nfsd: rip out the raparms cache

The raparms cache was set up in order to ensure that we carry readahead
information forward from one RPC call to the next. In other words, it
was set up because each RPC call was forced to open a struct file, then
close it, causing the loss of readahead information that is normally
cached in that struct file, and used to keep the page cache filled when
a user calls read() multiple times on the same file descriptor.

Now that we cache the struct file, and reuse it for all the I/O calls
to a given file by a given user, we no longer have to keep a separate
readahead cache.

Signed-off-by: Jeff Layton <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>
Signed-off-by: J. Bruce Fields <[email protected]>

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index a6b1eab7b722cc37c2d0b6439e2d2ce2c1ed251d..d02712ca2685215dfc05dc909e6553bdd41e2fb6 100644 (file)
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -317,22 +317,12 @@ static int nfsd_startup_generic(int nrservs)
        ret = nfsd_file_cache_init();
        if (ret)
                goto dec_users;
        ret = nfsd_file_cache_init();
        if (ret)
                goto dec_users;

-       /*
-        * Readahead param cache - will no-op if it already exists.
-        * (Note therefore results will be suboptimal if number of
-        * threads is modified after nfsd start.)
-        */
-       ret = nfsd_racache_init(2*nrservs);
-       if (ret)
-               goto out_file_cache;

 
        ret = nfs4_state_start();
        if (ret)
 
        ret = nfs4_state_start();
        if (ret)

-               goto out_racache;
+               goto out_file_cache;

        return 0;
 
        return 0;
 

-out_racache:
-       nfsd_racache_shutdown();

 out_file_cache:
        nfsd_file_cache_shutdown();
 dec_users:
 out_file_cache:
        nfsd_file_cache_shutdown();
 dec_users:


@@ -347,7 +337,6 @@ static void nfsd_shutdown_generic(void)
 
        nfs4_state_shutdown();
        nfsd_file_cache_shutdown();
 
        nfs4_state_shutdown();
        nfsd_file_cache_shutdown();

-       nfsd_racache_shutdown();

 }
 
 static bool nfsd_needs_lockd(struct nfsd_net *nn)
 }
 
 static bool nfsd_needs_lockd(struct nfsd_net *nn)

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index ec254bff1893084ad1d5a8fbc42da1d8aa32068a..8e2c8f36eba338a4a2f85df125c6bca9ede7eb2f 100644 (file)
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -49,34 +49,6 @@
 
 #define NFSDDBG_FACILITY               NFSDDBG_FILEOP
 
 
 #define NFSDDBG_FACILITY               NFSDDBG_FILEOP
 

-
-/*
- * This is a cache of readahead params that help us choose the proper
- * readahead strategy. Initially, we set all readahead parameters to 0
- * and let the VFS handle things.
- * If you increase the number of cached files very much, you'll need to
- * add a hash table here.
- */
-struct raparms {
-       struct raparms          *p_next;
-       unsigned int            p_count;
-       ino_t                   p_ino;
-       dev_t                   p_dev;
-       int                     p_set;
-       struct file_ra_state    p_ra;
-       unsigned int            p_hindex;
-};
-
-struct raparm_hbucket {
-       struct raparms          *pb_head;
-       spinlock_t              pb_lock;
-} ____cacheline_aligned_in_smp;
-
-#define RAPARM_HASH_BITS       4
-#define RAPARM_HASH_SIZE       (1<<RAPARM_HASH_BITS)
-#define RAPARM_HASH_MASK       (RAPARM_HASH_SIZE-1)
-static struct raparm_hbucket   raparm_hash[RAPARM_HASH_SIZE];
-

 /* 
  * Called from nfsd_lookup and encode_dirent. Check if we have crossed 
  * a mount point.
 /* 
  * Called from nfsd_lookup and encode_dirent. Check if we have crossed 
  * a mount point.


@@ -822,67 +794,6 @@ nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
        return err;
 }
 
        return err;
 }
 

-
-
-struct raparms *
-nfsd_init_raparms(struct file *file)
-{
-       struct inode *inode = file_inode(file);
-       dev_t dev = inode->i_sb->s_dev;
-       ino_t ino = inode->i_ino;
-       struct raparms  *ra, **rap, **frap = NULL;
-       int depth = 0;
-       unsigned int hash;
-       struct raparm_hbucket *rab;
-
-       hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
-       rab = &raparm_hash[hash];
-
-       spin_lock(&rab->pb_lock);
-       for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) {
-               if (ra->p_ino == ino && ra->p_dev == dev)
-                       goto found;
-               depth++;
-               if (ra->p_count == 0)
-                       frap = rap;
-       }
-       depth = nfsdstats.ra_size;
-       if (!frap) {    
-               spin_unlock(&rab->pb_lock);
-               return NULL;
-       }
-       rap = frap;
-       ra = *frap;
-       ra->p_dev = dev;
-       ra->p_ino = ino;
-       ra->p_set = 0;
-       ra->p_hindex = hash;
-found:
-       if (rap != &rab->pb_head) {
-               *rap = ra->p_next;
-               ra->p_next   = rab->pb_head;
-               rab->pb_head = ra;
-       }
-       ra->p_count++;
-       nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
-       spin_unlock(&rab->pb_lock);
-
-       if (ra->p_set)
-               file->f_ra = ra->p_ra;
-       return ra;
-}
-
-void nfsd_put_raparams(struct file *file, struct raparms *ra)
-{
-       struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
-
-       spin_lock(&rab->pb_lock);
-       ra->p_ra = file->f_ra;
-       ra->p_set = 1;
-       ra->p_count--;
-       spin_unlock(&rab->pb_lock);
-}
-

 /*
  * Grab and keep cached pages associated with a file in the svc_rqst
  * so that they can be passed to the network sendmsg/sendpage routines
 /*
  * Grab and keep cached pages associated with a file in the svc_rqst
  * so that they can be passed to the network sendmsg/sendpage routines


@@ -2094,63 +2005,3 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
 
        return err? nfserrno(err) : 0;
 }
 
        return err? nfserrno(err) : 0;
 }

-
-void
-nfsd_racache_shutdown(void)
-{
-       struct raparms *raparm, *last_raparm;
-       unsigned int i;
-
-       dprintk("nfsd: freeing readahead buffers.\n");
-
-       for (i = 0; i < RAPARM_HASH_SIZE; i++) {
-               raparm = raparm_hash[i].pb_head;
-               while(raparm) {
-                       last_raparm = raparm;
-                       raparm = raparm->p_next;
-                       kfree(last_raparm);
-               }
-               raparm_hash[i].pb_head = NULL;
-       }
-}
-/*
- * Initialize readahead param cache
- */
-int
-nfsd_racache_init(int cache_size)
-{
-       int     i;
-       int     j = 0;
-       int     nperbucket;
-       struct raparms **raparm = NULL;
-
-
-       if (raparm_hash[0].pb_head)
-               return 0;
-       nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
-       nperbucket = max(2, nperbucket);
-       cache_size = nperbucket * RAPARM_HASH_SIZE;
-
-       dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
-
-       for (i = 0; i < RAPARM_HASH_SIZE; i++) {
-               spin_lock_init(&raparm_hash[i].pb_lock);
-
-               raparm = &raparm_hash[i].pb_head;
-               for (j = 0; j < nperbucket; j++) {
-                       *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL);
-                       if (!*raparm)
-                               goto out_nomem;
-                       raparm = &(*raparm)->p_next;
-               }
-               *raparm = NULL;
-       }
-
-       nfsdstats.ra_size = cache_size;
-       return 0;
-
-out_nomem:
-       dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
-       nfsd_racache_shutdown();
-       return -ENOMEM;
-}

diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
index 31fdae34e028f43410fa4e5da791005a8b4d7fcf..e0f7792165a6855aefd15c10954a045d1dbe7379 100644 (file)
--- a/fs/nfsd/vfs.h
+++ b/fs/nfsd/vfs.h
@@ -40,8 +40,6 @@
 typedef int (*nfsd_filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
 
 /* nfsd/vfs.c */
 typedef int (*nfsd_filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
 
 /* nfsd/vfs.c */

-int            nfsd_racache_init(int);
-void           nfsd_racache_shutdown(void);

 int            nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
                                struct svc_export **expp);
 __be32         nfsd_lookup(struct svc_rqst *, struct svc_fh *,
 int            nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
                                struct svc_export **expp);
 __be32         nfsd_lookup(struct svc_rqst *, struct svc_fh *,


@@ -80,7 +78,6 @@ __be32                nfsd_open(struct svc_rqst *, struct svc_fh *, umode_t,
                                int, struct file **);
 __be32         nfsd_open_verified(struct svc_rqst *, struct svc_fh *, umode_t,
                                int, struct file **);
                                int, struct file **);
 __be32         nfsd_open_verified(struct svc_rqst *, struct svc_fh *, umode_t,
                                int, struct file **);

-struct raparms;

 __be32         nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
                                struct file *file, loff_t offset,
                                unsigned long *count);
 __be32         nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
                                struct file *file, loff_t offset,
                                unsigned long *count);


@@ -118,9 +115,6 @@ __be32              nfsd_statfs(struct svc_rqst *, struct svc_fh *,
 __be32         nfsd_permission(struct svc_rqst *, struct svc_export *,
                                struct dentry *, int);
 
 __be32         nfsd_permission(struct svc_rqst *, struct svc_export *,
                                struct dentry *, int);
 

-struct raparms *nfsd_init_raparms(struct file *file);
-void           nfsd_put_raparams(struct file *file, struct raparms *ra);
-

 static inline int fh_want_write(struct svc_fh *fh)
 {
        int ret;
 static inline int fh_want_write(struct svc_fh *fh)
 {
        int ret;