diff options
author | Len Brown <len.brown@intel.com> | 2006-01-07 03:50:18 -0500 |
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committer | Len Brown <len.brown@intel.com> | 2006-01-07 03:50:18 -0500 |
commit | ed03f430cdc8c802652467e9097606fedc2c7abc (patch) | |
tree | 30941ec1e6f93e99358fefe18175e5dd800a4379 /fs/fuse/dir.c | |
parent | ed349a8a0a780ed27e2a765f16cee54d9b63bfee (diff) | |
parent | 6f957eaf79356a32e838f5f262ee9a60544b1d5b (diff) | |
download | op-kernel-dev-ed03f430cdc8c802652467e9097606fedc2c7abc.zip op-kernel-dev-ed03f430cdc8c802652467e9097606fedc2c7abc.tar.gz |
Pull pnpacpi into acpica branch
Diffstat (limited to 'fs/fuse/dir.c')
-rw-r--r-- | fs/fuse/dir.c | 278 |
1 files changed, 179 insertions, 99 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 51f5da6..417bcee 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -13,8 +13,16 @@ #include <linux/gfp.h> #include <linux/sched.h> #include <linux/namei.h> -#include <linux/mount.h> +/* + * FUSE caches dentries and attributes with separate timeout. The + * time in jiffies until the dentry/attributes are valid is stored in + * dentry->d_time and fuse_inode->i_time respectively. + */ + +/* + * Calculate the time in jiffies until a dentry/attributes are valid + */ static inline unsigned long time_to_jiffies(unsigned long sec, unsigned long nsec) { @@ -22,6 +30,50 @@ static inline unsigned long time_to_jiffies(unsigned long sec, return jiffies + timespec_to_jiffies(&ts); } +/* + * Set dentry and possibly attribute timeouts from the lookup/mk* + * replies + */ +static void fuse_change_timeout(struct dentry *entry, struct fuse_entry_out *o) +{ + entry->d_time = time_to_jiffies(o->entry_valid, o->entry_valid_nsec); + if (entry->d_inode) + get_fuse_inode(entry->d_inode)->i_time = + time_to_jiffies(o->attr_valid, o->attr_valid_nsec); +} + +/* + * Mark the attributes as stale, so that at the next call to + * ->getattr() they will be fetched from userspace + */ +void fuse_invalidate_attr(struct inode *inode) +{ + get_fuse_inode(inode)->i_time = jiffies - 1; +} + +/* + * Just mark the entry as stale, so that a next attempt to look it up + * will result in a new lookup call to userspace + * + * This is called when a dentry is about to become negative and the + * timeout is unknown (unlink, rmdir, rename and in some cases + * lookup) + */ +static void fuse_invalidate_entry_cache(struct dentry *entry) +{ + entry->d_time = jiffies - 1; +} + +/* + * Same as fuse_invalidate_entry_cache(), but also try to remove the + * dentry from the hash + */ +static void fuse_invalidate_entry(struct dentry *entry) +{ + d_invalidate(entry); + fuse_invalidate_entry_cache(entry); +} + static void fuse_lookup_init(struct fuse_req *req, struct inode *dir, struct dentry *entry, struct fuse_entry_out *outarg) @@ -37,17 +89,34 @@ static void fuse_lookup_init(struct fuse_req *req, struct inode *dir, req->out.args[0].value = outarg; } +/* + * Check whether the dentry is still valid + * + * If the entry validity timeout has expired and the dentry is + * positive, try to redo the lookup. If the lookup results in a + * different inode, then let the VFS invalidate the dentry and redo + * the lookup once more. If the lookup results in the same inode, + * then refresh the attributes, timeouts and mark the dentry valid. + */ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) { - if (!entry->d_inode || is_bad_inode(entry->d_inode)) + struct inode *inode = entry->d_inode; + + if (inode && is_bad_inode(inode)) return 0; else if (time_after(jiffies, entry->d_time)) { int err; struct fuse_entry_out outarg; - struct inode *inode = entry->d_inode; - struct fuse_inode *fi = get_fuse_inode(inode); - struct fuse_conn *fc = get_fuse_conn(inode); - struct fuse_req *req = fuse_get_request(fc); + struct fuse_conn *fc; + struct fuse_req *req; + + /* Doesn't hurt to "reset" the validity timeout */ + fuse_invalidate_entry_cache(entry); + if (!inode) + return 0; + + fc = get_fuse_conn(inode); + req = fuse_get_request(fc); if (!req) return 0; @@ -55,6 +124,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) request_send(fc, req); err = req->out.h.error; if (!err) { + struct fuse_inode *fi = get_fuse_inode(inode); if (outarg.nodeid != get_node_id(inode)) { fuse_send_forget(fc, req, outarg.nodeid, 1); return 0; @@ -66,18 +136,18 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) return 0; fuse_change_attributes(inode, &outarg.attr); - entry->d_time = time_to_jiffies(outarg.entry_valid, - outarg.entry_valid_nsec); - fi->i_time = time_to_jiffies(outarg.attr_valid, - outarg.attr_valid_nsec); + fuse_change_timeout(entry, &outarg); } return 1; } +/* + * Check if there's already a hashed alias of this directory inode. + * If yes, then lookup and mkdir must not create a new alias. + */ static int dir_alias(struct inode *inode) { if (S_ISDIR(inode->i_mode)) { - /* Don't allow creating an alias to a directory */ struct dentry *alias = d_find_alias(inode); if (alias) { dput(alias); @@ -96,8 +166,14 @@ static struct dentry_operations fuse_dentry_operations = { .d_revalidate = fuse_dentry_revalidate, }; -static int fuse_lookup_iget(struct inode *dir, struct dentry *entry, - struct inode **inodep) +static inline int valid_mode(int m) +{ + return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) || + S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m); +} + +static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, + struct nameidata *nd) { int err; struct fuse_entry_out outarg; @@ -106,53 +182,49 @@ static int fuse_lookup_iget(struct inode *dir, struct dentry *entry, struct fuse_req *req; if (entry->d_name.len > FUSE_NAME_MAX) - return -ENAMETOOLONG; + return ERR_PTR(-ENAMETOOLONG); req = fuse_get_request(fc); if (!req) - return -EINTR; + return ERR_PTR(-EINTR); fuse_lookup_init(req, dir, entry, &outarg); request_send(fc, req); err = req->out.h.error; - if (!err && invalid_nodeid(outarg.nodeid)) + if (!err && ((outarg.nodeid && invalid_nodeid(outarg.nodeid)) || + !valid_mode(outarg.attr.mode))) err = -EIO; - if (!err) { + if (!err && outarg.nodeid) { inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, &outarg.attr); if (!inode) { fuse_send_forget(fc, req, outarg.nodeid, 1); - return -ENOMEM; + return ERR_PTR(-ENOMEM); } } fuse_put_request(fc, req); if (err && err != -ENOENT) - return err; + return ERR_PTR(err); - if (inode) { - struct fuse_inode *fi = get_fuse_inode(inode); - entry->d_time = time_to_jiffies(outarg.entry_valid, - outarg.entry_valid_nsec); - fi->i_time = time_to_jiffies(outarg.attr_valid, - outarg.attr_valid_nsec); + if (inode && dir_alias(inode)) { + iput(inode); + return ERR_PTR(-EIO); } - + d_add(entry, inode); entry->d_op = &fuse_dentry_operations; - *inodep = inode; - return 0; -} - -void fuse_invalidate_attr(struct inode *inode) -{ - get_fuse_inode(inode)->i_time = jiffies - 1; -} - -static void fuse_invalidate_entry(struct dentry *entry) -{ - d_invalidate(entry); - entry->d_time = jiffies - 1; + if (!err) + fuse_change_timeout(entry, &outarg); + else + fuse_invalidate_entry_cache(entry); + return NULL; } +/* + * Atomic create+open operation + * + * If the filesystem doesn't support this, then fall back to separate + * 'mknod' + 'open' requests. + */ static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode, struct nameidata *nd) { @@ -163,7 +235,6 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode, struct fuse_open_in inarg; struct fuse_open_out outopen; struct fuse_entry_out outentry; - struct fuse_inode *fi; struct fuse_file *ff; struct file *file; int flags = nd->intent.open.flags - 1; @@ -172,10 +243,6 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode, if (fc->no_create) goto out; - err = -ENAMETOOLONG; - if (entry->d_name.len > FUSE_NAME_MAX) - goto out; - err = -EINTR; req = fuse_get_request(fc); if (!req) @@ -220,17 +287,15 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode, if (!inode) { flags &= ~(O_CREAT | O_EXCL | O_TRUNC); ff->fh = outopen.fh; + /* Special release, with inode = NULL, this will + trigger a 'forget' request when the release is + complete */ fuse_send_release(fc, ff, outentry.nodeid, NULL, flags, 0); goto out_put_request; } fuse_put_request(fc, req); - entry->d_time = time_to_jiffies(outentry.entry_valid, - outentry.entry_valid_nsec); - fi = get_fuse_inode(inode); - fi->i_time = time_to_jiffies(outentry.attr_valid, - outentry.attr_valid_nsec); - d_instantiate(entry, inode); + fuse_change_timeout(entry, &outentry); file = lookup_instantiate_filp(nd, entry, generic_file_open); if (IS_ERR(file)) { ff->fh = outopen.fh; @@ -248,13 +313,15 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode, return err; } +/* + * Code shared between mknod, mkdir, symlink and link + */ static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req, struct inode *dir, struct dentry *entry, int mode) { struct fuse_entry_out outarg; struct inode *inode; - struct fuse_inode *fi; int err; req->in.h.nodeid = get_node_id(dir); @@ -268,10 +335,13 @@ static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req, fuse_put_request(fc, req); return err; } - if (invalid_nodeid(outarg.nodeid)) { - fuse_put_request(fc, req); - return -EIO; - } + err = -EIO; + if (invalid_nodeid(outarg.nodeid)) + goto out_put_request; + + if ((outarg.attr.mode ^ mode) & S_IFMT) + goto out_put_request; + inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, &outarg.attr); if (!inode) { @@ -280,22 +350,19 @@ static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req, } fuse_put_request(fc, req); - /* Don't allow userspace to do really stupid things... */ - if (((inode->i_mode ^ mode) & S_IFMT) || dir_alias(inode)) { + if (dir_alias(inode)) { iput(inode); return -EIO; } - entry->d_time = time_to_jiffies(outarg.entry_valid, - outarg.entry_valid_nsec); - - fi = get_fuse_inode(inode); - fi->i_time = time_to_jiffies(outarg.attr_valid, - outarg.attr_valid_nsec); - d_instantiate(entry, inode); + fuse_change_timeout(entry, &outarg); fuse_invalidate_attr(dir); return 0; + + out_put_request: + fuse_put_request(fc, req); + return err; } static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode, @@ -355,12 +422,7 @@ static int fuse_symlink(struct inode *dir, struct dentry *entry, { struct fuse_conn *fc = get_fuse_conn(dir); unsigned len = strlen(link) + 1; - struct fuse_req *req; - - if (len > FUSE_SYMLINK_MAX) - return -ENAMETOOLONG; - - req = fuse_get_request(fc); + struct fuse_req *req = fuse_get_request(fc); if (!req) return -EINTR; @@ -399,6 +461,7 @@ static int fuse_unlink(struct inode *dir, struct dentry *entry) inode->i_nlink = 0; fuse_invalidate_attr(inode); fuse_invalidate_attr(dir); + fuse_invalidate_entry_cache(entry); } else if (err == -EINTR) fuse_invalidate_entry(entry); return err; @@ -424,6 +487,7 @@ static int fuse_rmdir(struct inode *dir, struct dentry *entry) if (!err) { entry->d_inode->i_nlink = 0; fuse_invalidate_attr(dir); + fuse_invalidate_entry_cache(entry); } else if (err == -EINTR) fuse_invalidate_entry(entry); return err; @@ -459,6 +523,10 @@ static int fuse_rename(struct inode *olddir, struct dentry *oldent, fuse_invalidate_attr(olddir); if (olddir != newdir) fuse_invalidate_attr(newdir); + + /* newent will end up negative */ + if (newent->d_inode) + fuse_invalidate_entry_cache(newent); } else if (err == -EINTR) { /* If request was interrupted, DEITY only knows if the rename actually took place. If the invalidation @@ -566,6 +634,15 @@ static int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task) return 0; } +/* + * Check whether the inode attributes are still valid + * + * If the attribute validity timeout has expired, then fetch the fresh + * attributes with a 'getattr' request + * + * I'm not sure why cached attributes are never returned for the root + * inode, this is probably being too cautious. + */ static int fuse_revalidate(struct dentry *entry) { struct inode *inode = entry->d_inode; @@ -613,6 +690,19 @@ static int fuse_access(struct inode *inode, int mask) return err; } +/* + * Check permission. The two basic access models of FUSE are: + * + * 1) Local access checking ('default_permissions' mount option) based + * on file mode. This is the plain old disk filesystem permission + * modell. + * + * 2) "Remote" access checking, where server is responsible for + * checking permission in each inode operation. An exception to this + * is if ->permission() was invoked from sys_access() in which case an + * access request is sent. Execute permission is still checked + * locally based on file mode. + */ static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd) { struct fuse_conn *fc = get_fuse_conn(inode); @@ -631,14 +721,10 @@ static int fuse_permission(struct inode *inode, int mask, struct nameidata *nd) err = generic_permission(inode, mask, NULL); } - /* FIXME: Need some mechanism to revoke permissions: - currently if the filesystem suddenly changes the - file mode, we will not be informed about it, and - continue to allow access to the file/directory. - - This is actually not so grave, since the user can - simply keep access to the file/directory anyway by - keeping it open... */ + /* Note: the opposite of the above test does not + exist. So if permissions are revoked this won't be + noticed immediately, only after the attribute + timeout has expired */ return err; } else { @@ -691,7 +777,12 @@ static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir) struct page *page; struct inode *inode = file->f_dentry->d_inode; struct fuse_conn *fc = get_fuse_conn(inode); - struct fuse_req *req = fuse_get_request(fc); + struct fuse_req *req; + + if (is_bad_inode(inode)) + return -EIO; + + req = fuse_get_request(fc); if (!req) return -EINTR; @@ -806,6 +897,15 @@ static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg) } } +/* + * Set attributes, and at the same time refresh them. + * + * Truncation is slightly complicated, because the 'truncate' request + * may fail, in which case we don't want to touch the mapping. + * vmtruncate() doesn't allow for this case. So do the rlimit + * checking by hand and call vmtruncate() only after the file has + * actually been truncated. + */ static int fuse_setattr(struct dentry *entry, struct iattr *attr) { struct inode *inode = entry->d_inode; @@ -883,23 +983,6 @@ static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, return err; } -static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, - struct nameidata *nd) -{ - struct inode *inode; - int err; - - err = fuse_lookup_iget(dir, entry, &inode); - if (err) - return ERR_PTR(err); - if (inode && dir_alias(inode)) { - iput(inode); - return ERR_PTR(-EIO); - } - d_add(entry, inode); - return NULL; -} - static int fuse_setxattr(struct dentry *entry, const char *name, const void *value, size_t size, int flags) { @@ -909,9 +992,6 @@ static int fuse_setxattr(struct dentry *entry, const char *name, struct fuse_setxattr_in inarg; int err; - if (size > FUSE_XATTR_SIZE_MAX) - return -E2BIG; - if (fc->no_setxattr) return -EOPNOTSUPP; |