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[CIFS] move close processing from cifs_close to cifsFileInfo_put
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Now that it's feasible for a cifsFileInfo to outlive the filp under
which it was created, move the close processing into cifsFileInfo_put.

This means that the last user of the filehandle always does the actual
on the wire close call. This also allows us to get rid of the closePend
flag from cifsFileInfo. If we have an active reference to the file
then it's never going to have a close pending.

cifs_close is converted to simply put the filehandle.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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Steve French committed Oct 21, 2010
1 parent 3f9bcca commit cdff08e
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Showing 3 changed files with 60 additions and 138 deletions.
1 change: 0 additions & 1 deletion fs/cifs/cifsglob.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -393,7 +393,6 @@ struct cifsFileInfo {
struct tcon_link *tlink;
struct mutex lock_mutex;
struct list_head llist; /* list of byte range locks we have. */
bool closePend:1; /* file is marked to close */
bool invalidHandle:1; /* file closed via session abend */
bool oplock_break_cancelled:1;
atomic_t count; /* reference count */
Expand Down
187 changes: 60 additions & 127 deletions fs/cifs/file.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -238,7 +238,6 @@ cifs_new_fileinfo(__u16 fileHandle, struct file *file,
pCifsFile->dentry = dget(dentry);
pCifsFile->f_flags = file->f_flags;
pCifsFile->invalidHandle = false;
pCifsFile->closePend = false;
pCifsFile->tlink = cifs_get_tlink(tlink);
mutex_init(&pCifsFile->fh_mutex);
mutex_init(&pCifsFile->lock_mutex);
Expand Down Expand Up @@ -266,14 +265,55 @@ cifs_new_fileinfo(__u16 fileHandle, struct file *file,
return pCifsFile;
}

/* Release a reference on the file private data */
/*
* Release a reference on the file private data. This may involve closing
* the filehandle out on the server.
*/
void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
{
if (atomic_dec_and_test(&cifs_file->count)) {
cifs_put_tlink(cifs_file->tlink);
dput(cifs_file->dentry);
kfree(cifs_file);
struct cifsTconInfo *tcon = tlink_tcon(cifs_file->tlink);
struct cifsInodeInfo *cifsi = CIFS_I(cifs_file->dentry->d_inode);
struct cifsLockInfo *li, *tmp;

spin_lock(&cifs_file_list_lock);
if (!atomic_dec_and_test(&cifs_file->count)) {
spin_unlock(&cifs_file_list_lock);
return;
}

/* remove it from the lists */
list_del(&cifs_file->flist);
list_del(&cifs_file->tlist);

if (list_empty(&cifsi->openFileList)) {
cFYI(1, "closing last open instance for inode %p",
cifs_file->dentry->d_inode);
cifsi->clientCanCacheRead = false;
cifsi->clientCanCacheAll = false;
}
spin_unlock(&cifs_file_list_lock);

if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
int xid, rc;

xid = GetXid();
rc = CIFSSMBClose(xid, tcon, cifs_file->netfid);
FreeXid(xid);
}

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

cifs_put_tlink(cifs_file->tlink);
dput(cifs_file->dentry);
kfree(cifs_file);
}

int cifs_open(struct inode *inode, struct file *file)
Expand Down Expand Up @@ -605,79 +645,11 @@ static int cifs_reopen_file(struct cifsFileInfo *pCifsFile, bool can_flush)

int cifs_close(struct inode *inode, struct file *file)
{
int rc = 0;
int xid, timeout;
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
struct cifsFileInfo *pSMBFile = file->private_data;

xid = GetXid();

cifs_sb = CIFS_SB(inode->i_sb);
pTcon = tlink_tcon(pSMBFile->tlink);
if (pSMBFile) {
struct cifsLockInfo *li, *tmp;
spin_lock(&cifs_file_list_lock);
pSMBFile->closePend = true;
if (pTcon) {
/* no sense reconnecting to close a file that is
already closed */
if (!pTcon->need_reconnect) {
spin_unlock(&cifs_file_list_lock);
timeout = 2;
while ((atomic_read(&pSMBFile->count) != 1)
&& (timeout <= 2048)) {
/* Give write a better chance to get to
server ahead of the close. We do not
want to add a wait_q here as it would
increase the memory utilization as
the struct would be in each open file,
but this should give enough time to
clear the socket */
cFYI(DBG2, "close delay, write pending");
msleep(timeout);
timeout *= 4;
}
if (!pTcon->need_reconnect &&
!pSMBFile->invalidHandle)
rc = CIFSSMBClose(xid, pTcon,
pSMBFile->netfid);
} else
spin_unlock(&cifs_file_list_lock);
} else
spin_unlock(&cifs_file_list_lock);

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

spin_lock(&cifs_file_list_lock);
list_del(&pSMBFile->flist);
list_del(&pSMBFile->tlist);
spin_unlock(&cifs_file_list_lock);
cifsFileInfo_put(file->private_data);
file->private_data = NULL;
} else
rc = -EBADF;

spin_lock(&cifs_file_list_lock);
if (list_empty(&(CIFS_I(inode)->openFileList))) {
cFYI(1, "closing last open instance for inode %p", inode);
/* if the file is not open we do not know if we can cache info
on this inode, much less write behind and read ahead */
CIFS_I(inode)->clientCanCacheRead = false;
CIFS_I(inode)->clientCanCacheAll = false;
}
spin_unlock(&cifs_file_list_lock);
if ((rc == 0) && CIFS_I(inode)->write_behind_rc)
rc = CIFS_I(inode)->write_behind_rc;
FreeXid(xid);
return rc;
/* return code from the ->release op is always ignored */
return 0;
}

int cifs_closedir(struct inode *inode, struct file *file)
Expand Down Expand Up @@ -1024,13 +996,6 @@ ssize_t cifs_user_write(struct file *file, const char __user *write_data,
we blocked so return what we managed to write */
return total_written;
}
if (open_file->closePend) {
FreeXid(xid);
if (total_written)
return total_written;
else
return -EBADF;
}
if (open_file->invalidHandle) {
/* we could deadlock if we called
filemap_fdatawait from here so tell
Expand Down Expand Up @@ -1111,13 +1076,6 @@ static ssize_t cifs_write(struct cifsFileInfo *open_file,
total_written += bytes_written) {
rc = -EAGAIN;
while (rc == -EAGAIN) {
if (open_file->closePend) {
FreeXid(xid);
if (total_written)
return total_written;
else
return -EBADF;
}
if (open_file->invalidHandle) {
/* we could deadlock if we called
filemap_fdatawait from here so tell
Expand Down Expand Up @@ -1197,8 +1155,6 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
are always at the end of the list but since the first entry might
have a close pending, we go through the whole list */
list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
if (open_file->closePend)
continue;
if (fsuid_only && open_file->uid != current_fsuid())
continue;
if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
Expand Down Expand Up @@ -1244,8 +1200,6 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
spin_lock(&cifs_file_list_lock);
refind_writable:
list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
if (open_file->closePend)
continue;
if (!any_available && open_file->pid != current->tgid)
continue;
if (fsuid_only && open_file->uid != current_fsuid())
Expand All @@ -1260,34 +1214,18 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
}

spin_unlock(&cifs_file_list_lock);

/* Had to unlock since following call can block */
rc = cifs_reopen_file(open_file, false);
if (!rc) {
if (!open_file->closePend)
return open_file;
else { /* start over in case this was deleted */
/* since the list could be modified */
spin_lock(&cifs_file_list_lock);
cifsFileInfo_put(open_file);
goto refind_writable;
}
}
if (!rc)
return open_file;

/* if it fails, try another handle if possible -
(we can not do this if closePending since
loop could be modified - in which case we
have to start at the beginning of the list
again. Note that it would be bad
to hold up writepages here (rather than
in caller) with continuous retries */
/* if it fails, try another handle if possible */
cFYI(1, "wp failed on reopen file");
spin_lock(&cifs_file_list_lock);
/* can not use this handle, no write
pending on this one after all */
cifsFileInfo_put(open_file);

if (open_file->closePend) /* list could have changed */
goto refind_writable;
spin_lock(&cifs_file_list_lock);

/* else we simply continue to the next entry. Thus
we do not loop on reopen errors. If we
can not reopen the file, for example if we
Expand Down Expand Up @@ -1808,8 +1746,7 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data,
smb_read_data = NULL;
while (rc == -EAGAIN) {
int buf_type = CIFS_NO_BUFFER;
if ((open_file->invalidHandle) &&
(!open_file->closePend)) {
if (open_file->invalidHandle) {
rc = cifs_reopen_file(open_file, true);
if (rc != 0)
break;
Expand Down Expand Up @@ -1894,8 +1831,7 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
}
rc = -EAGAIN;
while (rc == -EAGAIN) {
if ((open_file->invalidHandle) &&
(!open_file->closePend)) {
if (open_file->invalidHandle) {
rc = cifs_reopen_file(open_file, true);
if (rc != 0)
break;
Expand Down Expand Up @@ -2059,8 +1995,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
read_size, contig_pages);
rc = -EAGAIN;
while (rc == -EAGAIN) {
if ((open_file->invalidHandle) &&
(!open_file->closePend)) {
if (open_file->invalidHandle) {
rc = cifs_reopen_file(open_file, true);
if (rc != 0)
break;
Expand Down Expand Up @@ -2212,8 +2147,6 @@ static int is_inode_writable(struct cifsInodeInfo *cifs_inode)

spin_lock(&cifs_file_list_lock);
list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
if (open_file->closePend)
continue;
if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
spin_unlock(&cifs_file_list_lock);
return 1;
Expand Down Expand Up @@ -2372,7 +2305,7 @@ void cifs_oplock_break(struct work_struct *work)
* not bother sending an oplock release if session to server still is
* disconnected since oplock already released by the server
*/
if (!cfile->closePend && !cfile->oplock_break_cancelled) {
if (!cfile->oplock_break_cancelled) {
rc = CIFSSMBLock(0, tlink_tcon(cfile->tlink), cfile->netfid, 0,
0, 0, 0, LOCKING_ANDX_OPLOCK_RELEASE, false);
cFYI(1, "Oplock release rc = %d", rc);
Expand Down
10 changes: 0 additions & 10 deletions fs/cifs/misc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -567,16 +567,6 @@ is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv)
if (pSMB->Fid != netfile->netfid)
continue;

/*
* don't do anything if file is about to be
* closed anyway.
*/
if (netfile->closePend) {
spin_unlock(&cifs_file_list_lock);
spin_unlock(&cifs_tcp_ses_lock);
return true;
}

cFYI(1, "file id match, oplock break");
pCifsInode = CIFS_I(netfile->dentry->d_inode);
pCifsInode->clientCanCacheAll = false;
Expand Down

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