From: "Ken Chen" For historical reason, expanding ftruncate that increases file size on hugetlbfs is not allowed due to pages were pre-faulted and lack of fault handler. Now that we have demand faulting on hugetlb since 2.6.15, there is no reason to hold back that limitation. This will make hugetlbfs behave more like a normal fs. I'm writing a user level code that uses hugetlbfs but will fall back to tmpfs if there are no hugetlb page available in the system. Having hugetlbfs specific ftruncate behavior is a bit quirky and I would like to remove that artificial limitation. Signed-off-by: Acked-by: Wiliam Irwin Cc: Adam Litke Cc: David Gibson Cc: Nishanth Aravamudan Signed-off-by: Andrew Morton --- fs/hugetlbfs/inode.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff -puN fs/hugetlbfs/inode.c~hugetlb-allow-extending-ftruncate-on-hugetlbfs fs/hugetlbfs/inode.c --- a/fs/hugetlbfs/inode.c~hugetlb-allow-extending-ftruncate-on-hugetlbfs +++ a/fs/hugetlbfs/inode.c @@ -318,21 +318,15 @@ hugetlb_vmtruncate_list(struct prio_tree } } -/* - * Expanding truncates are not allowed. - */ static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) { pgoff_t pgoff; struct address_space *mapping = inode->i_mapping; - if (offset > inode->i_size) - return -EINVAL; - BUG_ON(offset & ~HPAGE_MASK); pgoff = offset >> PAGE_SHIFT; - inode->i_size = offset; + i_size_write(inode, offset); spin_lock(&mapping->i_mmap_lock); if (!prio_tree_empty(&mapping->i_mmap)) hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); _