Revision 4860abb91f3d7fbaf8147d54782149bb1fc45892 authored by Steve French on 06 February 2024, 22:34:22 UTC, committed by Steve French on 16 February 2024, 04:19:23 UTC
The conversion to netfs in the 6.3 kernel caused a regression when maximum write size is set by the server to an unexpected value which is not a multiple of 4096 (similarly if the user overrides the maximum write size by setting mount parm "wsize", but sets it to a value that is not a multiple of 4096). When negotiated write size is not a multiple of 4096 the netfs code can skip the end of the final page when doing large sequential writes, causing data corruption. This section of code is being rewritten/removed due to a large netfs change, but until that point (ie for the 6.3 kernel until now) we can not support non-standard maximum write sizes. Add a warning if a user specifies a wsize on mount that is not a multiple of 4096 (and round down), also add a change where we round down the maximum write size if the server negotiates a value that is not a multiple of 4096 (we also have to check to make sure that we do not round it down to zero). Reported-by: R. Diez" <rdiez-2006@rd10.de> Fixes: d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list") Suggested-by: Ronnie Sahlberg <ronniesahlberg@gmail.com> Acked-by: Ronnie Sahlberg <ronniesahlberg@gmail.com> Tested-by: Matthew Ruffell <matthew.ruffell@canonical.com> Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Cc: stable@vger.kernel.org # v6.3+ Cc: David Howells <dhowells@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
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bucket_locks.c
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
/* Allocate an array of spinlocks to be accessed by a hash. Two arguments
* indicate the number of elements to allocate in the array. max_size
* gives the maximum number of elements to allocate. cpu_mult gives
* the number of locks per CPU to allocate. The size is rounded up
* to a power of 2 to be suitable as a hash table.
*/
int __alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask,
size_t max_size, unsigned int cpu_mult, gfp_t gfp,
const char *name, struct lock_class_key *key)
{
spinlock_t *tlocks = NULL;
unsigned int i, size;
#if defined(CONFIG_PROVE_LOCKING)
unsigned int nr_pcpus = 2;
#else
unsigned int nr_pcpus = num_possible_cpus();
#endif
if (cpu_mult) {
nr_pcpus = min_t(unsigned int, nr_pcpus, 64UL);
size = min_t(unsigned int, nr_pcpus * cpu_mult, max_size);
} else {
size = max_size;
}
if (sizeof(spinlock_t) != 0) {
tlocks = kvmalloc_array(size, sizeof(spinlock_t), gfp);
if (!tlocks)
return -ENOMEM;
for (i = 0; i < size; i++) {
spin_lock_init(&tlocks[i]);
lockdep_init_map(&tlocks[i].dep_map, name, key, 0);
}
}
*locks = tlocks;
*locks_mask = size - 1;
return 0;
}
EXPORT_SYMBOL(__alloc_bucket_spinlocks);
void free_bucket_spinlocks(spinlock_t *locks)
{
kvfree(locks);
}
EXPORT_SYMBOL(free_bucket_spinlocks);
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