diff options
Diffstat (limited to 'fs/autofs4/root.c')
-rw-r--r-- | fs/autofs4/root.c | 324 |
1 files changed, 178 insertions, 146 deletions
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index 62d8d4acb8b..c8fe43a475e 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -4,7 +4,7 @@ * * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org> - * Copyright 2001-2003 Ian Kent <raven@themaw.net> + * Copyright 2001-2006 Ian Kent <raven@themaw.net> * * 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 @@ -30,7 +30,7 @@ static int autofs4_dir_close(struct inode *inode, struct file *file); static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t filldir); static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir); static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *); -static int autofs4_dcache_readdir(struct file *, void *, filldir_t); +static void *autofs4_follow_link(struct dentry *, struct nameidata *); struct file_operations autofs4_root_operations = { .open = dcache_dir_open, @@ -47,7 +47,7 @@ struct file_operations autofs4_dir_operations = { .readdir = autofs4_dir_readdir, }; -struct inode_operations autofs4_root_inode_operations = { +struct inode_operations autofs4_indirect_root_inode_operations = { .lookup = autofs4_lookup, .unlink = autofs4_dir_unlink, .symlink = autofs4_dir_symlink, @@ -55,6 +55,14 @@ struct inode_operations autofs4_root_inode_operations = { .rmdir = autofs4_dir_rmdir, }; +struct inode_operations autofs4_direct_root_inode_operations = { + .lookup = autofs4_lookup, + .unlink = autofs4_dir_unlink, + .mkdir = autofs4_dir_mkdir, + .rmdir = autofs4_dir_rmdir, + .follow_link = autofs4_follow_link, +}; + struct inode_operations autofs4_dir_inode_operations = { .lookup = autofs4_lookup, .unlink = autofs4_dir_unlink, @@ -82,87 +90,7 @@ static int autofs4_root_readdir(struct file *file, void *dirent, DPRINTK("needs_reghost = %d", sbi->needs_reghost); - return autofs4_dcache_readdir(file, dirent, filldir); -} - -/* Update usage from here to top of tree, so that scan of - top-level directories will give a useful result */ -static void autofs4_update_usage(struct vfsmount *mnt, struct dentry *dentry) -{ - struct dentry *top = dentry->d_sb->s_root; - - spin_lock(&dcache_lock); - for(; dentry != top; dentry = dentry->d_parent) { - struct autofs_info *ino = autofs4_dentry_ino(dentry); - - if (ino) { - touch_atime(mnt, dentry); - ino->last_used = jiffies; - } - } - spin_unlock(&dcache_lock); -} - -/* - * From 2.4 kernel readdir.c - */ -static int autofs4_dcache_readdir(struct file * filp, void * dirent, filldir_t filldir) -{ - int i; - struct dentry *dentry = filp->f_dentry; - - i = filp->f_pos; - switch (i) { - case 0: - if (filldir(dirent, ".", 1, i, dentry->d_inode->i_ino, DT_DIR) < 0) - break; - i++; - filp->f_pos++; - /* fallthrough */ - case 1: - if (filldir(dirent, "..", 2, i, dentry->d_parent->d_inode->i_ino, DT_DIR) < 0) - break; - i++; - filp->f_pos++; - /* fallthrough */ - default: { - struct list_head *list; - int j = i-2; - - spin_lock(&dcache_lock); - list = dentry->d_subdirs.next; - - for (;;) { - if (list == &dentry->d_subdirs) { - spin_unlock(&dcache_lock); - return 0; - } - if (!j) - break; - j--; - list = list->next; - } - - while(1) { - struct dentry *de = list_entry(list, - struct dentry, d_u.d_child); - - if (!d_unhashed(de) && de->d_inode) { - spin_unlock(&dcache_lock); - if (filldir(dirent, de->d_name.name, de->d_name.len, filp->f_pos, de->d_inode->i_ino, DT_UNKNOWN) < 0) - break; - spin_lock(&dcache_lock); - } - filp->f_pos++; - list = list->next; - if (list != &dentry->d_subdirs) - continue; - spin_unlock(&dcache_lock); - break; - } - } - } - return 0; + return dcache_readdir(file, dirent, filldir); } static int autofs4_dir_open(struct inode *inode, struct file *file) @@ -170,8 +98,16 @@ static int autofs4_dir_open(struct inode *inode, struct file *file) struct dentry *dentry = file->f_dentry; struct vfsmount *mnt = file->f_vfsmnt; struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct dentry *cursor; int status; + status = dcache_dir_open(inode, file); + if (status) + goto out; + + cursor = file->private_data; + cursor->d_fsdata = NULL; + DPRINTK("file=%p dentry=%p %.*s", file, dentry, dentry->d_name.len, dentry->d_name.name); @@ -180,12 +116,15 @@ static int autofs4_dir_open(struct inode *inode, struct file *file) if (autofs4_ispending(dentry)) { DPRINTK("dentry busy"); - return -EBUSY; + dcache_dir_close(inode, file); + status = -EBUSY; + goto out; } + status = -ENOENT; if (!d_mountpoint(dentry) && dentry->d_op && dentry->d_op->d_revalidate) { struct nameidata nd; - int empty; + int empty, ret; /* In case there are stale directory dentrys from a failed mount */ spin_lock(&dcache_lock); @@ -195,13 +134,13 @@ static int autofs4_dir_open(struct inode *inode, struct file *file) if (!empty) d_invalidate(dentry); - nd.dentry = dentry; - nd.mnt = mnt; nd.flags = LOOKUP_DIRECTORY; - status = (dentry->d_op->d_revalidate)(dentry, &nd); + ret = (dentry->d_op->d_revalidate)(dentry, &nd); - if (!status) - return -ENOENT; + if (!ret) { + dcache_dir_close(inode, file); + goto out; + } } if (d_mountpoint(dentry)) { @@ -212,25 +151,29 @@ static int autofs4_dir_open(struct inode *inode, struct file *file) if (!autofs4_follow_mount(&fp_mnt, &fp_dentry)) { dput(fp_dentry); mntput(fp_mnt); - return -ENOENT; + dcache_dir_close(inode, file); + goto out; } fp = dentry_open(fp_dentry, fp_mnt, file->f_flags); status = PTR_ERR(fp); if (IS_ERR(fp)) { - file->private_data = NULL; - return status; + dcache_dir_close(inode, file); + goto out; } - file->private_data = fp; + cursor->d_fsdata = fp; } -out: return 0; +out: + return status; } static int autofs4_dir_close(struct inode *inode, struct file *file) { struct dentry *dentry = file->f_dentry; struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct dentry *cursor = file->private_data; + int status = 0; DPRINTK("file=%p dentry=%p %.*s", file, dentry, dentry->d_name.len, dentry->d_name.name); @@ -240,26 +183,28 @@ static int autofs4_dir_close(struct inode *inode, struct file *file) if (autofs4_ispending(dentry)) { DPRINTK("dentry busy"); - return -EBUSY; + status = -EBUSY; + goto out; } if (d_mountpoint(dentry)) { - struct file *fp = file->private_data; - - if (!fp) - return -ENOENT; - + struct file *fp = cursor->d_fsdata; + if (!fp) { + status = -ENOENT; + goto out; + } filp_close(fp, current->files); - file->private_data = NULL; } out: - return 0; + dcache_dir_close(inode, file); + return status; } static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldir) { struct dentry *dentry = file->f_dentry; struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct dentry *cursor = file->private_data; int status; DPRINTK("file=%p dentry=%p %.*s", @@ -274,7 +219,7 @@ static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldi } if (d_mountpoint(dentry)) { - struct file *fp = file->private_data; + struct file *fp = cursor->d_fsdata; if (!fp) return -ENOENT; @@ -289,27 +234,26 @@ static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldi return status; } out: - return autofs4_dcache_readdir(file, dirent, filldir); + return dcache_readdir(file, dirent, filldir); } -static int try_to_fill_dentry(struct vfsmount *mnt, struct dentry *dentry, int flags) +static int try_to_fill_dentry(struct dentry *dentry, int flags) { - struct super_block *sb = mnt->mnt_sb; - struct autofs_sb_info *sbi = autofs4_sbi(sb); - struct autofs_info *de_info = autofs4_dentry_ino(dentry); + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + struct autofs_info *ino = autofs4_dentry_ino(dentry); int status = 0; /* Block on any pending expiry here; invalidate the dentry when expiration is done to trigger mount request with a new dentry */ - if (de_info && (de_info->flags & AUTOFS_INF_EXPIRING)) { + if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { DPRINTK("waiting for expire %p name=%.*s", dentry, dentry->d_name.len, dentry->d_name.name); status = autofs4_wait(sbi, dentry, NFY_NONE); - + DPRINTK("expire done status=%d", status); - + /* * If the directory still exists the mount request must * continue otherwise it can't be followed at the right @@ -317,34 +261,36 @@ static int try_to_fill_dentry(struct vfsmount *mnt, struct dentry *dentry, int f */ status = d_invalidate(dentry); if (status != -EBUSY) - return 0; + return -ENOENT; } DPRINTK("dentry=%p %.*s ino=%p", dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); - /* Wait for a pending mount, triggering one if there isn't one already */ + /* + * Wait for a pending mount, triggering one if there + * isn't one already + */ if (dentry->d_inode == NULL) { DPRINTK("waiting for mount name=%.*s", dentry->d_name.len, dentry->d_name.name); status = autofs4_wait(sbi, dentry, NFY_MOUNT); - + DPRINTK("mount done status=%d", status); if (status && dentry->d_inode) - return 0; /* Try to get the kernel to invalidate this dentry */ - + return status; /* Try to get the kernel to invalidate this dentry */ + /* Turn this into a real negative dentry? */ if (status == -ENOENT) { - dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT; spin_lock(&dentry->d_lock); dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; spin_unlock(&dentry->d_lock); - return 1; + return status; } else if (status) { /* Return a negative dentry, but leave it "pending" */ - return 1; + return status; } /* Trigger mount for path component or follow link */ } else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) || @@ -363,19 +309,87 @@ static int try_to_fill_dentry(struct vfsmount *mnt, struct dentry *dentry, int f spin_lock(&dentry->d_lock); dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; spin_unlock(&dentry->d_lock); - return 0; + return status; } } - /* We don't update the usages for the autofs daemon itself, this - is necessary for recursive autofs mounts */ - if (!autofs4_oz_mode(sbi)) - autofs4_update_usage(mnt, dentry); + /* Initialize expiry counter after successful mount */ + if (ino) + ino->last_used = jiffies; spin_lock(&dentry->d_lock); dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; spin_unlock(&dentry->d_lock); - return 1; + return status; +} + +/* For autofs direct mounts the follow link triggers the mount */ +static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) +{ + struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); + int oz_mode = autofs4_oz_mode(sbi); + unsigned int lookup_type; + int status; + + DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d", + dentry, dentry->d_name.len, dentry->d_name.name, oz_mode, + nd->flags); + + /* If it's our master or we shouldn't trigger a mount we're done */ + lookup_type = nd->flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY); + if (oz_mode || !lookup_type) + goto done; + + /* + * If a request is pending wait for it. + * If it's a mount then it won't be expired till at least + * a liitle later and if it's an expire then we might need + * to mount it again. + */ + if (autofs4_ispending(dentry)) { + DPRINTK("waiting for active request %p name=%.*s", + dentry, dentry->d_name.len, dentry->d_name.name); + + status = autofs4_wait(sbi, dentry, NFY_NONE); + + DPRINTK("request done status=%d", status); + } + + /* + * If the dentry contains directories then it is an + * autofs multi-mount with no root mount offset. So + * don't try to mount it again. + */ + spin_lock(&dcache_lock); + if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { + spin_unlock(&dcache_lock); + + status = try_to_fill_dentry(dentry, 0); + if (status) + goto out_error; + + /* + * The mount succeeded but if there is no root mount + * it must be an autofs multi-mount with no root offset + * so we don't need to follow the mount. + */ + if (d_mountpoint(dentry)) { + if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) { + status = -ENOENT; + goto out_error; + } + } + + goto done; + } + spin_unlock(&dcache_lock); + +done: + return NULL; + +out_error: + path_release(nd); + return ERR_PTR(status); } /* @@ -384,47 +398,43 @@ static int try_to_fill_dentry(struct vfsmount *mnt, struct dentry *dentry, int f * yet completely filled in, and revalidate has to delay such * lookups.. */ -static int autofs4_revalidate(struct dentry * dentry, struct nameidata *nd) +static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) { - struct inode * dir = dentry->d_parent->d_inode; + struct inode *dir = dentry->d_parent->d_inode; struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); int oz_mode = autofs4_oz_mode(sbi); int flags = nd ? nd->flags : 0; - int status = 1; + int status = 0; /* Pending dentry */ if (autofs4_ispending(dentry)) { if (!oz_mode) - status = try_to_fill_dentry(nd->mnt, dentry, flags); - return status; + status = try_to_fill_dentry(dentry, flags); + return !status; } /* Negative dentry.. invalidate if "old" */ if (dentry->d_inode == NULL) - return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT); + return 0; /* Check for a non-mountpoint directory with no contents */ spin_lock(&dcache_lock); if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) && - list_empty(&dentry->d_subdirs)) { + __simple_empty(dentry)) { DPRINTK("dentry=%p %.*s, emptydir", dentry, dentry->d_name.len, dentry->d_name.name); spin_unlock(&dcache_lock); if (!oz_mode) - status = try_to_fill_dentry(nd->mnt, dentry, flags); - return status; + status = try_to_fill_dentry(dentry, flags); + return !status; } spin_unlock(&dcache_lock); - /* Update the usage list */ - if (!oz_mode) - autofs4_update_usage(nd->mnt, dentry); - return 1; } -static void autofs4_dentry_release(struct dentry *de) +void autofs4_dentry_release(struct dentry *de) { struct autofs_info *inf; @@ -462,12 +472,13 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s DPRINTK("name = %.*s", dentry->d_name.len, dentry->d_name.name); + /* File name too long to exist */ if (dentry->d_name.len > NAME_MAX) - return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */ + return ERR_PTR(-ENAMETOOLONG); sbi = autofs4_sbi(dir->i_sb); - oz_mode = autofs4_oz_mode(sbi); + DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", current->pid, process_group(current), sbi->catatonic, oz_mode); @@ -519,7 +530,7 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s * doesn't do the right thing for all system calls, but it should * be OK for the operations we permit from an autofs. */ - if ( dentry->d_inode && d_unhashed(dentry) ) + if (dentry->d_inode && d_unhashed(dentry)) return ERR_PTR(-ENOENT); return NULL; @@ -531,6 +542,7 @@ static int autofs4_dir_symlink(struct inode *dir, { struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); struct autofs_info *ino = autofs4_dentry_ino(dentry); + struct autofs_info *p_ino; struct inode *inode; char *cp; @@ -564,6 +576,10 @@ static int autofs4_dir_symlink(struct inode *dir, dentry->d_fsdata = ino; ino->dentry = dget(dentry); + atomic_inc(&ino->count); + p_ino = autofs4_dentry_ino(dentry->d_parent); + if (p_ino && dentry->d_parent != dentry) + atomic_inc(&p_ino->count); ino->inode = inode; dir->i_mtime = CURRENT_TIME; @@ -590,11 +606,17 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) { struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); struct autofs_info *ino = autofs4_dentry_ino(dentry); + struct autofs_info *p_ino; /* This allows root to remove symlinks */ if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) return -EACCES; + if (atomic_dec_and_test(&ino->count)) { + p_ino = autofs4_dentry_ino(dentry->d_parent); + if (p_ino && dentry->d_parent != dentry) + atomic_dec(&p_ino->count); + } dput(ino->dentry); dentry->d_inode->i_size = 0; @@ -611,6 +633,7 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) { struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); struct autofs_info *ino = autofs4_dentry_ino(dentry); + struct autofs_info *p_ino; if (!autofs4_oz_mode(sbi)) return -EACCES; @@ -625,8 +648,12 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) spin_unlock(&dentry->d_lock); spin_unlock(&dcache_lock); + if (atomic_dec_and_test(&ino->count)) { + p_ino = autofs4_dentry_ino(dentry->d_parent); + if (p_ino && dentry->d_parent != dentry) + atomic_dec(&p_ino->count); + } dput(ino->dentry); - dentry->d_inode->i_size = 0; dentry->d_inode->i_nlink = 0; @@ -640,6 +667,7 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) { struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); struct autofs_info *ino = autofs4_dentry_ino(dentry); + struct autofs_info *p_ino; struct inode *inode; if ( !autofs4_oz_mode(sbi) ) @@ -662,6 +690,10 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) dentry->d_fsdata = ino; ino->dentry = dget(dentry); + atomic_inc(&ino->count); + p_ino = autofs4_dentry_ino(dentry->d_parent); + if (p_ino && dentry->d_parent != dentry) + atomic_inc(&p_ino->count); ino->inode = inode; dir->i_nlink++; dir->i_mtime = CURRENT_TIME; @@ -745,7 +777,7 @@ static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) { int status = 0; - if (may_umount(mnt) == 0) + if (may_umount(mnt)) status = 1; DPRINTK("returning %d", status); |