linux/net/sunrpc/cache.c, branch v4.9

sunrpc: queue work on system_power_efficient_wq

2016-09-27T18:35:36Z

sunrpc uses workqueue to clean cache regulary. There is no real dependency of executing work on the cpu which queueing it. On a idle system, especially for a heterogeneous systems like big.LITTLE, it is observed that the big idle cpu was woke up many times just to service this work, which against the principle of power saving. It would be better if we can schedule it on a cpu which the scheduler believes to be the most appropriate one. After apply this patch, system_wq will be replaced by system_power_efficient_wq for sunrpc. This functionality is enabled when CONFIG_WQ_POWER_EFFICIENT is selected. Signed-off-by: Ke Wang Signed-off-by: Anna Schumaker

sunrpc: remove 'inuse' flag from struct cache_detail.

2016-07-13T19:32:47Z

This field is not currently in use. Signed-off-by: NeilBrown Signed-off-by: J. Bruce Fields

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

sunrpc/cache: drop reference when sunrpc_cache_pipe_upcall() detects a race

2016-03-17T18:57:15Z

sunrpc_cache_pipe_upcall() can detect a race if CACHE_PENDING is no longer set. In this case it aborts the queuing of the upcall. However it has already taken a new counted reference on "h" and doesn't "put" it, even though it frees the data structure holding the reference. So let's delay the "cache_get" until we know we need it. Fixes: f9e1aedc6c79 ("sunrpc/cache: remove races with queuing an upcall.") Signed-off-by: NeilBrown Signed-off-by: J. Bruce Fields

sunrpc/cache: fix off-by-one in qword_get()

2016-02-23T18:20:16Z

The qword_get() function NUL-terminates its output buffer. If the input string is in hex format \xXXXX... and the same length as the output buffer, there is an off-by-one: int qword_get(char **bpp, char *dest, int bufsize) { ... while (len < bufsize) { ... *dest++ = (h << 4) | l; len++; } ... *dest = '\0'; return len; } This patch ensures the NUL terminator doesn't fall outside the output buffer. Signed-off-by: Stefan Hajnoczi Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields

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

sunrpc/cache: make cache flushing more reliable.

2015-10-23T19:57:30Z

The caches used to store sunrpc authentication information can be flushed by writing a timestamp to a file in /proc. This timestamp has a one-second resolution and any entry in cache that was last_refreshed *before* that time is treated as expired. This is problematic as it is not possible to reliably flush the cache without interrupting NFS service. If the current time is written to the "flush" file, any entry that was added since the current second started will still be treated as valid. If one second beyond than the current time is written to the file then no entries can be valid until the second ticks over. This will mean that no NFS request will be handled for up to 1 second. To resolve this issue we make two changes: 1/ treat an entry as expired if the timestamp when it was last_refreshed is before *or the same as* the expiry time. This means that current code which writes out the current time will now flush the cache reliably. 2/ when a new entry in added to the cache - set the last_refresh timestamp to 1 second *beyond* the current flush time, when that not in the past. This ensures that newly added entries will always be valid. Now that we have a very reliable way to flush the cache, and also since we are using "since-boot" timestamps which are monotonic, change cache_purge() to set the smallest future flush_time which will work, and leave it there: don't revert to '1'. Also disable the setting of the 'flush_time' far into the future. That has never been useful and is now awkward as it would cause last_refresh times to be strange. Finally: if a request is made to set the 'flush_time' to the current second, assume the intent is to flush the cache and advance it, if necessary, to 1 second beyond the current 'flush_time' so that all active entries will be deemed to be expired. As part of this we need to add a 'cache_detail' arg to cache_init() and cache_fresh_locked() so they can find the current ->flush_time. Signed-off-by: NeilBrown Reported-by: Olaf Kirch Signed-off-by: J. Bruce Fields

sunrpc: Switch to using hash list instead single list

2015-08-13T12:59:03Z

Switch using list_head for cache_head in cache_detail, it is useful of remove an cache_head entry directly from cache_detail. v8, using hash list, not head list Signed-off-by: Kinglong Mee Reviewed-by: NeilBrown Signed-off-by: J. Bruce Fields

sunrpc/nfsd: Remove redundant code by exports seq_operations functions

2015-08-13T12:59:02Z

Nfsd has implement a site of seq_operations functions as sunrpc's cache. Just exports sunrpc's codes, and remove nfsd's redundant codes. v8, same as v6 Signed-off-by: Kinglong Mee Reviewed-by: NeilBrown Signed-off-by: J. Bruce Fields

sunrpc: Store cache_detail in seq_file's private directly

2015-08-13T12:59:01Z

Cleanup. Just store cache_detail in seq_file's private, an allocated handle is redundant. v8, same as v6. Signed-off-by: Kinglong Mee Reviewed-by: NeilBrown Signed-off-by: J. Bruce Fields