X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=mm%2Fshmem.c;h=ff85863587ee16b0097a554723d0d3148253fd0a;hb=c4280b28cd3e96b3c838edb61ef1590402864cb3;hp=902a14842b74a6efe5a0de23f965e8a2a9dad820;hpb=c9cdd9a6ae49704f12a289706551536ec842693f;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git diff --git a/mm/shmem.c b/mm/shmem.c index 902a148..ff85863 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -45,7 +45,7 @@ static struct vfsmount *shm_mnt; #include #include #include -#include +#include #include #include #include @@ -80,11 +80,12 @@ static struct vfsmount *shm_mnt; #define SHORT_SYMLINK_LEN 128 /* - * shmem_fallocate and shmem_writepage communicate via inode->i_private - * (with i_mutex making sure that it has only one user at a time): - * we would prefer not to enlarge the shmem inode just for that. + * shmem_fallocate communicates with shmem_fault or shmem_writepage via + * inode->i_private (with i_mutex making sure that it has only one user at + * a time): we would prefer not to enlarge the shmem inode just for that. */ struct shmem_falloc { + wait_queue_head_t *waitq; /* faults into hole wait for punch to end */ pgoff_t start; /* start of range currently being fallocated */ pgoff_t next; /* the next page offset to be fallocated */ pgoff_t nr_falloced; /* how many new pages have been fallocated */ @@ -285,8 +286,8 @@ static int shmem_add_to_page_cache(struct page *page, { int error; - VM_BUG_ON(!PageLocked(page)); - VM_BUG_ON(!PageSwapBacked(page)); + VM_BUG_ON_PAGE(!PageLocked(page), page); + VM_BUG_ON_PAGE(!PageSwapBacked(page), page); page_cache_get(page); page->mapping = mapping; @@ -491,7 +492,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, continue; if (!unfalloc || !PageUptodate(page)) { if (page->mapping == mapping) { - VM_BUG_ON(PageWriteback(page)); + VM_BUG_ON_PAGE(PageWriteback(page), page); truncate_inode_page(mapping, page); } } @@ -533,22 +534,19 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, return; index = start; - for ( ; ; ) { + while (index < end) { cond_resched(); pvec.nr = shmem_find_get_pages_and_swap(mapping, index, min(end - index, (pgoff_t)PAGEVEC_SIZE), pvec.pages, indices); if (!pvec.nr) { - if (index == start || unfalloc) + /* If all gone or hole-punch or unfalloc, we're done */ + if (index == start || end != -1) break; + /* But if truncating, restart to make sure all gone */ index = start; continue; } - if ((index == start || unfalloc) && indices[0] >= end) { - shmem_deswap_pagevec(&pvec); - pagevec_release(&pvec); - break; - } mem_cgroup_uncharge_start(); for (i = 0; i < pagevec_count(&pvec); i++) { struct page *page = pvec.pages[i]; @@ -560,16 +558,25 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, if (radix_tree_exceptional_entry(page)) { if (unfalloc) continue; - nr_swaps_freed += !shmem_free_swap(mapping, - index, page); + if (shmem_free_swap(mapping, index, page)) { + /* Swap was replaced by page: retry */ + index--; + break; + } + nr_swaps_freed++; continue; } lock_page(page); if (!unfalloc || !PageUptodate(page)) { if (page->mapping == mapping) { - VM_BUG_ON(PageWriteback(page)); + VM_BUG_ON_PAGE(PageWriteback(page), page); truncate_inode_page(mapping, page); + } else { + /* Page was replaced by swap: retry */ + unlock_page(page); + index--; + break; } } unlock_page(page); @@ -620,10 +627,8 @@ static int shmem_setattr(struct dentry *dentry, struct iattr *attr) } setattr_copy(inode, attr); -#ifdef CONFIG_TMPFS_POSIX_ACL if (attr->ia_valid & ATTR_MODE) - error = generic_acl_chmod(inode); -#endif + error = posix_acl_chmod(inode, inode->i_mode); return error; } @@ -826,6 +831,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) spin_lock(&inode->i_lock); shmem_falloc = inode->i_private; if (shmem_falloc && + !shmem_falloc->waitq && index >= shmem_falloc->start && index < shmem_falloc->next) shmem_falloc->nr_unswapped++; @@ -1300,6 +1306,64 @@ static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) int error; int ret = VM_FAULT_LOCKED; + /* + * Trinity finds that probing a hole which tmpfs is punching can + * prevent the hole-punch from ever completing: which in turn + * locks writers out with its hold on i_mutex. So refrain from + * faulting pages into the hole while it's being punched. Although + * shmem_undo_range() does remove the additions, it may be unable to + * keep up, as each new page needs its own unmap_mapping_range() call, + * and the i_mmap tree grows ever slower to scan if new vmas are added. + * + * It does not matter if we sometimes reach this check just before the + * hole-punch begins, so that one fault then races with the punch: + * we just need to make racing faults a rare case. + * + * The implementation below would be much simpler if we just used a + * standard mutex or completion: but we cannot take i_mutex in fault, + * and bloating every shmem inode for this unlikely case would be sad. + */ + if (unlikely(inode->i_private)) { + struct shmem_falloc *shmem_falloc; + + spin_lock(&inode->i_lock); + shmem_falloc = inode->i_private; + if (shmem_falloc && + shmem_falloc->waitq && + vmf->pgoff >= shmem_falloc->start && + vmf->pgoff < shmem_falloc->next) { + wait_queue_head_t *shmem_falloc_waitq; + DEFINE_WAIT(shmem_fault_wait); + + ret = VM_FAULT_NOPAGE; + if ((vmf->flags & FAULT_FLAG_ALLOW_RETRY) && + !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) { + /* It's polite to up mmap_sem if we can */ + up_read(&vma->vm_mm->mmap_sem); + ret = VM_FAULT_RETRY; + } + + shmem_falloc_waitq = shmem_falloc->waitq; + prepare_to_wait(shmem_falloc_waitq, &shmem_fault_wait, + TASK_UNINTERRUPTIBLE); + spin_unlock(&inode->i_lock); + schedule(); + + /* + * shmem_falloc_waitq points into the shmem_fallocate() + * stack of the hole-punching task: shmem_falloc_waitq + * is usually invalid by the time we reach here, but + * finish_wait() does not dereference it in that case; + * though i_lock needed lest racing with wake_up_all(). + */ + spin_lock(&inode->i_lock); + finish_wait(shmem_falloc_waitq, &shmem_fault_wait); + spin_unlock(&inode->i_lock); + return ret; + } + spin_unlock(&inode->i_lock); + } + error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_CACHE, &ret); if (error) return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS); @@ -1819,12 +1883,25 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset, struct address_space *mapping = file->f_mapping; loff_t unmap_start = round_up(offset, PAGE_SIZE); loff_t unmap_end = round_down(offset + len, PAGE_SIZE) - 1; + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(shmem_falloc_waitq); + + shmem_falloc.waitq = &shmem_falloc_waitq; + shmem_falloc.start = unmap_start >> PAGE_SHIFT; + shmem_falloc.next = (unmap_end + 1) >> PAGE_SHIFT; + spin_lock(&inode->i_lock); + inode->i_private = &shmem_falloc; + spin_unlock(&inode->i_lock); if ((u64)unmap_end > (u64)unmap_start) unmap_mapping_range(mapping, unmap_start, 1 + unmap_end - unmap_start, 0); shmem_truncate_range(inode, offset, offset + len - 1); /* No need to unmap again: hole-punching leaves COWed pages */ + + spin_lock(&inode->i_lock); + inode->i_private = NULL; + wake_up_all(&shmem_falloc_waitq); + spin_unlock(&inode->i_lock); error = 0; goto out; } @@ -1842,6 +1919,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset, goto out; } + shmem_falloc.waitq = NULL; shmem_falloc.start = start; shmem_falloc.next = start; shmem_falloc.nr_falloced = 0; @@ -1937,22 +2015,14 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE); if (inode) { -#ifdef CONFIG_TMPFS_POSIX_ACL - error = generic_acl_init(inode, dir); - if (error) { - iput(inode); - return error; - } -#endif + error = simple_acl_create(dir, inode); + if (error) + goto out_iput; error = security_inode_init_security(inode, dir, &dentry->d_name, shmem_initxattrs, NULL); - if (error) { - if (error != -EOPNOTSUPP) { - iput(inode); - return error; - } - } + if (error && error != -EOPNOTSUPP) + goto out_iput; error = 0; dir->i_size += BOGO_DIRENT_SIZE; @@ -1961,6 +2031,9 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) dget(dentry); /* Extra count - pin the dentry in core */ } return error; +out_iput: + iput(inode); + return error; } static int @@ -1974,24 +2047,17 @@ shmem_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) error = security_inode_init_security(inode, dir, NULL, shmem_initxattrs, NULL); - if (error) { - if (error != -EOPNOTSUPP) { - iput(inode); - return error; - } - } -#ifdef CONFIG_TMPFS_POSIX_ACL - error = generic_acl_init(inode, dir); - if (error) { - iput(inode); - return error; - } -#else - error = 0; -#endif + if (error && error != -EOPNOTSUPP) + goto out_iput; + error = simple_acl_create(dir, inode); + if (error) + goto out_iput; d_tmpfile(dentry, inode); } return error; +out_iput: + iput(inode); + return error; } static int shmem_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) @@ -2223,8 +2289,8 @@ static int shmem_initxattrs(struct inode *inode, static const struct xattr_handler *shmem_xattr_handlers[] = { #ifdef CONFIG_TMPFS_POSIX_ACL - &generic_acl_access_handler, - &generic_acl_default_handler, + &posix_acl_access_xattr_handler, + &posix_acl_default_xattr_handler, #endif NULL }; @@ -2740,6 +2806,7 @@ static const struct inode_operations shmem_inode_operations = { .getxattr = shmem_getxattr, .listxattr = shmem_listxattr, .removexattr = shmem_removexattr, + .set_acl = simple_set_acl, #endif }; @@ -2764,6 +2831,7 @@ static const struct inode_operations shmem_dir_inode_operations = { #endif #ifdef CONFIG_TMPFS_POSIX_ACL .setattr = shmem_setattr, + .set_acl = simple_set_acl, #endif }; @@ -2776,6 +2844,7 @@ static const struct inode_operations shmem_special_inode_operations = { #endif #ifdef CONFIG_TMPFS_POSIX_ACL .setattr = shmem_setattr, + .set_acl = simple_set_acl, #endif };