Write access to folder mounted with webdav fails with Input/output error

[gonzo115]

Describe the bug

when i mount a space via WebDAV as described here i can mount the space as a volume just fine, read all files but i can't upload a new file or replace/edit an old file. Trying to results in either an error message: Input/output error

Steps to reproduce

1. Check "Show WebDAV in Spaces" option in WebUI settings, create AppToken, copy WebDAV URL from space info
2. Mount folder using /etc/fstab: https://192.168.0.197:4443/remote.php/dav/spaces/e050f5cd-669d-4ac6-ba13-d4d204eeccf4$a0f996cc-a7a4-4c2a-aa4b-9c2b9bf996ac/Data /media/opencloud davfs rw,user,auto,nofail,file_mode=0777,dir_mode=0777 0 1
3. touch /media/opencloud/test.txt

Expected behavior

Creation of a new file called test.txt in the mounted folder

Actual behavior

Error: touch: cannot touch '/media/opencloud/test.txt': Input/output error
Log: journalctl -t mount.davfs --since "2 min ago"
May 29 07:56:19 dirkfl mount.davfs[4775]: SELECT: 1
22 │ May 29 07:56:19 dirkfl mount.davfs[4775]: FUSE_LOOKUP:
23 │ May 29 07:56:19 dirkfl mount.davfs[4775]: p 0x5555ad52cd00, test.txt
24 │ May 29 07:56:19 dirkfl mount.davfs[4775]: lookup /remote.php/dav/spaces/e050f5cd-669d-4ac6-ba13-d4d204eeccf4$a0f996cc-a7a4-4c2a-aa4b-9c2b9bf996ac/Data/test.txt
25 │ May 29 07:56:19 dirkfl mount.davfs[4775]: Running pre_send hooks
26 │ May 29 07:56:19 dirkfl mount.davfs[4775]: Sending request headers:
27 │ PROPFIND /remote.php/dav/spaces/e050f5cd-669d-4ac6-ba13-d4d204eeccf4%%24a0f996cc-a7a4-4c2a-aa4b-9c2b9bf9
28 │ May 29 07:56:19 dirkfl mount.davfs[4775]: 96ac/Data/ HTTP/1.1
29 │ User-Agent: davfs2/1.7.1 neon/0.34.2
30 │ Connection: TE
31 │ TE: trailers
32 │ Host: 192.168.0.197:4443
33 │ Depth: 1
34 │ Con
35 │ May 29 07:56:19 dirkfl mount.davfs[4775]: tent-Length: 257
36 │ Content-Type: application/xml
37 │ Authorization: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
38 │ May 29 07:56:19 dirkfl mount.davfs[4775]: xxxxxxxxxxxxxx
39 │ May 29 07:56:19 dirkfl mount.davfs[4775]: Sending request-line and headers:
40 │ May 29 07:56:19 dirkfl mount.davfs[4775]: Sending request body:
41 │ May 29 07:56:19 dirkfl mount.davfs[4775]: Request sent; retry is 1.
42 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: HTTP/1.1 207 Multi-Status
43 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: Access-Control-Expose-Headers: Tus-Resumable, Tus-Version, Tus-Extension
44 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [access-control-expose-headers] = [Tus-Resumable, Tus-Version, Tus-Extension]
45 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: Content-Length: 1921
46 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [content-length] = [1921]
47 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: Content-Security-Policy: child-src 'self'; connect-src 'self' blob: https://raw.githubusercontent.com/opencloud-eu/aw
48 │ May 29 07:56:19 dirkfl mount.davfs[4775]: esome-apps/ https://update.opencloud.eu/ https://companion.opencloud.test:4443/ wss://companion.opencloud.test:4443/ https://key
49 │ May 29 07:56:19 dirkfl mount.davfs[4775]: cloak.opencloud.test:4443/; default-src 'none'; font-src 'self'; frame-ancestors 'self'; frame-src 'self' blob: https://embed.di
50 │ May 29 07:56:19 dirkfl mount.davfs[4775]: agrams.net/ https://collabora.xxxx.xx:4443/ https://docs.opencloud.eu; img-src 'self' data: blob: https://raw.githubusercontent.
51 │ May 29 07:56:19 dirkfl mount.davfs[4775]: com/opencloud-eu/awesome-apps/ https://tile.openstreetmap.org/ https://collabora.dirk.fl:4443/; manifest-src 'self'; media-src '
52 │ May 29 07:56:19 dirkfl mount.davfs[4775]: self'; object-src 'self' blob:; script-src 'self' 'unsafe-inline' https://keycloak.opencloud.test:4443/; style-src 'self' 'unsaf
53 │ May 29 07:56:19 dirkfl mount.davfs[4775]: e-inline'
54 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [content-security-policy] = [child-src 'self'; connect-src 'self' blob: https://raw.githubusercontent.com/opencloud
55 │ May 29 07:56:19 dirkfl mount.davfs[4775]: -eu/awesome-apps/ https://update.opencloud.eu/ https://companion.opencloud.test:4443/ wss://companion.opencloud.test:4443/ https
56 │ May 29 07:56:19 dirkfl mount.davfs[4775]: ://keycloak.opencloud.test:4443/; default-src 'none'; font-src 'self'; frame-ancestors 'self'; frame-src 'self' blob: https://em
57 │ May 29 07:56:19 dirkfl mount.davfs[4775]: bed.diagrams.net/ https://collabora.xxxx.xx:4443/ https://docs.opencloud.eu; img-src 'self' data: blob: https://raw.githubuserco
58 │ May 29 07:56:19 dirkfl mount.davfs[4775]: ntent.com/opencloud-eu/awesome-apps/ https://tile.openstreetmap.org/ https://collabora.dirk.fl:4443/; manifest-src 'self'; media
59 │ May 29 07:56:19 dirkfl mount.davfs[4775]: -src 'self'; object-src 'self' blob:; script-src 'self' 'unsafe-inline' https://keycloak.opencloud.test:4443/; style-src 'self'
60 │ May 29 07:56:19 dirkfl mount.davfs[4775]: 'unsafe-inline']
61 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: Content-Type: application/xml; charset=utf-8
62 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [content-type] = [application/xml; charset=utf-8]
63 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: Date: Fri, 29 May 2026 11:56:19 GMT
64 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [date] = [Fri, 29 May 2026 11:56:19 GMT]
65 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: Dav: 1, 3, extended-mkcol
66 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [dav] = [1, 3, extended-mkcol]
67 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: Referrer-Policy: strict-origin-when-cross-origin
68 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [referrer-policy] = [strict-origin-when-cross-origin]
69 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: Tus-Extension: creation, creation-with-upload, checksum, expiration
70 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [tus-extension] = [creation, creation-with-upload, checksum, expiration]
71 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: Tus-Resumable: 1.0.0
72 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [tus-resumable] = [1.0.0]
73 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: Tus-Version: 1.0.0
74 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [tus-version] = [1.0.0]
75 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: Vary: Origin, Prefer
76 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [vary] = [Origin, Prefer]
77 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: X-Content-Type-Options: nosniff
78 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [x-content-type-options] = [nosniff]
79 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: X-Frame-Options: SAMEORIGIN
80 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [x-frame-options] = [SAMEORIGIN]
81 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: X-Permitted-Cross-Domain-Policies: none
82 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [x-permitted-cross-domain-policies] = [none]
83 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: X-Request-Id: f7fd731f7bbb/GWZ7ri6yMW-000050
84 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [x-request-id] = [f7fd731f7bbb/GWZ7ri6yMW-000050]
85 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: X-Robots-Tag: none
86 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [x-robots-tag] = [none]
87 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line: X-Xss-Protection: 1; mode=block
88 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Header: [x-xss-protection] = [1; mode=block]
89 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: Line:
90 │ May 29 07:56:19 dirkfl mount.davfs[4775]: req: End of headers.
91 │ May 29 07:56:19 dirkfl mount.davfs[4775]: Running post_headers hooks
92 │ May 29 07:56:19 dirkfl mount.davfs[4775]: Reading 1921 bytes of response body.
93 │ May 29 07:56:19 dirkfl mount.davfs[4775]: Got 1921 bytes.
94 │ May 29 07:56:19 dirkfl mount.davfs[4775]: Running post_send hooks
95 │ May 29 07:56:19 dirkfl mount.davfs[4775]: Request ends, status 207 class 2xx, error line:
96 │ 207 Multi-Status
97 │ May 29 07:56:19 dirkfl mount.davfs[4775]: Running destroy hooks.
98 │ May 29 07:56:19 dirkfl mount.davfs[4775]: Request ends.

Setup

latest docker-compose version of opencloud running on latest raspios (Debian Trixie)
davfs2 version 1.7.1

[michaelstingl]

@gonzo115 thanks for opening this and capturing the davfs2 log.

I reproduced this on a separate instance (opencloud-rolling, reva v2.43.0, PosixFS) and traced it to a server-side WebDAV LOCK bug, not a davfs2 or TLS problem.

davfs2 (use_locks 1, the default) sends a LOCK before creating a new file. OpenCloud returns HTTP 500 for a LOCK on a path that does not exist yet, instead of creating an empty locked resource and returning 201 (RFC 4918 §7.3). davfs2 maps that 500 to Input/output error. A LOCK on an existing file returns 200, which is why reads and edits of existing files work and only new-file creation fails.

Minimal reproduction with curl (app token as basic-auth password):

BASE="https://<host>/remote.php/dav/spaces/<spaceID>"
AUTH="-u user:<app-token>"
LOCKBODY='<?xml version="1.0"?><d:lockinfo xmlns:d="DAV:"><d:lockscope><d:exclusive/></d:lockscope><d:locktype><d:write/></d:locktype><d:owner><d:href>x</d:href></d:owner></d:lockinfo>'
curl -s -X LOCK $AUTH "$BASE/new-file.txt" --data "$LOCKBODY"
#   HTTP/2 500
#   <s:message>set lock: error: not found: <spaceID>/new-file.txt</s:message>

Root cause: two lines turn a LOCK on a missing file into a 500. NewErrFromStatus (error.go:199) has no CODE_NOT_FOUND case, so the untyped error reaches the LOCK handler switch (locks.go:557), which maps anything but ErrLocked/ErrForbidden to default → 500. Full path:

LOCK on a new (unmapped) path (davfs2 use_locks=1):

  proxy → ocdav LOCK handler   locks.go:552
    → cs3LS.SetLock            locks.go:232   (gRPC)
    → storageprovider.SetLock  storageprovider.go:236
    → Decomposedfs.SetLock     decomposedfs.go:1198   node missing

error back up:
  decomposedfs.go:1207   errtypes.NotFound(…)   ← origin
  storageprovider.go:245   → CS3 CODE_NOT_FOUND
  error.go:199   ★ NewErrFromStatus: no CODE_NOT_FOUND case
  locks.go:557   ★ unknown error → default → HTTP 500
  ⇒ "set lock: error: not found: …"

★ = where NotFound is mishandled (the two fix sites).

The lock-null create path that would return 201 instead is a commented-out TODO at locks.go:574, present since the original locking PR (cs3org/reva#2460, 2022).

This is not PosixFS-specific. The 500 mapping (storageprovider + ocdav) is driver-independent, and PosixFS embeds Decomposedfs (fs/posix/posix.go builds via decomposedfs.New(...), no SetLock override), so both shipping storage drivers return NotFound here and hit the same path.

Expected per RFC 4918 §7.3: a LOCK on an unmapped URL creates an empty locked resource and returns 201. sabre/dav (ownCloud 10, Nextcloud) does this.

Workaround on the client: set use_locks 0 in /etc/davfs2/davfs2.conf and remount. File creation then works.

Side note (not the cause): the DAV compliance header is inconsistent across methods on the same resource. OPTIONS returns DAV: 1, 2, PROPFIND returns DAV: 1, 3, extended-mkcol. The server clearly supports locking (LOCK on an existing file returns 200) and RFC 4918, so the complete value would be 1, 2, 3; instead OPTIONS omits class 3 and PROPFIND omits class 2. I see the same on my instance, so the 1, 3 in your log is expected and not a clue to this bug.

_{🤖 drafted with Claude Code, reviewed before submitting.}

[gonzo115]

@michaelstingl Thanks for the reply. Your workaround seems to be working. I assume as I'm the only one assessing these files, there is no drawback setting the lock to 0?

[michaelstingl]

The server-side fix is now open as a PR against reva: opencloud-eu/reva#652.

It makes a LOCK on a not-yet-existing path create the empty locked resource and return 201 (200 if the path already exists), per RFC 4918 section 7.3 and section 9.10.6, instead of the 500 that davfs2 reports as Input/output error.

Until it ships in a release, the client-side workaround stands: set use_locks 0 in /etc/davfs2/davfs2.conf and remount.

_{🤖 drafted with Claude Code, reviewed before submitting.}