

@ -192,6 +192,7 @@ struct p9_rdma_opts {
* @dfltgid: default numeric groupid to mount hierarchy as
* @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
* @session_lock_timeout: retry interval for blocking locks
* @ndentry_timeout_ms: Negative dentry lookup cache retention time in ms
*
* This strucure holds options which are parsed and will be transferred
* to the v9fs_session_info structure when mounted, and therefore largely
@ -203,6 +204,7 @@ struct p9_session_opts {
unsigned short debug;
unsigned int afid;
unsigned int cache;
unsigned int ndentry_timeout_ms;
#ifdef CONFIG_9P_FSCACHE
char *cachetag;
#endif

7
net/9p/client.c
View File

@ -600,6 +600,8 @@ p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
if (err == -ERESTARTSYS && c->status == Connected &&
type == P9_TFLUSH) {
if (fatal_signal_pending(current))
goto recalc_sigpending;
sigpending = 1;
clear_thread_flag(TIF_SIGPENDING);
goto again;
@ -765,7 +767,7 @@ static void p9_fid_destroy(struct p9_fid *fid)
spin_lock_irqsave(&clnt->lock, flags);
idr_remove(&clnt->fids, fid->fid);
spin_unlock_irqrestore(&clnt->lock, flags);
kfree(fid->rdir);
kvfree(fid->rdir);
kfree(fid);
}
@ -1092,7 +1094,8 @@ struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
clunk_fid:
kfree(wqids);
p9_fid_put(fid);
if (fid != oldfid)
p9_fid_put(fid);
fid = NULL;
error:

6
net/9p/trans_fd.c
View File

@ -940,14 +940,12 @@ p9_fd_create_unix(struct p9_client *client, struct fs_context *fc)
if (!addr || !strlen(addr))
return -EINVAL;
if (strlen(addr) >= UNIX_PATH_MAX) {
sun_server.sun_family = PF_UNIX;
if (strscpy(sun_server.sun_path, addr) < 0) {
pr_err("%s (%d): address too long: %s\n",
__func__, task_pid_nr(current), addr);
return -ENAMETOOLONG;
}
sun_server.sun_family = PF_UNIX;
strcpy(sun_server.sun_path, addr);
err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
SOCK_STREAM, 0, &csocket, 1);
if (err < 0) {

19
net/9p/trans_rdma.c
View File

@ -128,25 +128,36 @@ p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
{
struct p9_client *c = id->context;
struct p9_trans_rdma *rdma = c->trans;
unsigned long flags;
switch (event->event) {
case RDMA_CM_EVENT_ADDR_RESOLVED:
spin_lock_irqsave(&rdma->req_lock, flags);
BUG_ON(rdma->state != P9_RDMA_INIT);
rdma->state = P9_RDMA_ADDR_RESOLVED;
spin_unlock_irqrestore(&rdma->req_lock, flags);
break;
case RDMA_CM_EVENT_ROUTE_RESOLVED:
spin_lock_irqsave(&rdma->req_lock, flags);
BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
rdma->state = P9_RDMA_ROUTE_RESOLVED;
spin_unlock_irqrestore(&rdma->req_lock, flags);
break;
case RDMA_CM_EVENT_ESTABLISHED:
spin_lock_irqsave(&rdma->req_lock, flags);
BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
rdma->state = P9_RDMA_CONNECTED;
spin_unlock_irqrestore(&rdma->req_lock, flags);
break;
case RDMA_CM_EVENT_DISCONNECTED:
if (rdma)
if (rdma) {
spin_lock_irqsave(&rdma->req_lock, flags);
rdma->state = P9_RDMA_CLOSED;
spin_unlock_irqrestore(&rdma->req_lock, flags);
}
c->status = Disconnected;
break;
@ -184,6 +195,7 @@ recv_done(struct ib_cq *cq, struct ib_wc *wc)
struct p9_req_t *req;
int err = 0;
int16_t tag;
unsigned long flags;
req = NULL;
ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
@ -220,7 +232,10 @@ recv_done(struct ib_cq *cq, struct ib_wc *wc)
err_out:
p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n",
req, err, wc->status);
rdma->state = P9_RDMA_FLUSHING;
spin_lock_irqsave(&rdma->req_lock, flags);
if (rdma->state < P9_RDMA_FLUSHING)
rdma->state = P9_RDMA_FLUSHING;
spin_unlock_irqrestore(&rdma->req_lock, flags);
client->status = Disconnected;
goto out;
}

2
net/9p/trans_usbg.c
View File

@ -804,7 +804,7 @@ static void usb9pfs_attr_release(struct config_item *item)
usb_put_function_instance(&usb9pfs_opts->func_inst);
}
static struct configfs_item_operations usb9pfs_item_ops = {
static const struct configfs_item_operations usb9pfs_item_ops = {
.release = usb9pfs_attr_release,
};

5
net/9p/trans_virtio.c
View File

@ -532,6 +532,11 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
err = io_wait_event_killable(req->wq,
READ_ONCE(req->status) >= REQ_STATUS_RCVD);
/*
* Make sure our req is coherent with regard to updates in other
* threads - echoes to wmb() in the callback
*/
smp_rmb();
// RERROR needs reply (== error string) in static data
if (READ_ONCE(req->status) == REQ_STATUS_RCVD &&
unlikely(req->rc.sdata[4] == P9_RERROR))