X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=mm%2Fshmem.c;h=f92fea94d037b4b469cc8e55096f0e7d5f57cbf0;hb=762b8291be6944bd891fbe2c8976a2b2e5bbc726;hp=f514dd392cd93570e108ba5a489a28975d85034a;hpb=d67e91117d104d98635e1b1623aafb26604cecbb;p=pandora-kernel.git

diff --git a/mm/shmem.c b/mm/shmem.c
index f514dd392cd9..f92fea94d037 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -201,7 +201,7 @@ static struct vm_operations_struct shmem_vm_ops;
 
 static struct backing_dev_info shmem_backing_dev_info  __read_mostly = {
 	.ra_pages	= 0,	/* No readahead */
-	.capabilities	= BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
+	.capabilities	= BDI_CAP_NO_ACCT_AND_WRITEBACK,
 	.unplug_io_fn	= default_unplug_io_fn,
 };
 
@@ -922,20 +922,26 @@ found:
 	error = 1;
 	if (!inode)
 		goto out;
-	/* Precharge page while we can wait, compensate afterwards */
+	/* Precharge page using GFP_KERNEL while we can wait */
 	error = mem_cgroup_cache_charge(page, current->mm, GFP_KERNEL);
 	if (error)
 		goto out;
 	error = radix_tree_preload(GFP_KERNEL);
-	if (error)
-		goto uncharge;
+	if (error) {
+		mem_cgroup_uncharge_cache_page(page);
+		goto out;
+	}
 	error = 1;
 
 	spin_lock(&info->lock);
 	ptr = shmem_swp_entry(info, idx, NULL);
-	if (ptr && ptr->val == entry.val)
+	if (ptr && ptr->val == entry.val) {
 		error = add_to_page_cache(page, inode->i_mapping,
 						idx, GFP_NOWAIT);
+		/* does mem_cgroup_uncharge_cache_page on error */
+	} else	/* we must compensate for our precharge above */
+		mem_cgroup_uncharge_cache_page(page);
+
 	if (error == -EEXIST) {
 		struct page *filepage = find_get_page(inode->i_mapping, idx);
 		error = 1;
@@ -961,8 +967,6 @@ found:
 		shmem_swp_unmap(ptr);
 	spin_unlock(&info->lock);
 	radix_tree_preload_end();
-uncharge:
-	mem_cgroup_uncharge_page(page);
 out:
 	unlock_page(page);
 	page_cache_release(page);
@@ -1079,104 +1083,47 @@ redirty:
 
 #ifdef CONFIG_NUMA
 #ifdef CONFIG_TMPFS
-static int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes)
+static void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol)
 {
-	char *nodelist = strchr(value, ':');
-	int err = 1;
+	char buffer[64];
 
-	if (nodelist) {
-		/* NUL-terminate policy string */
-		*nodelist++ = '\0';
-		if (nodelist_parse(nodelist, *policy_nodes))
-			goto out;
-		if (!nodes_subset(*policy_nodes, node_states[N_HIGH_MEMORY]))
-			goto out;
-	}
-	if (!strcmp(value, "default")) {
-		*policy = MPOL_DEFAULT;
-		/* Don't allow a nodelist */
-		if (!nodelist)
-			err = 0;
-	} else if (!strcmp(value, "prefer")) {
-		*policy = MPOL_PREFERRED;
-		/* Insist on a nodelist of one node only */
-		if (nodelist) {
-			char *rest = nodelist;
-			while (isdigit(*rest))
-				rest++;
-			if (!*rest)
-				err = 0;
-		}
-	} else if (!strcmp(value, "bind")) {
-		*policy = MPOL_BIND;
-		/* Insist on a nodelist */
-		if (nodelist)
-			err = 0;
-	} else if (!strcmp(value, "interleave")) {
-		*policy = MPOL_INTERLEAVE;
-		/*
-		 * Default to online nodes with memory if no nodelist
-		 */
-		if (!nodelist)
-			*policy_nodes = node_states[N_HIGH_MEMORY];
-		err = 0;
-	}
-out:
-	/* Restore string for error message */
-	if (nodelist)
-		*--nodelist = ':';
-	return err;
-}
+	if (!mpol || mpol->mode == MPOL_DEFAULT)
+		return;		/* show nothing */
 
-static void shmem_show_mpol(struct seq_file *seq, int policy,
-			    const nodemask_t policy_nodes)
-{
-	char *policy_string;
+	mpol_to_str(buffer, sizeof(buffer), mpol, 1);
 
-	switch (policy) {
-	case MPOL_PREFERRED:
-		policy_string = "prefer";
-		break;
-	case MPOL_BIND:
-		policy_string = "bind";
-		break;
-	case MPOL_INTERLEAVE:
-		policy_string = "interleave";
-		break;
-	default:
-		/* MPOL_DEFAULT */
-		return;
-	}
-
-	seq_printf(seq, ",mpol=%s", policy_string);
-
-	if (policy != MPOL_INTERLEAVE ||
-	    !nodes_equal(policy_nodes, node_states[N_HIGH_MEMORY])) {
-		char buffer[64];
-		int len;
+	seq_printf(seq, ",mpol=%s", buffer);
+}
 
-		len = nodelist_scnprintf(buffer, sizeof(buffer), policy_nodes);
-		if (len < sizeof(buffer))
-			seq_printf(seq, ":%s", buffer);
-		else
-			seq_printf(seq, ":?");
+static struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo)
+{
+	struct mempolicy *mpol = NULL;
+	if (sbinfo->mpol) {
+		spin_lock(&sbinfo->stat_lock);	/* prevent replace/use races */
+		mpol = sbinfo->mpol;
+		mpol_get(mpol);
+		spin_unlock(&sbinfo->stat_lock);
 	}
+	return mpol;
 }
 #endif /* CONFIG_TMPFS */
 
 static struct page *shmem_swapin(swp_entry_t entry, gfp_t gfp,
 			struct shmem_inode_info *info, unsigned long idx)
 {
+	struct mempolicy mpol, *spol;
 	struct vm_area_struct pvma;
 	struct page *page;
 
+	spol = mpol_cond_copy(&mpol,
+				mpol_shared_policy_lookup(&info->policy, idx));
+
 	/* Create a pseudo vma that just contains the policy */
 	pvma.vm_start = 0;
 	pvma.vm_pgoff = idx;
 	pvma.vm_ops = NULL;
-	pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx);
+	pvma.vm_policy = spol;
 	page = swapin_readahead(entry, gfp, &pvma, 0);
-	mpol_free(pvma.vm_policy);
 	return page;
 }
 
@@ -1184,27 +1131,21 @@ static struct page *shmem_alloc_page(gfp_t gfp,
 			struct shmem_inode_info *info, unsigned long idx)
 {
 	struct vm_area_struct pvma;
-	struct page *page;
 
 	/* Create a pseudo vma that just contains the policy */
 	pvma.vm_start = 0;
 	pvma.vm_pgoff = idx;
 	pvma.vm_ops = NULL;
 	pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx);
-	page = alloc_page_vma(gfp, &pvma, 0);
-	mpol_free(pvma.vm_policy);
-	return page;
+
+	/*
+	 * alloc_page_vma() will drop the shared policy reference
+	 */
+	return alloc_page_vma(gfp, &pvma, 0);
 }
 #else /* !CONFIG_NUMA */
 #ifdef CONFIG_TMPFS
-static inline int shmem_parse_mpol(char *value, int *policy,
-						nodemask_t *policy_nodes)
-{
-	return 1;
-}
-
-static inline void shmem_show_mpol(struct seq_file *seq, int policy,
-			    const nodemask_t policy_nodes)
+static inline void shmem_show_mpol(struct seq_file *seq, struct mempolicy *p)
 {
 }
 #endif /* CONFIG_TMPFS */
@@ -1222,6 +1163,13 @@ static inline struct page *shmem_alloc_page(gfp_t gfp,
 }
 #endif /* CONFIG_NUMA */
 
+#if !defined(CONFIG_NUMA) || !defined(CONFIG_TMPFS)
+static inline struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo)
+{
+	return NULL;
+}
+#endif
+
 /*
  * shmem_getpage - either get the page from swap or allocate a new one
  *
@@ -1367,17 +1315,14 @@ repeat:
 			shmem_swp_unmap(entry);
 			spin_unlock(&info->lock);
 			unlock_page(swappage);
+			page_cache_release(swappage);
 			if (error == -ENOMEM) {
 				/* allow reclaim from this memory cgroup */
-				error = mem_cgroup_cache_charge(swappage,
-					current->mm, gfp & ~__GFP_HIGHMEM);
-				if (error) {
-					page_cache_release(swappage);
+				error = mem_cgroup_shrink_usage(current->mm,
+								gfp);
+				if (error)
 					goto failed;
-				}
-				mem_cgroup_uncharge_page(swappage);
 			}
-			page_cache_release(swappage);
 			goto repeat;
 		}
 	} else if (sgp == SGP_READ && !filepage) {
@@ -1414,6 +1359,8 @@ repeat:
 		}
 
 		if (!filepage) {
+			int ret;
+
 			spin_unlock(&info->lock);
 			filepage = shmem_alloc_page(gfp, info, idx);
 			if (!filepage) {
@@ -1442,10 +1389,18 @@ repeat:
 				swap = *entry;
 				shmem_swp_unmap(entry);
 			}
-			if (error || swap.val || 0 != add_to_page_cache_lru(
-					filepage, mapping, idx, GFP_NOWAIT)) {
+			ret = error || swap.val;
+			if (ret)
+				mem_cgroup_uncharge_cache_page(filepage);
+			else
+				ret = add_to_page_cache_lru(filepage, mapping,
+						idx, GFP_NOWAIT);
+			/*
+			 * At add_to_page_cache_lru() failure, uncharge will
+			 * be done automatically.
+			 */
+			if (ret) {
 				spin_unlock(&info->lock);
-				mem_cgroup_uncharge_page(filepage);
 				page_cache_release(filepage);
 				shmem_unacct_blocks(info->flags, 1);
 				shmem_free_blocks(inode, 1);
@@ -1454,7 +1409,6 @@ repeat:
 					goto failed;
 				goto repeat;
 			}
-			mem_cgroup_uncharge_page(filepage);
 			info->flags |= SHMEM_PAGEIN;
 		}
 
@@ -1576,8 +1530,8 @@ shmem_get_inode(struct super_block *sb, int mode, dev_t dev)
 		case S_IFREG:
 			inode->i_op = &shmem_inode_operations;
 			inode->i_fop = &shmem_file_operations;
-			mpol_shared_policy_init(&info->policy, sbinfo->policy,
-							&sbinfo->policy_nodes);
+			mpol_shared_policy_init(&info->policy,
+						 shmem_get_sbmpol(sbinfo));
 			break;
 		case S_IFDIR:
 			inc_nlink(inode);
@@ -1591,8 +1545,7 @@ shmem_get_inode(struct super_block *sb, int mode, dev_t dev)
 			 * Must not load anything in the rbtree,
 			 * mpol_free_shared_policy will not be called.
 			 */
-			mpol_shared_policy_init(&info->policy, MPOL_DEFAULT,
-						NULL);
+			mpol_shared_policy_init(&info->policy, NULL);
 			break;
 		}
 	} else
@@ -1747,26 +1700,38 @@ static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_
 	file_accessed(filp);
 }
 
-static ssize_t shmem_file_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
+static ssize_t shmem_file_aio_read(struct kiocb *iocb,
+		const struct iovec *iov, unsigned long nr_segs, loff_t pos)
 {
-	read_descriptor_t desc;
+	struct file *filp = iocb->ki_filp;
+	ssize_t retval;
+	unsigned long seg;
+	size_t count;
+	loff_t *ppos = &iocb->ki_pos;
 
-	if ((ssize_t) count < 0)
-		return -EINVAL;
-	if (!access_ok(VERIFY_WRITE, buf, count))
-		return -EFAULT;
-	if (!count)
-		return 0;
+	retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
+	if (retval)
+		return retval;
 
-	desc.written = 0;
-	desc.count = count;
-	desc.arg.buf = buf;
-	desc.error = 0;
+	for (seg = 0; seg < nr_segs; seg++) {
+		read_descriptor_t desc;
 
-	do_shmem_file_read(filp, ppos, &desc, file_read_actor);
-	if (desc.written)
-		return desc.written;
-	return desc.error;
+		desc.written = 0;
+		desc.arg.buf = iov[seg].iov_base;
+		desc.count = iov[seg].iov_len;
+		if (desc.count == 0)
+			continue;
+		desc.error = 0;
+		do_shmem_file_read(filp, ppos, &desc, file_read_actor);
+		retval += desc.written;
+		if (desc.error) {
+			retval = retval ?: desc.error;
+			break;
+		}
+		if (desc.count > 0)
+			break;
+	}
+	return retval;
 }
 
 static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf)
@@ -2207,8 +2172,7 @@ static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo,
 			if (*rest)
 				goto bad_val;
 		} else if (!strcmp(this_char,"mpol")) {
-			if (shmem_parse_mpol(value, &sbinfo->policy,
-					     &sbinfo->policy_nodes))
+			if (mpol_parse_str(value, &sbinfo->mpol, 1))
 				goto bad_val;
 		} else {
 			printk(KERN_ERR "tmpfs: Bad mount option %s\n",
@@ -2259,8 +2223,9 @@ static int shmem_remount_fs(struct super_block *sb, int *flags, char *data)
 	sbinfo->free_blocks = config.max_blocks - blocks;
 	sbinfo->max_inodes  = config.max_inodes;
 	sbinfo->free_inodes = config.max_inodes - inodes;
-	sbinfo->policy      = config.policy;
-	sbinfo->policy_nodes = config.policy_nodes;
+
+	mpol_put(sbinfo->mpol);
+	sbinfo->mpol        = config.mpol;	/* transfers initial ref */
 out:
 	spin_unlock(&sbinfo->stat_lock);
 	return error;
@@ -2281,7 +2246,7 @@ static int shmem_show_options(struct seq_file *seq, struct vfsmount *vfs)
 		seq_printf(seq, ",uid=%u", sbinfo->uid);
 	if (sbinfo->gid != 0)
 		seq_printf(seq, ",gid=%u", sbinfo->gid);
-	shmem_show_mpol(seq, sbinfo->policy, sbinfo->policy_nodes);
+	shmem_show_mpol(seq, sbinfo->mpol);
 	return 0;
 }
 #endif /* CONFIG_TMPFS */
@@ -2311,8 +2276,7 @@ static int shmem_fill_super(struct super_block *sb,
 	sbinfo->mode = S_IRWXUGO | S_ISVTX;
 	sbinfo->uid = current->fsuid;
 	sbinfo->gid = current->fsgid;
-	sbinfo->policy = MPOL_DEFAULT;
-	sbinfo->policy_nodes = node_states[N_HIGH_MEMORY];
+	sbinfo->mpol = NULL;
 	sb->s_fs_info = sbinfo;
 
 #ifdef CONFIG_TMPFS
@@ -2427,8 +2391,9 @@ static const struct file_operations shmem_file_operations = {
 	.mmap		= shmem_mmap,
 #ifdef CONFIG_TMPFS
 	.llseek		= generic_file_llseek,
-	.read		= shmem_file_read,
+	.read		= do_sync_read,
 	.write		= do_sync_write,
+	.aio_read	= shmem_file_aio_read,
 	.aio_write	= generic_file_aio_write,
 	.fsync		= simple_sync_file,
 	.splice_read	= generic_file_splice_read,