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author | Christoph Hellwig <hch@lst.de> | 2008-02-04 22:28:56 -0800 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-05 09:44:16 -0800 |
commit | 61d5048f149572434daee0cce5e1374a8a7cf3e8 (patch) | |
tree | 97ac9c25bc44a58145a750a99887195df31cbe40 /mm | |
parent | 1b1b32f2c6f6bb32535d2da62075b51c980880eb (diff) | |
download | kernel_samsung_smdk4412-61d5048f149572434daee0cce5e1374a8a7cf3e8.zip kernel_samsung_smdk4412-61d5048f149572434daee0cce5e1374a8a7cf3e8.tar.gz kernel_samsung_smdk4412-61d5048f149572434daee0cce5e1374a8a7cf3e8.tar.bz2 |
clean up vmtruncate
vmtruncate is a twisted maze of gotos, this patch cleans it up to have a
proper if else for the two major cases of extending and truncating truncate
and thus makes it a lot more readable while keeping exactly the same
functinality.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/memory.c | 69 |
1 files changed, 34 insertions, 35 deletions
diff --git a/mm/memory.c b/mm/memory.c index bc13775..b7cb2e0 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1909,50 +1909,49 @@ EXPORT_SYMBOL(unmap_mapping_range); */ int vmtruncate(struct inode * inode, loff_t offset) { - struct address_space *mapping = inode->i_mapping; - unsigned long limit; + if (inode->i_size < offset) { + unsigned long limit; + + limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; + if (limit != RLIM_INFINITY && offset > limit) + goto out_sig; + if (offset > inode->i_sb->s_maxbytes) + goto out_big; + i_size_write(inode, offset); + } else { + struct address_space *mapping = inode->i_mapping; - if (inode->i_size < offset) - goto do_expand; - /* - * truncation of in-use swapfiles is disallowed - it would cause - * subsequent swapout to scribble on the now-freed blocks. - */ - if (IS_SWAPFILE(inode)) - goto out_busy; - i_size_write(inode, offset); + /* + * truncation of in-use swapfiles is disallowed - it would + * cause subsequent swapout to scribble on the now-freed + * blocks. + */ + if (IS_SWAPFILE(inode)) + return -ETXTBSY; + i_size_write(inode, offset); + + /* + * unmap_mapping_range is called twice, first simply for + * efficiency so that truncate_inode_pages does fewer + * single-page unmaps. However after this first call, and + * before truncate_inode_pages finishes, it is possible for + * private pages to be COWed, which remain after + * truncate_inode_pages finishes, hence the second + * unmap_mapping_range call must be made for correctness. + */ + unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); + truncate_inode_pages(mapping, offset); + unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); + } - /* - * unmap_mapping_range is called twice, first simply for efficiency - * so that truncate_inode_pages does fewer single-page unmaps. However - * after this first call, and before truncate_inode_pages finishes, - * it is possible for private pages to be COWed, which remain after - * truncate_inode_pages finishes, hence the second unmap_mapping_range - * call must be made for correctness. - */ - unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); - truncate_inode_pages(mapping, offset); - unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); - goto out_truncate; - -do_expand: - limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; - if (limit != RLIM_INFINITY && offset > limit) - goto out_sig; - if (offset > inode->i_sb->s_maxbytes) - goto out_big; - i_size_write(inode, offset); - -out_truncate: if (inode->i_op && inode->i_op->truncate) inode->i_op->truncate(inode); return 0; + out_sig: send_sig(SIGXFSZ, current, 0); out_big: return -EFBIG; -out_busy: - return -ETXTBSY; } EXPORT_SYMBOL(vmtruncate); |