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| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-04-02 19:29:52 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-04-30 22:17:06 -0700 |
| commit | c63c7b051395368573779c8309aa5c990dcf2f96 (patch) | |
| tree | db54090eef99349d15b95fcd8c2620a2403d8db8 /include/linux | |
| parent | 8b09bee3083897e375bd0bf9d60f48daedfab3e0 (diff) | |
| download | linux-c63c7b051395368573779c8309aa5c990dcf2f96.tar.gz linux-c63c7b051395368573779c8309aa5c990dcf2f96.tar.bz2 linux-c63c7b051395368573779c8309aa5c990dcf2f96.zip | |
NFS: Fix a race when doing NFS write coalescing
Currently we do write coalescing in a very inefficient manner: one pass in
generic_writepages() in order to lock the pages for writing, then one pass
in nfs_flush_mapping() and/or nfs_sync_mapping_wait() in order to gather
the locked pages for coalescing into RPC requests of size "wsize".
In fact, it turns out there is actually a deadlock possible here since we
only start I/O on the second pass. If the user signals the process while
we're in nfs_sync_mapping_wait(), for instance, then we may exit before
starting I/O on all the requests that have been queued up.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/nfs_page.h | 8 | ||||
| -rw-r--r-- | include/linux/writeback.h | 2 |
2 files changed, 3 insertions, 7 deletions
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h index b8b7bca3bac8..e556e57ef7ad 100644 --- a/include/linux/nfs_page.h +++ b/include/linux/nfs_page.h @@ -21,8 +21,7 @@ /* * Valid flags for the radix tree */ -#define NFS_PAGE_TAG_DIRTY 0 -#define NFS_PAGE_TAG_WRITEBACK 1 +#define NFS_PAGE_TAG_WRITEBACK 0 /* * Valid flags for a dirty buffer @@ -72,9 +71,6 @@ extern void nfs_clear_request(struct nfs_page *req); extern void nfs_release_request(struct nfs_page *req); -extern long nfs_scan_dirty(struct address_space *mapping, - struct writeback_control *wbc, - struct list_head *dst); extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *head, struct list_head *dst, unsigned long idx_start, unsigned int npages); extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, @@ -84,8 +80,6 @@ extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, int how); extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *, struct nfs_page *); -extern void nfs_pageio_add_list(struct nfs_pageio_descriptor *, - struct list_head *); extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc); extern int nfs_wait_on_request(struct nfs_page *); extern void nfs_unlock_request(struct nfs_page *req); diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 0c78f7f4a976..daa6c125f66e 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -59,6 +59,8 @@ struct writeback_control { unsigned for_reclaim:1; /* Invoked from the page allocator */ unsigned for_writepages:1; /* This is a writepages() call */ unsigned range_cyclic:1; /* range_start is cyclic */ + + void *fs_private; /* For use by ->writepages() */ }; /* |