[PATCH 02/17] CacheFiles: Downgrade the requirements passed to theallocator

From: David Howells
Date: Wed Feb 08 2012 - 16:33:36 EST


Downgrade the requirements passed to the allocator in the gfp flags parameter.
FS-Cache/CacheFiles can handle OOM conditions simply by aborting the attempt to
store an object or a page in the cache.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

fs/cachefiles/interface.c | 8 ++++----
fs/cachefiles/internal.h | 2 ++
fs/cachefiles/key.c | 2 +-
fs/cachefiles/rdwr.c | 18 ++++++++++--------
fs/cachefiles/xattr.c | 2 +-
fs/fscache/page.c | 2 +-
6 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index 67bef6d..9bff0f8 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -41,12 +41,12 @@ static struct fscache_object *cachefiles_alloc_object(

_enter("{%s},%p,", cache->cache.identifier, cookie);

- lookup_data = kmalloc(sizeof(*lookup_data), GFP_KERNEL);
+ lookup_data = kmalloc(sizeof(*lookup_data), cachefiles_gfp);
if (!lookup_data)
goto nomem_lookup_data;

/* create a new object record and a temporary leaf image */
- object = kmem_cache_alloc(cachefiles_object_jar, GFP_KERNEL);
+ object = kmem_cache_alloc(cachefiles_object_jar, cachefiles_gfp);
if (!object)
goto nomem_object;

@@ -63,7 +63,7 @@ static struct fscache_object *cachefiles_alloc_object(
* - stick the length on the front and leave space on the back for the
* encoder
*/
- buffer = kmalloc((2 + 512) + 3, GFP_KERNEL);
+ buffer = kmalloc((2 + 512) + 3, cachefiles_gfp);
if (!buffer)
goto nomem_buffer;

@@ -219,7 +219,7 @@ static void cachefiles_update_object(struct fscache_object *_object)
return;
}

- auxdata = kmalloc(2 + 512 + 3, GFP_KERNEL);
+ auxdata = kmalloc(2 + 512 + 3, cachefiles_gfp);
if (!auxdata) {
_leave(" [nomem]");
return;
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index bd6bc1b..4938251 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -23,6 +23,8 @@ extern unsigned cachefiles_debug;
#define CACHEFILES_DEBUG_KLEAVE 2
#define CACHEFILES_DEBUG_KDEBUG 4

+#define cachefiles_gfp (__GFP_WAIT | __GFP_NORETRY | __GFP_NOMEMALLOC)
+
/*
* node records
*/
diff --git a/fs/cachefiles/key.c b/fs/cachefiles/key.c
index 81b8b2b..33b58c6 100644
--- a/fs/cachefiles/key.c
+++ b/fs/cachefiles/key.c
@@ -78,7 +78,7 @@ char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type)

_debug("max: %d", max);

- key = kmalloc(max, GFP_KERNEL);
+ key = kmalloc(max, cachefiles_gfp);
if (!key)
return NULL;

diff --git a/fs/cachefiles/rdwr.c b/fs/cachefiles/rdwr.c
index 0186fc1..26a6f52 100644
--- a/fs/cachefiles/rdwr.c
+++ b/fs/cachefiles/rdwr.c
@@ -238,7 +238,7 @@ static int cachefiles_read_backing_file_one(struct cachefiles_object *object,
_debug("read back %p{%lu,%d}",
netpage, netpage->index, page_count(netpage));

- monitor = kzalloc(sizeof(*monitor), GFP_KERNEL);
+ monitor = kzalloc(sizeof(*monitor), cachefiles_gfp);
if (!monitor)
goto nomem;

@@ -257,13 +257,14 @@ static int cachefiles_read_backing_file_one(struct cachefiles_object *object,
goto backing_page_already_present;

if (!newpage) {
- newpage = page_cache_alloc_cold(bmapping);
+ newpage = __page_cache_alloc(cachefiles_gfp |
+ __GFP_COLD);
if (!newpage)
goto nomem_monitor;
}

ret = add_to_page_cache(newpage, bmapping,
- netpage->index, GFP_KERNEL);
+ netpage->index, cachefiles_gfp);
if (ret == 0)
goto installed_new_backing_page;
if (ret != -EEXIST)
@@ -481,7 +482,7 @@ static int cachefiles_read_backing_file(struct cachefiles_object *object,
netpage, netpage->index, page_count(netpage));

if (!monitor) {
- monitor = kzalloc(sizeof(*monitor), GFP_KERNEL);
+ monitor = kzalloc(sizeof(*monitor), cachefiles_gfp);
if (!monitor)
goto nomem;

@@ -496,13 +497,14 @@ static int cachefiles_read_backing_file(struct cachefiles_object *object,
goto backing_page_already_present;

if (!newpage) {
- newpage = page_cache_alloc_cold(bmapping);
+ newpage = __page_cache_alloc(cachefiles_gfp |
+ __GFP_COLD);
if (!newpage)
goto nomem;
}

ret = add_to_page_cache(newpage, bmapping,
- netpage->index, GFP_KERNEL);
+ netpage->index, cachefiles_gfp);
if (ret == 0)
goto installed_new_backing_page;
if (ret != -EEXIST)
@@ -532,7 +534,7 @@ static int cachefiles_read_backing_file(struct cachefiles_object *object,
_debug("- monitor add");

ret = add_to_page_cache(netpage, op->mapping, netpage->index,
- GFP_KERNEL);
+ cachefiles_gfp);
if (ret < 0) {
if (ret == -EEXIST) {
page_cache_release(netpage);
@@ -608,7 +610,7 @@ static int cachefiles_read_backing_file(struct cachefiles_object *object,
_debug("- uptodate");

ret = add_to_page_cache(netpage, op->mapping, netpage->index,
- GFP_KERNEL);
+ cachefiles_gfp);
if (ret < 0) {
if (ret == -EEXIST) {
page_cache_release(netpage);
diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c
index e18b183..73b4628 100644
--- a/fs/cachefiles/xattr.c
+++ b/fs/cachefiles/xattr.c
@@ -174,7 +174,7 @@ int cachefiles_check_object_xattr(struct cachefiles_object *object,
ASSERT(dentry);
ASSERT(dentry->d_inode);

- auxbuf = kmalloc(sizeof(struct cachefiles_xattr) + 512, GFP_KERNEL);
+ auxbuf = kmalloc(sizeof(struct cachefiles_xattr) + 512, cachefiles_gfp);
if (!auxbuf) {
_leave(" = -ENOMEM");
return -ENOMEM;
diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index d7c663c..248a12e 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -759,7 +759,7 @@ int __fscache_write_page(struct fscache_cookie *cookie,

fscache_stat(&fscache_n_stores);

- op = kzalloc(sizeof(*op), GFP_NOIO);
+ op = kzalloc(sizeof(*op), GFP_NOIO | __GFP_NOMEMALLOC | __GFP_NORETRY);
if (!op)
goto nomem;


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