diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-12-12 20:22:09 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-12-12 20:22:09 -0800 |
commit | 043930b1c8895d626d340decfe9e418f7233edb8 (patch) | |
tree | a13edba88cfd63bce2f5c68f8e39182283a4a8b0 /fs | |
parent | 6df7cc2268745e91d090830c58689aa7fcbde6f9 (diff) | |
parent | b138777786f780b9d5ce1989032608acbede0493 (diff) |
Merge tag 'fuse-update-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse update from Miklos Szeredi:
- Allow some write requests to proceed in parallel
- Fix a performance problem with allow_sys_admin_access
- Add a special kind of invalidation that doesn't immediately purge
submounts
- On revalidation treat the target of rename(RENAME_NOREPLACE) the same
as open(O_EXCL)
- Use type safe helpers for some mnt_userns transformations
* tag 'fuse-update-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: Rearrange fuse_allow_current_process checks
fuse: allow non-extending parallel direct writes on the same file
fuse: remove the unneeded result variable
fuse: port to vfs{g,u}id_t and associated helpers
fuse: Remove user_ns check for FUSE_DEV_IOC_CLONE
fuse: always revalidate rename target dentry
fuse: add "expire only" mode to FUSE_NOTIFY_INVAL_ENTRY
fs/fuse: Replace kmap() with kmap_local_page()
Diffstat (limited to 'fs')
-rw-r--r-- | fs/fuse/cuse.c | 5 | ||||
-rw-r--r-- | fs/fuse/dev.c | 7 | ||||
-rw-r--r-- | fs/fuse/dir.c | 43 | ||||
-rw-r--r-- | fs/fuse/file.c | 43 | ||||
-rw-r--r-- | fs/fuse/fuse_i.h | 4 | ||||
-rw-r--r-- | fs/fuse/readdir.c | 4 |
6 files changed, 73 insertions, 33 deletions
diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c index c7d882a9fe33..a06fbb1a8a5b 100644 --- a/fs/fuse/cuse.c +++ b/fs/fuse/cuse.c @@ -545,7 +545,6 @@ static int cuse_channel_release(struct inode *inode, struct file *file) { struct fuse_dev *fud = file->private_data; struct cuse_conn *cc = fc_to_cc(fud->fc); - int rc; /* remove from the conntbl, no more access from this point on */ mutex_lock(&cuse_lock); @@ -560,9 +559,7 @@ static int cuse_channel_release(struct inode *inode, struct file *file) cdev_del(cc->cdev); } - rc = fuse_dev_release(inode, file); /* puts the base reference */ - - return rc; + return fuse_dev_release(inode, file); } static struct file_operations cuse_channel_fops; /* initialized during init */ diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index b4a6e0a1b945..c73d9c4132f6 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1498,7 +1498,7 @@ static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size, buf[outarg.namelen] = 0; down_read(&fc->killsb); - err = fuse_reverse_inval_entry(fc, outarg.parent, 0, &name); + err = fuse_reverse_inval_entry(fc, outarg.parent, 0, &name, outarg.flags); up_read(&fc->killsb); kfree(buf); return err; @@ -1546,7 +1546,7 @@ static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size, buf[outarg.namelen] = 0; down_read(&fc->killsb); - err = fuse_reverse_inval_entry(fc, outarg.parent, outarg.child, &name); + err = fuse_reverse_inval_entry(fc, outarg.parent, outarg.child, &name, 0); up_read(&fc->killsb); kfree(buf); return err; @@ -2267,8 +2267,7 @@ static long fuse_dev_ioctl(struct file *file, unsigned int cmd, * Check against file->f_op because CUSE * uses the same ioctl handler. */ - if (old->f_op == file->f_op && - old->f_cred->user_ns == file->f_cred->user_ns) + if (old->f_op == file->f_op) fud = fuse_get_dev(old); if (fud) { diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 25e6b0f7e73d..cd1a071b625a 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -214,7 +214,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags) if (inode && fuse_is_bad(inode)) goto invalid; else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) || - (flags & (LOOKUP_EXCL | LOOKUP_REVAL))) { + (flags & (LOOKUP_EXCL | LOOKUP_REVAL | LOOKUP_RENAME_TARGET))) { struct fuse_entry_out outarg; FUSE_ARGS(args); struct fuse_forget_link *forget; @@ -1170,7 +1170,7 @@ int fuse_update_attributes(struct inode *inode, struct file *file, u32 mask) } int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid, - u64 child_nodeid, struct qstr *name) + u64 child_nodeid, struct qstr *name, u32 flags) { int err = -ENOTDIR; struct inode *parent; @@ -1197,7 +1197,9 @@ int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid, goto unlock; fuse_dir_changed(parent); - fuse_invalidate_entry(entry); + if (!(flags & FUSE_EXPIRE_ONLY)) + d_invalidate(entry); + fuse_invalidate_entry_cache(entry); if (child_nodeid != 0 && d_really_is_positive(entry)) { inode_lock(d_inode(entry)); @@ -1235,6 +1237,18 @@ int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid, return err; } +static inline bool fuse_permissible_uidgid(struct fuse_conn *fc) +{ + const struct cred *cred = current_cred(); + + return (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)); +} + /* * Calling into a user-controlled filesystem gives the filesystem * daemon ptrace-like capabilities over the current process. This @@ -1248,26 +1262,19 @@ int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid, * 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) +bool fuse_allow_current_process(struct fuse_conn *fc) { - const struct cred *cred; - - if (allow_sys_admin_access && capable(CAP_SYS_ADMIN)) - return 1; + bool allow; if (fc->allow_other) - return current_in_userns(fc->user_ns); + allow = current_in_userns(fc->user_ns); + else + allow = fuse_permissible_uidgid(fc); - 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; + if (!allow && allow_sys_admin_access && capable(CAP_SYS_ADMIN)) + allow = true; - return 0; + return allow; } static int fuse_access(struct inode *inode, int mask) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index c996c0ef8c63..875314ee6f59 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1563,14 +1563,47 @@ static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to) return res; } +static bool fuse_direct_write_extending_i_size(struct kiocb *iocb, + struct iov_iter *iter) +{ + struct inode *inode = file_inode(iocb->ki_filp); + + return iocb->ki_pos + iov_iter_count(iter) > i_size_read(inode); +} + static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from) { struct inode *inode = file_inode(iocb->ki_filp); + struct file *file = iocb->ki_filp; + struct fuse_file *ff = file->private_data; struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb); ssize_t res; + bool exclusive_lock = + !(ff->open_flags & FOPEN_PARALLEL_DIRECT_WRITES) || + iocb->ki_flags & IOCB_APPEND || + fuse_direct_write_extending_i_size(iocb, from); + + /* + * Take exclusive lock if + * - Parallel direct writes are disabled - a user space decision + * - Parallel direct writes are enabled and i_size is being extended. + * This might not be needed at all, but needs further investigation. + */ + if (exclusive_lock) + inode_lock(inode); + else { + inode_lock_shared(inode); + + /* A race with truncate might have come up as the decision for + * the lock type was done without holding the lock, check again. + */ + if (fuse_direct_write_extending_i_size(iocb, from)) { + inode_unlock_shared(inode); + inode_lock(inode); + exclusive_lock = true; + } + } - /* Don't allow parallel writes to the same file */ - inode_lock(inode); res = generic_write_checks(iocb, from); if (res > 0) { if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) { @@ -1581,7 +1614,10 @@ static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from) fuse_write_update_attr(inode, iocb->ki_pos, res); } } - inode_unlock(inode); + if (exclusive_lock) + inode_unlock(inode); + else + inode_unlock_shared(inode); return res; } @@ -2931,6 +2967,7 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter) if (iov_iter_rw(iter) == WRITE) { fuse_write_update_attr(inode, pos, ret); + /* For extending writes we already hold exclusive lock */ if (ret < 0 && offset + count > i_size) fuse_do_truncate(file); } diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 26a7c524eb70..c673faefdcb9 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -1179,7 +1179,7 @@ bool fuse_invalid_attr(struct fuse_attr *attr); /** * Is current process allowed to perform filesystem operation? */ -int fuse_allow_current_process(struct fuse_conn *fc); +bool fuse_allow_current_process(struct fuse_conn *fc); u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id); @@ -1220,7 +1220,7 @@ int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid, * then the dentry is unhashed (d_delete()). */ int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid, - u64 child_nodeid, struct qstr *name); + u64 child_nodeid, struct qstr *name, u32 flags); int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file, bool isdir); diff --git a/fs/fuse/readdir.c b/fs/fuse/readdir.c index e8deaacf1832..dc603479b30e 100644 --- a/fs/fuse/readdir.c +++ b/fs/fuse/readdir.c @@ -547,9 +547,9 @@ retry_locked: * Contents of the page are now protected against changing by holding * the page lock. */ - addr = kmap(page); + addr = kmap_local_page(page); res = fuse_parse_cache(ff, addr, size, ctx); - kunmap(page); + kunmap_local(addr); unlock_page(page); put_page(page); |