From 905685f68fc72844b8c2689c39a5c6c35e840152 Mon Sep 17 00:00:00 2001 From: Anton Altaparmakov Date: Thu, 10 Mar 2005 11:06:19 +0000 Subject: [PATCH] NTFS: - Modify ->readpage and ->writepage (fs/ntfs/aops.c) so they detect and handle the case where an attribute is converted from resident to non-resident by a concurrent file write. - Reorder some operations when converting an attribute from resident to non-resident (fs/ntfs/attrib.c) so it is safe wrt concurrent ->readpage and ->writepage. Signed-off-by: Anton Altaparmakov --- fs/ntfs/ChangeLog | 3 +++ fs/ntfs/aops.c | 18 ++++++++++++++++++ fs/ntfs/attrib.c | 41 +++++++++++++++++++++++++---------------- 3 files changed, 46 insertions(+), 16 deletions(-) diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog index e0b4adf5adce..b29e0618f358 100644 --- a/fs/ntfs/ChangeLog +++ b/fs/ntfs/ChangeLog @@ -100,6 +100,9 @@ ToDo/Notes: - Add fs/ntfs/attrib.[hc]::ntfs_attr_make_non_resident(). - Fix sign of various error return values to be negative in fs/ntfs/lcnalloc.c. + - Modify ->readpage and ->writepage (fs/ntfs/aops.c) so they detect and + handle the case where an attribute is converted from resident to + non-resident by a concurrent file write. 2.1.22 - Many bug and race fixes and error handling improvements. diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c index 2a7cba258cca..6241c4cfbe28 100644 --- a/fs/ntfs/aops.c +++ b/fs/ntfs/aops.c @@ -355,6 +355,7 @@ static int ntfs_readpage(struct file *file, struct page *page) u32 attr_len; int err = 0; +retry_readpage: BUG_ON(!PageLocked(page)); /* * This can potentially happen because we clear PageUptodate() during @@ -408,6 +409,14 @@ static int ntfs_readpage(struct file *file, struct page *page) err = PTR_ERR(mrec); goto err_out; } + /* + * If a parallel write made the attribute non-resident, drop the mft + * record and retry the readpage. + */ + if (unlikely(NInoNonResident(ni))) { + unmap_mft_record(base_ni); + goto retry_readpage; + } ctx = ntfs_attr_get_search_ctx(base_ni, mrec); if (unlikely(!ctx)) { err = -ENOMEM; @@ -1248,6 +1257,7 @@ static int ntfs_writepage(struct page *page, struct writeback_control *wbc) u32 attr_len; int err; +retry_writepage: BUG_ON(!PageLocked(page)); i_size = i_size_read(vi); /* Is the page fully outside i_size? (truncate in progress) */ @@ -1338,6 +1348,14 @@ static int ntfs_writepage(struct page *page, struct writeback_control *wbc) ctx = NULL; goto err_out; } + /* + * If a parallel write made the attribute non-resident, drop the mft + * record and retry the writepage. + */ + if (unlikely(NInoNonResident(ni))) { + unmap_mft_record(base_ni); + goto retry_writepage; + } ctx = ntfs_attr_get_search_ctx(base_ni, m); if (unlikely(!ctx)) { err = -ENOMEM; diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c index 3b9de4040216..41859343a0c8 100644 --- a/fs/ntfs/attrib.c +++ b/fs/ntfs/attrib.c @@ -1376,19 +1376,6 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni) err = ntfs_attr_record_resize(m, a, arec_size); if (unlikely(err)) goto err_out; - /* Setup the in-memory attribute structure to be non-resident. */ - NInoSetNonResident(ni); - ni->runlist.rl = rl; - write_lock_irqsave(&ni->size_lock, flags); - ni->allocated_size = new_size; - write_unlock_irqrestore(&ni->size_lock, flags); - /* - * FIXME: For now just clear all of these as we do not support them - * when writing. - */ - NInoClearCompressed(ni); - NInoClearSparse(ni); - NInoClearEncrypted(ni); /* * Convert the resident part of the attribute record to describe a * non-resident attribute. @@ -1399,7 +1386,10 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni) memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset), a->name_length * sizeof(ntfschar)); a->name_offset = cpu_to_le16(name_ofs); - /* Update the flags to match the in-memory ones. */ + /* + * FIXME: For now just clear all of these as we do not support them + * when writing. + */ a->flags &= cpu_to_le16(0xffff & ~le16_to_cpu(ATTR_IS_SPARSE | ATTR_IS_ENCRYPTED | ATTR_COMPRESSION_MASK)); /* Setup the fields specific to non-resident attributes. */ @@ -1422,6 +1412,25 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni) err); goto undo_err_out; } + /* Setup the in-memory attribute structure to be non-resident. */ + /* + * FIXME: For now just clear all of these as we do not support them + * when writing. + */ + NInoClearSparse(ni); + NInoClearEncrypted(ni); + NInoClearCompressed(ni); + ni->runlist.rl = rl; + write_lock_irqsave(&ni->size_lock, flags); + ni->allocated_size = new_size; + write_unlock_irqrestore(&ni->size_lock, flags); + /* + * This needs to be last since the address space operations ->readpage + * and ->writepage can run concurrently with us as they are not + * serialized on i_sem. Note, we are not allowed to fail once we flip + * this switch, which is another reason to do this last. + */ + NInoSetNonResident(ni); /* Mark the mft record dirty, so it gets written back. */ flush_dcache_mft_record_page(ctx->ntfs_ino); mark_mft_record_dirty(ctx->ntfs_ino); @@ -1431,6 +1440,7 @@ int ntfs_attr_make_non_resident(ntfs_inode *ni) if (page) { set_page_dirty(page); unlock_page(page); + mark_page_accessed(page); page_cache_release(page); } ntfs_debug("Done."); @@ -1492,11 +1502,10 @@ undo_err_out: memcpy((u8*)a + mp_ofs, kaddr, attr_size); kunmap_atomic(kaddr, KM_USER0); } - /* Finally setup the ntfs inode appropriately. */ + /* Setup the allocated size in the ntfs inode in case it changed. */ write_lock_irqsave(&ni->size_lock, flags); ni->allocated_size = arec_size - mp_ofs; write_unlock_irqrestore(&ni->size_lock, flags); - NInoClearNonResident(ni); /* Mark the mft record dirty, so it gets written back. */ flush_dcache_mft_record_page(ctx->ntfs_ino); mark_mft_record_dirty(ctx->ntfs_ino); -- 2.20.1