Linus, ncpfs used the same kludge as I've fixed in smbfs back in
June - ncp_iget() grabs the mutex, stores the data in global variable,
calls iget() with fake inumber (guaranteed cache miss) and releases mutex.
read_inode() picks the data from the global variable.
(a) it's an ugly kludge - after all C is not BASIC.
(b) it means that iget() for NCPFS works _only_ if called by
ncp_iget() (i.e. is worse than nothing)
(c) it gives an artificial contention point for no good reason.
Fix: instead of all this kludge-o-rama we should call get_empty_inode(),
fill it with data and call insert_inode_hash(). ->read_inode is set to
NULL (see (b)). Less significant cleanup: ncp_invent_ino() duplicates
iunique(). Replaced and removed.
Patch (against 20-pre2) follows. Please, apply it.
Cheers,
Al
diff -urN linux-2.3.20-pre2/fs/ncpfs/dir.c linux-bird.ncpfs/fs/ncpfs/dir.c
--- linux-2.3.20-pre2/fs/ncpfs/dir.c Fri Oct 8 06:00:32 1999
+++ linux-bird.ncpfs/fs/ncpfs/dir.c Sat Oct 9 11:24:57 1999
@@ -183,22 +183,6 @@
}
}
-/*
- * Generate a unique inode number.
- */
-ino_t ncp_invent_inos(unsigned long n)
-{
- static ino_t ino = 2;
-
- if (ino + 2*n < ino)
- {
- /* wrap around */
- ino = 2;
- }
- ino += n;
- return ino;
-}
-
static inline int
ncp_single_volume(struct ncp_server *server)
{
@@ -449,7 +433,7 @@
ino = find_inode_number(dentry, &qname);
if (!ino)
- ino = ncp_invent_inos(1);
+ ino = iunique(2);
result = filldir(dirent, name, len, filp->f_pos, ino);
if (!result)
@@ -494,7 +478,7 @@
if (!newdent->d_inode) {
entry->opened = 0;
- entry->ino = ncp_invent_inos(1);
+ entry->ino = iunique(2);
newino = ncp_iget(inode->i_sb, entry);
if (newino) {
newdent->d_op = &ncp_dentry_operations;
@@ -517,7 +501,7 @@
ino = find_inode_number(dentry, &qname);
if (!ino)
- ino = ncp_invent_inos(1);
+ ino = iunique(2);
result = filldir(dirent, entry->i.entryName, entry->i.nameLen,
filp->f_pos, ino);
@@ -810,7 +794,7 @@
* Create an inode for the entry.
*/
finfo.opened = 0;
- finfo.ino = ncp_invent_inos(1);
+ finfo.ino = iunique(2);
error = -EACCES;
inode = ncp_iget(dir->i_sb, &finfo);
@@ -838,7 +822,7 @@
struct inode *inode;
int error = -EINVAL;
- finfo->ino = ncp_invent_inos(1);
+ finfo->ino = iunique(2);
inode = ncp_iget(dir->i_sb, finfo);
if (!inode)
goto out_close;
diff -urN linux-2.3.20-pre2/fs/ncpfs/inode.c linux-bird.ncpfs/fs/ncpfs/inode.c
--- linux-2.3.20-pre2/fs/ncpfs/inode.c Fri Oct 8 06:00:32 1999
+++ linux-bird.ncpfs/fs/ncpfs/inode.c Sat Oct 9 11:23:23 1999
@@ -31,7 +31,6 @@
#include "ncplib_kernel.h"
-static void ncp_read_inode(struct inode *);
static void ncp_put_inode(struct inode *);
static void ncp_delete_inode(struct inode *);
static void ncp_put_super(struct super_block *);
@@ -39,7 +38,7 @@
static struct super_operations ncp_sops =
{
- ncp_read_inode, /* read inode */
+ NULL, /* read inode */
NULL, /* write inode */
ncp_put_inode, /* put inode */
ncp_delete_inode, /* delete inode */
@@ -56,9 +55,6 @@
extern int ncp_symlink(struct inode*, struct dentry*, const char*);
#endif
-static struct ncp_entry_info *read_nwinfo = NULL;
-static DECLARE_MUTEX(read_sem);
-
/*
* Fill in the ncpfs-specific information in the inode.
*/
@@ -216,33 +212,7 @@
}
/*
- * This is called from iget() with the read semaphore held.
- * The global ncp_entry_info structure has been set up by ncp_iget.
- */
-static void ncp_read_inode(struct inode *inode)
-{
- if (read_nwinfo == NULL) {
- printk(KERN_ERR "ncp_read_inode: invalid call\n");
- return;
- }
-
- ncp_set_attr(inode, read_nwinfo);
-
- if (S_ISREG(inode->i_mode)) {
- inode->i_op = &ncp_file_inode_operations;
- } else if (S_ISDIR(inode->i_mode)) {
- inode->i_op = &ncp_dir_inode_operations;
-#ifdef CONFIG_NCPFS_EXTRAS
- } else if (S_ISLNK(inode->i_mode)) {
- inode->i_op = &ncp_symlink_inode_operations;
-#endif
- } else {
- inode->i_op = NULL;
- }
-}
-
-/*
- * Set up the ncp_entry_info pointer and get a new inode.
+ * Get a new inode.
*/
struct inode *
ncp_iget(struct super_block *sb, struct ncp_entry_info *info)
@@ -254,12 +224,23 @@
return NULL;
}
- down(&read_sem);
- read_nwinfo = info;
- inode = iget(sb, info->ino);
- read_nwinfo = NULL;
- up(&read_sem);
- if (!inode)
+ inode = get_empty_inode();
+ if (inode) {
+ inode->i_sb = sb;
+ inode->i_dev = sb->s_dev;
+ inode->i_ino = info->ino;
+ ncp_set_attr(inode, info);
+ if (S_ISREG(inode->i_mode)) {
+ inode->i_op = &ncp_file_inode_operations;
+ } else if (S_ISDIR(inode->i_mode)) {
+ inode->i_op = &ncp_dir_inode_operations;
+#ifdef CONFIG_NCPFS_EXTRAS
+ } else if (S_ISLNK(inode->i_mode)) {
+ inode->i_op = &ncp_symlink_inode_operations;
+#endif
+ }
+ insert_inode_hash(inode);
+ } else
printk(KERN_ERR "ncp_iget: iget failed!\n");
return inode;
}
@@ -709,9 +690,6 @@
int init_module(void)
{
DPRINTK(KERN_DEBUG "ncpfs: init_module called\n");
-
- init_MUTEX(&read_sem);
- read_nwinfo = NULL;
#ifdef DEBUG_NCP_MALLOC
ncp_malloced = 0;
