ext4: Properly update i_disksize.

With delayed allocation we use i_data_sem to update i_disksize.  We need
to update i_disksize only if the new size specified is greater than the
current value and we need to make sure we don't race with other
i_disksize update.  With delayed allocation we will switch to the
write_begin function for non-delayed allocation if we are low on free
blocks.  This means the write_begin function for non-delayed allocation
also needs to use the same locking.

We also need to check and update i_disksize even if the new size is less
that inode.i_size because of delayed allocation.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Aneesh Kumar K.V 2008-09-13 13:06:18 -04:00 committed by Theodore Ts'o
parent ae4d537211
commit cf17fea657
3 changed files with 46 additions and 28 deletions

View File

@ -1218,6 +1218,17 @@ do { \
#define EXT4_FREEBLOCKS_WATERMARK 0
#endif
static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
{
/*
* XXX: replace with spinlock if seen contended -bzzz
*/
down_write(&EXT4_I(inode)->i_data_sem);
if (newsize > EXT4_I(inode)->i_disksize)
EXT4_I(inode)->i_disksize = newsize;
up_write(&EXT4_I(inode)->i_data_sem);
return ;
}
/*
* Inodes and files operations

View File

@ -2878,10 +2878,11 @@ static void ext4_falloc_update_inode(struct inode *inode,
* Update only when preallocation was requested beyond
* the file size.
*/
if (!(mode & FALLOC_FL_KEEP_SIZE) &&
new_size > i_size_read(inode)) {
i_size_write(inode, new_size);
EXT4_I(inode)->i_disksize = new_size;
if (!(mode & FALLOC_FL_KEEP_SIZE)) {
if (new_size > i_size_read(inode))
i_size_write(inode, new_size);
if (new_size > EXT4_I(inode)->i_disksize)
ext4_update_i_disksize(inode, new_size);
}
}

View File

@ -1434,16 +1434,18 @@ static int ext4_ordered_write_end(struct file *file,
ret = ext4_jbd2_file_inode(handle, inode);
if (ret == 0) {
/*
* generic_write_end() will run mark_inode_dirty() if i_size
* changes. So let's piggyback the i_disksize mark_inode_dirty
* into that.
*/
loff_t new_i_size;
new_i_size = pos + copied;
if (new_i_size > EXT4_I(inode)->i_disksize)
EXT4_I(inode)->i_disksize = new_i_size;
if (new_i_size > EXT4_I(inode)->i_disksize) {
ext4_update_i_disksize(inode, new_i_size);
/* We need to mark inode dirty even if
* new_i_size is less that inode->i_size
* bu greater than i_disksize.(hint delalloc)
*/
ext4_mark_inode_dirty(handle, inode);
}
ret2 = generic_write_end(file, mapping, pos, len, copied,
page, fsdata);
copied = ret2;
@ -1468,8 +1470,14 @@ static int ext4_writeback_write_end(struct file *file,
loff_t new_i_size;
new_i_size = pos + copied;
if (new_i_size > EXT4_I(inode)->i_disksize)
EXT4_I(inode)->i_disksize = new_i_size;
if (new_i_size > EXT4_I(inode)->i_disksize) {
ext4_update_i_disksize(inode, new_i_size);
/* We need to mark inode dirty even if
* new_i_size is less that inode->i_size
* bu greater than i_disksize.(hint delalloc)
*/
ext4_mark_inode_dirty(handle, inode);
}
ret2 = generic_write_end(file, mapping, pos, len, copied,
page, fsdata);
@ -1494,6 +1502,7 @@ static int ext4_journalled_write_end(struct file *file,
int ret = 0, ret2;
int partial = 0;
unsigned from, to;
loff_t new_i_size;
from = pos & (PAGE_CACHE_SIZE - 1);
to = from + len;
@ -1508,11 +1517,12 @@ static int ext4_journalled_write_end(struct file *file,
to, &partial, write_end_fn);
if (!partial)
SetPageUptodate(page);
if (pos+copied > inode->i_size)
new_i_size = pos + copied;
if (new_i_size > inode->i_size)
i_size_write(inode, pos+copied);
EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
if (inode->i_size > EXT4_I(inode)->i_disksize) {
EXT4_I(inode)->i_disksize = inode->i_size;
if (new_i_size > EXT4_I(inode)->i_disksize) {
ext4_update_i_disksize(inode, new_i_size);
ret2 = ext4_mark_inode_dirty(handle, inode);
if (!ret)
ret = ret2;
@ -2227,18 +2237,9 @@ static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
if (disksize > i_size_read(inode))
disksize = i_size_read(inode);
if (disksize > EXT4_I(inode)->i_disksize) {
/*
* XXX: replace with spinlock if seen contended -bzzz
*/
down_write(&EXT4_I(inode)->i_data_sem);
if (disksize > EXT4_I(inode)->i_disksize)
EXT4_I(inode)->i_disksize = disksize;
up_write(&EXT4_I(inode)->i_data_sem);
if (EXT4_I(inode)->i_disksize == disksize) {
ret = ext4_mark_inode_dirty(handle, inode);
return ret;
}
ext4_update_i_disksize(inode, disksize);
ret = ext4_mark_inode_dirty(handle, inode);
return ret;
}
ret = 0;
}
@ -2654,6 +2655,11 @@ static int ext4_da_write_end(struct file *file,
EXT4_I(inode)->i_disksize = new_i_size;
}
up_write(&EXT4_I(inode)->i_data_sem);
/* We need to mark inode dirty even if
* new_i_size is less that inode->i_size
* bu greater than i_disksize.(hint delalloc)
*/
ext4_mark_inode_dirty(handle, inode);
}
}
ret2 = generic_write_end(file, mapping, pos, len, copied,