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1938 lines
48 KiB
1938 lines
48 KiB
/* |
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FUSE: Filesystem in Userspace |
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Copyright (C) 2001-2008 Miklos Szeredi <[email protected]> |
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|
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This program can be distributed under the terms of the GNU GPL. |
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See the file COPYING. |
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*/ |
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|
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#include "fuse_i.h" |
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|
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#include <linux/pagemap.h> |
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#include <linux/file.h> |
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#include <linux/fs_context.h> |
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#include <linux/sched.h> |
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#include <linux/namei.h> |
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#include <linux/slab.h> |
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#include <linux/xattr.h> |
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#include <linux/iversion.h> |
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#include <linux/posix_acl.h> |
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|
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static void fuse_advise_use_readdirplus(struct inode *dir) |
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{ |
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struct fuse_inode *fi = get_fuse_inode(dir); |
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|
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set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state); |
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} |
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|
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#if BITS_PER_LONG >= 64 |
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static inline void __fuse_dentry_settime(struct dentry *entry, u64 time) |
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{ |
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entry->d_fsdata = (void *) time; |
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} |
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static inline u64 fuse_dentry_time(const struct dentry *entry) |
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{ |
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return (u64)entry->d_fsdata; |
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} |
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#else |
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union fuse_dentry { |
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u64 time; |
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struct rcu_head rcu; |
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}; |
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|
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static inline void __fuse_dentry_settime(struct dentry *dentry, u64 time) |
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{ |
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((union fuse_dentry *) dentry->d_fsdata)->time = time; |
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} |
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static inline u64 fuse_dentry_time(const struct dentry *entry) |
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{ |
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return ((union fuse_dentry *) entry->d_fsdata)->time; |
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} |
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#endif |
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|
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static void fuse_dentry_settime(struct dentry *dentry, u64 time) |
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{ |
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struct fuse_conn *fc = get_fuse_conn_super(dentry->d_sb); |
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bool delete = !time && fc->delete_stale; |
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/* |
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* Mess with DCACHE_OP_DELETE because dput() will be faster without it. |
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* Don't care about races, either way it's just an optimization |
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*/ |
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if ((!delete && (dentry->d_flags & DCACHE_OP_DELETE)) || |
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(delete && !(dentry->d_flags & DCACHE_OP_DELETE))) { |
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spin_lock(&dentry->d_lock); |
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if (!delete) |
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dentry->d_flags &= ~DCACHE_OP_DELETE; |
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else |
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dentry->d_flags |= DCACHE_OP_DELETE; |
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spin_unlock(&dentry->d_lock); |
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} |
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__fuse_dentry_settime(dentry, time); |
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} |
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|
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/* |
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* FUSE caches dentries and attributes with separate timeout. The |
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* time in jiffies until the dentry/attributes are valid is stored in |
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* dentry->d_fsdata and fuse_inode->i_time respectively. |
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*/ |
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|
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/* |
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* Calculate the time in jiffies until a dentry/attributes are valid |
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*/ |
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static u64 time_to_jiffies(u64 sec, u32 nsec) |
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{ |
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if (sec || nsec) { |
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struct timespec64 ts = { |
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sec, |
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min_t(u32, nsec, NSEC_PER_SEC - 1) |
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}; |
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return get_jiffies_64() + timespec64_to_jiffies(&ts); |
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} else |
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return 0; |
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} |
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/* |
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* Set dentry and possibly attribute timeouts from the lookup/mk* |
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* replies |
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*/ |
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void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o) |
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{ |
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fuse_dentry_settime(entry, |
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time_to_jiffies(o->entry_valid, o->entry_valid_nsec)); |
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} |
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static u64 attr_timeout(struct fuse_attr_out *o) |
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{ |
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return time_to_jiffies(o->attr_valid, o->attr_valid_nsec); |
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} |
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u64 entry_attr_timeout(struct fuse_entry_out *o) |
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{ |
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return time_to_jiffies(o->attr_valid, o->attr_valid_nsec); |
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} |
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|
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static void fuse_invalidate_attr_mask(struct inode *inode, u32 mask) |
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{ |
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set_mask_bits(&get_fuse_inode(inode)->inval_mask, 0, mask); |
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} |
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|
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/* |
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* Mark the attributes as stale, so that at the next call to |
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* ->getattr() they will be fetched from userspace |
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*/ |
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void fuse_invalidate_attr(struct inode *inode) |
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{ |
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fuse_invalidate_attr_mask(inode, STATX_BASIC_STATS); |
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} |
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static void fuse_dir_changed(struct inode *dir) |
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{ |
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fuse_invalidate_attr(dir); |
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inode_maybe_inc_iversion(dir, false); |
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} |
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/** |
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* Mark the attributes as stale due to an atime change. Avoid the invalidate if |
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* atime is not used. |
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*/ |
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void fuse_invalidate_atime(struct inode *inode) |
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{ |
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if (!IS_RDONLY(inode)) |
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fuse_invalidate_attr_mask(inode, STATX_ATIME); |
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} |
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|
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/* |
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* Just mark the entry as stale, so that a next attempt to look it up |
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* will result in a new lookup call to userspace |
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* |
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* This is called when a dentry is about to become negative and the |
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* timeout is unknown (unlink, rmdir, rename and in some cases |
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* lookup) |
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*/ |
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void fuse_invalidate_entry_cache(struct dentry *entry) |
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{ |
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fuse_dentry_settime(entry, 0); |
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} |
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/* |
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* Same as fuse_invalidate_entry_cache(), but also try to remove the |
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* dentry from the hash |
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*/ |
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static void fuse_invalidate_entry(struct dentry *entry) |
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{ |
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d_invalidate(entry); |
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fuse_invalidate_entry_cache(entry); |
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} |
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|
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static void fuse_lookup_init(struct fuse_conn *fc, struct fuse_args *args, |
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u64 nodeid, const struct qstr *name, |
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struct fuse_entry_out *outarg) |
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{ |
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memset(outarg, 0, sizeof(struct fuse_entry_out)); |
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args->opcode = FUSE_LOOKUP; |
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args->nodeid = nodeid; |
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args->in_numargs = 1; |
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args->in_args[0].size = name->len + 1; |
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args->in_args[0].value = name->name; |
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args->out_numargs = 1; |
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args->out_args[0].size = sizeof(struct fuse_entry_out); |
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args->out_args[0].value = outarg; |
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} |
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/* |
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* Check whether the dentry is still valid |
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* |
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* If the entry validity timeout has expired and the dentry is |
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* positive, try to redo the lookup. If the lookup results in a |
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* different inode, then let the VFS invalidate the dentry and redo |
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* the lookup once more. If the lookup results in the same inode, |
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* then refresh the attributes, timeouts and mark the dentry valid. |
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*/ |
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static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags) |
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{ |
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struct inode *inode; |
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struct dentry *parent; |
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struct fuse_mount *fm; |
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struct fuse_inode *fi; |
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int ret; |
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inode = d_inode_rcu(entry); |
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if (inode && fuse_is_bad(inode)) |
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goto invalid; |
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else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) || |
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(flags & (LOOKUP_EXCL | LOOKUP_REVAL))) { |
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struct fuse_entry_out outarg; |
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FUSE_ARGS(args); |
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struct fuse_forget_link *forget; |
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u64 attr_version; |
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|
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/* For negative dentries, always do a fresh lookup */ |
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if (!inode) |
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goto invalid; |
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ret = -ECHILD; |
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if (flags & LOOKUP_RCU) |
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goto out; |
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fm = get_fuse_mount(inode); |
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forget = fuse_alloc_forget(); |
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ret = -ENOMEM; |
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if (!forget) |
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goto out; |
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attr_version = fuse_get_attr_version(fm->fc); |
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parent = dget_parent(entry); |
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fuse_lookup_init(fm->fc, &args, get_node_id(d_inode(parent)), |
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&entry->d_name, &outarg); |
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ret = fuse_simple_request(fm, &args); |
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dput(parent); |
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/* Zero nodeid is same as -ENOENT */ |
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if (!ret && !outarg.nodeid) |
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ret = -ENOENT; |
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if (!ret) { |
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fi = get_fuse_inode(inode); |
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if (outarg.nodeid != get_node_id(inode) || |
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(bool) IS_AUTOMOUNT(inode) != (bool) (outarg.attr.flags & FUSE_ATTR_SUBMOUNT)) { |
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fuse_queue_forget(fm->fc, forget, |
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outarg.nodeid, 1); |
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goto invalid; |
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} |
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spin_lock(&fi->lock); |
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fi->nlookup++; |
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spin_unlock(&fi->lock); |
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} |
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kfree(forget); |
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if (ret == -ENOMEM) |
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goto out; |
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if (ret || fuse_invalid_attr(&outarg.attr) || |
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(outarg.attr.mode ^ inode->i_mode) & S_IFMT) |
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goto invalid; |
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forget_all_cached_acls(inode); |
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fuse_change_attributes(inode, &outarg.attr, |
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entry_attr_timeout(&outarg), |
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attr_version); |
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fuse_change_entry_timeout(entry, &outarg); |
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} else if (inode) { |
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fi = get_fuse_inode(inode); |
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if (flags & LOOKUP_RCU) { |
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if (test_bit(FUSE_I_INIT_RDPLUS, &fi->state)) |
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return -ECHILD; |
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} else if (test_and_clear_bit(FUSE_I_INIT_RDPLUS, &fi->state)) { |
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parent = dget_parent(entry); |
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fuse_advise_use_readdirplus(d_inode(parent)); |
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dput(parent); |
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} |
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} |
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ret = 1; |
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out: |
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return ret; |
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invalid: |
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ret = 0; |
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goto out; |
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} |
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#if BITS_PER_LONG < 64 |
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static int fuse_dentry_init(struct dentry *dentry) |
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{ |
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dentry->d_fsdata = kzalloc(sizeof(union fuse_dentry), |
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GFP_KERNEL_ACCOUNT | __GFP_RECLAIMABLE); |
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return dentry->d_fsdata ? 0 : -ENOMEM; |
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} |
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static void fuse_dentry_release(struct dentry *dentry) |
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{ |
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union fuse_dentry *fd = dentry->d_fsdata; |
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kfree_rcu(fd, rcu); |
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} |
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#endif |
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static int fuse_dentry_delete(const struct dentry *dentry) |
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{ |
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return time_before64(fuse_dentry_time(dentry), get_jiffies_64()); |
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} |
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/* |
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* Create a fuse_mount object with a new superblock (with path->dentry |
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* as the root), and return that mount so it can be auto-mounted on |
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* @path. |
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*/ |
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static struct vfsmount *fuse_dentry_automount(struct path *path) |
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{ |
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struct fs_context *fsc; |
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struct fuse_mount *parent_fm = get_fuse_mount_super(path->mnt->mnt_sb); |
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struct fuse_conn *fc = parent_fm->fc; |
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struct fuse_mount *fm; |
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struct vfsmount *mnt; |
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struct fuse_inode *mp_fi = get_fuse_inode(d_inode(path->dentry)); |
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struct super_block *sb; |
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int err; |
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fsc = fs_context_for_submount(path->mnt->mnt_sb->s_type, path->dentry); |
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if (IS_ERR(fsc)) { |
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err = PTR_ERR(fsc); |
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goto out; |
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} |
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err = -ENOMEM; |
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fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL); |
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if (!fm) |
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goto out_put_fsc; |
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fsc->s_fs_info = fm; |
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sb = sget_fc(fsc, NULL, set_anon_super_fc); |
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if (IS_ERR(sb)) { |
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err = PTR_ERR(sb); |
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kfree(fm); |
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goto out_put_fsc; |
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} |
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fm->fc = fuse_conn_get(fc); |
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/* Initialize superblock, making @mp_fi its root */ |
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err = fuse_fill_super_submount(sb, mp_fi); |
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if (err) |
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goto out_put_sb; |
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sb->s_flags |= SB_ACTIVE; |
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fsc->root = dget(sb->s_root); |
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/* We are done configuring the superblock, so unlock it */ |
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up_write(&sb->s_umount); |
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down_write(&fc->killsb); |
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list_add_tail(&fm->fc_entry, &fc->mounts); |
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up_write(&fc->killsb); |
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/* Create the submount */ |
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mnt = vfs_create_mount(fsc); |
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if (IS_ERR(mnt)) { |
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err = PTR_ERR(mnt); |
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goto out_put_fsc; |
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} |
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mntget(mnt); |
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put_fs_context(fsc); |
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return mnt; |
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out_put_sb: |
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/* |
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* Only jump here when fsc->root is NULL and sb is still locked |
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* (otherwise put_fs_context() will put the superblock) |
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*/ |
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deactivate_locked_super(sb); |
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out_put_fsc: |
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put_fs_context(fsc); |
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out: |
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return ERR_PTR(err); |
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} |
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const struct dentry_operations fuse_dentry_operations = { |
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.d_revalidate = fuse_dentry_revalidate, |
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.d_delete = fuse_dentry_delete, |
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#if BITS_PER_LONG < 64 |
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.d_init = fuse_dentry_init, |
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.d_release = fuse_dentry_release, |
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#endif |
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.d_automount = fuse_dentry_automount, |
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}; |
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|
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const struct dentry_operations fuse_root_dentry_operations = { |
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#if BITS_PER_LONG < 64 |
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.d_init = fuse_dentry_init, |
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.d_release = fuse_dentry_release, |
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#endif |
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}; |
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|
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int fuse_valid_type(int m) |
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{ |
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return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) || |
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S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m); |
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} |
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|
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bool fuse_invalid_attr(struct fuse_attr *attr) |
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{ |
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return !fuse_valid_type(attr->mode) || |
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attr->size > LLONG_MAX; |
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} |
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|
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int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name, |
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struct fuse_entry_out *outarg, struct inode **inode) |
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{ |
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struct fuse_mount *fm = get_fuse_mount_super(sb); |
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FUSE_ARGS(args); |
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struct fuse_forget_link *forget; |
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u64 attr_version; |
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int err; |
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*inode = NULL; |
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err = -ENAMETOOLONG; |
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if (name->len > FUSE_NAME_MAX) |
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goto out; |
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forget = fuse_alloc_forget(); |
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err = -ENOMEM; |
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if (!forget) |
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goto out; |
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attr_version = fuse_get_attr_version(fm->fc); |
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fuse_lookup_init(fm->fc, &args, nodeid, name, outarg); |
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err = fuse_simple_request(fm, &args); |
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/* Zero nodeid is same as -ENOENT, but with valid timeout */ |
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if (err || !outarg->nodeid) |
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goto out_put_forget; |
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err = -EIO; |
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if (!outarg->nodeid) |
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goto out_put_forget; |
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if (fuse_invalid_attr(&outarg->attr)) |
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goto out_put_forget; |
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|
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*inode = fuse_iget(sb, outarg->nodeid, outarg->generation, |
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&outarg->attr, entry_attr_timeout(outarg), |
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attr_version); |
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err = -ENOMEM; |
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if (!*inode) { |
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fuse_queue_forget(fm->fc, forget, outarg->nodeid, 1); |
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goto out; |
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} |
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err = 0; |
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|
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out_put_forget: |
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kfree(forget); |
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out: |
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return err; |
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} |
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|
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static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, |
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unsigned int flags) |
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{ |
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int err; |
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struct fuse_entry_out outarg; |
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struct inode *inode; |
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struct dentry *newent; |
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bool outarg_valid = true; |
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bool locked; |
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|
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if (fuse_is_bad(dir)) |
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return ERR_PTR(-EIO); |
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|
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locked = fuse_lock_inode(dir); |
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err = fuse_lookup_name(dir->i_sb, get_node_id(dir), &entry->d_name, |
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&outarg, &inode); |
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fuse_unlock_inode(dir, locked); |
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if (err == -ENOENT) { |
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outarg_valid = false; |
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err = 0; |
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} |
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if (err) |
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goto out_err; |
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|
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err = -EIO; |
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if (inode && get_node_id(inode) == FUSE_ROOT_ID) |
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goto out_iput; |
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|
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newent = d_splice_alias(inode, entry); |
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err = PTR_ERR(newent); |
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if (IS_ERR(newent)) |
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goto out_err; |
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|
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entry = newent ? newent : entry; |
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if (outarg_valid) |
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fuse_change_entry_timeout(entry, &outarg); |
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else |
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fuse_invalidate_entry_cache(entry); |
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|
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if (inode) |
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fuse_advise_use_readdirplus(dir); |
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return newent; |
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|
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out_iput: |
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iput(inode); |
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out_err: |
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return ERR_PTR(err); |
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} |
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|
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/* |
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* Atomic create+open operation |
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* |
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* If the filesystem doesn't support this, then fall back to separate |
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* 'mknod' + 'open' requests. |
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*/ |
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static int fuse_create_open(struct inode *dir, struct dentry *entry, |
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struct file *file, unsigned flags, |
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umode_t mode) |
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{ |
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int err; |
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struct inode *inode; |
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struct fuse_mount *fm = get_fuse_mount(dir); |
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FUSE_ARGS(args); |
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struct fuse_forget_link *forget; |
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struct fuse_create_in inarg; |
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struct fuse_open_out outopen; |
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struct fuse_entry_out outentry; |
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struct fuse_inode *fi; |
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struct fuse_file *ff; |
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|
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/* Userspace expects S_IFREG in create mode */ |
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BUG_ON((mode & S_IFMT) != S_IFREG); |
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|
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forget = fuse_alloc_forget(); |
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err = -ENOMEM; |
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if (!forget) |
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goto out_err; |
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|
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err = -ENOMEM; |
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ff = fuse_file_alloc(fm); |
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if (!ff) |
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goto out_put_forget_req; |
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|
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if (!fm->fc->dont_mask) |
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mode &= ~current_umask(); |
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|
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flags &= ~O_NOCTTY; |
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memset(&inarg, 0, sizeof(inarg)); |
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memset(&outentry, 0, sizeof(outentry)); |
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inarg.flags = flags; |
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inarg.mode = mode; |
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inarg.umask = current_umask(); |
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|
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if (fm->fc->handle_killpriv_v2 && (flags & O_TRUNC) && |
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!(flags & O_EXCL) && !capable(CAP_FSETID)) { |
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inarg.open_flags |= FUSE_OPEN_KILL_SUIDGID; |
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} |
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|
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args.opcode = FUSE_CREATE; |
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args.nodeid = get_node_id(dir); |
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args.in_numargs = 2; |
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args.in_args[0].size = sizeof(inarg); |
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args.in_args[0].value = &inarg; |
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args.in_args[1].size = entry->d_name.len + 1; |
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args.in_args[1].value = entry->d_name.name; |
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args.out_numargs = 2; |
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args.out_args[0].size = sizeof(outentry); |
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args.out_args[0].value = &outentry; |
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args.out_args[1].size = sizeof(outopen); |
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args.out_args[1].value = &outopen; |
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err = fuse_simple_request(fm, &args); |
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if (err) |
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goto out_free_ff; |
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|
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err = -EIO; |
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if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid) || |
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fuse_invalid_attr(&outentry.attr)) |
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goto out_free_ff; |
|
|
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ff->fh = outopen.fh; |
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ff->nodeid = outentry.nodeid; |
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ff->open_flags = outopen.open_flags; |
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inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation, |
|
&outentry.attr, entry_attr_timeout(&outentry), 0); |
|
if (!inode) { |
|
flags &= ~(O_CREAT | O_EXCL | O_TRUNC); |
|
fuse_sync_release(NULL, ff, flags); |
|
fuse_queue_forget(fm->fc, forget, outentry.nodeid, 1); |
|
err = -ENOMEM; |
|
goto out_err; |
|
} |
|
kfree(forget); |
|
d_instantiate(entry, inode); |
|
fuse_change_entry_timeout(entry, &outentry); |
|
fuse_dir_changed(dir); |
|
err = finish_open(file, entry, generic_file_open); |
|
if (err) { |
|
fi = get_fuse_inode(inode); |
|
fuse_sync_release(fi, ff, flags); |
|
} else { |
|
file->private_data = ff; |
|
fuse_finish_open(inode, file); |
|
} |
|
return err; |
|
|
|
out_free_ff: |
|
fuse_file_free(ff); |
|
out_put_forget_req: |
|
kfree(forget); |
|
out_err: |
|
return err; |
|
} |
|
|
|
static int fuse_mknod(struct user_namespace *, struct inode *, struct dentry *, |
|
umode_t, dev_t); |
|
static int fuse_atomic_open(struct inode *dir, struct dentry *entry, |
|
struct file *file, unsigned flags, |
|
umode_t mode) |
|
{ |
|
int err; |
|
struct fuse_conn *fc = get_fuse_conn(dir); |
|
struct dentry *res = NULL; |
|
|
|
if (fuse_is_bad(dir)) |
|
return -EIO; |
|
|
|
if (d_in_lookup(entry)) { |
|
res = fuse_lookup(dir, entry, 0); |
|
if (IS_ERR(res)) |
|
return PTR_ERR(res); |
|
|
|
if (res) |
|
entry = res; |
|
} |
|
|
|
if (!(flags & O_CREAT) || d_really_is_positive(entry)) |
|
goto no_open; |
|
|
|
/* Only creates */ |
|
file->f_mode |= FMODE_CREATED; |
|
|
|
if (fc->no_create) |
|
goto mknod; |
|
|
|
err = fuse_create_open(dir, entry, file, flags, mode); |
|
if (err == -ENOSYS) { |
|
fc->no_create = 1; |
|
goto mknod; |
|
} |
|
out_dput: |
|
dput(res); |
|
return err; |
|
|
|
mknod: |
|
err = fuse_mknod(&init_user_ns, dir, entry, mode, 0); |
|
if (err) |
|
goto out_dput; |
|
no_open: |
|
return finish_no_open(file, res); |
|
} |
|
|
|
/* |
|
* Code shared between mknod, mkdir, symlink and link |
|
*/ |
|
static int create_new_entry(struct fuse_mount *fm, struct fuse_args *args, |
|
struct inode *dir, struct dentry *entry, |
|
umode_t mode) |
|
{ |
|
struct fuse_entry_out outarg; |
|
struct inode *inode; |
|
struct dentry *d; |
|
int err; |
|
struct fuse_forget_link *forget; |
|
|
|
if (fuse_is_bad(dir)) |
|
return -EIO; |
|
|
|
forget = fuse_alloc_forget(); |
|
if (!forget) |
|
return -ENOMEM; |
|
|
|
memset(&outarg, 0, sizeof(outarg)); |
|
args->nodeid = get_node_id(dir); |
|
args->out_numargs = 1; |
|
args->out_args[0].size = sizeof(outarg); |
|
args->out_args[0].value = &outarg; |
|
err = fuse_simple_request(fm, args); |
|
if (err) |
|
goto out_put_forget_req; |
|
|
|
err = -EIO; |
|
if (invalid_nodeid(outarg.nodeid) || fuse_invalid_attr(&outarg.attr)) |
|
goto out_put_forget_req; |
|
|
|
if ((outarg.attr.mode ^ mode) & S_IFMT) |
|
goto out_put_forget_req; |
|
|
|
inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, |
|
&outarg.attr, entry_attr_timeout(&outarg), 0); |
|
if (!inode) { |
|
fuse_queue_forget(fm->fc, forget, outarg.nodeid, 1); |
|
return -ENOMEM; |
|
} |
|
kfree(forget); |
|
|
|
d_drop(entry); |
|
d = d_splice_alias(inode, entry); |
|
if (IS_ERR(d)) |
|
return PTR_ERR(d); |
|
|
|
if (d) { |
|
fuse_change_entry_timeout(d, &outarg); |
|
dput(d); |
|
} else { |
|
fuse_change_entry_timeout(entry, &outarg); |
|
} |
|
fuse_dir_changed(dir); |
|
return 0; |
|
|
|
out_put_forget_req: |
|
kfree(forget); |
|
return err; |
|
} |
|
|
|
static int fuse_mknod(struct user_namespace *mnt_userns, struct inode *dir, |
|
struct dentry *entry, umode_t mode, dev_t rdev) |
|
{ |
|
struct fuse_mknod_in inarg; |
|
struct fuse_mount *fm = get_fuse_mount(dir); |
|
FUSE_ARGS(args); |
|
|
|
if (!fm->fc->dont_mask) |
|
mode &= ~current_umask(); |
|
|
|
memset(&inarg, 0, sizeof(inarg)); |
|
inarg.mode = mode; |
|
inarg.rdev = new_encode_dev(rdev); |
|
inarg.umask = current_umask(); |
|
args.opcode = FUSE_MKNOD; |
|
args.in_numargs = 2; |
|
args.in_args[0].size = sizeof(inarg); |
|
args.in_args[0].value = &inarg; |
|
args.in_args[1].size = entry->d_name.len + 1; |
|
args.in_args[1].value = entry->d_name.name; |
|
return create_new_entry(fm, &args, dir, entry, mode); |
|
} |
|
|
|
static int fuse_create(struct user_namespace *mnt_userns, struct inode *dir, |
|
struct dentry *entry, umode_t mode, bool excl) |
|
{ |
|
return fuse_mknod(&init_user_ns, dir, entry, mode, 0); |
|
} |
|
|
|
static int fuse_mkdir(struct user_namespace *mnt_userns, struct inode *dir, |
|
struct dentry *entry, umode_t mode) |
|
{ |
|
struct fuse_mkdir_in inarg; |
|
struct fuse_mount *fm = get_fuse_mount(dir); |
|
FUSE_ARGS(args); |
|
|
|
if (!fm->fc->dont_mask) |
|
mode &= ~current_umask(); |
|
|
|
memset(&inarg, 0, sizeof(inarg)); |
|
inarg.mode = mode; |
|
inarg.umask = current_umask(); |
|
args.opcode = FUSE_MKDIR; |
|
args.in_numargs = 2; |
|
args.in_args[0].size = sizeof(inarg); |
|
args.in_args[0].value = &inarg; |
|
args.in_args[1].size = entry->d_name.len + 1; |
|
args.in_args[1].value = entry->d_name.name; |
|
return create_new_entry(fm, &args, dir, entry, S_IFDIR); |
|
} |
|
|
|
static int fuse_symlink(struct user_namespace *mnt_userns, struct inode *dir, |
|
struct dentry *entry, const char *link) |
|
{ |
|
struct fuse_mount *fm = get_fuse_mount(dir); |
|
unsigned len = strlen(link) + 1; |
|
FUSE_ARGS(args); |
|
|
|
args.opcode = FUSE_SYMLINK; |
|
args.in_numargs = 2; |
|
args.in_args[0].size = entry->d_name.len + 1; |
|
args.in_args[0].value = entry->d_name.name; |
|
args.in_args[1].size = len; |
|
args.in_args[1].value = link; |
|
return create_new_entry(fm, &args, dir, entry, S_IFLNK); |
|
} |
|
|
|
void fuse_update_ctime(struct inode *inode) |
|
{ |
|
if (!IS_NOCMTIME(inode)) { |
|
inode->i_ctime = current_time(inode); |
|
mark_inode_dirty_sync(inode); |
|
} |
|
} |
|
|
|
static int fuse_unlink(struct inode *dir, struct dentry *entry) |
|
{ |
|
int err; |
|
struct fuse_mount *fm = get_fuse_mount(dir); |
|
FUSE_ARGS(args); |
|
|
|
if (fuse_is_bad(dir)) |
|
return -EIO; |
|
|
|
args.opcode = FUSE_UNLINK; |
|
args.nodeid = get_node_id(dir); |
|
args.in_numargs = 1; |
|
args.in_args[0].size = entry->d_name.len + 1; |
|
args.in_args[0].value = entry->d_name.name; |
|
err = fuse_simple_request(fm, &args); |
|
if (!err) { |
|
struct inode *inode = d_inode(entry); |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
|
|
spin_lock(&fi->lock); |
|
fi->attr_version = atomic64_inc_return(&fm->fc->attr_version); |
|
/* |
|
* If i_nlink == 0 then unlink doesn't make sense, yet this can |
|
* happen if userspace filesystem is careless. It would be |
|
* difficult to enforce correct nlink usage so just ignore this |
|
* condition here |
|
*/ |
|
if (inode->i_nlink > 0) |
|
drop_nlink(inode); |
|
spin_unlock(&fi->lock); |
|
fuse_invalidate_attr(inode); |
|
fuse_dir_changed(dir); |
|
fuse_invalidate_entry_cache(entry); |
|
fuse_update_ctime(inode); |
|
} else if (err == -EINTR) |
|
fuse_invalidate_entry(entry); |
|
return err; |
|
} |
|
|
|
static int fuse_rmdir(struct inode *dir, struct dentry *entry) |
|
{ |
|
int err; |
|
struct fuse_mount *fm = get_fuse_mount(dir); |
|
FUSE_ARGS(args); |
|
|
|
if (fuse_is_bad(dir)) |
|
return -EIO; |
|
|
|
args.opcode = FUSE_RMDIR; |
|
args.nodeid = get_node_id(dir); |
|
args.in_numargs = 1; |
|
args.in_args[0].size = entry->d_name.len + 1; |
|
args.in_args[0].value = entry->d_name.name; |
|
err = fuse_simple_request(fm, &args); |
|
if (!err) { |
|
clear_nlink(d_inode(entry)); |
|
fuse_dir_changed(dir); |
|
fuse_invalidate_entry_cache(entry); |
|
} else if (err == -EINTR) |
|
fuse_invalidate_entry(entry); |
|
return err; |
|
} |
|
|
|
static int fuse_rename_common(struct inode *olddir, struct dentry *oldent, |
|
struct inode *newdir, struct dentry *newent, |
|
unsigned int flags, int opcode, size_t argsize) |
|
{ |
|
int err; |
|
struct fuse_rename2_in inarg; |
|
struct fuse_mount *fm = get_fuse_mount(olddir); |
|
FUSE_ARGS(args); |
|
|
|
memset(&inarg, 0, argsize); |
|
inarg.newdir = get_node_id(newdir); |
|
inarg.flags = flags; |
|
args.opcode = opcode; |
|
args.nodeid = get_node_id(olddir); |
|
args.in_numargs = 3; |
|
args.in_args[0].size = argsize; |
|
args.in_args[0].value = &inarg; |
|
args.in_args[1].size = oldent->d_name.len + 1; |
|
args.in_args[1].value = oldent->d_name.name; |
|
args.in_args[2].size = newent->d_name.len + 1; |
|
args.in_args[2].value = newent->d_name.name; |
|
err = fuse_simple_request(fm, &args); |
|
if (!err) { |
|
/* ctime changes */ |
|
fuse_invalidate_attr(d_inode(oldent)); |
|
fuse_update_ctime(d_inode(oldent)); |
|
|
|
if (flags & RENAME_EXCHANGE) { |
|
fuse_invalidate_attr(d_inode(newent)); |
|
fuse_update_ctime(d_inode(newent)); |
|
} |
|
|
|
fuse_dir_changed(olddir); |
|
if (olddir != newdir) |
|
fuse_dir_changed(newdir); |
|
|
|
/* newent will end up negative */ |
|
if (!(flags & RENAME_EXCHANGE) && d_really_is_positive(newent)) { |
|
fuse_invalidate_attr(d_inode(newent)); |
|
fuse_invalidate_entry_cache(newent); |
|
fuse_update_ctime(d_inode(newent)); |
|
} |
|
} else if (err == -EINTR) { |
|
/* If request was interrupted, DEITY only knows if the |
|
rename actually took place. If the invalidation |
|
fails (e.g. some process has CWD under the renamed |
|
directory), then there can be inconsistency between |
|
the dcache and the real filesystem. Tough luck. */ |
|
fuse_invalidate_entry(oldent); |
|
if (d_really_is_positive(newent)) |
|
fuse_invalidate_entry(newent); |
|
} |
|
|
|
return err; |
|
} |
|
|
|
static int fuse_rename2(struct user_namespace *mnt_userns, struct inode *olddir, |
|
struct dentry *oldent, struct inode *newdir, |
|
struct dentry *newent, unsigned int flags) |
|
{ |
|
struct fuse_conn *fc = get_fuse_conn(olddir); |
|
int err; |
|
|
|
if (fuse_is_bad(olddir)) |
|
return -EIO; |
|
|
|
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) |
|
return -EINVAL; |
|
|
|
if (flags) { |
|
if (fc->no_rename2 || fc->minor < 23) |
|
return -EINVAL; |
|
|
|
err = fuse_rename_common(olddir, oldent, newdir, newent, flags, |
|
FUSE_RENAME2, |
|
sizeof(struct fuse_rename2_in)); |
|
if (err == -ENOSYS) { |
|
fc->no_rename2 = 1; |
|
err = -EINVAL; |
|
} |
|
} else { |
|
err = fuse_rename_common(olddir, oldent, newdir, newent, 0, |
|
FUSE_RENAME, |
|
sizeof(struct fuse_rename_in)); |
|
} |
|
|
|
return err; |
|
} |
|
|
|
static int fuse_link(struct dentry *entry, struct inode *newdir, |
|
struct dentry *newent) |
|
{ |
|
int err; |
|
struct fuse_link_in inarg; |
|
struct inode *inode = d_inode(entry); |
|
struct fuse_mount *fm = get_fuse_mount(inode); |
|
FUSE_ARGS(args); |
|
|
|
memset(&inarg, 0, sizeof(inarg)); |
|
inarg.oldnodeid = get_node_id(inode); |
|
args.opcode = FUSE_LINK; |
|
args.in_numargs = 2; |
|
args.in_args[0].size = sizeof(inarg); |
|
args.in_args[0].value = &inarg; |
|
args.in_args[1].size = newent->d_name.len + 1; |
|
args.in_args[1].value = newent->d_name.name; |
|
err = create_new_entry(fm, &args, newdir, newent, inode->i_mode); |
|
/* Contrary to "normal" filesystems it can happen that link |
|
makes two "logical" inodes point to the same "physical" |
|
inode. We invalidate the attributes of the old one, so it |
|
will reflect changes in the backing inode (link count, |
|
etc.) |
|
*/ |
|
if (!err) { |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
|
|
spin_lock(&fi->lock); |
|
fi->attr_version = atomic64_inc_return(&fm->fc->attr_version); |
|
if (likely(inode->i_nlink < UINT_MAX)) |
|
inc_nlink(inode); |
|
spin_unlock(&fi->lock); |
|
fuse_invalidate_attr(inode); |
|
fuse_update_ctime(inode); |
|
} else if (err == -EINTR) { |
|
fuse_invalidate_attr(inode); |
|
} |
|
return err; |
|
} |
|
|
|
static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr, |
|
struct kstat *stat) |
|
{ |
|
unsigned int blkbits; |
|
struct fuse_conn *fc = get_fuse_conn(inode); |
|
|
|
/* see the comment in fuse_change_attributes() */ |
|
if (fc->writeback_cache && S_ISREG(inode->i_mode)) { |
|
attr->size = i_size_read(inode); |
|
attr->mtime = inode->i_mtime.tv_sec; |
|
attr->mtimensec = inode->i_mtime.tv_nsec; |
|
attr->ctime = inode->i_ctime.tv_sec; |
|
attr->ctimensec = inode->i_ctime.tv_nsec; |
|
} |
|
|
|
stat->dev = inode->i_sb->s_dev; |
|
stat->ino = attr->ino; |
|
stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); |
|
stat->nlink = attr->nlink; |
|
stat->uid = make_kuid(fc->user_ns, attr->uid); |
|
stat->gid = make_kgid(fc->user_ns, attr->gid); |
|
stat->rdev = inode->i_rdev; |
|
stat->atime.tv_sec = attr->atime; |
|
stat->atime.tv_nsec = attr->atimensec; |
|
stat->mtime.tv_sec = attr->mtime; |
|
stat->mtime.tv_nsec = attr->mtimensec; |
|
stat->ctime.tv_sec = attr->ctime; |
|
stat->ctime.tv_nsec = attr->ctimensec; |
|
stat->size = attr->size; |
|
stat->blocks = attr->blocks; |
|
|
|
if (attr->blksize != 0) |
|
blkbits = ilog2(attr->blksize); |
|
else |
|
blkbits = inode->i_sb->s_blocksize_bits; |
|
|
|
stat->blksize = 1 << blkbits; |
|
} |
|
|
|
static int fuse_do_getattr(struct inode *inode, struct kstat *stat, |
|
struct file *file) |
|
{ |
|
int err; |
|
struct fuse_getattr_in inarg; |
|
struct fuse_attr_out outarg; |
|
struct fuse_mount *fm = get_fuse_mount(inode); |
|
FUSE_ARGS(args); |
|
u64 attr_version; |
|
|
|
attr_version = fuse_get_attr_version(fm->fc); |
|
|
|
memset(&inarg, 0, sizeof(inarg)); |
|
memset(&outarg, 0, sizeof(outarg)); |
|
/* Directories have separate file-handle space */ |
|
if (file && S_ISREG(inode->i_mode)) { |
|
struct fuse_file *ff = file->private_data; |
|
|
|
inarg.getattr_flags |= FUSE_GETATTR_FH; |
|
inarg.fh = ff->fh; |
|
} |
|
args.opcode = FUSE_GETATTR; |
|
args.nodeid = get_node_id(inode); |
|
args.in_numargs = 1; |
|
args.in_args[0].size = sizeof(inarg); |
|
args.in_args[0].value = &inarg; |
|
args.out_numargs = 1; |
|
args.out_args[0].size = sizeof(outarg); |
|
args.out_args[0].value = &outarg; |
|
err = fuse_simple_request(fm, &args); |
|
if (!err) { |
|
if (fuse_invalid_attr(&outarg.attr) || |
|
(inode->i_mode ^ outarg.attr.mode) & S_IFMT) { |
|
fuse_make_bad(inode); |
|
err = -EIO; |
|
} else { |
|
fuse_change_attributes(inode, &outarg.attr, |
|
attr_timeout(&outarg), |
|
attr_version); |
|
if (stat) |
|
fuse_fillattr(inode, &outarg.attr, stat); |
|
} |
|
} |
|
return err; |
|
} |
|
|
|
static int fuse_update_get_attr(struct inode *inode, struct file *file, |
|
struct kstat *stat, u32 request_mask, |
|
unsigned int flags) |
|
{ |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
int err = 0; |
|
bool sync; |
|
|
|
if (flags & AT_STATX_FORCE_SYNC) |
|
sync = true; |
|
else if (flags & AT_STATX_DONT_SYNC) |
|
sync = false; |
|
else if (request_mask & READ_ONCE(fi->inval_mask)) |
|
sync = true; |
|
else |
|
sync = time_before64(fi->i_time, get_jiffies_64()); |
|
|
|
if (sync) { |
|
forget_all_cached_acls(inode); |
|
err = fuse_do_getattr(inode, stat, file); |
|
} else if (stat) { |
|
generic_fillattr(&init_user_ns, inode, stat); |
|
stat->mode = fi->orig_i_mode; |
|
stat->ino = fi->orig_ino; |
|
} |
|
|
|
return err; |
|
} |
|
|
|
int fuse_update_attributes(struct inode *inode, struct file *file) |
|
{ |
|
/* Do *not* need to get atime for internal purposes */ |
|
return fuse_update_get_attr(inode, file, NULL, |
|
STATX_BASIC_STATS & ~STATX_ATIME, 0); |
|
} |
|
|
|
int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid, |
|
u64 child_nodeid, struct qstr *name) |
|
{ |
|
int err = -ENOTDIR; |
|
struct inode *parent; |
|
struct dentry *dir; |
|
struct dentry *entry; |
|
|
|
parent = fuse_ilookup(fc, parent_nodeid, NULL); |
|
if (!parent) |
|
return -ENOENT; |
|
|
|
inode_lock(parent); |
|
if (!S_ISDIR(parent->i_mode)) |
|
goto unlock; |
|
|
|
err = -ENOENT; |
|
dir = d_find_alias(parent); |
|
if (!dir) |
|
goto unlock; |
|
|
|
name->hash = full_name_hash(dir, name->name, name->len); |
|
entry = d_lookup(dir, name); |
|
dput(dir); |
|
if (!entry) |
|
goto unlock; |
|
|
|
fuse_dir_changed(parent); |
|
fuse_invalidate_entry(entry); |
|
|
|
if (child_nodeid != 0 && d_really_is_positive(entry)) { |
|
inode_lock(d_inode(entry)); |
|
if (get_node_id(d_inode(entry)) != child_nodeid) { |
|
err = -ENOENT; |
|
goto badentry; |
|
} |
|
if (d_mountpoint(entry)) { |
|
err = -EBUSY; |
|
goto badentry; |
|
} |
|
if (d_is_dir(entry)) { |
|
shrink_dcache_parent(entry); |
|
if (!simple_empty(entry)) { |
|
err = -ENOTEMPTY; |
|
goto badentry; |
|
} |
|
d_inode(entry)->i_flags |= S_DEAD; |
|
} |
|
dont_mount(entry); |
|
clear_nlink(d_inode(entry)); |
|
err = 0; |
|
badentry: |
|
inode_unlock(d_inode(entry)); |
|
if (!err) |
|
d_delete(entry); |
|
} else { |
|
err = 0; |
|
} |
|
dput(entry); |
|
|
|
unlock: |
|
inode_unlock(parent); |
|
iput(parent); |
|
return err; |
|
} |
|
|
|
/* |
|
* Calling into a user-controlled filesystem gives the filesystem |
|
* daemon ptrace-like capabilities over the current process. This |
|
* means, that the filesystem daemon is able to record the exact |
|
* filesystem operations performed, and can also control the behavior |
|
* of the requester process in otherwise impossible ways. For example |
|
* it can delay the operation for arbitrary length of time allowing |
|
* DoS against the requester. |
|
* |
|
* For this reason only those processes can call into the filesystem, |
|
* for which the owner of the mount has ptrace privilege. This |
|
* excludes processes started by other users, suid or sgid processes. |
|
*/ |
|
int fuse_allow_current_process(struct fuse_conn *fc) |
|
{ |
|
const struct cred *cred; |
|
|
|
if (fc->allow_other) |
|
return current_in_userns(fc->user_ns); |
|
|
|
cred = current_cred(); |
|
if (uid_eq(cred->euid, fc->user_id) && |
|
uid_eq(cred->suid, fc->user_id) && |
|
uid_eq(cred->uid, fc->user_id) && |
|
gid_eq(cred->egid, fc->group_id) && |
|
gid_eq(cred->sgid, fc->group_id) && |
|
gid_eq(cred->gid, fc->group_id)) |
|
return 1; |
|
|
|
return 0; |
|
} |
|
|
|
static int fuse_access(struct inode *inode, int mask) |
|
{ |
|
struct fuse_mount *fm = get_fuse_mount(inode); |
|
FUSE_ARGS(args); |
|
struct fuse_access_in inarg; |
|
int err; |
|
|
|
BUG_ON(mask & MAY_NOT_BLOCK); |
|
|
|
if (fm->fc->no_access) |
|
return 0; |
|
|
|
memset(&inarg, 0, sizeof(inarg)); |
|
inarg.mask = mask & (MAY_READ | MAY_WRITE | MAY_EXEC); |
|
args.opcode = FUSE_ACCESS; |
|
args.nodeid = get_node_id(inode); |
|
args.in_numargs = 1; |
|
args.in_args[0].size = sizeof(inarg); |
|
args.in_args[0].value = &inarg; |
|
err = fuse_simple_request(fm, &args); |
|
if (err == -ENOSYS) { |
|
fm->fc->no_access = 1; |
|
err = 0; |
|
} |
|
return err; |
|
} |
|
|
|
static int fuse_perm_getattr(struct inode *inode, int mask) |
|
{ |
|
if (mask & MAY_NOT_BLOCK) |
|
return -ECHILD; |
|
|
|
forget_all_cached_acls(inode); |
|
return fuse_do_getattr(inode, NULL, NULL); |
|
} |
|
|
|
/* |
|
* 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 user_namespace *mnt_userns, |
|
struct inode *inode, int mask) |
|
{ |
|
struct fuse_conn *fc = get_fuse_conn(inode); |
|
bool refreshed = false; |
|
int err = 0; |
|
|
|
if (fuse_is_bad(inode)) |
|
return -EIO; |
|
|
|
if (!fuse_allow_current_process(fc)) |
|
return -EACCES; |
|
|
|
/* |
|
* If attributes are needed, refresh them before proceeding |
|
*/ |
|
if (fc->default_permissions || |
|
((mask & MAY_EXEC) && S_ISREG(inode->i_mode))) { |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
u32 perm_mask = STATX_MODE | STATX_UID | STATX_GID; |
|
|
|
if (perm_mask & READ_ONCE(fi->inval_mask) || |
|
time_before64(fi->i_time, get_jiffies_64())) { |
|
refreshed = true; |
|
|
|
err = fuse_perm_getattr(inode, mask); |
|
if (err) |
|
return err; |
|
} |
|
} |
|
|
|
if (fc->default_permissions) { |
|
err = generic_permission(&init_user_ns, inode, mask); |
|
|
|
/* If permission is denied, try to refresh file |
|
attributes. This is also needed, because the root |
|
node will at first have no permissions */ |
|
if (err == -EACCES && !refreshed) { |
|
err = fuse_perm_getattr(inode, mask); |
|
if (!err) |
|
err = generic_permission(&init_user_ns, |
|
inode, mask); |
|
} |
|
|
|
/* 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 */ |
|
} else if (mask & (MAY_ACCESS | MAY_CHDIR)) { |
|
err = fuse_access(inode, mask); |
|
} else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) { |
|
if (!(inode->i_mode & S_IXUGO)) { |
|
if (refreshed) |
|
return -EACCES; |
|
|
|
err = fuse_perm_getattr(inode, mask); |
|
if (!err && !(inode->i_mode & S_IXUGO)) |
|
return -EACCES; |
|
} |
|
} |
|
return err; |
|
} |
|
|
|
static int fuse_readlink_page(struct inode *inode, struct page *page) |
|
{ |
|
struct fuse_mount *fm = get_fuse_mount(inode); |
|
struct fuse_page_desc desc = { .length = PAGE_SIZE - 1 }; |
|
struct fuse_args_pages ap = { |
|
.num_pages = 1, |
|
.pages = &page, |
|
.descs = &desc, |
|
}; |
|
char *link; |
|
ssize_t res; |
|
|
|
ap.args.opcode = FUSE_READLINK; |
|
ap.args.nodeid = get_node_id(inode); |
|
ap.args.out_pages = true; |
|
ap.args.out_argvar = true; |
|
ap.args.page_zeroing = true; |
|
ap.args.out_numargs = 1; |
|
ap.args.out_args[0].size = desc.length; |
|
res = fuse_simple_request(fm, &ap.args); |
|
|
|
fuse_invalidate_atime(inode); |
|
|
|
if (res < 0) |
|
return res; |
|
|
|
if (WARN_ON(res >= PAGE_SIZE)) |
|
return -EIO; |
|
|
|
link = page_address(page); |
|
link[res] = '\0'; |
|
|
|
return 0; |
|
} |
|
|
|
static const char *fuse_get_link(struct dentry *dentry, struct inode *inode, |
|
struct delayed_call *callback) |
|
{ |
|
struct fuse_conn *fc = get_fuse_conn(inode); |
|
struct page *page; |
|
int err; |
|
|
|
err = -EIO; |
|
if (fuse_is_bad(inode)) |
|
goto out_err; |
|
|
|
if (fc->cache_symlinks) |
|
return page_get_link(dentry, inode, callback); |
|
|
|
err = -ECHILD; |
|
if (!dentry) |
|
goto out_err; |
|
|
|
page = alloc_page(GFP_KERNEL); |
|
err = -ENOMEM; |
|
if (!page) |
|
goto out_err; |
|
|
|
err = fuse_readlink_page(inode, page); |
|
if (err) { |
|
__free_page(page); |
|
goto out_err; |
|
} |
|
|
|
set_delayed_call(callback, page_put_link, page); |
|
|
|
return page_address(page); |
|
|
|
out_err: |
|
return ERR_PTR(err); |
|
} |
|
|
|
static int fuse_dir_open(struct inode *inode, struct file *file) |
|
{ |
|
return fuse_open_common(inode, file, true); |
|
} |
|
|
|
static int fuse_dir_release(struct inode *inode, struct file *file) |
|
{ |
|
fuse_release_common(file, true); |
|
|
|
return 0; |
|
} |
|
|
|
static int fuse_dir_fsync(struct file *file, loff_t start, loff_t end, |
|
int datasync) |
|
{ |
|
struct inode *inode = file->f_mapping->host; |
|
struct fuse_conn *fc = get_fuse_conn(inode); |
|
int err; |
|
|
|
if (fuse_is_bad(inode)) |
|
return -EIO; |
|
|
|
if (fc->no_fsyncdir) |
|
return 0; |
|
|
|
inode_lock(inode); |
|
err = fuse_fsync_common(file, start, end, datasync, FUSE_FSYNCDIR); |
|
if (err == -ENOSYS) { |
|
fc->no_fsyncdir = 1; |
|
err = 0; |
|
} |
|
inode_unlock(inode); |
|
|
|
return err; |
|
} |
|
|
|
static long fuse_dir_ioctl(struct file *file, unsigned int cmd, |
|
unsigned long arg) |
|
{ |
|
struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host); |
|
|
|
/* FUSE_IOCTL_DIR only supported for API version >= 7.18 */ |
|
if (fc->minor < 18) |
|
return -ENOTTY; |
|
|
|
return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_DIR); |
|
} |
|
|
|
static long fuse_dir_compat_ioctl(struct file *file, unsigned int cmd, |
|
unsigned long arg) |
|
{ |
|
struct fuse_conn *fc = get_fuse_conn(file->f_mapping->host); |
|
|
|
if (fc->minor < 18) |
|
return -ENOTTY; |
|
|
|
return fuse_ioctl_common(file, cmd, arg, |
|
FUSE_IOCTL_COMPAT | FUSE_IOCTL_DIR); |
|
} |
|
|
|
static bool update_mtime(unsigned ivalid, bool trust_local_mtime) |
|
{ |
|
/* Always update if mtime is explicitly set */ |
|
if (ivalid & ATTR_MTIME_SET) |
|
return true; |
|
|
|
/* Or if kernel i_mtime is the official one */ |
|
if (trust_local_mtime) |
|
return true; |
|
|
|
/* If it's an open(O_TRUNC) or an ftruncate(), don't update */ |
|
if ((ivalid & ATTR_SIZE) && (ivalid & (ATTR_OPEN | ATTR_FILE))) |
|
return false; |
|
|
|
/* In all other cases update */ |
|
return true; |
|
} |
|
|
|
static void iattr_to_fattr(struct fuse_conn *fc, struct iattr *iattr, |
|
struct fuse_setattr_in *arg, bool trust_local_cmtime) |
|
{ |
|
unsigned ivalid = iattr->ia_valid; |
|
|
|
if (ivalid & ATTR_MODE) |
|
arg->valid |= FATTR_MODE, arg->mode = iattr->ia_mode; |
|
if (ivalid & ATTR_UID) |
|
arg->valid |= FATTR_UID, arg->uid = from_kuid(fc->user_ns, iattr->ia_uid); |
|
if (ivalid & ATTR_GID) |
|
arg->valid |= FATTR_GID, arg->gid = from_kgid(fc->user_ns, iattr->ia_gid); |
|
if (ivalid & ATTR_SIZE) |
|
arg->valid |= FATTR_SIZE, arg->size = iattr->ia_size; |
|
if (ivalid & ATTR_ATIME) { |
|
arg->valid |= FATTR_ATIME; |
|
arg->atime = iattr->ia_atime.tv_sec; |
|
arg->atimensec = iattr->ia_atime.tv_nsec; |
|
if (!(ivalid & ATTR_ATIME_SET)) |
|
arg->valid |= FATTR_ATIME_NOW; |
|
} |
|
if ((ivalid & ATTR_MTIME) && update_mtime(ivalid, trust_local_cmtime)) { |
|
arg->valid |= FATTR_MTIME; |
|
arg->mtime = iattr->ia_mtime.tv_sec; |
|
arg->mtimensec = iattr->ia_mtime.tv_nsec; |
|
if (!(ivalid & ATTR_MTIME_SET) && !trust_local_cmtime) |
|
arg->valid |= FATTR_MTIME_NOW; |
|
} |
|
if ((ivalid & ATTR_CTIME) && trust_local_cmtime) { |
|
arg->valid |= FATTR_CTIME; |
|
arg->ctime = iattr->ia_ctime.tv_sec; |
|
arg->ctimensec = iattr->ia_ctime.tv_nsec; |
|
} |
|
} |
|
|
|
/* |
|
* Prevent concurrent writepages on inode |
|
* |
|
* This is done by adding a negative bias to the inode write counter |
|
* and waiting for all pending writes to finish. |
|
*/ |
|
void fuse_set_nowrite(struct inode *inode) |
|
{ |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
|
|
BUG_ON(!inode_is_locked(inode)); |
|
|
|
spin_lock(&fi->lock); |
|
BUG_ON(fi->writectr < 0); |
|
fi->writectr += FUSE_NOWRITE; |
|
spin_unlock(&fi->lock); |
|
wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE); |
|
} |
|
|
|
/* |
|
* Allow writepages on inode |
|
* |
|
* Remove the bias from the writecounter and send any queued |
|
* writepages. |
|
*/ |
|
static void __fuse_release_nowrite(struct inode *inode) |
|
{ |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
|
|
BUG_ON(fi->writectr != FUSE_NOWRITE); |
|
fi->writectr = 0; |
|
fuse_flush_writepages(inode); |
|
} |
|
|
|
void fuse_release_nowrite(struct inode *inode) |
|
{ |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
|
|
spin_lock(&fi->lock); |
|
__fuse_release_nowrite(inode); |
|
spin_unlock(&fi->lock); |
|
} |
|
|
|
static void fuse_setattr_fill(struct fuse_conn *fc, struct fuse_args *args, |
|
struct inode *inode, |
|
struct fuse_setattr_in *inarg_p, |
|
struct fuse_attr_out *outarg_p) |
|
{ |
|
args->opcode = FUSE_SETATTR; |
|
args->nodeid = get_node_id(inode); |
|
args->in_numargs = 1; |
|
args->in_args[0].size = sizeof(*inarg_p); |
|
args->in_args[0].value = inarg_p; |
|
args->out_numargs = 1; |
|
args->out_args[0].size = sizeof(*outarg_p); |
|
args->out_args[0].value = outarg_p; |
|
} |
|
|
|
/* |
|
* Flush inode->i_mtime to the server |
|
*/ |
|
int fuse_flush_times(struct inode *inode, struct fuse_file *ff) |
|
{ |
|
struct fuse_mount *fm = get_fuse_mount(inode); |
|
FUSE_ARGS(args); |
|
struct fuse_setattr_in inarg; |
|
struct fuse_attr_out outarg; |
|
|
|
memset(&inarg, 0, sizeof(inarg)); |
|
memset(&outarg, 0, sizeof(outarg)); |
|
|
|
inarg.valid = FATTR_MTIME; |
|
inarg.mtime = inode->i_mtime.tv_sec; |
|
inarg.mtimensec = inode->i_mtime.tv_nsec; |
|
if (fm->fc->minor >= 23) { |
|
inarg.valid |= FATTR_CTIME; |
|
inarg.ctime = inode->i_ctime.tv_sec; |
|
inarg.ctimensec = inode->i_ctime.tv_nsec; |
|
} |
|
if (ff) { |
|
inarg.valid |= FATTR_FH; |
|
inarg.fh = ff->fh; |
|
} |
|
fuse_setattr_fill(fm->fc, &args, inode, &inarg, &outarg); |
|
|
|
return fuse_simple_request(fm, &args); |
|
} |
|
|
|
/* |
|
* 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 |
|
* and the actual truncation by hand. |
|
*/ |
|
int fuse_do_setattr(struct dentry *dentry, struct iattr *attr, |
|
struct file *file) |
|
{ |
|
struct inode *inode = d_inode(dentry); |
|
struct fuse_mount *fm = get_fuse_mount(inode); |
|
struct fuse_conn *fc = fm->fc; |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
FUSE_ARGS(args); |
|
struct fuse_setattr_in inarg; |
|
struct fuse_attr_out outarg; |
|
bool is_truncate = false; |
|
bool is_wb = fc->writeback_cache; |
|
loff_t oldsize; |
|
int err; |
|
bool trust_local_cmtime = is_wb && S_ISREG(inode->i_mode); |
|
bool fault_blocked = false; |
|
|
|
if (!fc->default_permissions) |
|
attr->ia_valid |= ATTR_FORCE; |
|
|
|
err = setattr_prepare(&init_user_ns, dentry, attr); |
|
if (err) |
|
return err; |
|
|
|
if (attr->ia_valid & ATTR_SIZE) { |
|
if (WARN_ON(!S_ISREG(inode->i_mode))) |
|
return -EIO; |
|
is_truncate = true; |
|
} |
|
|
|
if (FUSE_IS_DAX(inode) && is_truncate) { |
|
down_write(&fi->i_mmap_sem); |
|
fault_blocked = true; |
|
err = fuse_dax_break_layouts(inode, 0, 0); |
|
if (err) { |
|
up_write(&fi->i_mmap_sem); |
|
return err; |
|
} |
|
} |
|
|
|
if (attr->ia_valid & ATTR_OPEN) { |
|
/* This is coming from open(..., ... | O_TRUNC); */ |
|
WARN_ON(!(attr->ia_valid & ATTR_SIZE)); |
|
WARN_ON(attr->ia_size != 0); |
|
if (fc->atomic_o_trunc) { |
|
/* |
|
* No need to send request to userspace, since actual |
|
* truncation has already been done by OPEN. But still |
|
* need to truncate page cache. |
|
*/ |
|
i_size_write(inode, 0); |
|
truncate_pagecache(inode, 0); |
|
goto out; |
|
} |
|
file = NULL; |
|
} |
|
|
|
/* Flush dirty data/metadata before non-truncate SETATTR */ |
|
if (is_wb && S_ISREG(inode->i_mode) && |
|
attr->ia_valid & |
|
(ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_MTIME_SET | |
|
ATTR_TIMES_SET)) { |
|
err = write_inode_now(inode, true); |
|
if (err) |
|
return err; |
|
|
|
fuse_set_nowrite(inode); |
|
fuse_release_nowrite(inode); |
|
} |
|
|
|
if (is_truncate) { |
|
fuse_set_nowrite(inode); |
|
set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
|
if (trust_local_cmtime && attr->ia_size != inode->i_size) |
|
attr->ia_valid |= ATTR_MTIME | ATTR_CTIME; |
|
} |
|
|
|
memset(&inarg, 0, sizeof(inarg)); |
|
memset(&outarg, 0, sizeof(outarg)); |
|
iattr_to_fattr(fc, attr, &inarg, trust_local_cmtime); |
|
if (file) { |
|
struct fuse_file *ff = file->private_data; |
|
inarg.valid |= FATTR_FH; |
|
inarg.fh = ff->fh; |
|
} |
|
|
|
/* Kill suid/sgid for non-directory chown unconditionally */ |
|
if (fc->handle_killpriv_v2 && !S_ISDIR(inode->i_mode) && |
|
attr->ia_valid & (ATTR_UID | ATTR_GID)) |
|
inarg.valid |= FATTR_KILL_SUIDGID; |
|
|
|
if (attr->ia_valid & ATTR_SIZE) { |
|
/* For mandatory locking in truncate */ |
|
inarg.valid |= FATTR_LOCKOWNER; |
|
inarg.lock_owner = fuse_lock_owner_id(fc, current->files); |
|
|
|
/* Kill suid/sgid for truncate only if no CAP_FSETID */ |
|
if (fc->handle_killpriv_v2 && !capable(CAP_FSETID)) |
|
inarg.valid |= FATTR_KILL_SUIDGID; |
|
} |
|
fuse_setattr_fill(fc, &args, inode, &inarg, &outarg); |
|
err = fuse_simple_request(fm, &args); |
|
if (err) { |
|
if (err == -EINTR) |
|
fuse_invalidate_attr(inode); |
|
goto error; |
|
} |
|
|
|
if (fuse_invalid_attr(&outarg.attr) || |
|
(inode->i_mode ^ outarg.attr.mode) & S_IFMT) { |
|
fuse_make_bad(inode); |
|
err = -EIO; |
|
goto error; |
|
} |
|
|
|
spin_lock(&fi->lock); |
|
/* the kernel maintains i_mtime locally */ |
|
if (trust_local_cmtime) { |
|
if (attr->ia_valid & ATTR_MTIME) |
|
inode->i_mtime = attr->ia_mtime; |
|
if (attr->ia_valid & ATTR_CTIME) |
|
inode->i_ctime = attr->ia_ctime; |
|
/* FIXME: clear I_DIRTY_SYNC? */ |
|
} |
|
|
|
fuse_change_attributes_common(inode, &outarg.attr, |
|
attr_timeout(&outarg)); |
|
oldsize = inode->i_size; |
|
/* see the comment in fuse_change_attributes() */ |
|
if (!is_wb || is_truncate || !S_ISREG(inode->i_mode)) |
|
i_size_write(inode, outarg.attr.size); |
|
|
|
if (is_truncate) { |
|
/* NOTE: this may release/reacquire fi->lock */ |
|
__fuse_release_nowrite(inode); |
|
} |
|
spin_unlock(&fi->lock); |
|
|
|
/* |
|
* Only call invalidate_inode_pages2() after removing |
|
* FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock. |
|
*/ |
|
if ((is_truncate || !is_wb) && |
|
S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { |
|
truncate_pagecache(inode, outarg.attr.size); |
|
invalidate_inode_pages2(inode->i_mapping); |
|
} |
|
|
|
clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
|
out: |
|
if (fault_blocked) |
|
up_write(&fi->i_mmap_sem); |
|
|
|
return 0; |
|
|
|
error: |
|
if (is_truncate) |
|
fuse_release_nowrite(inode); |
|
|
|
clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state); |
|
|
|
if (fault_blocked) |
|
up_write(&fi->i_mmap_sem); |
|
return err; |
|
} |
|
|
|
static int fuse_setattr(struct user_namespace *mnt_userns, struct dentry *entry, |
|
struct iattr *attr) |
|
{ |
|
struct inode *inode = d_inode(entry); |
|
struct fuse_conn *fc = get_fuse_conn(inode); |
|
struct file *file = (attr->ia_valid & ATTR_FILE) ? attr->ia_file : NULL; |
|
int ret; |
|
|
|
if (fuse_is_bad(inode)) |
|
return -EIO; |
|
|
|
if (!fuse_allow_current_process(get_fuse_conn(inode))) |
|
return -EACCES; |
|
|
|
if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID)) { |
|
attr->ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | |
|
ATTR_MODE); |
|
|
|
/* |
|
* The only sane way to reliably kill suid/sgid is to do it in |
|
* the userspace filesystem |
|
* |
|
* This should be done on write(), truncate() and chown(). |
|
*/ |
|
if (!fc->handle_killpriv && !fc->handle_killpriv_v2) { |
|
/* |
|
* ia_mode calculation may have used stale i_mode. |
|
* Refresh and recalculate. |
|
*/ |
|
ret = fuse_do_getattr(inode, NULL, file); |
|
if (ret) |
|
return ret; |
|
|
|
attr->ia_mode = inode->i_mode; |
|
if (inode->i_mode & S_ISUID) { |
|
attr->ia_valid |= ATTR_MODE; |
|
attr->ia_mode &= ~S_ISUID; |
|
} |
|
if ((inode->i_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { |
|
attr->ia_valid |= ATTR_MODE; |
|
attr->ia_mode &= ~S_ISGID; |
|
} |
|
} |
|
} |
|
if (!attr->ia_valid) |
|
return 0; |
|
|
|
ret = fuse_do_setattr(entry, attr, file); |
|
if (!ret) { |
|
/* |
|
* If filesystem supports acls it may have updated acl xattrs in |
|
* the filesystem, so forget cached acls for the inode. |
|
*/ |
|
if (fc->posix_acl) |
|
forget_all_cached_acls(inode); |
|
|
|
/* Directory mode changed, may need to revalidate access */ |
|
if (d_is_dir(entry) && (attr->ia_valid & ATTR_MODE)) |
|
fuse_invalidate_entry_cache(entry); |
|
} |
|
return ret; |
|
} |
|
|
|
static int fuse_getattr(struct user_namespace *mnt_userns, |
|
const struct path *path, struct kstat *stat, |
|
u32 request_mask, unsigned int flags) |
|
{ |
|
struct inode *inode = d_inode(path->dentry); |
|
struct fuse_conn *fc = get_fuse_conn(inode); |
|
|
|
if (fuse_is_bad(inode)) |
|
return -EIO; |
|
|
|
if (!fuse_allow_current_process(fc)) { |
|
if (!request_mask) { |
|
/* |
|
* If user explicitly requested *nothing* then don't |
|
* error out, but return st_dev only. |
|
*/ |
|
stat->result_mask = 0; |
|
stat->dev = inode->i_sb->s_dev; |
|
return 0; |
|
} |
|
return -EACCES; |
|
} |
|
|
|
return fuse_update_get_attr(inode, NULL, stat, request_mask, flags); |
|
} |
|
|
|
static const struct inode_operations fuse_dir_inode_operations = { |
|
.lookup = fuse_lookup, |
|
.mkdir = fuse_mkdir, |
|
.symlink = fuse_symlink, |
|
.unlink = fuse_unlink, |
|
.rmdir = fuse_rmdir, |
|
.rename = fuse_rename2, |
|
.link = fuse_link, |
|
.setattr = fuse_setattr, |
|
.create = fuse_create, |
|
.atomic_open = fuse_atomic_open, |
|
.mknod = fuse_mknod, |
|
.permission = fuse_permission, |
|
.getattr = fuse_getattr, |
|
.listxattr = fuse_listxattr, |
|
.get_acl = fuse_get_acl, |
|
.set_acl = fuse_set_acl, |
|
}; |
|
|
|
static const struct file_operations fuse_dir_operations = { |
|
.llseek = generic_file_llseek, |
|
.read = generic_read_dir, |
|
.iterate_shared = fuse_readdir, |
|
.open = fuse_dir_open, |
|
.release = fuse_dir_release, |
|
.fsync = fuse_dir_fsync, |
|
.unlocked_ioctl = fuse_dir_ioctl, |
|
.compat_ioctl = fuse_dir_compat_ioctl, |
|
}; |
|
|
|
static const struct inode_operations fuse_common_inode_operations = { |
|
.setattr = fuse_setattr, |
|
.permission = fuse_permission, |
|
.getattr = fuse_getattr, |
|
.listxattr = fuse_listxattr, |
|
.get_acl = fuse_get_acl, |
|
.set_acl = fuse_set_acl, |
|
}; |
|
|
|
static const struct inode_operations fuse_symlink_inode_operations = { |
|
.setattr = fuse_setattr, |
|
.get_link = fuse_get_link, |
|
.getattr = fuse_getattr, |
|
.listxattr = fuse_listxattr, |
|
}; |
|
|
|
void fuse_init_common(struct inode *inode) |
|
{ |
|
inode->i_op = &fuse_common_inode_operations; |
|
} |
|
|
|
void fuse_init_dir(struct inode *inode) |
|
{ |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
|
|
inode->i_op = &fuse_dir_inode_operations; |
|
inode->i_fop = &fuse_dir_operations; |
|
|
|
spin_lock_init(&fi->rdc.lock); |
|
fi->rdc.cached = false; |
|
fi->rdc.size = 0; |
|
fi->rdc.pos = 0; |
|
fi->rdc.version = 0; |
|
} |
|
|
|
static int fuse_symlink_readpage(struct file *null, struct page *page) |
|
{ |
|
int err = fuse_readlink_page(page->mapping->host, page); |
|
|
|
if (!err) |
|
SetPageUptodate(page); |
|
|
|
unlock_page(page); |
|
|
|
return err; |
|
} |
|
|
|
static const struct address_space_operations fuse_symlink_aops = { |
|
.readpage = fuse_symlink_readpage, |
|
}; |
|
|
|
void fuse_init_symlink(struct inode *inode) |
|
{ |
|
inode->i_op = &fuse_symlink_inode_operations; |
|
inode->i_data.a_ops = &fuse_symlink_aops; |
|
inode_nohighmem(inode); |
|
}
|
|
|