diff options
Diffstat (limited to 'fs/autofs/dirhash.c')
-rw-r--r-- | fs/autofs/dirhash.c | 250 |
1 files changed, 0 insertions, 250 deletions
diff --git a/fs/autofs/dirhash.c b/fs/autofs/dirhash.c deleted file mode 100644 index e947915..0000000 --- a/fs/autofs/dirhash.c +++ /dev/null @@ -1,250 +0,0 @@ -/* -*- linux-c -*- --------------------------------------------------------- * - * - * linux/fs/autofs/dirhash.c - * - * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved - * - * This file is part of the Linux kernel and is made available under - * the terms of the GNU General Public License, version 2, or at your - * option, any later version, incorporated herein by reference. - * - * ------------------------------------------------------------------------- */ - -#include "autofs_i.h" - -/* Functions for maintenance of expiry queue */ - -static void autofs_init_usage(struct autofs_dirhash *dh, - struct autofs_dir_ent *ent) -{ - list_add_tail(&ent->exp, &dh->expiry_head); - ent->last_usage = jiffies; -} - -static void autofs_delete_usage(struct autofs_dir_ent *ent) -{ - list_del(&ent->exp); -} - -void autofs_update_usage(struct autofs_dirhash *dh, - struct autofs_dir_ent *ent) -{ - autofs_delete_usage(ent); /* Unlink from current position */ - autofs_init_usage(dh,ent); /* Relink at queue tail */ -} - -struct autofs_dir_ent *autofs_expire(struct super_block *sb, - struct autofs_sb_info *sbi, - struct vfsmount *mnt) -{ - struct autofs_dirhash *dh = &sbi->dirhash; - struct autofs_dir_ent *ent; - unsigned long timeout = sbi->exp_timeout; - - while (1) { - struct path path; - int umount_ok; - - if ( list_empty(&dh->expiry_head) || sbi->catatonic ) - return NULL; /* No entries */ - /* We keep the list sorted by last_usage and want old stuff */ - ent = list_entry(dh->expiry_head.next, struct autofs_dir_ent, exp); - if (jiffies - ent->last_usage < timeout) - break; - /* Move to end of list in case expiry isn't desirable */ - autofs_update_usage(dh, ent); - - /* Check to see that entry is expirable */ - if ( ent->ino < AUTOFS_FIRST_DIR_INO ) - return ent; /* Symlinks are always expirable */ - - /* Get the dentry for the autofs subdirectory */ - path.dentry = ent->dentry; - - if (!path.dentry) { - /* Should only happen in catatonic mode */ - printk("autofs: dentry == NULL but inode range is directory, entry %s\n", ent->name); - autofs_delete_usage(ent); - continue; - } - - if (!path.dentry->d_inode) { - dput(path.dentry); - printk("autofs: negative dentry on expiry queue: %s\n", - ent->name); - autofs_delete_usage(ent); - continue; - } - - /* Make sure entry is mounted and unused; note that dentry will - point to the mounted-on-top root. */ - if (!S_ISDIR(path.dentry->d_inode->i_mode) || - !d_mountpoint(path.dentry)) { - DPRINTK(("autofs: not expirable (not a mounted directory): %s\n", ent->name)); - continue; - } - path.mnt = mnt; - path_get(&path); - if (!follow_down(&path)) { - path_put(&path); - DPRINTK(("autofs: not expirable (not a mounted directory): %s\n", ent->name)); - continue; - } - while (d_mountpoint(path.dentry) && follow_down(&path)) - ; - umount_ok = may_umount(path.mnt); - path_put(&path); - - if (umount_ok) { - DPRINTK(("autofs: signaling expire on %s\n", ent->name)); - return ent; /* Expirable! */ - } - DPRINTK(("autofs: didn't expire due to may_umount: %s\n", ent->name)); - } - return NULL; /* No expirable entries */ -} - -void autofs_initialize_hash(struct autofs_dirhash *dh) { - memset(&dh->h, 0, AUTOFS_HASH_SIZE*sizeof(struct autofs_dir_ent *)); - INIT_LIST_HEAD(&dh->expiry_head); -} - -struct autofs_dir_ent *autofs_hash_lookup(const struct autofs_dirhash *dh, struct qstr *name) -{ - struct autofs_dir_ent *dhn; - - DPRINTK(("autofs_hash_lookup: hash = 0x%08x, name = ", name->hash)); - autofs_say(name->name,name->len); - - for ( dhn = dh->h[(unsigned) name->hash % AUTOFS_HASH_SIZE] ; dhn ; dhn = dhn->next ) { - if ( name->hash == dhn->hash && - name->len == dhn->len && - !memcmp(name->name, dhn->name, name->len) ) - break; - } - - return dhn; -} - -void autofs_hash_insert(struct autofs_dirhash *dh, struct autofs_dir_ent *ent) -{ - struct autofs_dir_ent **dhnp; - - DPRINTK(("autofs_hash_insert: hash = 0x%08x, name = ", ent->hash)); - autofs_say(ent->name,ent->len); - - autofs_init_usage(dh,ent); - if (ent->dentry) - dget(ent->dentry); - - dhnp = &dh->h[(unsigned) ent->hash % AUTOFS_HASH_SIZE]; - ent->next = *dhnp; - ent->back = dhnp; - *dhnp = ent; - if ( ent->next ) - ent->next->back = &(ent->next); -} - -void autofs_hash_delete(struct autofs_dir_ent *ent) -{ - *(ent->back) = ent->next; - if ( ent->next ) - ent->next->back = ent->back; - - autofs_delete_usage(ent); - - if ( ent->dentry ) - dput(ent->dentry); - kfree(ent->name); - kfree(ent); -} - -/* - * Used by readdir(). We must validate "ptr", so we can't simply make it - * a pointer. Values below 0xffff are reserved; calling with any value - * <= 0x10000 will return the first entry found. - * - * "last" can be NULL or the value returned by the last search *if* we - * want the next sequential entry. - */ -struct autofs_dir_ent *autofs_hash_enum(const struct autofs_dirhash *dh, - off_t *ptr, struct autofs_dir_ent *last) -{ - int bucket, ecount, i; - struct autofs_dir_ent *ent; - - bucket = (*ptr >> 16) - 1; - ecount = *ptr & 0xffff; - - if ( bucket < 0 ) { - bucket = ecount = 0; - } - - DPRINTK(("autofs_hash_enum: bucket %d, entry %d\n", bucket, ecount)); - - ent = last ? last->next : NULL; - - if ( ent ) { - ecount++; - } else { - while ( bucket < AUTOFS_HASH_SIZE ) { - ent = dh->h[bucket]; - for ( i = ecount ; ent && i ; i-- ) - ent = ent->next; - - if (ent) { - ecount++; /* Point to *next* entry */ - break; - } - - bucket++; ecount = 0; - } - } - -#ifdef DEBUG - if ( !ent ) - printk("autofs_hash_enum: nothing found\n"); - else { - printk("autofs_hash_enum: found hash %08x, name", ent->hash); - autofs_say(ent->name,ent->len); - } -#endif - - *ptr = ((bucket+1) << 16) + ecount; - return ent; -} - -/* Iterate over all the ents, and remove all dentry pointers. Used on - entering catatonic mode, in order to make the filesystem unmountable. */ -void autofs_hash_dputall(struct autofs_dirhash *dh) -{ - int i; - struct autofs_dir_ent *ent; - - for ( i = 0 ; i < AUTOFS_HASH_SIZE ; i++ ) { - for ( ent = dh->h[i] ; ent ; ent = ent->next ) { - if ( ent->dentry ) { - dput(ent->dentry); - ent->dentry = NULL; - } - } - } -} - -/* Delete everything. This is used on filesystem destruction, so we - make no attempt to keep the pointers valid */ -void autofs_hash_nuke(struct autofs_sb_info *sbi) -{ - int i; - struct autofs_dir_ent *ent, *nent; - - for ( i = 0 ; i < AUTOFS_HASH_SIZE ; i++ ) { - for ( ent = sbi->dirhash.h[i] ; ent ; ent = nent ) { - nent = ent->next; - if ( ent->dentry ) - dput(ent->dentry); - kfree(ent->name); - kfree(ent); - } - } -} |