github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-12 16:18:45 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

lockd: Move nlm4svc_set_file_lock_range()

Browse Source 
Both client-side and server-side NLMv4 code convert lock byte ranges
from the wire format (start, length) to the kernel's file_lock format
(start, end). The current nlm4svc_set_file_lock_range() performs this
conversion, but the "svc" prefix incorrectly suggests server-only use,
and client code must include server-internal headers to access it.

Rename to lockd_set_file_lock_range4() and relocate to the shared
lockd.h header, making it accessible to both client and server code.
This eliminates the need for client code to include xdr4.h, reducing
coupling between the XDR implementation files.

While relocating the function, add input validation: clamp the
starting offset to OFFSET_MAX before use. Without this, a malformed
lock request with off > OFFSET_MAX results in fl_start > fl_end,
violating file_lock invariants and potentially causing incorrect
lock conflict detection.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
Chuck Lever 2026-01-28 10:19:34 -05:00
parent 5829352e56
commit b3f76a9b13
4 changed files with 27 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fs/lockd/clnt4xdr.c
View File

@ -287,7 +287,7 @@ static int decode_nlm4_holder(struct xdr_stream *xdr, struct nlm_res *result)
fl->c.flc_type = exclusive != 0 ? F_WRLCK : F_RDLCK;
p = xdr_decode_hyper(p, &l_offset);
xdr_decode_hyper(p, &l_len);
nlm4svc_set_file_lock_range(fl, l_offset, l_len);
lockd_set_file_lock_range4(fl, l_offset, l_len);
error = 0;
out:
return error;

25
fs/lockd/lockd.h
View File

@ -413,6 +413,31 @@ static inline int nlm_compare_locks(const struct file_lock *fl1,
&&(fl1->c.flc_type == fl2->c.flc_type || fl2->c.flc_type == F_UNLCK);
}
/**
* lockd_set_file_lock_range4 - set the byte range of a file_lock
* @fl: file_lock whose length fields are to be initialized
* @off: starting offset of the lock, in bytes
* @len: length of the byte range, in bytes, or zero
*
* The NLMv4 protocol represents lock byte ranges as (start, length),
* where length zero means "lock to end of file." The kernel's file_lock
* structure uses (start, end) representation. Convert from NLMv4 format
* to file_lock format, clamping the starting offset and treating
* arithmetic overflow as "lock to EOF."
*/
static inline void
lockd_set_file_lock_range4(struct file_lock *fl, u64 off, u64 len)
{
u64 clamped_off = (off > OFFSET_MAX) ? OFFSET_MAX : off;
s64 end = clamped_off + len - 1;
fl->fl_start = clamped_off;
if (len == 0 || end < 0)
fl->fl_end = OFFSET_MAX;
else
fl->fl_end = end;
}
extern const struct lock_manager_operations nlmsvc_lock_operations;
#endif /* _LOCKD_LOCKD_H */

13
fs/lockd/xdr4.c
View File

@ -34,17 +34,6 @@ loff_t_to_s64(loff_t offset)
return res;
}
void nlm4svc_set_file_lock_range(struct file_lock *fl, u64 off, u64 len)
{
s64 end = off + len - 1;
fl->fl_start = off;
if (len == 0 || end < 0)
fl->fl_end = OFFSET_MAX;
else
fl->fl_end = end;
}
/*
* NLM file handles are defined by specification to be a variable-length
* XDR opaque no longer than 1024 bytes. However, this implementation
@ -91,7 +80,7 @@ svcxdr_decode_lock(struct xdr_stream *xdr, struct nlm_lock *lock)
locks_init_lock(fl);
fl->c.flc_type = F_RDLCK;
nlm4svc_set_file_lock_range(fl, lock->lock_start, lock->lock_len);
lockd_set_file_lock_range4(fl, lock->lock_start, lock->lock_len);
return true;
}

1
fs/lockd/xdr4.h
View File

@ -15,7 +15,6 @@
#define nlm4_fbig cpu_to_be32(NLM_FBIG)
#define nlm4_failed cpu_to_be32(NLM_FAILED)
void nlm4svc_set_file_lock_range(struct file_lock *fl, u64 off, u64 len);
bool nlm4svc_decode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr);
bool nlm4svc_decode_testargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
bool nlm4svc_decode_lockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);