From ea0f04e59543bafb3d2cbe37a0d375acb0bb2c34 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 4 Jun 2010 11:29:54 +0200 Subject: get rid of nobh_write_begin_newtrunc Move the call to vmtruncate to get rid of accessive blocks to the only remaining caller and rename the non-truncating version to nobh_write_begin. Get rid of the superflous file argument to it while we're at it. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- fs/buffer.c | 37 ++++--------------------------------- 1 file changed, 4 insertions(+), 33 deletions(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index d54812b198e9..559daf76bca4 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2510,11 +2510,11 @@ static void attach_nobh_buffers(struct page *page, struct buffer_head *head) } /* - * Filesystems implementing the new truncate sequence should use the - * _newtrunc postfix variant which won't incorrectly call vmtruncate. + * On entry, the page is fully not uptodate. + * On exit the page is fully uptodate in the areas outside (from,to) * The filesystem needs to handle block truncation upon failure. */ -int nobh_write_begin_newtrunc(struct file *file, struct address_space *mapping, +int nobh_write_begin(struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata, get_block_t *get_block) @@ -2547,7 +2547,7 @@ int nobh_write_begin_newtrunc(struct file *file, struct address_space *mapping, unlock_page(page); page_cache_release(page); *pagep = NULL; - return block_write_begin_newtrunc(file, mapping, pos, len, + return block_write_begin_newtrunc(NULL, mapping, pos, len, flags, pagep, fsdata, get_block); } @@ -2654,35 +2654,6 @@ out_release: return ret; } -EXPORT_SYMBOL(nobh_write_begin_newtrunc); - -/* - * On entry, the page is fully not uptodate. - * On exit the page is fully uptodate in the areas outside (from,to) - */ -int nobh_write_begin(struct file *file, struct address_space *mapping, - loff_t pos, unsigned len, unsigned flags, - struct page **pagep, void **fsdata, - get_block_t *get_block) -{ - int ret; - - ret = nobh_write_begin_newtrunc(file, mapping, pos, len, flags, - pagep, fsdata, get_block); - - /* - * prepare_write() may have instantiated a few blocks - * outside i_size. Trim these off again. Don't need - * i_size_read because we hold i_mutex. - */ - if (unlikely(ret)) { - loff_t isize = mapping->host->i_size; - if (pos + len > isize) - vmtruncate(mapping->host, isize); - } - - return ret; -} EXPORT_SYMBOL(nobh_write_begin); int nobh_write_end(struct file *file, struct address_space *mapping, -- cgit v1.2.2 From 282dc178849882289d30e58b54be6b2799b351aa Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 4 Jun 2010 11:29:55 +0200 Subject: get rid of cont_write_begin_newtrunc Move the call to vmtruncate to get rid of accessive blocks to the callers in preparation of the new truncate sequence and rename the non-truncating version to cont_write_begin. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- fs/buffer.c | 21 +-------------------- 1 file changed, 1 insertion(+), 20 deletions(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index 559daf76bca4..14529ec759b9 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2351,7 +2351,7 @@ out: * For moronic filesystems that do not allow holes in file. * We may have to extend the file. */ -int cont_write_begin_newtrunc(struct file *file, struct address_space *mapping, +int cont_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata, get_block_t *get_block, loff_t *bytes) @@ -2377,25 +2377,6 @@ int cont_write_begin_newtrunc(struct file *file, struct address_space *mapping, out: return err; } -EXPORT_SYMBOL(cont_write_begin_newtrunc); - -int cont_write_begin(struct file *file, struct address_space *mapping, - loff_t pos, unsigned len, unsigned flags, - struct page **pagep, void **fsdata, - get_block_t *get_block, loff_t *bytes) -{ - int ret; - - ret = cont_write_begin_newtrunc(file, mapping, pos, len, flags, - pagep, fsdata, get_block, bytes); - if (unlikely(ret)) { - loff_t isize = mapping->host->i_size; - if (pos + len > isize) - vmtruncate(mapping->host, isize); - } - - return ret; -} EXPORT_SYMBOL(cont_write_begin); int block_prepare_write(struct page *page, unsigned from, unsigned to, -- cgit v1.2.2 From 6e1db88d536adcbbfe562b2d4b7d6425784fff12 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 4 Jun 2010 11:29:57 +0200 Subject: introduce __block_write_begin Split up the block_write_begin implementation - __block_write_begin is a new trivial wrapper for block_prepare_write that always takes an already allocated page and can be either called from block_write_begin or filesystem code that already has a page allocated. Remove the handling of already allocated pages from block_write_begin after switching all callers that do it to __block_write_begin. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- fs/buffer.c | 69 +++++++++++++++++++++++-------------------------------------- 1 file changed, 26 insertions(+), 43 deletions(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index 14529ec759b9..c319c49da511 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1833,9 +1833,10 @@ void page_zero_new_buffers(struct page *page, unsigned from, unsigned to) } EXPORT_SYMBOL(page_zero_new_buffers); -static int __block_prepare_write(struct inode *inode, struct page *page, - unsigned from, unsigned to, get_block_t *get_block) +int block_prepare_write(struct page *page, unsigned from, unsigned to, + get_block_t *get_block) { + struct inode *inode = page->mapping->host; unsigned block_start, block_end; sector_t block; int err = 0; @@ -1908,10 +1909,13 @@ static int __block_prepare_write(struct inode *inode, struct page *page, if (!buffer_uptodate(*wait_bh)) err = -EIO; } - if (unlikely(err)) + if (unlikely(err)) { page_zero_new_buffers(page, from, to); + ClearPageUptodate(page); + } return err; } +EXPORT_SYMBOL(block_prepare_write); static int __block_commit_write(struct inode *inode, struct page *page, unsigned from, unsigned to) @@ -1948,6 +1952,15 @@ static int __block_commit_write(struct inode *inode, struct page *page, return 0; } +int __block_write_begin(struct page *page, loff_t pos, unsigned len, + get_block_t *get_block) +{ + unsigned start = pos & (PAGE_CACHE_SIZE - 1); + + return block_prepare_write(page, start, start + len, get_block); +} +EXPORT_SYMBOL(__block_write_begin); + /* * Filesystems implementing the new truncate sequence should use the * _newtrunc postfix variant which won't incorrectly call vmtruncate. @@ -1958,41 +1971,22 @@ int block_write_begin_newtrunc(struct file *file, struct address_space *mapping, struct page **pagep, void **fsdata, get_block_t *get_block) { - struct inode *inode = mapping->host; - int status = 0; + pgoff_t index = pos >> PAGE_CACHE_SHIFT; struct page *page; - pgoff_t index; - unsigned start, end; - int ownpage = 0; + int status; - index = pos >> PAGE_CACHE_SHIFT; - start = pos & (PAGE_CACHE_SIZE - 1); - end = start + len; - - page = *pagep; - if (page == NULL) { - ownpage = 1; - page = grab_cache_page_write_begin(mapping, index, flags); - if (!page) { - status = -ENOMEM; - goto out; - } - *pagep = page; - } else - BUG_ON(!PageLocked(page)); + page = grab_cache_page_write_begin(mapping, index, flags); + if (!page) + return -ENOMEM; - status = __block_prepare_write(inode, page, start, end, get_block); + status = __block_write_begin(page, pos, len, get_block); if (unlikely(status)) { - ClearPageUptodate(page); - - if (ownpage) { - unlock_page(page); - page_cache_release(page); - *pagep = NULL; - } + unlock_page(page); + page_cache_release(page); + page = NULL; } -out: + *pagep = page; return status; } EXPORT_SYMBOL(block_write_begin_newtrunc); @@ -2379,17 +2373,6 @@ out: } EXPORT_SYMBOL(cont_write_begin); -int block_prepare_write(struct page *page, unsigned from, unsigned to, - get_block_t *get_block) -{ - struct inode *inode = page->mapping->host; - int err = __block_prepare_write(inode, page, from, to, get_block); - if (err) - ClearPageUptodate(page); - return err; -} -EXPORT_SYMBOL(block_prepare_write); - int block_commit_write(struct page *page, unsigned from, unsigned to) { struct inode *inode = page->mapping->host; -- cgit v1.2.2 From 155130a4f7848b1aac439cab6bda1a175507c71c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 4 Jun 2010 11:29:58 +0200 Subject: get rid of block_write_begin_newtrunc Move the call to vmtruncate to get rid of accessive blocks to the callers in preparation of the new truncate sequence and rename the non-truncating version to block_write_begin. While we're at it also remove several unused arguments to block_write_begin. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- fs/buffer.c | 61 +++++++++---------------------------------------------------- 1 file changed, 9 insertions(+), 52 deletions(-) (limited to 'fs/buffer.c') diff --git a/fs/buffer.c b/fs/buffer.c index c319c49da511..50efa339e051 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1962,14 +1962,13 @@ int __block_write_begin(struct page *page, loff_t pos, unsigned len, EXPORT_SYMBOL(__block_write_begin); /* - * Filesystems implementing the new truncate sequence should use the - * _newtrunc postfix variant which won't incorrectly call vmtruncate. + * block_write_begin takes care of the basic task of block allocation and + * bringing partial write blocks uptodate first. + * * The filesystem needs to handle block truncation upon failure. */ -int block_write_begin_newtrunc(struct file *file, struct address_space *mapping, - loff_t pos, unsigned len, unsigned flags, - struct page **pagep, void **fsdata, - get_block_t *get_block) +int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len, + unsigned flags, struct page **pagep, get_block_t *get_block) { pgoff_t index = pos >> PAGE_CACHE_SHIFT; struct page *page; @@ -1989,44 +1988,6 @@ int block_write_begin_newtrunc(struct file *file, struct address_space *mapping, *pagep = page; return status; } -EXPORT_SYMBOL(block_write_begin_newtrunc); - -/* - * block_write_begin takes care of the basic task of block allocation and - * bringing partial write blocks uptodate first. - * - * If *pagep is not NULL, then block_write_begin uses the locked page - * at *pagep rather than allocating its own. In this case, the page will - * not be unlocked or deallocated on failure. - */ -int block_write_begin(struct file *file, struct address_space *mapping, - loff_t pos, unsigned len, unsigned flags, - struct page **pagep, void **fsdata, - get_block_t *get_block) -{ - int ret; - - ret = block_write_begin_newtrunc(file, mapping, pos, len, flags, - pagep, fsdata, get_block); - - /* - * prepare_write() may have instantiated a few blocks - * outside i_size. Trim these off again. Don't need - * i_size_read because we hold i_mutex. - * - * Filesystems which pass down their own page also cannot - * call into vmtruncate here because it would lead to lock - * inversion problems (*pagep is locked). This is a further - * example of where the old truncate sequence is inadequate. - */ - if (unlikely(ret) && *pagep == NULL) { - loff_t isize = mapping->host->i_size; - if (pos + len > isize) - vmtruncate(mapping->host, isize); - } - - return ret; -} EXPORT_SYMBOL(block_write_begin); int block_write_end(struct file *file, struct address_space *mapping, @@ -2357,7 +2318,7 @@ int cont_write_begin(struct file *file, struct address_space *mapping, err = cont_expand_zero(file, mapping, pos, bytes); if (err) - goto out; + return err; zerofrom = *bytes & ~PAGE_CACHE_MASK; if (pos+len > *bytes && zerofrom & (blocksize-1)) { @@ -2365,11 +2326,7 @@ int cont_write_begin(struct file *file, struct address_space *mapping, (*bytes)++; } - *pagep = NULL; - err = block_write_begin_newtrunc(file, mapping, pos, len, - flags, pagep, fsdata, get_block); -out: - return err; + return block_write_begin(mapping, pos, len, flags, pagep, get_block); } EXPORT_SYMBOL(cont_write_begin); @@ -2511,8 +2468,8 @@ int nobh_write_begin(struct address_space *mapping, unlock_page(page); page_cache_release(page); *pagep = NULL; - return block_write_begin_newtrunc(NULL, mapping, pos, len, - flags, pagep, fsdata, get_block); + return block_write_begin(mapping, pos, len, flags, pagep, + get_block); } if (PageMappedToDisk(page)) -- cgit v1.2.2