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| author | James Morris <jmorris@namei.org> | 2011-06-30 18:43:56 +1000 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2011-06-30 18:43:56 +1000 |
| commit | 5b944a71a192977c1c018bbcfa0c52dca48e2368 (patch) | |
| tree | 9f234c4a93bb28890ad086c846d2bf0b35f7f7ae /mm/truncate.c | |
| parent | 0e4ae0e0dec634b2ae53ac57d14141b140467dbe (diff) | |
| parent | c017d0d1351f916c0ced3f358afc491fdcf490b4 (diff) | |
| download | op-kernel-dev-5b944a71a192977c1c018bbcfa0c52dca48e2368.zip op-kernel-dev-5b944a71a192977c1c018bbcfa0c52dca48e2368.tar.gz | |
Merge branch 'linus' into next
Diffstat (limited to 'mm/truncate.c')
| -rw-r--r-- | mm/truncate.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/mm/truncate.c b/mm/truncate.c index 3a29a61..e13f22e 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -304,6 +304,11 @@ EXPORT_SYMBOL(truncate_inode_pages_range); * @lstart: offset from which to truncate * * Called under (and serialised by) inode->i_mutex. + * + * Note: When this function returns, there can be a page in the process of + * deletion (inside __delete_from_page_cache()) in the specified range. Thus + * mapping->nrpages can be non-zero when this function returns even after + * truncation of the whole mapping. */ void truncate_inode_pages(struct address_space *mapping, loff_t lstart) { @@ -603,3 +608,27 @@ int vmtruncate(struct inode *inode, loff_t offset) return 0; } EXPORT_SYMBOL(vmtruncate); + +int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end) +{ + struct address_space *mapping = inode->i_mapping; + + /* + * If the underlying filesystem is not going to provide + * a way to truncate a range of blocks (punch a hole) - + * we should return failure right now. + */ + if (!inode->i_op->truncate_range) + return -ENOSYS; + + mutex_lock(&inode->i_mutex); + down_write(&inode->i_alloc_sem); + unmap_mapping_range(mapping, offset, (end - offset), 1); + inode->i_op->truncate_range(inode, offset, end); + /* unmap again to remove racily COWed private pages */ + unmap_mapping_range(mapping, offset, (end - offset), 1); + up_write(&inode->i_alloc_sem); + mutex_unlock(&inode->i_mutex); + + return 0; +} |
