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CIFS: Move locks to cifsFileInfo structure
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CIFS brlock cache can be used by several file handles if we have a
write-caching lease on the file that is supported by SMB2 protocol.
Prepate the code to handle this situation correctly by sorting brlocks
by a fid to easily push them in portions when lease break comes.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
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Pavel Shilovsky authored and Steve French committed May 17, 2012
1 parent 121b046 commit fbd35ac
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Showing 3 changed files with 58 additions and 44 deletions.
1 change: 0 additions & 1 deletion fs/cifs/cifsfs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -955,7 +955,6 @@ cifs_init_once(void *inode)
struct cifsInodeInfo *cifsi = inode;

inode_init_once(&cifsi->vfs_inode);
INIT_LIST_HEAD(&cifsi->llist);
mutex_init(&cifsi->lock_mutex);
}

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12 changes: 9 additions & 3 deletions fs/cifs/cifsglob.h
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Original file line number Diff line number Diff line change
Expand Up @@ -568,7 +568,6 @@ struct cifsLockInfo {
__u64 length;
__u32 pid;
__u8 type;
__u16 netfid;
};

/*
Expand All @@ -593,6 +592,10 @@ struct cifs_search_info {
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
*/
unsigned int uid; /* allows finding which FileInfo structure */
__u32 pid; /* process id who opened file */
__u16 netfid; /* file id from remote */
Expand Down Expand Up @@ -635,9 +638,12 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file);
*/

struct cifsInodeInfo {
struct list_head llist; /* brlocks for this inode */
bool can_cache_brlcks;
struct mutex lock_mutex; /* protect two fields above */
struct mutex lock_mutex; /*
* protect the field above and llist
* from every cifsFileInfo structure
* from openFileList
*/
/* 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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89 changes: 49 additions & 40 deletions fs/cifs/file.c
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Original file line number Diff line number Diff line change
Expand Up @@ -264,6 +264,7 @@ cifs_new_fileinfo(__u16 fileHandle, struct file *file,
pCifsFile->tlink = cifs_get_tlink(tlink);
mutex_init(&pCifsFile->fh_mutex);
INIT_WORK(&pCifsFile->oplock_break, cifs_oplock_break);
INIT_LIST_HEAD(&pCifsFile->llist);

spin_lock(&cifs_file_list_lock);
list_add(&pCifsFile->tlist, &(tlink_tcon(tlink)->openFileList));
Expand Down Expand Up @@ -334,9 +335,7 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
* is closed anyway.
*/
mutex_lock(&cifsi->lock_mutex);
list_for_each_entry_safe(li, tmp, &cifsi->llist, llist) {
if (li->netfid != cifs_file->netfid)
continue;
list_for_each_entry_safe(li, tmp, &cifs_file->llist, llist) {
list_del(&li->llist);
cifs_del_lock_waiters(li);
kfree(li);
Expand Down Expand Up @@ -645,7 +644,7 @@ int cifs_closedir(struct inode *inode, struct file *file)
}

static struct cifsLockInfo *
cifs_lock_init(__u64 offset, __u64 length, __u8 type, __u16 netfid)
cifs_lock_init(__u64 offset, __u64 length, __u8 type)
{
struct cifsLockInfo *lock =
kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
Expand All @@ -654,7 +653,6 @@ cifs_lock_init(__u64 offset, __u64 length, __u8 type, __u16 netfid)
lock->offset = offset;
lock->length = length;
lock->type = type;
lock->netfid = netfid;
lock->pid = current->tgid;
INIT_LIST_HEAD(&lock->blist);
init_waitqueue_head(&lock->block_q);
Expand All @@ -672,19 +670,19 @@ cifs_del_lock_waiters(struct cifsLockInfo *lock)
}

static bool
__cifs_find_lock_conflict(struct cifsInodeInfo *cinode, __u64 offset,
__u64 length, __u8 type, __u16 netfid,
struct cifsLockInfo **conf_lock)
cifs_find_fid_lock_conflict(struct cifsFileInfo *cfile, __u64 offset,
__u64 length, __u8 type, __u16 netfid,
struct cifsLockInfo **conf_lock)
{
struct cifsLockInfo *li, *tmp;
struct cifsLockInfo *li;

list_for_each_entry_safe(li, tmp, &cinode->llist, llist) {
list_for_each_entry(li, &cfile->llist, llist) {
if (offset + length <= li->offset ||
offset >= li->offset + li->length)
continue;
else if ((type & LOCKING_ANDX_SHARED_LOCK) &&
((netfid == li->netfid && current->tgid == li->pid) ||
type == li->type))
((netfid == cfile->netfid && current->tgid == li->pid)
|| type == li->type))
continue;
else {
*conf_lock = li;
Expand All @@ -695,11 +693,23 @@ __cifs_find_lock_conflict(struct cifsInodeInfo *cinode, __u64 offset,
}

static bool
cifs_find_lock_conflict(struct cifsInodeInfo *cinode, struct cifsLockInfo *lock,
cifs_find_lock_conflict(struct cifsInodeInfo *cinode, __u64 offset,
__u64 length, __u8 type, __u16 netfid,
struct cifsLockInfo **conf_lock)
{
return __cifs_find_lock_conflict(cinode, lock->offset, lock->length,
lock->type, lock->netfid, conf_lock);
bool rc = false;
struct cifsFileInfo *fid, *tmp;

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,
netfid, conf_lock);
if (rc)
break;
}
spin_unlock(&cifs_file_list_lock);

return rc;
}

/*
Expand All @@ -710,17 +720,18 @@ cifs_find_lock_conflict(struct cifsInodeInfo *cinode, struct cifsLockInfo *lock,
* the server or 1 otherwise.
*/
static int
cifs_lock_test(struct cifsInodeInfo *cinode, __u64 offset, __u64 length,
__u8 type, __u16 netfid, struct file_lock *flock)
cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
__u8 type, struct file_lock *flock)
{
int rc = 0;
struct cifsLockInfo *conf_lock;
struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
bool exist;

mutex_lock(&cinode->lock_mutex);

exist = __cifs_find_lock_conflict(cinode, offset, length, type, netfid,
&conf_lock);
exist = cifs_find_lock_conflict(cinode, offset, length, type,
cfile->netfid, &conf_lock);
if (exist) {
flock->fl_start = conf_lock->offset;
flock->fl_end = conf_lock->offset + conf_lock->length - 1;
Expand All @@ -739,10 +750,11 @@ cifs_lock_test(struct cifsInodeInfo *cinode, __u64 offset, __u64 length,
}

static void
cifs_lock_add(struct cifsInodeInfo *cinode, struct cifsLockInfo *lock)
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, &cinode->llist);
list_add_tail(&lock->llist, &cfile->llist);
mutex_unlock(&cinode->lock_mutex);
}

Expand All @@ -753,20 +765,22 @@ cifs_lock_add(struct cifsInodeInfo *cinode, struct cifsLockInfo *lock)
* 3) -EACCESS, if there is a lock that prevents us and wait is false.
*/
static int
cifs_lock_add_if(struct cifsInodeInfo *cinode, struct cifsLockInfo *lock,
cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
bool wait)
{
struct cifsLockInfo *conf_lock;
struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
bool exist;
int rc = 0;

try_again:
exist = false;
mutex_lock(&cinode->lock_mutex);

exist = cifs_find_lock_conflict(cinode, lock, &conf_lock);
exist = cifs_find_lock_conflict(cinode, lock->offset, lock->length,
lock->type, cfile->netfid, &conf_lock);
if (!exist && cinode->can_cache_brlcks) {
list_add_tail(&lock->llist, &cinode->llist);
list_add_tail(&lock->llist, &cfile->llist);
mutex_unlock(&cinode->lock_mutex);
return rc;
}
Expand Down Expand Up @@ -888,7 +902,7 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
for (i = 0; i < 2; i++) {
cur = buf;
num = 0;
list_for_each_entry_safe(li, tmp, &cinode->llist, llist) {
list_for_each_entry_safe(li, tmp, &cfile->llist, llist) {
if (li->type != types[i])
continue;
cur->Pid = cpu_to_le16(li->pid);
Expand Down Expand Up @@ -1104,7 +1118,6 @@ cifs_getlk(struct file *file, struct file_lock *flock, __u8 type,
__u64 length = 1 + flock->fl_end - flock->fl_start;
struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
__u16 netfid = cfile->netfid;

if (posix_lck) {
Expand All @@ -1124,8 +1137,7 @@ cifs_getlk(struct file *file, struct file_lock *flock, __u8 type,
return rc;
}

rc = cifs_lock_test(cinode, flock->fl_start, length, type, netfid,
flock);
rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
if (!rc)
return rc;

Expand Down Expand Up @@ -1212,15 +1224,13 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, int xid)
for (i = 0; i < 2; i++) {
cur = buf;
num = 0;
list_for_each_entry_safe(li, tmp, &cinode->llist, llist) {
list_for_each_entry_safe(li, tmp, &cfile->llist, llist) {
if (flock->fl_start > li->offset ||
(flock->fl_start + length) <
(li->offset + li->length))
continue;
if (current->tgid != li->pid)
continue;
if (cfile->netfid != li->netfid)
continue;
if (types[i] != li->type)
continue;
if (!cinode->can_cache_brlcks) {
Expand All @@ -1233,7 +1243,7 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, int xid)
cpu_to_le32((u32)(li->offset>>32));
/*
* We need to save a lock here to let us add
* it again to the inode list if the unlock
* it again to the file's list if the unlock
* range request fails on the server.
*/
list_move(&li->llist, &tmp_llist);
Expand All @@ -1247,10 +1257,10 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, int xid)
* We failed on the unlock range
* request - add all locks from
* the tmp list to the head of
* the inode list.
* the file's list.
*/
cifs_move_llist(&tmp_llist,
&cinode->llist);
&cfile->llist);
rc = stored_rc;
} else
/*
Expand All @@ -1265,7 +1275,7 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, int xid)
} else {
/*
* We can cache brlock requests - simply remove
* a lock from the inode list.
* a lock from the file's list.
*/
list_del(&li->llist);
cifs_del_lock_waiters(li);
Expand All @@ -1276,7 +1286,7 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, int xid)
stored_rc = cifs_lockv(xid, tcon, cfile->netfid,
types[i], num, 0, buf);
if (stored_rc) {
cifs_move_llist(&tmp_llist, &cinode->llist);
cifs_move_llist(&tmp_llist, &cfile->llist);
rc = stored_rc;
} else
cifs_free_llist(&tmp_llist);
Expand All @@ -1296,7 +1306,6 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u8 type,
__u64 length = 1 + flock->fl_end - flock->fl_start;
struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
struct cifsInodeInfo *cinode = CIFS_I(file->f_path.dentry->d_inode);
__u16 netfid = cfile->netfid;

if (posix_lck) {
Expand All @@ -1323,11 +1332,11 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u8 type,
if (lock) {
struct cifsLockInfo *lock;

lock = cifs_lock_init(flock->fl_start, length, type, netfid);
lock = cifs_lock_init(flock->fl_start, length, type);
if (!lock)
return -ENOMEM;

rc = cifs_lock_add_if(cinode, lock, wait_flag);
rc = cifs_lock_add_if(cfile, lock, wait_flag);
if (rc < 0)
kfree(lock);
if (rc <= 0)
Expand All @@ -1340,7 +1349,7 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u8 type,
goto out;
}

cifs_lock_add(cinode, lock);
cifs_lock_add(cfile, lock);
} else if (unlock)
rc = cifs_unlock_range(cfile, flock, xid);

Expand Down

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