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authorDavid Howells <dhowells@redhat.com>2021-11-18 08:58:08 +0000
committerDavid Howells <dhowells@redhat.com>2022-01-07 13:42:29 +0000
commit169379eaef933ca98c279257cacb313a02f9984d (patch)
treef6f4ebe27265f948217b25a3adde5685f90d4806 /fs/cachefiles
parent72b957856b0c09eee542afcff29705dd0adda654 (diff)
downloadlinux-169379eaef933ca98c279257cacb313a02f9984d.tar.bz2
cachefiles: Mark a backing file in use with an inode flag
Use an inode flag, S_KERNEL_FILE, to mark that a backing file is in use by the kernel to prevent cachefiles or other kernel services from interfering with that file. Using S_SWAPFILE instead isn't really viable as that has other effects in the I/O paths. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819642273.215744.6414248677118690672.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906943215.143852.16972351425323967014.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967154118.1823006.13227551961786743991.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021541207.640689.564689725898537127.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/164021552299.640689.10578652796777392062.stgit@warthog.procyon.org.uk/ # v4
Diffstat (limited to 'fs/cachefiles')
-rw-r--r--fs/cachefiles/internal.h2
-rw-r--r--fs/cachefiles/namei.c35
2 files changed, 37 insertions, 0 deletions
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index 01071e7a7c02..7c67a70a3dff 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -187,6 +187,8 @@ extern struct kmem_cache *cachefiles_object_jar;
/*
* namei.c
*/
+extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
+ struct file *file);
extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
struct dentry *dir,
const char *name,
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 11a33209ab5f..db60a671c3fc 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -31,6 +31,18 @@ static bool __cachefiles_mark_inode_in_use(struct cachefiles_object *object,
return can_use;
}
+static bool cachefiles_mark_inode_in_use(struct cachefiles_object *object,
+ struct dentry *dentry)
+{
+ struct inode *inode = d_backing_inode(dentry);
+ bool can_use;
+
+ inode_lock(inode);
+ can_use = __cachefiles_mark_inode_in_use(object, dentry);
+ inode_unlock(inode);
+ return can_use;
+}
+
/*
* Unmark a backing inode. The caller must hold the inode lock.
*/
@@ -44,6 +56,29 @@ static void __cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
}
/*
+ * Unmark a backing inode and tell cachefilesd that there's something that can
+ * be culled.
+ */
+void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
+ struct file *file)
+{
+ struct cachefiles_cache *cache = object->volume->cache;
+ struct inode *inode = file_inode(file);
+
+ if (inode) {
+ inode_lock(inode);
+ __cachefiles_unmark_inode_in_use(object, file->f_path.dentry);
+ inode_unlock(inode);
+
+ if (!test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags)) {
+ atomic_long_add(inode->i_blocks, &cache->b_released);
+ if (atomic_inc_return(&cache->f_released))
+ cachefiles_state_changed(cache);
+ }
+ }
+}
+
+/*
* get a subdirectory
*/
struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,