On Fri, 19 Dec 2008 08:44:57 +0300 Yuri Tikhonov <[email protected]> wrote:
> > The following patch fixes division by zero, which we have in > shmem_truncate_range() and shmem_unuse_inode(), if use big > PAGE_SIZE values (e.g. 256KB on ppc44x). > > With 256KB PAGE_SIZE the ENTRIES_PER_PAGEPAGE constant becomes > too large (0x1.0000.0000), so this patch just changes the types > from 'ulong' to 'ullong' where it's necessary. > > Signed-off-by: Yuri Tikhonov <[email protected]> > --- > mm/shmem.c | 8 ++++---- > 1 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/mm/shmem.c b/mm/shmem.c > index 0ed0752..99d7c91 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -57,7 +57,7 @@ > #include <asm/pgtable.h> > > #define ENTRIES_PER_PAGE (PAGE_CACHE_SIZE/sizeof(unsigned long)) > -#define ENTRIES_PER_PAGEPAGE (ENTRIES_PER_PAGE*ENTRIES_PER_PAGE) > +#define ENTRIES_PER_PAGEPAGE ((unsigned long > long)ENTRIES_PER_PAGE*ENTRIES_PER_PAGE) > #define BLOCKS_PER_PAGE (PAGE_CACHE_SIZE/512) > > #define SHMEM_MAX_INDEX (SHMEM_NR_DIRECT + (ENTRIES_PER_PAGEPAGE/2) * > (ENTRIES_PER_PAGE+1)) > @@ -95,7 +95,7 @@ static unsigned long shmem_default_max_inodes(void) > } > #endif > > -static int shmem_getpage(struct inode *inode, unsigned long idx, > +static int shmem_getpage(struct inode *inode, unsigned long long idx, > struct page **pagep, enum sgp_type sgp, int *type); > > static inline struct page *shmem_dir_alloc(gfp_t gfp_mask) > @@ -533,7 +533,7 @@ static void shmem_truncate_range(struct inode *inode, > loff_t start, loff_t end) > int punch_hole; > spinlock_t *needs_lock; > spinlock_t *punch_lock; > - unsigned long upper_limit; > + unsigned long long upper_limit; > > inode->i_ctime = inode->i_mtime = CURRENT_TIME; > idx = (start + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; > @@ -1175,7 +1175,7 @@ static inline struct mempolicy *shmem_get_sbmpol(struct > shmem_sb_info *sbinfo) > * vm. If we swap it in we mark it dirty since we also free the swap > * entry since a page cannot live in both the swap and page cache > */ > -static int shmem_getpage(struct inode *inode, unsigned long idx, > +static int shmem_getpage(struct inode *inode, unsigned long long idx, > struct page **pagep, enum sgp_type sgp, int *type) > { > struct address_space *mapping = inode->i_mapping; umm, ok, maybe. I guess that it would be more appropriate to use loff_t in here, and things like if (!diroff && !offset && upper_limit >= stage) { need a bit of thought (`stage' is still unsigned long). I'll queue the patch as-is pending review from Hugh. Thanks. _______________________________________________ Linuxppc-dev mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-dev
