diff options
| -rw-r--r-- | fs/ntfs/ChangeLog | 5 | ||||
| -rw-r--r-- | fs/ntfs/Makefile | 2 | ||||
| -rw-r--r-- | fs/ntfs/attrib.c | 232 | ||||
| -rw-r--r-- | fs/ntfs/attrib.h | 3 |
4 files changed, 209 insertions, 33 deletions
diff --git a/fs/ntfs/ChangeLog b/fs/ntfs/ChangeLog index de58579..85f797a 100644 --- a/fs/ntfs/ChangeLog +++ b/fs/ntfs/ChangeLog @@ -22,6 +22,11 @@ ToDo/Notes: - Enable the code for setting the NT4 compatibility flag when we start making NTFS 1.2 specific modifications. +2.1.25-WIP + + - Change ntfs_map_runlist_nolock() to also take an optional attribute + search context. This allows calling it with the mft record mapped. + 2.1.24 - Lots of bug fixes and support more clean journal states. - Support journals ($LogFile) which have been modified by chkdsk. This diff --git a/fs/ntfs/Makefile b/fs/ntfs/Makefile index 894b2b8..a3ce2c0 100644 --- a/fs/ntfs/Makefile +++ b/fs/ntfs/Makefile @@ -6,7 +6,7 @@ ntfs-objs := aops.o attrib.o collate.o compress.o debug.o dir.o file.o \ index.o inode.o mft.o mst.o namei.o runlist.o super.o sysctl.o \ unistr.o upcase.o -EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.24\" +EXTRA_CFLAGS = -DNTFS_VERSION=\"2.1.25-WIP\" ifeq ($(CONFIG_NTFS_DEBUG),y) EXTRA_CFLAGS += -DDEBUG diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c index 3f9a4ff..b194197 100644 --- a/fs/ntfs/attrib.c +++ b/fs/ntfs/attrib.c @@ -36,9 +36,27 @@ * ntfs_map_runlist_nolock - map (a part of) a runlist of an ntfs inode * @ni: ntfs inode for which to map (part of) a runlist * @vcn: map runlist part containing this vcn + * @ctx: active attribute search context if present or NULL if not * * Map the part of a runlist containing the @vcn of the ntfs inode @ni. * + * If @ctx is specified, it is an active search context of @ni and its base mft + * record. This is needed when ntfs_map_runlist_nolock() encounters unmapped + * runlist fragments and allows their mapping. If you do not have the mft + * record mapped, you can specify @ctx as NULL and ntfs_map_runlist_nolock() + * will perform the necessary mapping and unmapping. + * + * Note, ntfs_map_runlist_nolock() saves the state of @ctx on entry and + * restores it before returning. Thus, @ctx will be left pointing to the same + * attribute on return as on entry. However, the actual pointers in @ctx may + * point to different memory locations on return, so you must remember to reset + * any cached pointers from the @ctx, i.e. after the call to + * ntfs_map_runlist_nolock(), you will probably want to do: + * m = ctx->mrec; + * a = ctx->attr; + * Assuming you cache ctx->attr in a variable @a of type ATTR_RECORD * and that + * you cache ctx->mrec in a variable @m of type MFT_RECORD *. + * * Return 0 on success and -errno on error. There is one special error code * which is not an error as such. This is -ENOENT. It means that @vcn is out * of bounds of the runlist. @@ -46,19 +64,32 @@ * Note the runlist can be NULL after this function returns if @vcn is zero and * the attribute has zero allocated size, i.e. there simply is no runlist. * - * Locking: - The runlist must be locked for writing. - * - This function modifies the runlist. + * WARNING: If @ctx is supplied, regardless of whether success or failure is + * returned, you need to check IS_ERR(@ctx->mrec) and if TRUE the @ctx + * is no longer valid, i.e. you need to either call + * ntfs_attr_reinit_search_ctx() or ntfs_attr_put_search_ctx() on it. + * In that case PTR_ERR(@ctx->mrec) will give you the error code for + * why the mapping of the old inode failed. + * + * Locking: - The runlist described by @ni must be locked for writing on entry + * and is locked on return. Note the runlist will be modified. + * - If @ctx is NULL, the base mft record of @ni must not be mapped on + * entry and it will be left unmapped on return. + * - If @ctx is not NULL, the base mft record must be mapped on entry + * and it will be left mapped on return. */ -int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn) +int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn, ntfs_attr_search_ctx *ctx) { VCN end_vcn; + unsigned long flags; ntfs_inode *base_ni; MFT_RECORD *m; ATTR_RECORD *a; - ntfs_attr_search_ctx *ctx; runlist_element *rl; - unsigned long flags; + struct page *put_this_page = NULL; int err = 0; + BOOL ctx_is_temporary, ctx_needs_reset; + ntfs_attr_search_ctx old_ctx; ntfs_debug("Mapping runlist part containing vcn 0x%llx.", (unsigned long long)vcn); @@ -66,20 +97,77 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn) base_ni = ni; else base_ni = ni->ext.base_ntfs_ino; - m = map_mft_record(base_ni); - if (IS_ERR(m)) - return PTR_ERR(m); - ctx = ntfs_attr_get_search_ctx(base_ni, m); - if (unlikely(!ctx)) { - err = -ENOMEM; - goto err_out; + if (!ctx) { + ctx_is_temporary = ctx_needs_reset = TRUE; + m = map_mft_record(base_ni); + if (IS_ERR(m)) + return PTR_ERR(m); + ctx = ntfs_attr_get_search_ctx(base_ni, m); + if (unlikely(!ctx)) { + err = -ENOMEM; + goto err_out; + } + } else { + VCN allocated_size_vcn; + + BUG_ON(IS_ERR(ctx->mrec)); + a = ctx->attr; + BUG_ON(!a->non_resident); + ctx_is_temporary = FALSE; + end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn); + read_lock_irqsave(&ni->size_lock, flags); + allocated_size_vcn = ni->allocated_size >> + ni->vol->cluster_size_bits; + read_unlock_irqrestore(&ni->size_lock, flags); + if (!a->data.non_resident.lowest_vcn && end_vcn <= 0) + end_vcn = allocated_size_vcn - 1; + /* + * If we already have the attribute extent containing @vcn in + * @ctx, no need to look it up again. We slightly cheat in + * that if vcn exceeds the allocated size, we will refuse to + * map the runlist below, so there is definitely no need to get + * the right attribute extent. + */ + if (vcn >= allocated_size_vcn || (a->type == ni->type && + a->name_length == ni->name_len && + !memcmp((u8*)a + le16_to_cpu(a->name_offset), + ni->name, ni->name_len) && + sle64_to_cpu(a->data.non_resident.lowest_vcn) + <= vcn && end_vcn >= vcn)) + ctx_needs_reset = FALSE; + else { + /* Save the old search context. */ + old_ctx = *ctx; + /* + * If the currently mapped (extent) inode is not the + * base inode we will unmap it when we reinitialize the + * search context which means we need to get a + * reference to the page containing the mapped mft + * record so we do not accidentally drop changes to the + * mft record when it has not been marked dirty yet. + */ + if (old_ctx.base_ntfs_ino && old_ctx.ntfs_ino != + old_ctx.base_ntfs_ino) { + put_this_page = old_ctx.ntfs_ino->page; + page_cache_get(put_this_page); + } + /* + * Reinitialize the search context so we can lookup the + * needed attribute extent. + */ + ntfs_attr_reinit_search_ctx(ctx); + ctx_needs_reset = TRUE; + } } - err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, - CASE_SENSITIVE, vcn, NULL, 0, ctx); - if (unlikely(err)) { - if (err == -ENOENT) - err = -EIO; - goto err_out; + if (ctx_needs_reset) { + err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, + CASE_SENSITIVE, vcn, NULL, 0, ctx); + if (unlikely(err)) { + if (err == -ENOENT) + err = -EIO; + goto err_out; + } + BUG_ON(!ctx->attr->non_resident); } a = ctx->attr; /* @@ -89,11 +177,9 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn) * ntfs_mapping_pairs_decompress() fails. */ end_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn) + 1; - if (unlikely(!a->data.non_resident.lowest_vcn && end_vcn <= 1)) { - read_lock_irqsave(&ni->size_lock, flags); - end_vcn = ni->allocated_size >> ni->vol->cluster_size_bits; - read_unlock_irqrestore(&ni->size_lock, flags); - } + if (!a->data.non_resident.lowest_vcn && end_vcn == 1) + end_vcn = sle64_to_cpu(a->data.non_resident.allocated_size) >> + ni->vol->cluster_size_bits; if (unlikely(vcn >= end_vcn)) { err = -ENOENT; goto err_out; @@ -104,9 +190,93 @@ int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn) else ni->runlist.rl = rl; err_out: - if (likely(ctx)) - ntfs_attr_put_search_ctx(ctx); - unmap_mft_record(base_ni); + if (ctx_is_temporary) { + if (likely(ctx)) + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(base_ni); + } else if (ctx_needs_reset) { + /* + * If there is no attribute list, restoring the search context + * is acomplished simply by copying the saved context back over + * the caller supplied context. If there is an attribute list, + * things are more complicated as we need to deal with mapping + * of mft records and resulting potential changes in pointers. + */ + if (NInoAttrList(base_ni)) { + /* + * If the currently mapped (extent) inode is not the + * one we had before, we need to unmap it and map the + * old one. + */ + if (ctx->ntfs_ino != old_ctx.ntfs_ino) { + /* + * If the currently mapped inode is not the + * base inode, unmap it. + */ + if (ctx->base_ntfs_ino && ctx->ntfs_ino != + ctx->base_ntfs_ino) { + unmap_extent_mft_record(ctx->ntfs_ino); + ctx->mrec = ctx->base_mrec; + BUG_ON(!ctx->mrec); + } + /* + * If the old mapped inode is not the base + * inode, map it. + */ + if (old_ctx.base_ntfs_ino && + old_ctx.ntfs_ino != + old_ctx.base_ntfs_ino) { +retry_map: + ctx->mrec = map_mft_record( + old_ctx.ntfs_ino); + /* + * Something bad has happened. If out + * of memory retry till it succeeds. + * Any other errors are fatal and we + * return the error code in ctx->mrec. + * Let the caller deal with it... We + * just need to fudge things so the + * caller can reinit and/or put the + * search context safely. + */ + if (IS_ERR(ctx->mrec)) { + if (PTR_ERR(ctx->mrec) == + -ENOMEM) { + schedule(); + goto retry_map; + } else + old_ctx.ntfs_ino = + old_ctx. + base_ntfs_ino; + } + } + } + /* Update the changed pointers in the saved context. */ + if (ctx->mrec != old_ctx.mrec) { + if (!IS_ERR(ctx->mrec)) + old_ctx.attr = (ATTR_RECORD*)( + (u8*)ctx->mrec + + ((u8*)old_ctx.attr - + (u8*)old_ctx.mrec)); + old_ctx.mrec = ctx->mrec; + } + } + /* Restore the search context to the saved one. */ + *ctx = old_ctx; + /* + * We drop the reference on the page we took earlier. In the + * case that IS_ERR(ctx->mrec) is true this means we might lose + * some changes to the mft record that had been made between + * the last time it was marked dirty/written out and now. This + * at this stage is not a problem as the mapping error is fatal + * enough that the mft record cannot be written out anyway and + * the caller is very likely to shutdown the whole inode + * immediately and mark the volume dirty for chkdsk to pick up + * the pieces anyway. + */ + if (put_this_page) + page_cache_release(put_this_page); + } return err; } @@ -122,8 +292,8 @@ err_out: * of bounds of the runlist. * * Locking: - The runlist must be unlocked on entry and is unlocked on return. - * - This function takes the runlist lock for writing and modifies the - * runlist. + * - This function takes the runlist lock for writing and may modify + * the runlist. */ int ntfs_map_runlist(ntfs_inode *ni, VCN vcn) { @@ -133,7 +303,7 @@ int ntfs_map_runlist(ntfs_inode *ni, VCN vcn) /* Make sure someone else didn't do the work while we were sleeping. */ if (likely(ntfs_rl_vcn_to_lcn(ni->runlist.rl, vcn) <= LCN_RL_NOT_MAPPED)) - err = ntfs_map_runlist_nolock(ni, vcn); + err = ntfs_map_runlist_nolock(ni, vcn, NULL); up_write(&ni->runlist.lock); return err; } @@ -212,7 +382,7 @@ retry_remap: goto retry_remap; } } - err = ntfs_map_runlist_nolock(ni, vcn); + err = ntfs_map_runlist_nolock(ni, vcn, NULL); if (!write_locked) { up_write(&ni->runlist.lock); down_read(&ni->runlist.lock); @@ -325,7 +495,7 @@ retry_remap: goto retry_remap; } } - err = ntfs_map_runlist_nolock(ni, vcn); + err = ntfs_map_runlist_nolock(ni, vcn, NULL); if (!write_locked) { up_write(&ni->runlist.lock); down_read(&ni->runlist.lock); diff --git a/fs/ntfs/attrib.h b/fs/ntfs/attrib.h index 0618ed6..eeca8e5 100644 --- a/fs/ntfs/attrib.h +++ b/fs/ntfs/attrib.h @@ -60,7 +60,8 @@ typedef struct { ATTR_RECORD *base_attr; } ntfs_attr_search_ctx; -extern int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn); +extern int ntfs_map_runlist_nolock(ntfs_inode *ni, VCN vcn, + ntfs_attr_search_ctx *ctx); extern int ntfs_map_runlist(ntfs_inode *ni, VCN vcn); extern LCN ntfs_attr_vcn_to_lcn_nolock(ntfs_inode *ni, const VCN vcn, |