Re: [PATCH 2/8] ext4: remove i_alloc_sem abuse
On Tue, 21 Jun 2011, Lukas Czerner wrote: > On Mon, 20 Jun 2011, Christoph Hellwig wrote: > > > Add a new rw_semaphore to protect page_mkwrite against truncate. Previous > > i_alloc_sem was abused for this, but it's going away in this series. > > > > Signed-off-by: Christoph Hellwig > > > > Index: linux-2.6/fs/ext4/inode.c > > === > > --- linux-2.6.orig/fs/ext4/inode.c 2011-06-20 14:25:33.779248128 +0200 > > +++ linux-2.6/fs/ext4/inode.c 2011-06-20 14:27:53.025907745 +0200 > > @@ -5357,6 +5357,7 @@ int ext4_setattr(struct dentry *dentry, > > if (attr->ia_size > sbi->s_bitmap_maxbytes) > > return -EFBIG; > > } > > + down_write(&(EXT4_I(inode)->truncate_lock)); > > } > > > > if (S_ISREG(inode->i_mode) && > > @@ -5405,6 +5406,9 @@ int ext4_setattr(struct dentry *dentry, > > ext4_truncate(inode); > > } > > > > + if (attr->ia_valid & ATTR_SIZE) > > + up_write(&(EXT4_I(inode)->truncate_lock)); > > + > > Hi Christoph, > > this looks like a bug fix, so we should rather do it in a separate > commit. Could you send it separately, or at least mention that in commit > description ? That's stupid note, it is not a bugfix of course. Ignore it, sorry for the noise. > > Otherwise the patch looks good. > > Thanks! > -Lukas > > > if (!rc) { > > setattr_copy(inode, attr); > > mark_inode_dirty(inode); > > @@ -5850,10 +5854,10 @@ int ext4_page_mkwrite(struct vm_area_str > > struct address_space *mapping = inode->i_mapping; > > > > /* > > -* Get i_alloc_sem to stop truncates messing with the inode. We cannot > > -* get i_mutex because we are already holding mmap_sem. > > +* Get truncate_lock to stop truncates messing with the inode. We > > +* cannot get i_mutex because we are already holding mmap_sem. > > */ > > - down_read(&inode->i_alloc_sem); > > + down_read(&(EXT4_I(inode)->truncate_lock)); > > size = i_size_read(inode); > > if (page->mapping != mapping || size <= page_offset(page) > > || !PageUptodate(page)) { > > @@ -5865,7 +5869,7 @@ int ext4_page_mkwrite(struct vm_area_str > > lock_page(page); > > wait_on_page_writeback(page); > > if (PageMappedToDisk(page)) { > > - up_read(&inode->i_alloc_sem); > > + up_read(&(EXT4_I(inode)->truncate_lock)); > > return VM_FAULT_LOCKED; > > } > > > > @@ -5883,7 +5887,7 @@ int ext4_page_mkwrite(struct vm_area_str > > if (page_has_buffers(page)) { > > if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL, > > ext4_bh_unmapped)) { > > - up_read(&inode->i_alloc_sem); > > + up_read(&(EXT4_I(inode)->truncate_lock)); > > return VM_FAULT_LOCKED; > > } > > } > > @@ -5912,11 +5916,11 @@ int ext4_page_mkwrite(struct vm_area_str > > */ > > lock_page(page); > > wait_on_page_writeback(page); > > - up_read(&inode->i_alloc_sem); > > + up_read(&(EXT4_I(inode)->truncate_lock)); > > return VM_FAULT_LOCKED; > > out_unlock: > > if (ret) > > ret = VM_FAULT_SIGBUS; > > - up_read(&inode->i_alloc_sem); > > + up_read(&(EXT4_I(inode)->truncate_lock)); > > return ret; > > } > > Index: linux-2.6/fs/ext4/super.c > > === > > --- linux-2.6.orig/fs/ext4/super.c 2011-06-20 14:25:33.795914793 +0200 > > +++ linux-2.6/fs/ext4/super.c 2011-06-20 14:27:06.269243443 +0200 > > @@ -871,6 +871,7 @@ static struct inode *ext4_alloc_inode(st > > ei->i_datasync_tid = 0; > > atomic_set(&ei->i_ioend_count, 0); > > atomic_set(&ei->i_aiodio_unwritten, 0); > > + init_rwsem(&ei->truncate_lock); > > > > return &ei->vfs_inode; > > } > > Index: linux-2.6/fs/ext4/ext4.h > > === > > --- linux-2.6.orig/fs/ext4/ext4.h 2011-06-20 14:25:33.752581461 +0200 > > +++ linux-2.6/fs/ext4/ext4.h2011-06-20 14:27:06.272576777 +0200 > > @@ -844,6 +844,9 @@ struct ext4_inode_info { > > /* on-disk additional length */ > > __u16 i_extra_isize; > > > > + /* protect page_mkwrite against truncates */ > > + struct rw_semaphore truncate_lock; > > + > > #ifdef CONFIG_QUOTA > > /* quota space reservation, managed internally by quota code */ > > qsize_t i_reserved_quota; > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > > the body of a message to majord...@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > -- -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info
Re: [PATCH 2/8] ext4: remove i_alloc_sem abuse
On Tue, Jun 21, 2011 at 06:34:50PM +0200, Lukas Czerner wrote: > this looks like a bug fix, so we should rather do it in a separate > commit. Could you send it separately, or at least mention that in commit > description ? What looks like a bugfix? -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/8] ext4: remove i_alloc_sem abuse
On Mon, 20 Jun 2011, Christoph Hellwig wrote: > Add a new rw_semaphore to protect page_mkwrite against truncate. Previous > i_alloc_sem was abused for this, but it's going away in this series. > > Signed-off-by: Christoph Hellwig > > Index: linux-2.6/fs/ext4/inode.c > === > --- linux-2.6.orig/fs/ext4/inode.c2011-06-20 14:25:33.779248128 +0200 > +++ linux-2.6/fs/ext4/inode.c 2011-06-20 14:27:53.025907745 +0200 > @@ -5357,6 +5357,7 @@ int ext4_setattr(struct dentry *dentry, > if (attr->ia_size > sbi->s_bitmap_maxbytes) > return -EFBIG; > } > + down_write(&(EXT4_I(inode)->truncate_lock)); > } > > if (S_ISREG(inode->i_mode) && > @@ -5405,6 +5406,9 @@ int ext4_setattr(struct dentry *dentry, > ext4_truncate(inode); > } > > + if (attr->ia_valid & ATTR_SIZE) > + up_write(&(EXT4_I(inode)->truncate_lock)); > + Hi Christoph, this looks like a bug fix, so we should rather do it in a separate commit. Could you send it separately, or at least mention that in commit description ? Otherwise the patch looks good. Thanks! -Lukas > if (!rc) { > setattr_copy(inode, attr); > mark_inode_dirty(inode); > @@ -5850,10 +5854,10 @@ int ext4_page_mkwrite(struct vm_area_str > struct address_space *mapping = inode->i_mapping; > > /* > - * Get i_alloc_sem to stop truncates messing with the inode. We cannot > - * get i_mutex because we are already holding mmap_sem. > + * Get truncate_lock to stop truncates messing with the inode. We > + * cannot get i_mutex because we are already holding mmap_sem. >*/ > - down_read(&inode->i_alloc_sem); > + down_read(&(EXT4_I(inode)->truncate_lock)); > size = i_size_read(inode); > if (page->mapping != mapping || size <= page_offset(page) > || !PageUptodate(page)) { > @@ -5865,7 +5869,7 @@ int ext4_page_mkwrite(struct vm_area_str > lock_page(page); > wait_on_page_writeback(page); > if (PageMappedToDisk(page)) { > - up_read(&inode->i_alloc_sem); > + up_read(&(EXT4_I(inode)->truncate_lock)); > return VM_FAULT_LOCKED; > } > > @@ -5883,7 +5887,7 @@ int ext4_page_mkwrite(struct vm_area_str > if (page_has_buffers(page)) { > if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL, > ext4_bh_unmapped)) { > - up_read(&inode->i_alloc_sem); > + up_read(&(EXT4_I(inode)->truncate_lock)); > return VM_FAULT_LOCKED; > } > } > @@ -5912,11 +5916,11 @@ int ext4_page_mkwrite(struct vm_area_str >*/ > lock_page(page); > wait_on_page_writeback(page); > - up_read(&inode->i_alloc_sem); > + up_read(&(EXT4_I(inode)->truncate_lock)); > return VM_FAULT_LOCKED; > out_unlock: > if (ret) > ret = VM_FAULT_SIGBUS; > - up_read(&inode->i_alloc_sem); > + up_read(&(EXT4_I(inode)->truncate_lock)); > return ret; > } > Index: linux-2.6/fs/ext4/super.c > === > --- linux-2.6.orig/fs/ext4/super.c2011-06-20 14:25:33.795914793 +0200 > +++ linux-2.6/fs/ext4/super.c 2011-06-20 14:27:06.269243443 +0200 > @@ -871,6 +871,7 @@ static struct inode *ext4_alloc_inode(st > ei->i_datasync_tid = 0; > atomic_set(&ei->i_ioend_count, 0); > atomic_set(&ei->i_aiodio_unwritten, 0); > + init_rwsem(&ei->truncate_lock); > > return &ei->vfs_inode; > } > Index: linux-2.6/fs/ext4/ext4.h > === > --- linux-2.6.orig/fs/ext4/ext4.h 2011-06-20 14:25:33.752581461 +0200 > +++ linux-2.6/fs/ext4/ext4.h 2011-06-20 14:27:06.272576777 +0200 > @@ -844,6 +844,9 @@ struct ext4_inode_info { > /* on-disk additional length */ > __u16 i_extra_isize; > > + /* protect page_mkwrite against truncates */ > + struct rw_semaphore truncate_lock; > + > #ifdef CONFIG_QUOTA > /* quota space reservation, managed internally by quota code */ > qsize_t i_reserved_quota; > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 2/8] ext4: remove i_alloc_sem abuse
Add a new rw_semaphore to protect page_mkwrite against truncate. Previous i_alloc_sem was abused for this, but it's going away in this series. Signed-off-by: Christoph Hellwig Index: linux-2.6/fs/ext4/inode.c === --- linux-2.6.orig/fs/ext4/inode.c 2011-06-20 14:25:33.779248128 +0200 +++ linux-2.6/fs/ext4/inode.c 2011-06-20 14:27:53.025907745 +0200 @@ -5357,6 +5357,7 @@ int ext4_setattr(struct dentry *dentry, if (attr->ia_size > sbi->s_bitmap_maxbytes) return -EFBIG; } + down_write(&(EXT4_I(inode)->truncate_lock)); } if (S_ISREG(inode->i_mode) && @@ -5405,6 +5406,9 @@ int ext4_setattr(struct dentry *dentry, ext4_truncate(inode); } + if (attr->ia_valid & ATTR_SIZE) + up_write(&(EXT4_I(inode)->truncate_lock)); + if (!rc) { setattr_copy(inode, attr); mark_inode_dirty(inode); @@ -5850,10 +5854,10 @@ int ext4_page_mkwrite(struct vm_area_str struct address_space *mapping = inode->i_mapping; /* -* Get i_alloc_sem to stop truncates messing with the inode. We cannot -* get i_mutex because we are already holding mmap_sem. +* Get truncate_lock to stop truncates messing with the inode. We +* cannot get i_mutex because we are already holding mmap_sem. */ - down_read(&inode->i_alloc_sem); + down_read(&(EXT4_I(inode)->truncate_lock)); size = i_size_read(inode); if (page->mapping != mapping || size <= page_offset(page) || !PageUptodate(page)) { @@ -5865,7 +5869,7 @@ int ext4_page_mkwrite(struct vm_area_str lock_page(page); wait_on_page_writeback(page); if (PageMappedToDisk(page)) { - up_read(&inode->i_alloc_sem); + up_read(&(EXT4_I(inode)->truncate_lock)); return VM_FAULT_LOCKED; } @@ -5883,7 +5887,7 @@ int ext4_page_mkwrite(struct vm_area_str if (page_has_buffers(page)) { if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL, ext4_bh_unmapped)) { - up_read(&inode->i_alloc_sem); + up_read(&(EXT4_I(inode)->truncate_lock)); return VM_FAULT_LOCKED; } } @@ -5912,11 +5916,11 @@ int ext4_page_mkwrite(struct vm_area_str */ lock_page(page); wait_on_page_writeback(page); - up_read(&inode->i_alloc_sem); + up_read(&(EXT4_I(inode)->truncate_lock)); return VM_FAULT_LOCKED; out_unlock: if (ret) ret = VM_FAULT_SIGBUS; - up_read(&inode->i_alloc_sem); + up_read(&(EXT4_I(inode)->truncate_lock)); return ret; } Index: linux-2.6/fs/ext4/super.c === --- linux-2.6.orig/fs/ext4/super.c 2011-06-20 14:25:33.795914793 +0200 +++ linux-2.6/fs/ext4/super.c 2011-06-20 14:27:06.269243443 +0200 @@ -871,6 +871,7 @@ static struct inode *ext4_alloc_inode(st ei->i_datasync_tid = 0; atomic_set(&ei->i_ioend_count, 0); atomic_set(&ei->i_aiodio_unwritten, 0); + init_rwsem(&ei->truncate_lock); return &ei->vfs_inode; } Index: linux-2.6/fs/ext4/ext4.h === --- linux-2.6.orig/fs/ext4/ext4.h 2011-06-20 14:25:33.752581461 +0200 +++ linux-2.6/fs/ext4/ext4.h2011-06-20 14:27:06.272576777 +0200 @@ -844,6 +844,9 @@ struct ext4_inode_info { /* on-disk additional length */ __u16 i_extra_isize; + /* protect page_mkwrite against truncates */ + struct rw_semaphore truncate_lock; + #ifdef CONFIG_QUOTA /* quota space reservation, managed internally by quota code */ qsize_t i_reserved_quota; -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html