X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fautofs4%2Fexpire.c;h=3da18d4534881a199dccfa223d77c3019c813269;hb=7f59203abeaf18bf3497b308891f95a4489810ad;hp=6ae2fc8233ff9cabdabb3adb44ecd2585dca2db4;hpb=e0a7aae94030b878601eb67686b696de4a3764f0;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c index 6ae2fc8..3da18d4 100644 --- a/fs/autofs4/expire.c +++ b/fs/autofs4/expire.c @@ -4,7 +4,7 @@ * * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved * Copyright 1999-2000 Jeremy Fitzhardinge - * Copyright 2001-2003 Ian Kent + * Copyright 2001-2006 Ian Kent * * 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 @@ -32,7 +32,7 @@ static inline int autofs4_can_expire(struct dentry *dentry, if (!do_now) { /* Too young to die */ - if (time_after(ino->last_used + timeout, now)) + if (!timeout || time_after(ino->last_used + timeout, now)) return 0; /* update last_used here :- @@ -48,23 +48,36 @@ static inline int autofs4_can_expire(struct dentry *dentry, static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry) { struct dentry *top = dentry; + struct path path = {.mnt = mnt, .dentry = dentry}; int status = 1; DPRINTK("dentry %p %.*s", dentry, (int)dentry->d_name.len, dentry->d_name.name); - mntget(mnt); - dget(dentry); + path_get(&path); - if (!autofs4_follow_mount(&mnt, &dentry)) + if (!follow_down(&path)) goto done; - /* This is an autofs submount, we can't expire it */ - if (is_autofs4_dentry(dentry)) - goto done; + if (is_autofs4_dentry(path.dentry)) { + struct autofs_sb_info *sbi = autofs4_sbi(path.dentry->d_sb); + + /* This is an autofs submount, we can't expire it */ + if (autofs_type_indirect(sbi->type)) + goto done; + + /* + * Otherwise it's an offset mount and we need to check + * if we can umount its mount, if there is one. + */ + if (!d_mountpoint(path.dentry)) { + status = 0; + goto done; + } + } /* Update the expiry counter if fs is busy */ - if (may_umount_tree(mnt)) { + if (!may_umount_tree(path.mnt)) { struct autofs_info *ino = autofs4_dentry_ino(top); ino->last_used = jiffies; goto done; @@ -73,8 +86,7 @@ static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry) status = 0; done: DPRINTK("returning = %d", status); - mntput(mnt); - dput(dentry); + path_put(&path); return status; } @@ -99,6 +111,35 @@ static struct dentry *next_dentry(struct dentry *p, struct dentry *root) return list_entry(next, struct dentry, d_u.d_child); } +/* + * Check a direct mount point for busyness. + * Direct mounts have similar expiry semantics to tree mounts. + * The tree is not busy iff no mountpoints are busy and there are no + * autofs submounts. + */ +static int autofs4_direct_busy(struct vfsmount *mnt, + struct dentry *top, + unsigned long timeout, + int do_now) +{ + DPRINTK("top %p %.*s", + top, (int) top->d_name.len, top->d_name.name); + + /* If it's busy update the expiry counters */ + if (!may_umount_tree(mnt)) { + struct autofs_info *ino = autofs4_dentry_ino(top); + if (ino) + ino->last_used = jiffies; + return 1; + } + + /* Timeout of a direct mount is determined by its top dentry */ + if (!autofs4_can_expire(top, timeout, do_now)) + return 1; + + return 0; +} + /* Check a directory tree of mount points for busyness * The tree is not busy iff no mountpoints are busy */ @@ -145,6 +186,12 @@ static int autofs4_tree_busy(struct vfsmount *mnt, struct autofs_info *ino = autofs4_dentry_ino(p); unsigned int ino_count = atomic_read(&ino->count); + /* + * Clean stale dentries below that have not been + * invalidated after a mount fail during lookup + */ + d_invalidate(p); + /* allow for dget above and top is already dgot */ if (p == top) ino_count += 2; @@ -208,16 +255,50 @@ cont: return NULL; } +/* Check if we can expire a direct mount (possibly a tree) */ +struct dentry *autofs4_expire_direct(struct super_block *sb, + struct vfsmount *mnt, + struct autofs_sb_info *sbi, + int how) +{ + unsigned long timeout; + struct dentry *root = dget(sb->s_root); + int do_now = how & AUTOFS_EXP_IMMEDIATE; + + if (!root) + return NULL; + + now = jiffies; + timeout = sbi->exp_timeout; + + spin_lock(&sbi->fs_lock); + if (!autofs4_direct_busy(mnt, root, timeout, do_now)) { + struct autofs_info *ino = autofs4_dentry_ino(root); + if (d_mountpoint(root)) { + ino->flags |= AUTOFS_INF_MOUNTPOINT; + root->d_mounted--; + } + ino->flags |= AUTOFS_INF_EXPIRING; + init_completion(&ino->expire_complete); + spin_unlock(&sbi->fs_lock); + return root; + } + spin_unlock(&sbi->fs_lock); + dput(root); + + return NULL; +} + /* * Find an eligible tree to time-out * A tree is eligible if :- * - it is unused by any user process * - it has been unused for exp_timeout time */ -static struct dentry *autofs4_expire(struct super_block *sb, - struct vfsmount *mnt, - struct autofs_sb_info *sbi, - int how) +struct dentry *autofs4_expire_indirect(struct super_block *sb, + struct vfsmount *mnt, + struct autofs_sb_info *sbi, + int how) { unsigned long timeout; struct dentry *root = sb->s_root; @@ -225,8 +306,10 @@ static struct dentry *autofs4_expire(struct super_block *sb, struct list_head *next; int do_now = how & AUTOFS_EXP_IMMEDIATE; int exp_leaves = how & AUTOFS_EXP_LEAVES; + struct autofs_info *ino; + unsigned int ino_count; - if ( !sbi->exp_timeout || !root ) + if (!root) return NULL; now = jiffies; @@ -249,11 +332,24 @@ static struct dentry *autofs4_expire(struct super_block *sb, dentry = dget(dentry); spin_unlock(&dcache_lock); - /* Case 1: indirect mount or top level direct mount */ + spin_lock(&sbi->fs_lock); + ino = autofs4_dentry_ino(dentry); + + /* + * Case 1: (i) indirect mount or top level pseudo direct mount + * (autofs-4.1). + * (ii) indirect mount with offset mount, check the "/" + * offset (autofs-5.0+). + */ if (d_mountpoint(dentry)) { DPRINTK("checking mountpoint %p %.*s", dentry, (int)dentry->d_name.len, dentry->d_name.name); + /* Path walk currently on this dentry? */ + ino_count = atomic_read(&ino->count) + 2; + if (atomic_read(&dentry->d_count) > ino_count) + goto next; + /* Can we umount this guy */ if (autofs4_mount_busy(mnt, dentry)) goto next; @@ -261,7 +357,7 @@ static struct dentry *autofs4_expire(struct super_block *sb, /* Can we expire this guy */ if (autofs4_can_expire(dentry, timeout, do_now)) { expired = dentry; - break; + goto found; } goto next; } @@ -271,44 +367,80 @@ static struct dentry *autofs4_expire(struct super_block *sb, /* Case 2: tree mount, expire iff entire tree is not busy */ if (!exp_leaves) { - /* Lock the tree as we must expire as a whole */ - spin_lock(&sbi->fs_lock); - if (!autofs4_tree_busy(mnt, dentry, timeout, do_now)) { - struct autofs_info *inf = autofs4_dentry_ino(dentry); + /* Path walk currently on this dentry? */ + ino_count = atomic_read(&ino->count) + 1; + if (atomic_read(&dentry->d_count) > ino_count) + goto next; - /* Set this flag early to catch sys_chdir and the like */ - inf->flags |= AUTOFS_INF_EXPIRING; - spin_unlock(&sbi->fs_lock); + if (!autofs4_tree_busy(mnt, dentry, timeout, do_now)) { expired = dentry; - break; + goto found; } - spin_unlock(&sbi->fs_lock); - /* Case 3: direct mount, expire individual leaves */ + /* + * Case 3: pseudo direct mount, expire individual leaves + * (autofs-4.1). + */ } else { + /* Path walk currently on this dentry? */ + ino_count = atomic_read(&ino->count) + 1; + if (atomic_read(&dentry->d_count) > ino_count) + goto next; + expired = autofs4_check_leaves(mnt, dentry, timeout, do_now); if (expired) { dput(dentry); - break; + goto found; } } next: + spin_unlock(&sbi->fs_lock); dput(dentry); spin_lock(&dcache_lock); next = next->next; } + spin_unlock(&dcache_lock); + return NULL; - if (expired) { - DPRINTK("returning %p %.*s", - expired, (int)expired->d_name.len, expired->d_name.name); - spin_lock(&dcache_lock); - list_del(&expired->d_parent->d_subdirs); - list_add(&expired->d_parent->d_subdirs, &expired->d_u.d_child); - spin_unlock(&dcache_lock); - return expired; - } +found: + DPRINTK("returning %p %.*s", + expired, (int)expired->d_name.len, expired->d_name.name); + ino = autofs4_dentry_ino(expired); + ino->flags |= AUTOFS_INF_EXPIRING; + init_completion(&ino->expire_complete); + spin_unlock(&sbi->fs_lock); + spin_lock(&dcache_lock); + list_move(&expired->d_parent->d_subdirs, &expired->d_u.d_child); spin_unlock(&dcache_lock); + return expired; +} - return NULL; +int autofs4_expire_wait(struct dentry *dentry) +{ + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct autofs_info *ino = autofs4_dentry_ino(dentry); + int status; + + /* Block on any pending expire */ + spin_lock(&sbi->fs_lock); + if (ino->flags & AUTOFS_INF_EXPIRING) { + spin_unlock(&sbi->fs_lock); + + DPRINTK("waiting for expire %p name=%.*s", + dentry, dentry->d_name.len, dentry->d_name.name); + + status = autofs4_wait(sbi, dentry, NFY_NONE); + wait_for_completion(&ino->expire_complete); + + DPRINTK("expire done status=%d", status); + + if (d_unhashed(dentry)) + return -EAGAIN; + + return status; + } + spin_unlock(&sbi->fs_lock); + + return 0; } /* Perform an expiry operation */ @@ -318,14 +450,16 @@ int autofs4_expire_run(struct super_block *sb, struct autofs_packet_expire __user *pkt_p) { struct autofs_packet_expire pkt; + struct autofs_info *ino; struct dentry *dentry; + int ret = 0; memset(&pkt,0,sizeof pkt); pkt.hdr.proto_version = sbi->version; pkt.hdr.type = autofs_ptype_expire; - if ((dentry = autofs4_expire(sb, mnt, sbi, 0)) == NULL) + if ((dentry = autofs4_expire_indirect(sb, mnt, sbi, 0)) == NULL) return -EAGAIN; pkt.len = dentry->d_name.len; @@ -334,34 +468,59 @@ int autofs4_expire_run(struct super_block *sb, dput(dentry); if ( copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)) ) - return -EFAULT; + ret = -EFAULT; - return 0; + spin_lock(&sbi->fs_lock); + ino = autofs4_dentry_ino(dentry); + ino->flags &= ~AUTOFS_INF_EXPIRING; + complete_all(&ino->expire_complete); + spin_unlock(&sbi->fs_lock); + + return ret; } -/* Call repeatedly until it returns -EAGAIN, meaning there's nothing - more to be done */ -int autofs4_expire_multi(struct super_block *sb, struct vfsmount *mnt, - struct autofs_sb_info *sbi, int __user *arg) +int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt, + struct autofs_sb_info *sbi, int when) { struct dentry *dentry; int ret = -EAGAIN; - int do_now = 0; - if (arg && get_user(do_now, arg)) - return -EFAULT; + if (autofs_type_trigger(sbi->type)) + dentry = autofs4_expire_direct(sb, mnt, sbi, when); + else + dentry = autofs4_expire_indirect(sb, mnt, sbi, when); - if ((dentry = autofs4_expire(sb, mnt, sbi, do_now)) != NULL) { + if (dentry) { struct autofs_info *ino = autofs4_dentry_ino(dentry); /* This is synchronous because it makes the daemon a little easier */ - ino->flags |= AUTOFS_INF_EXPIRING; ret = autofs4_wait(sbi, dentry, NFY_EXPIRE); + + spin_lock(&sbi->fs_lock); + if (ino->flags & AUTOFS_INF_MOUNTPOINT) { + sb->s_root->d_mounted++; + ino->flags &= ~AUTOFS_INF_MOUNTPOINT; + } ino->flags &= ~AUTOFS_INF_EXPIRING; + complete_all(&ino->expire_complete); + spin_unlock(&sbi->fs_lock); dput(dentry); } return ret; } +/* Call repeatedly until it returns -EAGAIN, meaning there's nothing + more to be done */ +int autofs4_expire_multi(struct super_block *sb, struct vfsmount *mnt, + struct autofs_sb_info *sbi, int __user *arg) +{ + int do_now = 0; + + if (arg && get_user(do_now, arg)) + return -EFAULT; + + return autofs4_do_expire_multi(sb, mnt, sbi, do_now); +} +