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Diffstat (limited to 'fs/cachefiles/io.c')
-rw-r--r--fs/cachefiles/io.c34
1 files changed, 21 insertions, 13 deletions
diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c
index 5857241c5918..1d685357e67f 100644
--- a/fs/cachefiles/io.c
+++ b/fs/cachefiles/io.c
@@ -517,18 +517,26 @@ cachefiles_prepare_ondemand_read(struct netfs_cache_resources *cres,
*/
int __cachefiles_prepare_write(struct cachefiles_object *object,
struct file *file,
- loff_t *_start, size_t *_len,
+ loff_t *_start, size_t *_len, size_t upper_len,
bool no_space_allocated_yet)
{
struct cachefiles_cache *cache = object->volume->cache;
loff_t start = *_start, pos;
- size_t len = *_len, down;
+ size_t len = *_len;
int ret;
/* Round to DIO size */
- down = start - round_down(start, PAGE_SIZE);
- *_start = start - down;
- *_len = round_up(down + len, PAGE_SIZE);
+ start = round_down(*_start, PAGE_SIZE);
+ if (start != *_start || *_len > upper_len) {
+ /* Probably asked to cache a streaming write written into the
+ * pagecache when the cookie was temporarily out of service to
+ * culling.
+ */
+ fscache_count_dio_misfit();
+ return -ENOBUFS;
+ }
+
+ *_len = round_up(len, PAGE_SIZE);
/* We need to work out whether there's sufficient disk space to perform
* the write - but we can skip that check if we have space already
@@ -539,7 +547,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
pos = cachefiles_inject_read_error();
if (pos == 0)
- pos = vfs_llseek(file, *_start, SEEK_DATA);
+ pos = vfs_llseek(file, start, SEEK_DATA);
if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) {
if (pos == -ENXIO)
goto check_space; /* Unallocated tail */
@@ -547,7 +555,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
cachefiles_trace_seek_error);
return pos;
}
- if ((u64)pos >= (u64)*_start + *_len)
+ if ((u64)pos >= (u64)start + *_len)
goto check_space; /* Unallocated region */
/* We have a block that's at least partially filled - if we're low on
@@ -560,13 +568,13 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
pos = cachefiles_inject_read_error();
if (pos == 0)
- pos = vfs_llseek(file, *_start, SEEK_HOLE);
+ pos = vfs_llseek(file, start, SEEK_HOLE);
if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) {
trace_cachefiles_io_error(object, file_inode(file), pos,
cachefiles_trace_seek_error);
return pos;
}
- if ((u64)pos >= (u64)*_start + *_len)
+ if ((u64)pos >= (u64)start + *_len)
return 0; /* Fully allocated */
/* Partially allocated, but insufficient space: cull. */
@@ -574,7 +582,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
ret = cachefiles_inject_remove_error();
if (ret == 0)
ret = vfs_fallocate(file, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
- *_start, *_len);
+ start, *_len);
if (ret < 0) {
trace_cachefiles_io_error(object, file_inode(file), ret,
cachefiles_trace_fallocate_error);
@@ -591,8 +599,8 @@ check_space:
}
static int cachefiles_prepare_write(struct netfs_cache_resources *cres,
- loff_t *_start, size_t *_len, loff_t i_size,
- bool no_space_allocated_yet)
+ loff_t *_start, size_t *_len, size_t upper_len,
+ loff_t i_size, bool no_space_allocated_yet)
{
struct cachefiles_object *object = cachefiles_cres_object(cres);
struct cachefiles_cache *cache = object->volume->cache;
@@ -608,7 +616,7 @@ static int cachefiles_prepare_write(struct netfs_cache_resources *cres,
cachefiles_begin_secure(cache, &saved_cred);
ret = __cachefiles_prepare_write(object, cachefiles_cres_file(cres),
- _start, _len,
+ _start, _len, upper_len,
no_space_allocated_yet);
cachefiles_end_secure(cache, saved_cred);
return ret;