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author | Christoph Hellwig <hch@lst.de> | 2010-06-04 11:30:04 +0200 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2010-08-09 16:47:39 -0400 |
commit | 2c27c65ed0696f0b5df2dad2cf6462d72164d547 (patch) | |
tree | 7d9036e3dea98938f7fd7074366ee73929e9b2e5 /mm/truncate.c | |
parent | db78b877f7744bec4a9d9f9e7d10da3931d7cd39 (diff) | |
download | kernel_samsung_crespo-2c27c65ed0696f0b5df2dad2cf6462d72164d547.zip kernel_samsung_crespo-2c27c65ed0696f0b5df2dad2cf6462d72164d547.tar.gz kernel_samsung_crespo-2c27c65ed0696f0b5df2dad2cf6462d72164d547.tar.bz2 |
check ATTR_SIZE contraints in inode_change_ok
Make sure we check the truncate constraints early on in ->setattr by adding
those checks to inode_change_ok. Also clean up and document inode_change_ok
to make this obvious.
As a fallout we don't have to call inode_newsize_ok from simple_setsize and
simplify it down to a truncate_setsize which doesn't return an error. This
simplifies a lot of setattr implementations and means we use truncate_setsize
almost everywhere. Get rid of fat_setsize now that it's trivial and mark
ext2_setsize static to make the calling convention obvious.
Keep the inode_newsize_ok in vmtruncate for now as all callers need an
audit for its removal anyway.
Note: setattr code in ecryptfs doesn't call inode_change_ok at all and
needs a deeper audit, but that is left for later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'mm/truncate.c')
-rw-r--r-- | mm/truncate.c | 38 |
1 files changed, 29 insertions, 9 deletions
diff --git a/mm/truncate.c b/mm/truncate.c index 937571b..ba887bf 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -541,28 +541,48 @@ void truncate_pagecache(struct inode *inode, loff_t old, loff_t new) EXPORT_SYMBOL(truncate_pagecache); /** + * truncate_setsize - update inode and pagecache for a new file size + * @inode: inode + * @newsize: new file size + * + * truncate_setsize updastes i_size update and performs pagecache + * truncation (if necessary) for a file size updates. It will be + * typically be called from the filesystem's setattr function when + * ATTR_SIZE is passed in. + * + * Must be called with inode_mutex held and after all filesystem + * specific block truncation has been performed. + */ +void truncate_setsize(struct inode *inode, loff_t newsize) +{ + loff_t oldsize; + + oldsize = inode->i_size; + i_size_write(inode, newsize); + + truncate_pagecache(inode, oldsize, newsize); +} +EXPORT_SYMBOL(truncate_setsize); + +/** * vmtruncate - unmap mappings "freed" by truncate() syscall * @inode: inode of the file used * @offset: file offset to start truncating * - * NOTE! We have to be ready to update the memory sharing - * between the file and the memory map for a potential last - * incomplete page. Ugly, but necessary. - * - * This function is deprecated and simple_setsize or truncate_pagecache - * should be used instead. + * This function is deprecated and truncate_setsize or truncate_pagecache + * should be used instead, together with filesystem specific block truncation. */ int vmtruncate(struct inode *inode, loff_t offset) { int error; - error = simple_setsize(inode, offset); + error = inode_newsize_ok(inode, offset); if (error) return error; + truncate_setsize(inode, offset); if (inode->i_op->truncate) inode->i_op->truncate(inode); - - return error; + return 0; } EXPORT_SYMBOL(vmtruncate); |