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2024-03-06fuse: get rid of ff->readdir.lockMiklos Szeredi1-4/+0
The same protection is provided by file->f_pos_lock. Note, this relies on the fact that file->f_mode has FMODE_ATOMIC_POS. This flag is cleared by stream_open(), which would prevent locking of f_pos_lock. Prior to commit 7de64d521bf9 ("fuse: break up fuse_open_common()") FOPEN_STREAM on a directory would cause stream_open() to be called. After this commit this is not done anymore, so f_pos_lock will always be locked. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2023-10-18fuse: convert to new timestamp accessorsJeff Layton1-2/+4
Convert to using the new inode timestamp accessor functions. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20231004185347.80880-37-jlayton@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21fuse: cache btimeMiklos Szeredi1-1/+1
Not all inode attributes are supported by all filesystems, but for the basic stats (which are returned by stat(2) and friends) all of them will have some value, even if that doesn't reflect a real attribute of the file. Btime is different, in that filesystems are free to report or not report a value in statx. If the value is available, then STATX_BTIME bit is set in stx_mask. When caching the value of btime, remember the availability of the attribute as well as the value (if available). This is done by using the FUSE_I_BTIME bit in fuse_inode->state to indicate availability, while using fuse_inode->inval_mask & STATX_BTIME to indicate the state of the cache itself (i.e. set if cache is invalid, and cleared if cache is valid). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2023-08-16fuse: add ATTR_TIMEOUT macroMiklos Szeredi1-2/+2
Next patch will introduce yet another type attribute reply. Add a macro that can handle attribute timeouts for all of the structs. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2023-08-16fuse: nlookup missing decrement in fuse_direntplus_linkruanmeisi1-1/+9
During our debugging of glusterfs, we found an Assertion failed error: inode_lookup >= nlookup, which was caused by the nlookup value in the kernel being greater than that in the FUSE file system. The issue was introduced by fuse_direntplus_link, where in the function, fuse_iget increments nlookup, and if d_splice_alias returns failure, fuse_direntplus_link returns failure without decrementing nlookup https://github.com/gluster/glusterfs/pull/4081 Signed-off-by: ruanmeisi <ruan.meisi@zte.com.cn> Fixes: 0b05b18381ee ("fuse: implement NFS-like readdirplus support") Cc: <stable@vger.kernel.org> # v3.9 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2022-11-23fs/fuse: Replace kmap() with kmap_local_page()Fabio M. De Francesco1-2/+2
The use of kmap() is being deprecated in favor of kmap_local_page(). There are two main problems with kmap(): (1) It comes with an overhead as the mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap’s pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and still valid. Therefore, replace kmap() with kmap_local_page() in fuse_readdir_cached(), it being the only call site of kmap() currently left in fs/fuse. Cc: "Venkataramanan, Anirudh" <anirudh.venkataramanan@intel.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2022-10-20fuse: fix readdir cache raceMiklos Szeredi1-1/+9
There's a race in fuse's readdir cache that can result in an uninitilized page being read. The page lock is supposed to prevent this from happening but in the following case it doesn't: Two fuse_add_dirent_to_cache() start out and get the same parameters (size=0,offset=0). One of them wins the race to create and lock the page, after which it fills in data, sets rdc.size and unlocks the page. In the meantime the page gets evicted from the cache before the other instance gets to run. That one also creates the page, but finds the size to be mismatched, bails out and leaves the uninitialized page in the cache. Fix by marking a filled page uptodate and ignoring non-uptodate pages. Reported-by: Frank Sorenson <fsorenso@redhat.com> Fixes: 5d7bc7e8680c ("fuse: allow using readdir cache") Cc: <stable@vger.kernel.org> # v4.20 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-28fuse: only update necessary attributesMiklos Szeredi1-1/+1
fuse_update_attributes() refreshes metadata for internal use. Each use needs a particular set of attributes to be refreshed, but currently that cannot be expressed and all but atime are refreshed. Add a mask argument, which lets fuse_update_get_attr() to decide based on the cache_mask and the inval_mask whether a GETATTR call is needed or not. Reported-by: Yongji Xie <xieyongji@bytedance.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-10-22fuse: use kmap_local_page()Peng Hao1-2/+2
Due to the introduction of kmap_local_*, the storage of slots used for short-term mapping has changed from per-CPU to per-thread. kmap_atomic() disable preemption, while kmap_local_*() only disable migration. There is no need to disable preemption in several kamp_atomic places used in fuse. Link: https://lwn.net/Articles/836144/ Signed-off-by: Peng Hao <flyingpeng@tencent.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-06-22fuse: fix illegal access to inode with reused nodeidAmir Goldstein1-2/+5
Server responds to LOOKUP and other ops (READDIRPLUS/CREATE/MKNOD/...) with ourarg containing nodeid and generation. If a fuse inode is found in inode cache with the same nodeid but different generation, the existing fuse inode should be unhashed and marked "bad" and a new inode with the new generation should be hashed instead. This can happen, for example, with passhrough fuse filesystem that returns the real filesystem ino/generation on lookup and where real inode numbers can get recycled due to real files being unlinked not via the fuse passthrough filesystem. With current code, this situation will not be detected and an old fuse dentry that used to point to an older generation real inode, can be used to access a completely new inode, which should be accessed only via the new dentry. Note that because the FORGET message carries the nodeid w/o generation, the server should wait to get FORGET counts for the nlookup counts of the old and reused inodes combined, before it can free the resources associated to that nodeid. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-03-08new helper: inode_wrong_type()Al Viro1-1/+1
inode_wrong_type(inode, mode) returns true if setting inode->i_mode to given value would've changed the inode type. We have enough of those checks open-coded to make a helper worthwhile. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-12-10fuse: fix bad inodeMiklos Szeredi1-2/+2
Jan Kara's analysis of the syzbot report (edited): The reproducer opens a directory on FUSE filesystem, it then attaches dnotify mark to the open directory. After that a fuse_do_getattr() call finds that attributes returned by the server are inconsistent, and calls make_bad_inode() which, among other things does: inode->i_mode = S_IFREG; This then confuses dnotify which doesn't tear down its structures properly and eventually crashes. Avoid calling make_bad_inode() on a live inode: switch to a private flag on the fuse inode. Also add the test to ops which the bad_inode_ops would have caught. This bug goes back to the initial merge of fuse in 2.6.14... Reported-by: syzbot+f427adf9324b92652ccc@syzkaller.appspotmail.com Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Tested-by: Jan Kara <jack@suse.cz> Cc: <stable@vger.kernel.org>
2020-09-18fuse: split fuse_mount off of fuse_connMax Reitz1-5/+5
We want to allow submounts for the same fuse_conn, but with different superblocks so that each of the submounts has its own device ID. To do so, we need to split all mount-specific information off of fuse_conn into a new fuse_mount structure, so that multiple mounts can share a single fuse_conn. We need to take care only to perform connection-level actions once (i.e. when the fuse_conn and thus the first fuse_mount are established, or when the last fuse_mount and thus the fuse_conn are destroyed). For example, fuse_sb_destroy() must invoke fuse_send_destroy() until the last superblock is released. To do so, we keep track of which fuse_mount is the root mount and perform all fuse_conn-level actions only when this fuse_mount is involved. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-02-06fuse: use true,false for bool variablezhengbin1-1/+1
Fixes coccicheck warning: fs/fuse/readdir.c:335:1-19: WARNING: Assignment of 0/1 to bool variable fs/fuse/file.c:1398:2-19: WARNING: Assignment of 0/1 to bool variable fs/fuse/file.c:1400:2-20: WARNING: Assignment of 0/1 to bool variable fs/fuse/cuse.c:454:1-20: WARNING: Assignment of 0/1 to bool variable fs/fuse/cuse.c:455:1-19: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:497:2-17: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:504:2-23: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:511:2-22: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:518:2-23: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:522:2-26: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:526:2-18: WARNING: Assignment of 0/1 to bool variable fs/fuse/inode.c:1000:1-20: WARNING: Assignment of 0/1 to bool variable Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-11-12fuse: verify attributesMiklos Szeredi1-1/+1
If a filesystem returns negative inode sizes, future reads on the file were causing the cpu to spin on truncate_pagecache. Create a helper to validate the attributes. This now does two things: - check the file mode - check if the file size fits in i_size without overflowing Reported-by: Arijit Banerjee <arijit@rubrik.com> Fixes: d8a5ba45457e ("[PATCH] FUSE - core") Cc: <stable@vger.kernel.org> # v2.6.14 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-24fuse: fix beyond-end-of-page access in fuse_parse_cache()Tejun Heo1-1/+3
With DEBUG_PAGEALLOC on, the following triggers. BUG: unable to handle page fault for address: ffff88859367c000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 3001067 P4D 3001067 PUD 406d3a8067 PMD 406d30c067 PTE 800ffffa6c983060 Oops: 0000 [#1] SMP DEBUG_PAGEALLOC CPU: 38 PID: 3110657 Comm: python2.7 RIP: 0010:fuse_readdir+0x88f/0xe7a [fuse] Code: 49 8b 4d 08 49 39 4e 60 0f 84 44 04 00 00 48 8b 43 08 43 8d 1c 3c 4d 01 7e 68 49 89 dc 48 03 5c 24 38 49 89 46 60 8b 44 24 30 <8b> 4b 10 44 29 e0 48 89 ca 48 83 c1 1f 48 83 e1 f8 83 f8 17 49 89 RSP: 0018:ffffc90035edbde0 EFLAGS: 00010286 RAX: 0000000000001000 RBX: ffff88859367bff0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff88859367bfed RDI: 0000000000920907 RBP: ffffc90035edbe90 R08: 000000000000014b R09: 0000000000000004 R10: ffff88859367b000 R11: 0000000000000000 R12: 0000000000000ff0 R13: ffffc90035edbee0 R14: ffff889fb8546180 R15: 0000000000000020 FS: 00007f80b5f4a740(0000) GS:ffff889fffa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88859367c000 CR3: 0000001c170c2001 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: iterate_dir+0x122/0x180 __x64_sys_getdents+0xa6/0x140 do_syscall_64+0x42/0x100 entry_SYSCALL_64_after_hwframe+0x44/0xa9 It's in fuse_parse_cache(). %rbx (ffff88859367bff0) is fuse_dirent pointer - addr + offset. FUSE_DIRENT_SIZE() is trying to dereference namelen off of it but that derefs into the next page which is disabled by pagealloc debug causing a PF. This is caused by dirent->namelen being accessed before ensuring that there's enough bytes in the page for the dirent. Fix it by pushing down reclen calculation. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 5d7bc7e8680c ("fuse: allow using readdir cache") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: convert readdir to simple apiMiklos Szeredi1-27/+20
The old fuse_read_fill() helper can be deleted, now that the last user is gone. The fuse_io_args struct is moved to fuse_i.h so it can be shared between readdir/read code. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-09-10fuse: convert fuse_force_forget() to simple apiMiklos Szeredi1-0/+21
Move this function to the readdir.c where its only caller resides. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-02-13fuse: Protect fi->nlookup with fi->lockKirill Tkhai1-2/+2
This continues previous patch and introduces the same protection for nlookup field. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01fuse: use iversion for readdir cache verificationMiklos Szeredi1-1/+4
Use the internal iversion counter to make sure modifications of the directory through this filesystem are not missed by the mtime check (due to mtime granularity). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01fuse: use mtime for readdir cache verificationMiklos Szeredi1-4/+34
Store the modification time of the directory in the cache, obtained before starting to fill the cache. When reading the cache, verify that the directory hasn't changed, by checking if current modification time is the same as the one stored in the cache. This only needs to be done when the current file position is at the beginning of the directory, as mandated by POSIX. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01fuse: add readdir cache versionMiklos Szeredi1-1/+44
Allow the cache to be invalidated when page(s) have gone missing. In this case increment the version of the cache and reset to an empty state. Add a version number to the directory stream in struct fuse_file as well, indicating the version of the cache it's supposed to be reading. If the cache version doesn't match the stream's version, then reset the stream to the beginning of the cache. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01fuse: allow using readdir cacheMiklos Szeredi1-4/+144
The cache is only used if it's completed, not while it's still being filled; this constraint could be lifted later, if it turns out to be useful. Introduce state in struct fuse_file that indicates the position within the cache. After a seek, reset the position to the beginning of the cache and search the cache for the current position. If the current position is not found in the cache, then fall back to uncached readdir. It can also happen that page(s) disappear from the cache, in which case we must also fall back to uncached readdir. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-10-01fuse: allow caching readdirMiklos Szeredi1-1/+90
This patch just adds the cache filling functions, which are invoked if FOPEN_CACHE_DIR flag is set in the OPENDIR reply. Cache reading and cache invalidation are added by subsequent patches. The directory cache uses the page cache. Directory entries are packed into a page in the same format as in the READDIR reply. A page only contains whole entries, the space at the end of the page is cleared. The page is locked while being modified. Multiple parallel readdirs on the same directory can fill the cache; the only constraint is that continuity must be maintained (d_off of last entry points to position of current entry). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28fuse: extract fuse_emit() helperMiklos Szeredi1-4/+9
Prepare for cache filling by introducing a helper for emitting a single directory entry. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-09-28fuse: split out readdir.cMiklos Szeredi1-0/+259
Directory reading code is about to grow larger, so split it out from dir.c into a new source file. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>