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CIFS: Remove spinlock dependence in brlock processing
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Now we need to lock/unlock a spinlock while processing brlock ops
on the inode. Move brlocks of a fid to a separate list and attach
all such lists to the inode. This let us not hold a spinlock.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
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Pavel Shilovsky authored and Steve French committed Sep 25, 2012
1 parent 1c0bd60 commit f45d341
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Showing 3 changed files with 53 additions and 39 deletions.
1 change: 1 addition & 0 deletions fs/cifs/cifsfs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -233,6 +233,7 @@ cifs_alloc_inode(struct super_block *sb)
to zero by the VFS */
/* cifs_inode->vfs_inode.i_flags = S_NOATIME | S_NOCMTIME;*/
INIT_LIST_HEAD(&cifs_inode->openFileList);
INIT_LIST_HEAD(&cifs_inode->llist);
return &cifs_inode->vfs_inode;
}

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18 changes: 9 additions & 9 deletions fs/cifs/cifsglob.h
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Original file line number Diff line number Diff line change
Expand Up @@ -890,13 +890,16 @@ struct cifs_fid {
#endif
};

struct cifs_fid_locks {
struct list_head llist;
struct cifsFileInfo *cfile; /* fid that owns locks */
struct list_head locks; /* locks held by fid above */
};

struct cifsFileInfo {
struct list_head tlist; /* pointer to next fid owned by tcon */
struct list_head flist; /* next fid (file instance) for this inode */
struct list_head llist; /*
* brlocks held by this fid, protected by
* lock_mutex from cifsInodeInfo structure
*/
struct cifs_fid_locks *llist; /* brlocks held by this fid */
unsigned int uid; /* allows finding which FileInfo structure */
__u32 pid; /* process id who opened file */
struct cifs_fid fid; /* file id from remote */
Expand Down Expand Up @@ -988,11 +991,8 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file);

struct cifsInodeInfo {
bool can_cache_brlcks;
struct mutex lock_mutex; /*
* protect the field above and llist
* from every cifsFileInfo structure
* from openFileList
*/
struct list_head llist; /* locks helb by this inode */
struct mutex lock_mutex; /* protect the fields above */
/* BB add in lists for dirty pages i.e. write caching info for oplock */
struct list_head openFileList;
__u32 cifsAttrs; /* e.g. DOS archive bit, sparse, compressed, system */
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73 changes: 43 additions & 30 deletions fs/cifs/file.c
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Original file line number Diff line number Diff line change
Expand Up @@ -245,21 +245,34 @@ cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
struct inode *inode = dentry->d_inode;
struct cifsInodeInfo *cinode = CIFS_I(inode);
struct cifsFileInfo *cfile;
struct cifs_fid_locks *fdlocks;

cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
if (cfile == NULL)
return cfile;

fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
if (!fdlocks) {
kfree(cfile);
return NULL;
}

INIT_LIST_HEAD(&fdlocks->locks);
fdlocks->cfile = cfile;
cfile->llist = fdlocks;
mutex_lock(&cinode->lock_mutex);
list_add(&fdlocks->llist, &cinode->llist);
mutex_unlock(&cinode->lock_mutex);

cfile->count = 1;
cfile->pid = current->tgid;
cfile->uid = current_fsuid();
cfile->dentry = dget(dentry);
cfile->f_flags = file->f_flags;
cfile->invalidHandle = false;
cfile->tlink = cifs_get_tlink(tlink);
mutex_init(&cfile->fh_mutex);
INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
INIT_LIST_HEAD(&cfile->llist);
mutex_init(&cfile->fh_mutex);
tlink_tcon(tlink)->ses->server->ops->set_fid(cfile, fid, oplock);

spin_lock(&cifs_file_list_lock);
Expand Down Expand Up @@ -336,15 +349,18 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
free_xid(xid);
}

/* Delete any outstanding lock records. We'll lose them when the file
/*
* Delete any outstanding lock records. We'll lose them when the file
* is closed anyway.
*/
mutex_lock(&cifsi->lock_mutex);
list_for_each_entry_safe(li, tmp, &cifs_file->llist, llist) {
list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
list_del(&li->llist);
cifs_del_lock_waiters(li);
kfree(li);
}
list_del(&cifs_file->llist->llist);
kfree(cifs_file->llist);
mutex_unlock(&cifsi->lock_mutex);

cifs_put_tlink(cifs_file->tlink);
Expand Down Expand Up @@ -691,25 +707,24 @@ cifs_del_lock_waiters(struct cifsLockInfo *lock)
}

static bool
cifs_find_fid_lock_conflict(struct cifsFileInfo *cfile, __u64 offset,
__u64 length, __u8 type, struct cifsFileInfo *cur,
cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
__u64 length, __u8 type, struct cifsFileInfo *cfile,
struct cifsLockInfo **conf_lock)
{
struct cifsLockInfo *li;
struct cifsFileInfo *cur_cfile = fdlocks->cfile;
struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;

list_for_each_entry(li, &cfile->llist, llist) {
list_for_each_entry(li, &fdlocks->locks, llist) {
if (offset + length <= li->offset ||
offset >= li->offset + li->length)
continue;
else if ((type & server->vals->shared_lock_type) &&
((server->ops->compare_fids(cur, cfile) &&
current->tgid == li->pid) || type == li->type))
if ((type & server->vals->shared_lock_type) &&
((server->ops->compare_fids(cfile, cur_cfile) &&
current->tgid == li->pid) || type == li->type))
continue;
else {
*conf_lock = li;
return true;
}
*conf_lock = li;
return true;
}
return false;
}
Expand All @@ -719,17 +734,15 @@ cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
__u8 type, struct cifsLockInfo **conf_lock)
{
bool rc = false;
struct cifsFileInfo *fid, *tmp;
struct cifs_fid_locks *cur;
struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);

spin_lock(&cifs_file_list_lock);
list_for_each_entry_safe(fid, tmp, &cinode->openFileList, flist) {
rc = cifs_find_fid_lock_conflict(fid, offset, length, type,
list_for_each_entry(cur, &cinode->llist, llist) {
rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
cfile, conf_lock);
if (rc)
break;
}
spin_unlock(&cifs_file_list_lock);

return rc;
}
Expand Down Expand Up @@ -777,7 +790,7 @@ cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
{
struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
mutex_lock(&cinode->lock_mutex);
list_add_tail(&lock->llist, &cfile->llist);
list_add_tail(&lock->llist, &cfile->llist->locks);
mutex_unlock(&cinode->lock_mutex);
}

Expand All @@ -803,7 +816,7 @@ cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
lock->type, &conf_lock);
if (!exist && cinode->can_cache_brlcks) {
list_add_tail(&lock->llist, &cfile->llist);
list_add_tail(&lock->llist, &cfile->llist->locks);
mutex_unlock(&cinode->lock_mutex);
return rc;
}
Expand Down Expand Up @@ -937,7 +950,7 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
for (i = 0; i < 2; i++) {
cur = buf;
num = 0;
list_for_each_entry_safe(li, tmp, &cfile->llist, llist) {
list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
if (li->type != types[i])
continue;
cur->Pid = cpu_to_le16(li->pid);
Expand Down Expand Up @@ -1279,7 +1292,7 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
for (i = 0; i < 2; i++) {
cur = buf;
num = 0;
list_for_each_entry_safe(li, tmp, &cfile->llist, llist) {
list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
if (flock->fl_start > li->offset ||
(flock->fl_start + length) <
(li->offset + li->length))
Expand Down Expand Up @@ -1320,7 +1333,7 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
* list to the head of the file's list.
*/
cifs_move_llist(&tmp_llist,
&cfile->llist);
&cfile->llist->locks);
rc = stored_rc;
} else
/*
Expand All @@ -1337,7 +1350,8 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
types[i], num, 0, buf);
if (stored_rc) {
cifs_move_llist(&tmp_llist, &cfile->llist);
cifs_move_llist(&tmp_llist,
&cfile->llist->locks);
rc = stored_rc;
} else
cifs_free_llist(&tmp_llist);
Expand All @@ -1350,7 +1364,7 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
}

static int
cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
bool wait_flag, bool posix_lck, int lock, int unlock,
unsigned int xid)
{
Expand All @@ -1359,7 +1373,6 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
struct TCP_Server_Info *server = tcon->ses->server;
__u16 netfid = cfile->fid.netfid;

if (posix_lck) {
int posix_lock_type;
Expand All @@ -1376,9 +1389,9 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
if (unlock == 1)
posix_lock_type = CIFS_UNLCK;

rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
flock->fl_start, length, NULL,
posix_lock_type, wait_flag);
rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
current->tgid, flock->fl_start, length,
NULL, posix_lock_type, wait_flag);
goto out;
}

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