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 <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 0 insertions, 149 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index ec254bff1893..8e2c8f36eba3 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -49,34 +49,6 @@
 
 #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.
@@ -822,67 +794,6 @@ nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
         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
@@ -2094,63 +2005,3 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
 
         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;
-}