kernel.git/fs/jffs2/file.c, branch linux-4.8.y

mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

2016-04-04T17:41:08Z

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ; - >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov Acked-by: Michal Hocko Signed-off-by: Linus Torvalds

Revert "jffs2: Fix lock acquisition order bug in jffs2_write_begin"

2016-02-25T11:11:25Z

This reverts commit 5ffd3412ae55 ("jffs2: Fix lock acquisition order bug in jffs2_write_begin"). The commit modified jffs2_write_begin() to remove a deadlock with jffs2_garbage_collect_live(), but this introduced new deadlocks found by multiple users. page_lock() actually has to be called before mutex_lock(&c->alloc_sem) or mutex_lock(&f->sem) because jffs2_write_end() and jffs2_readpage() are called with the page locked, and they acquire c->alloc_sem and f->sem, resp. In other words, the lock order in jffs2_write_begin() was correct, and it is the jffs2_garbage_collect_live() path that has to be changed. Revert the commit to get rid of the new deadlocks, and to clear the way for a better fix of the original deadlock. Reported-by: Deng Chao Reported-by: Ming Liu Reported-by: wangzaiwei Signed-off-by: Thomas Betker Signed-off-by: David Woodhouse Cc: stable@vger.kernel.org

wrappers for ->i_mutex access

2016-01-22T23:04:28Z

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro

make new_sync_{read,write}() static

2015-04-12T02:29:40Z

All places outside of core VFS that checked ->read and ->write for being NULL or called the methods directly are gone now, so NULL {read,write} with non-NULL {read,write}_iter will do the right thing in all cases. Signed-off-by: Al Viro

write_iter variants of {__,}generic_file_aio_write()

2014-05-06T21:38:00Z

Signed-off-by: Al Viro

switch simple generic_file_aio_read() users to ->read_iter()

2014-05-06T21:37:55Z

Signed-off-by: Al Viro

jffs2: use generic posix ACL infrastructure

2014-01-26T04:58:20Z

Also don't bother to set up a .get_acl method for symlinks as we do not support access control (ACLs or even mode bits) for symlinks in Linux. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

jffs2: Fix lock acquisition order bug in jffs2_write_begin

2012-11-09T15:02:50Z

jffs2_write_begin() first acquires the page lock, then f->sem. This causes an AB-BA deadlock with jffs2_garbage_collect_live(), which first acquires f->sem, then the page lock: jffs2_garbage_collect_live mutex_lock(&f->sem) (A) jffs2_garbage_collect_dnode jffs2_gc_fetch_page read_cache_page_async do_read_cache_page lock_page(page) (B) jffs2_write_begin grab_cache_page_write_begin find_lock_page lock_page(page) (B) mutex_lock(&f->sem) (A) We fix this by restructuring jffs2_write_begin() to take f->sem before the page lock. However, we make sure that f->sem is not held when calling jffs2_reserve_space(), as this is not permitted by the locking rules. The deadlock above was observed multiple times on an SoC with a dual ARMv7 (Cortex-A9), running the long-term 3.4.11 kernel; it occurred when using scp to copy files from a host system to the ARM target system. The fix was heavily tested on the same target system. Cc: stable@vger.kernel.org Signed-off-by: Thomas Betker Acked-by: Joakim Tjernlund Signed-off-by: Artem Bityutskiy

userns: Convert jffs2 to use kuid and kgid where appropriate

2012-09-21T10:13:33Z

- General routine uid/gid conversion work - When storing posix acls treat ACL_USER and ACL_GROUP separately so I can call from_kuid or from_kgid as appropriate. - When reading posix acls treat ACL_USER and ACL_GROUP separately so I can call make_kuid or make_kgid as appropriate. Cc: David Woodhouse Signed-off-by: Eric W. Biederman

jffs2: Use pr_fmt and remove jffs: from formats

2012-03-26T23:40:19Z

Use pr_fmt to prefix KBUILD_MODNAME to appropriate logging messages. Remove now unnecessary internal prefixes from formats. Signed-off-by: Joe Perches Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse