Messages in this thread | | | Date | Wed, 27 Apr 2011 12:33:08 -0600 | From | Matthew Wilcox <> | Subject | Re: [PATCH v2] fadvise: introduce POSIX_FADV_DONTNEED_FS |
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On Wed, Apr 27, 2011 at 08:13:47PM +0200, Andrea Righi wrote: > @@ -127,6 +128,12 @@ SYSCALL_DEFINE(fadvise64_64)(int fd, loff_t offset, loff_t len, int advice) > invalidate_mapping_pages(mapping, start_index, > end_index); > break; > + case POSIX_FADV_DONTNEED_FS: > + if (capable(CAP_SYS_ADMIN)) > + drop_pagecache_sb(file->f_dentry->d_sb, NULL); > + else > + ret = -EPERM; > + break; > default: > ret = -EINVAL; > }
Mmm ... what if I open /dev/sdxyz and call fadvise() on it? I think you end up flushing /dev's page cache entries, instead of the filesystem which is on /dev/sdxyz.
If I understand correctly, you want mapping->host->i_sb instead of file->f_dentry->d_sb.
-- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."
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