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authorDavid Howells <dhowells@redhat.com>2023-11-22 18:18:17 +0100
committerDavid Howells <dhowells@redhat.com>2023-12-28 10:45:25 +0100
commite0ace6ca98bef0d8d354040f13ffc0a498813ee9 (patch)
treebf426f6aa6e3c0fa9f4b186eb79857675b7148ae /fs/cachefiles
parentnetfs: Provide netfs_file_read_iter() (diff)
downloadlinux-e0ace6ca98bef0d8d354040f13ffc0a498813ee9.tar.xz
linux-e0ace6ca98bef0d8d354040f13ffc0a498813ee9.zip
netfs, cachefiles: Pass upper bound length to allow expansion
Make netfslib pass the maximum length to the ->prepare_write() op to tell the cache how much it can expand the length of a write to. This allows a write to the server at the end of a file to be limited to a few bytes whilst writing an entire block to the cache (something required by direct I/O). Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org
Diffstat (limited to 'fs/cachefiles')
-rw-r--r--fs/cachefiles/internal.h2
-rw-r--r--fs/cachefiles/io.c10
-rw-r--r--fs/cachefiles/ondemand.c2
3 files changed, 8 insertions, 6 deletions
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index 2ad58c465208..1af48d576a34 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -233,7 +233,7 @@ extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres,
enum fscache_want_state want_state);
extern 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);
extern int __cachefiles_write(struct cachefiles_object *object,
struct file *file,
diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c
index 009d23cd435b..bffffedce4a9 100644
--- a/fs/cachefiles/io.c
+++ b/fs/cachefiles/io.c
@@ -518,7 +518,7 @@ 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;
@@ -530,6 +530,8 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
down = start - round_down(start, PAGE_SIZE);
*_start = start - down;
*_len = round_up(down + len, PAGE_SIZE);
+ if (down < start || *_len > upper_len)
+ return -ENOBUFS;
/* 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
@@ -592,8 +594,8 @@ 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;
@@ -609,7 +611,7 @@ 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;
diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c
index 0254ed39f68c..9301d1eb0504 100644
--- a/fs/cachefiles/ondemand.c
+++ b/fs/cachefiles/ondemand.c
@@ -52,7 +52,7 @@ static ssize_t cachefiles_ondemand_fd_write_iter(struct kiocb *kiocb,
return -ENOBUFS;
cachefiles_begin_secure(cache, &saved_cred);
- ret = __cachefiles_prepare_write(object, file, &pos, &len, true);
+ ret = __cachefiles_prepare_write(object, file, &pos, &len, len, true);
cachefiles_end_secure(cache, saved_cred);
if (ret < 0)
return ret;