diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_attr.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_attr.c | 1600 |
1 files changed, 1600 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c new file mode 100644 index 0000000000..e28d93d232 --- /dev/null +++ b/fs/xfs/libxfs/xfs_attr.c @@ -0,0 +1,1600 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2000-2005 Silicon Graphics, Inc. + * All Rights Reserved. + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_log_format.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.h" +#include "xfs_defer.h" +#include "xfs_da_format.h" +#include "xfs_da_btree.h" +#include "xfs_attr_sf.h" +#include "xfs_inode.h" +#include "xfs_trans.h" +#include "xfs_bmap.h" +#include "xfs_bmap_btree.h" +#include "xfs_attr.h" +#include "xfs_attr_leaf.h" +#include "xfs_attr_remote.h" +#include "xfs_quota.h" +#include "xfs_trans_space.h" +#include "xfs_trace.h" +#include "xfs_attr_item.h" +#include "xfs_xattr.h" + +struct kmem_cache *xfs_attr_intent_cache; + +/* + * xfs_attr.c + * + * Provide the external interfaces to manage attribute lists. + */ + +/*======================================================================== + * Function prototypes for the kernel. + *========================================================================*/ + +/* + * Internal routines when attribute list fits inside the inode. + */ +STATIC int xfs_attr_shortform_addname(xfs_da_args_t *args); + +/* + * Internal routines when attribute list is one block. + */ +STATIC int xfs_attr_leaf_get(xfs_da_args_t *args); +STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args); +STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp); +STATIC int xfs_attr_leaf_try_add(struct xfs_da_args *args); + +/* + * Internal routines when attribute list is more than one block. + */ +STATIC int xfs_attr_node_get(xfs_da_args_t *args); +STATIC void xfs_attr_restore_rmt_blk(struct xfs_da_args *args); +static int xfs_attr_node_try_addname(struct xfs_attr_intent *attr); +STATIC int xfs_attr_node_addname_find_attr(struct xfs_attr_intent *attr); +STATIC int xfs_attr_node_remove_attr(struct xfs_attr_intent *attr); +STATIC int xfs_attr_node_lookup(struct xfs_da_args *args, + struct xfs_da_state *state); + +int +xfs_inode_hasattr( + struct xfs_inode *ip) +{ + if (!xfs_inode_has_attr_fork(ip)) + return 0; + if (ip->i_af.if_format == XFS_DINODE_FMT_EXTENTS && + ip->i_af.if_nextents == 0) + return 0; + return 1; +} + +/* + * Returns true if the there is exactly only block in the attr fork, in which + * case the attribute fork consists of a single leaf block entry. + */ +bool +xfs_attr_is_leaf( + struct xfs_inode *ip) +{ + struct xfs_ifork *ifp = &ip->i_af; + struct xfs_iext_cursor icur; + struct xfs_bmbt_irec imap; + + if (ifp->if_nextents != 1 || ifp->if_format != XFS_DINODE_FMT_EXTENTS) + return false; + + xfs_iext_first(ifp, &icur); + xfs_iext_get_extent(ifp, &icur, &imap); + return imap.br_startoff == 0 && imap.br_blockcount == 1; +} + +/* + * XXX (dchinner): name path state saving and refilling is an optimisation to + * avoid needing to look up name entries after rolling transactions removing + * remote xattr blocks between the name entry lookup and name entry removal. + * This optimisation got sidelined when combining the set and remove state + * machines, but the code has been left in place because it is worthwhile to + * restore the optimisation once the combined state machine paths have settled. + * + * This comment is a public service announcement to remind Future Dave that he + * still needs to restore this code to working order. + */ +#if 0 +/* + * Fill in the disk block numbers in the state structure for the buffers + * that are attached to the state structure. + * This is done so that we can quickly reattach ourselves to those buffers + * after some set of transaction commits have released these buffers. + */ +static int +xfs_attr_fillstate(xfs_da_state_t *state) +{ + xfs_da_state_path_t *path; + xfs_da_state_blk_t *blk; + int level; + + trace_xfs_attr_fillstate(state->args); + + /* + * Roll down the "path" in the state structure, storing the on-disk + * block number for those buffers in the "path". + */ + path = &state->path; + ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH)); + for (blk = path->blk, level = 0; level < path->active; blk++, level++) { + if (blk->bp) { + blk->disk_blkno = xfs_buf_daddr(blk->bp); + blk->bp = NULL; + } else { + blk->disk_blkno = 0; + } + } + + /* + * Roll down the "altpath" in the state structure, storing the on-disk + * block number for those buffers in the "altpath". + */ + path = &state->altpath; + ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH)); + for (blk = path->blk, level = 0; level < path->active; blk++, level++) { + if (blk->bp) { + blk->disk_blkno = xfs_buf_daddr(blk->bp); + blk->bp = NULL; + } else { + blk->disk_blkno = 0; + } + } + + return 0; +} + +/* + * Reattach the buffers to the state structure based on the disk block + * numbers stored in the state structure. + * This is done after some set of transaction commits have released those + * buffers from our grip. + */ +static int +xfs_attr_refillstate(xfs_da_state_t *state) +{ + xfs_da_state_path_t *path; + xfs_da_state_blk_t *blk; + int level, error; + + trace_xfs_attr_refillstate(state->args); + + /* + * Roll down the "path" in the state structure, storing the on-disk + * block number for those buffers in the "path". + */ + path = &state->path; + ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH)); + for (blk = path->blk, level = 0; level < path->active; blk++, level++) { + if (blk->disk_blkno) { + error = xfs_da3_node_read_mapped(state->args->trans, + state->args->dp, blk->disk_blkno, + &blk->bp, XFS_ATTR_FORK); + if (error) + return error; + } else { + blk->bp = NULL; + } + } + + /* + * Roll down the "altpath" in the state structure, storing the on-disk + * block number for those buffers in the "altpath". + */ + path = &state->altpath; + ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH)); + for (blk = path->blk, level = 0; level < path->active; blk++, level++) { + if (blk->disk_blkno) { + error = xfs_da3_node_read_mapped(state->args->trans, + state->args->dp, blk->disk_blkno, + &blk->bp, XFS_ATTR_FORK); + if (error) + return error; + } else { + blk->bp = NULL; + } + } + + return 0; +} +#else +static int xfs_attr_fillstate(xfs_da_state_t *state) { return 0; } +#endif + +/*======================================================================== + * Overall external interface routines. + *========================================================================*/ + +/* + * Retrieve an extended attribute and its value. Must have ilock. + * Returns 0 on successful retrieval, otherwise an error. + */ +int +xfs_attr_get_ilocked( + struct xfs_da_args *args) +{ + ASSERT(xfs_isilocked(args->dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); + + if (!xfs_inode_hasattr(args->dp)) + return -ENOATTR; + + if (args->dp->i_af.if_format == XFS_DINODE_FMT_LOCAL) + return xfs_attr_shortform_getvalue(args); + if (xfs_attr_is_leaf(args->dp)) + return xfs_attr_leaf_get(args); + return xfs_attr_node_get(args); +} + +/* + * Retrieve an extended attribute by name, and its value if requested. + * + * If args->valuelen is zero, then the caller does not want the value, just an + * indication whether the attribute exists and the size of the value if it + * exists. The size is returned in args.valuelen. + * + * If args->value is NULL but args->valuelen is non-zero, allocate the buffer + * for the value after existence of the attribute has been determined. The + * caller always has to free args->value if it is set, no matter if this + * function was successful or not. + * + * If the attribute is found, but exceeds the size limit set by the caller in + * args->valuelen, return -ERANGE with the size of the attribute that was found + * in args->valuelen. + */ +int +xfs_attr_get( + struct xfs_da_args *args) +{ + uint lock_mode; + int error; + + XFS_STATS_INC(args->dp->i_mount, xs_attr_get); + + if (xfs_is_shutdown(args->dp->i_mount)) + return -EIO; + + args->geo = args->dp->i_mount->m_attr_geo; + args->whichfork = XFS_ATTR_FORK; + args->hashval = xfs_da_hashname(args->name, args->namelen); + + /* Entirely possible to look up a name which doesn't exist */ + args->op_flags = XFS_DA_OP_OKNOENT; + + lock_mode = xfs_ilock_attr_map_shared(args->dp); + error = xfs_attr_get_ilocked(args); + xfs_iunlock(args->dp, lock_mode); + + return error; +} + +/* + * Calculate how many blocks we need for the new attribute, + */ +int +xfs_attr_calc_size( + struct xfs_da_args *args, + int *local) +{ + struct xfs_mount *mp = args->dp->i_mount; + int size; + int nblks; + + /* + * Determine space new attribute will use, and if it would be + * "local" or "remote" (note: local != inline). + */ + size = xfs_attr_leaf_newentsize(args, local); + nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK); + if (*local) { + if (size > (args->geo->blksize / 2)) { + /* Double split possible */ + nblks *= 2; + } + } else { + /* + * Out of line attribute, cannot double split, but + * make room for the attribute value itself. + */ + uint dblocks = xfs_attr3_rmt_blocks(mp, args->valuelen); + nblks += dblocks; + nblks += XFS_NEXTENTADD_SPACE_RES(mp, dblocks, XFS_ATTR_FORK); + } + + return nblks; +} + +/* Initialize transaction reservation for attr operations */ +void +xfs_init_attr_trans( + struct xfs_da_args *args, + struct xfs_trans_res *tres, + unsigned int *total) +{ + struct xfs_mount *mp = args->dp->i_mount; + + if (args->value) { + tres->tr_logres = M_RES(mp)->tr_attrsetm.tr_logres + + M_RES(mp)->tr_attrsetrt.tr_logres * + args->total; + tres->tr_logcount = XFS_ATTRSET_LOG_COUNT; + tres->tr_logflags = XFS_TRANS_PERM_LOG_RES; + *total = args->total; + } else { + *tres = M_RES(mp)->tr_attrrm; + *total = XFS_ATTRRM_SPACE_RES(mp); + } +} + +/* + * Add an attr to a shortform fork. If there is no space, + * xfs_attr_shortform_addname() will convert to leaf format and return -ENOSPC. + * to use. + */ +STATIC int +xfs_attr_try_sf_addname( + struct xfs_inode *dp, + struct xfs_da_args *args) +{ + + int error; + + /* + * Build initial attribute list (if required). + */ + if (dp->i_af.if_format == XFS_DINODE_FMT_EXTENTS) + xfs_attr_shortform_create(args); + + error = xfs_attr_shortform_addname(args); + if (error == -ENOSPC) + return error; + + /* + * Commit the shortform mods, and we're done. + * NOTE: this is also the error path (EEXIST, etc). + */ + if (!error && !(args->op_flags & XFS_DA_OP_NOTIME)) + xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG); + + if (xfs_has_wsync(dp->i_mount)) + xfs_trans_set_sync(args->trans); + + return error; +} + +static int +xfs_attr_sf_addname( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + struct xfs_inode *dp = args->dp; + int error = 0; + + error = xfs_attr_try_sf_addname(dp, args); + if (error != -ENOSPC) { + ASSERT(!error || error == -EEXIST); + attr->xattri_dela_state = XFS_DAS_DONE; + goto out; + } + + /* + * It won't fit in the shortform, transform to a leaf block. GROT: + * another possible req'mt for a double-split btree op. + */ + error = xfs_attr_shortform_to_leaf(args); + if (error) + return error; + + attr->xattri_dela_state = XFS_DAS_LEAF_ADD; +out: + trace_xfs_attr_sf_addname_return(attr->xattri_dela_state, args->dp); + return error; +} + +/* + * Handle the state change on completion of a multi-state attr operation. + * + * If the XFS_DA_OP_REPLACE flag is set, this means the operation was the first + * modification in a attr replace operation and we still have to do the second + * state, indicated by @replace_state. + * + * We consume the XFS_DA_OP_REPLACE flag so that when we are called again on + * completion of the second half of the attr replace operation we correctly + * signal that it is done. + */ +static enum xfs_delattr_state +xfs_attr_complete_op( + struct xfs_attr_intent *attr, + enum xfs_delattr_state replace_state) +{ + struct xfs_da_args *args = attr->xattri_da_args; + bool do_replace = args->op_flags & XFS_DA_OP_REPLACE; + + args->op_flags &= ~XFS_DA_OP_REPLACE; + if (do_replace) { + args->attr_filter &= ~XFS_ATTR_INCOMPLETE; + return replace_state; + } + return XFS_DAS_DONE; +} + +static int +xfs_attr_leaf_addname( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + int error; + + ASSERT(xfs_attr_is_leaf(args->dp)); + + /* + * Use the leaf buffer we may already hold locked as a result of + * a sf-to-leaf conversion. + */ + error = xfs_attr_leaf_try_add(args); + + if (error == -ENOSPC) { + error = xfs_attr3_leaf_to_node(args); + if (error) + return error; + + /* + * We're not in leaf format anymore, so roll the transaction and + * retry the add to the newly allocated node block. + */ + attr->xattri_dela_state = XFS_DAS_NODE_ADD; + goto out; + } + if (error) + return error; + + /* + * We need to commit and roll if we need to allocate remote xattr blocks + * or perform more xattr manipulations. Otherwise there is nothing more + * to do and we can return success. + */ + if (args->rmtblkno) + attr->xattri_dela_state = XFS_DAS_LEAF_SET_RMT; + else + attr->xattri_dela_state = xfs_attr_complete_op(attr, + XFS_DAS_LEAF_REPLACE); +out: + trace_xfs_attr_leaf_addname_return(attr->xattri_dela_state, args->dp); + return error; +} + +/* + * Add an entry to a node format attr tree. + * + * Note that we might still have a leaf here - xfs_attr_is_leaf() cannot tell + * the difference between leaf + remote attr blocks and a node format tree, + * so we may still end up having to convert from leaf to node format here. + */ +static int +xfs_attr_node_addname( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + int error; + + error = xfs_attr_node_addname_find_attr(attr); + if (error) + return error; + + error = xfs_attr_node_try_addname(attr); + if (error == -ENOSPC) { + error = xfs_attr3_leaf_to_node(args); + if (error) + return error; + /* + * No state change, we really are in node form now + * but we need the transaction rolled to continue. + */ + goto out; + } + if (error) + return error; + + if (args->rmtblkno) + attr->xattri_dela_state = XFS_DAS_NODE_SET_RMT; + else + attr->xattri_dela_state = xfs_attr_complete_op(attr, + XFS_DAS_NODE_REPLACE); +out: + trace_xfs_attr_node_addname_return(attr->xattri_dela_state, args->dp); + return error; +} + +static int +xfs_attr_rmtval_alloc( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + int error = 0; + + /* + * If there was an out-of-line value, allocate the blocks we + * identified for its storage and copy the value. This is done + * after we create the attribute so that we don't overflow the + * maximum size of a transaction and/or hit a deadlock. + */ + if (attr->xattri_blkcnt > 0) { + error = xfs_attr_rmtval_set_blk(attr); + if (error) + return error; + /* Roll the transaction only if there is more to allocate. */ + if (attr->xattri_blkcnt > 0) + goto out; + } + + error = xfs_attr_rmtval_set_value(args); + if (error) + return error; + + attr->xattri_dela_state = xfs_attr_complete_op(attr, + ++attr->xattri_dela_state); + /* + * If we are not doing a rename, we've finished the operation but still + * have to clear the incomplete flag protecting the new attr from + * exposing partially initialised state if we crash during creation. + */ + if (attr->xattri_dela_state == XFS_DAS_DONE) + error = xfs_attr3_leaf_clearflag(args); +out: + trace_xfs_attr_rmtval_alloc(attr->xattri_dela_state, args->dp); + return error; +} + +/* + * Mark an attribute entry INCOMPLETE and save pointers to the relevant buffers + * for later deletion of the entry. + */ +static int +xfs_attr_leaf_mark_incomplete( + struct xfs_da_args *args, + struct xfs_da_state *state) +{ + int error; + + /* + * Fill in disk block numbers in the state structure + * so that we can get the buffers back after we commit + * several transactions in the following calls. + */ + error = xfs_attr_fillstate(state); + if (error) + return error; + + /* + * Mark the attribute as INCOMPLETE + */ + return xfs_attr3_leaf_setflag(args); +} + +/* Ensure the da state of an xattr deferred work item is ready to go. */ +static inline void +xfs_attr_item_init_da_state( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + + if (!attr->xattri_da_state) + attr->xattri_da_state = xfs_da_state_alloc(args); + else + xfs_da_state_reset(attr->xattri_da_state, args); +} + +/* + * Initial setup for xfs_attr_node_removename. Make sure the attr is there and + * the blocks are valid. Attr keys with remote blocks will be marked + * incomplete. + */ +static +int xfs_attr_node_removename_setup( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + struct xfs_da_state *state; + int error; + + xfs_attr_item_init_da_state(attr); + error = xfs_attr_node_lookup(args, attr->xattri_da_state); + if (error != -EEXIST) + goto out; + error = 0; + + state = attr->xattri_da_state; + ASSERT(state->path.blk[state->path.active - 1].bp != NULL); + ASSERT(state->path.blk[state->path.active - 1].magic == + XFS_ATTR_LEAF_MAGIC); + + error = xfs_attr_leaf_mark_incomplete(args, state); + if (error) + goto out; + if (args->rmtblkno > 0) + error = xfs_attr_rmtval_invalidate(args); +out: + if (error) { + xfs_da_state_free(attr->xattri_da_state); + attr->xattri_da_state = NULL; + } + + return error; +} + +/* + * Remove the original attr we have just replaced. This is dependent on the + * original lookup and insert placing the old attr in args->blkno/args->index + * and the new attr in args->blkno2/args->index2. + */ +static int +xfs_attr_leaf_remove_attr( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + struct xfs_inode *dp = args->dp; + struct xfs_buf *bp = NULL; + int forkoff; + int error; + + error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, + &bp); + if (error) + return error; + + xfs_attr3_leaf_remove(bp, args); + + forkoff = xfs_attr_shortform_allfit(bp, dp); + if (forkoff) + error = xfs_attr3_leaf_to_shortform(bp, args, forkoff); + /* bp is gone due to xfs_da_shrink_inode */ + + return error; +} + +/* + * Shrink an attribute from leaf to shortform. Used by the node format remove + * path when the node format collapses to a single block and so we have to check + * if it can be collapsed further. + */ +static int +xfs_attr_leaf_shrink( + struct xfs_da_args *args) +{ + struct xfs_inode *dp = args->dp; + struct xfs_buf *bp; + int forkoff; + int error; + + if (!xfs_attr_is_leaf(dp)) + return 0; + + error = xfs_attr3_leaf_read(args->trans, args->dp, 0, &bp); + if (error) + return error; + + forkoff = xfs_attr_shortform_allfit(bp, dp); + if (forkoff) { + error = xfs_attr3_leaf_to_shortform(bp, args, forkoff); + /* bp is gone due to xfs_da_shrink_inode */ + } else { + xfs_trans_brelse(args->trans, bp); + } + + return error; +} + +/* + * Run the attribute operation specified in @attr. + * + * This routine is meant to function as a delayed operation and will set the + * state to XFS_DAS_DONE when the operation is complete. Calling functions will + * need to handle this, and recall the function until either an error or + * XFS_DAS_DONE is detected. + */ +int +xfs_attr_set_iter( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + int error = 0; + + /* State machine switch */ +next_state: + switch (attr->xattri_dela_state) { + case XFS_DAS_UNINIT: + ASSERT(0); + return -EFSCORRUPTED; + case XFS_DAS_SF_ADD: + return xfs_attr_sf_addname(attr); + case XFS_DAS_LEAF_ADD: + return xfs_attr_leaf_addname(attr); + case XFS_DAS_NODE_ADD: + return xfs_attr_node_addname(attr); + + case XFS_DAS_SF_REMOVE: + error = xfs_attr_sf_removename(args); + attr->xattri_dela_state = xfs_attr_complete_op(attr, + xfs_attr_init_add_state(args)); + break; + case XFS_DAS_LEAF_REMOVE: + error = xfs_attr_leaf_removename(args); + attr->xattri_dela_state = xfs_attr_complete_op(attr, + xfs_attr_init_add_state(args)); + break; + case XFS_DAS_NODE_REMOVE: + error = xfs_attr_node_removename_setup(attr); + if (error == -ENOATTR && + (args->op_flags & XFS_DA_OP_RECOVERY)) { + attr->xattri_dela_state = xfs_attr_complete_op(attr, + xfs_attr_init_add_state(args)); + error = 0; + break; + } + if (error) + return error; + attr->xattri_dela_state = XFS_DAS_NODE_REMOVE_RMT; + if (args->rmtblkno == 0) + attr->xattri_dela_state++; + break; + + case XFS_DAS_LEAF_SET_RMT: + case XFS_DAS_NODE_SET_RMT: + error = xfs_attr_rmtval_find_space(attr); + if (error) + return error; + attr->xattri_dela_state++; + fallthrough; + + case XFS_DAS_LEAF_ALLOC_RMT: + case XFS_DAS_NODE_ALLOC_RMT: + error = xfs_attr_rmtval_alloc(attr); + if (error) + return error; + if (attr->xattri_dela_state == XFS_DAS_DONE) + break; + goto next_state; + + case XFS_DAS_LEAF_REPLACE: + case XFS_DAS_NODE_REPLACE: + /* + * We must "flip" the incomplete flags on the "new" and "old" + * attribute/value pairs so that one disappears and one appears + * atomically. + */ + error = xfs_attr3_leaf_flipflags(args); + if (error) + return error; + /* + * We must commit the flag value change now to make it atomic + * and then we can start the next trans in series at REMOVE_OLD. + */ + attr->xattri_dela_state++; + break; + + case XFS_DAS_LEAF_REMOVE_OLD: + case XFS_DAS_NODE_REMOVE_OLD: + /* + * If we have a remote attr, start the process of removing it + * by invalidating any cached buffers. + * + * If we don't have a remote attr, we skip the remote block + * removal state altogether with a second state increment. + */ + xfs_attr_restore_rmt_blk(args); + if (args->rmtblkno) { + error = xfs_attr_rmtval_invalidate(args); + if (error) + return error; + } else { + attr->xattri_dela_state++; + } + + attr->xattri_dela_state++; + goto next_state; + + case XFS_DAS_LEAF_REMOVE_RMT: + case XFS_DAS_NODE_REMOVE_RMT: + error = xfs_attr_rmtval_remove(attr); + if (error == -EAGAIN) { + error = 0; + break; + } + if (error) + return error; + + /* + * We've finished removing the remote attr blocks, so commit the + * transaction and move on to removing the attr name from the + * leaf/node block. Removing the attr might require a full + * transaction reservation for btree block freeing, so we + * can't do that in the same transaction where we removed the + * remote attr blocks. + */ + attr->xattri_dela_state++; + break; + + case XFS_DAS_LEAF_REMOVE_ATTR: + error = xfs_attr_leaf_remove_attr(attr); + attr->xattri_dela_state = xfs_attr_complete_op(attr, + xfs_attr_init_add_state(args)); + break; + + case XFS_DAS_NODE_REMOVE_ATTR: + error = xfs_attr_node_remove_attr(attr); + if (!error) + error = xfs_attr_leaf_shrink(args); + attr->xattri_dela_state = xfs_attr_complete_op(attr, + xfs_attr_init_add_state(args)); + break; + default: + ASSERT(0); + break; + } + + trace_xfs_attr_set_iter_return(attr->xattri_dela_state, args->dp); + return error; +} + + +/* + * Return EEXIST if attr is found, or ENOATTR if not + */ +static int +xfs_attr_lookup( + struct xfs_da_args *args) +{ + struct xfs_inode *dp = args->dp; + struct xfs_buf *bp = NULL; + struct xfs_da_state *state; + int error; + + if (!xfs_inode_hasattr(dp)) + return -ENOATTR; + + if (dp->i_af.if_format == XFS_DINODE_FMT_LOCAL) + return xfs_attr_sf_findname(args, NULL, NULL); + + if (xfs_attr_is_leaf(dp)) { + error = xfs_attr_leaf_hasname(args, &bp); + + if (bp) + xfs_trans_brelse(args->trans, bp); + + return error; + } + + state = xfs_da_state_alloc(args); + error = xfs_attr_node_lookup(args, state); + xfs_da_state_free(state); + return error; +} + +static int +xfs_attr_intent_init( + struct xfs_da_args *args, + unsigned int op_flags, /* op flag (set or remove) */ + struct xfs_attr_intent **attr) /* new xfs_attr_intent */ +{ + + struct xfs_attr_intent *new; + + new = kmem_cache_zalloc(xfs_attr_intent_cache, GFP_NOFS | __GFP_NOFAIL); + new->xattri_op_flags = op_flags; + new->xattri_da_args = args; + + *attr = new; + return 0; +} + +/* Sets an attribute for an inode as a deferred operation */ +static int +xfs_attr_defer_add( + struct xfs_da_args *args) +{ + struct xfs_attr_intent *new; + int error = 0; + + error = xfs_attr_intent_init(args, XFS_ATTRI_OP_FLAGS_SET, &new); + if (error) + return error; + + new->xattri_dela_state = xfs_attr_init_add_state(args); + xfs_defer_add(args->trans, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list); + trace_xfs_attr_defer_add(new->xattri_dela_state, args->dp); + + return 0; +} + +/* Sets an attribute for an inode as a deferred operation */ +static int +xfs_attr_defer_replace( + struct xfs_da_args *args) +{ + struct xfs_attr_intent *new; + int error = 0; + + error = xfs_attr_intent_init(args, XFS_ATTRI_OP_FLAGS_REPLACE, &new); + if (error) + return error; + + new->xattri_dela_state = xfs_attr_init_replace_state(args); + xfs_defer_add(args->trans, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list); + trace_xfs_attr_defer_replace(new->xattri_dela_state, args->dp); + + return 0; +} + +/* Removes an attribute for an inode as a deferred operation */ +static int +xfs_attr_defer_remove( + struct xfs_da_args *args) +{ + + struct xfs_attr_intent *new; + int error; + + error = xfs_attr_intent_init(args, XFS_ATTRI_OP_FLAGS_REMOVE, &new); + if (error) + return error; + + new->xattri_dela_state = xfs_attr_init_remove_state(args); + xfs_defer_add(args->trans, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list); + trace_xfs_attr_defer_remove(new->xattri_dela_state, args->dp); + + return 0; +} + +/* + * Note: If args->value is NULL the attribute will be removed, just like the + * Linux ->setattr API. + */ +int +xfs_attr_set( + struct xfs_da_args *args) +{ + struct xfs_inode *dp = args->dp; + struct xfs_mount *mp = dp->i_mount; + struct xfs_trans_res tres; + bool rsvd = (args->attr_filter & XFS_ATTR_ROOT); + int error, local; + int rmt_blks = 0; + unsigned int total; + + if (xfs_is_shutdown(dp->i_mount)) + return -EIO; + + error = xfs_qm_dqattach(dp); + if (error) + return error; + + args->geo = mp->m_attr_geo; + args->whichfork = XFS_ATTR_FORK; + args->hashval = xfs_da_hashname(args->name, args->namelen); + + /* + * We have no control over the attribute names that userspace passes us + * to remove, so we have to allow the name lookup prior to attribute + * removal to fail as well. Preserve the logged flag, since we need + * to pass that through to the logging code. + */ + args->op_flags = XFS_DA_OP_OKNOENT | + (args->op_flags & XFS_DA_OP_LOGGED); + + if (args->value) { + XFS_STATS_INC(mp, xs_attr_set); + args->total = xfs_attr_calc_size(args, &local); + + /* + * If the inode doesn't have an attribute fork, add one. + * (inode must not be locked when we call this routine) + */ + if (xfs_inode_has_attr_fork(dp) == 0) { + int sf_size = sizeof(struct xfs_attr_sf_hdr) + + xfs_attr_sf_entsize_byname(args->namelen, + args->valuelen); + + error = xfs_bmap_add_attrfork(dp, sf_size, rsvd); + if (error) + return error; + } + + if (!local) + rmt_blks = xfs_attr3_rmt_blocks(mp, args->valuelen); + } else { + XFS_STATS_INC(mp, xs_attr_remove); + rmt_blks = xfs_attr3_rmt_blocks(mp, XFS_XATTR_SIZE_MAX); + } + + /* + * Root fork attributes can use reserved data blocks for this + * operation if necessary + */ + xfs_init_attr_trans(args, &tres, &total); + error = xfs_trans_alloc_inode(dp, &tres, total, 0, rsvd, &args->trans); + if (error) + return error; + + if (args->value || xfs_inode_hasattr(dp)) { + error = xfs_iext_count_may_overflow(dp, XFS_ATTR_FORK, + XFS_IEXT_ATTR_MANIP_CNT(rmt_blks)); + if (error == -EFBIG) + error = xfs_iext_count_upgrade(args->trans, dp, + XFS_IEXT_ATTR_MANIP_CNT(rmt_blks)); + if (error) + goto out_trans_cancel; + } + + error = xfs_attr_lookup(args); + switch (error) { + case -EEXIST: + /* if no value, we are performing a remove operation */ + if (!args->value) { + error = xfs_attr_defer_remove(args); + break; + } + /* Pure create fails if the attr already exists */ + if (args->attr_flags & XATTR_CREATE) + goto out_trans_cancel; + + error = xfs_attr_defer_replace(args); + break; + case -ENOATTR: + /* Can't remove what isn't there. */ + if (!args->value) + goto out_trans_cancel; + + /* Pure replace fails if no existing attr to replace. */ + if (args->attr_flags & XATTR_REPLACE) + goto out_trans_cancel; + + error = xfs_attr_defer_add(args); + break; + default: + goto out_trans_cancel; + } + if (error) + goto out_trans_cancel; + + /* + * If this is a synchronous mount, make sure that the + * transaction goes to disk before returning to the user. + */ + if (xfs_has_wsync(mp)) + xfs_trans_set_sync(args->trans); + + if (!(args->op_flags & XFS_DA_OP_NOTIME)) + xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG); + + /* + * Commit the last in the sequence of transactions. + */ + xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE); + error = xfs_trans_commit(args->trans); +out_unlock: + xfs_iunlock(dp, XFS_ILOCK_EXCL); + return error; + +out_trans_cancel: + if (args->trans) + xfs_trans_cancel(args->trans); + goto out_unlock; +} + +/*======================================================================== + * External routines when attribute list is inside the inode + *========================================================================*/ + +static inline int xfs_attr_sf_totsize(struct xfs_inode *dp) +{ + struct xfs_attr_shortform *sf; + + sf = (struct xfs_attr_shortform *)dp->i_af.if_u1.if_data; + return be16_to_cpu(sf->hdr.totsize); +} + +/* + * Add a name to the shortform attribute list structure + * This is the external routine. + */ +static int +xfs_attr_shortform_addname( + struct xfs_da_args *args) +{ + int newsize, forkoff; + int error; + + trace_xfs_attr_sf_addname(args); + + error = xfs_attr_shortform_lookup(args); + switch (error) { + case -ENOATTR: + if (args->op_flags & XFS_DA_OP_REPLACE) + return error; + break; + case -EEXIST: + if (!(args->op_flags & XFS_DA_OP_REPLACE)) + return error; + + error = xfs_attr_sf_removename(args); + if (error) + return error; + + /* + * Since we have removed the old attr, clear XFS_DA_OP_REPLACE + * so that the new attr doesn't fit in shortform format, the + * leaf format add routine won't trip over the attr not being + * around. + */ + args->op_flags &= ~XFS_DA_OP_REPLACE; + break; + case 0: + break; + default: + return error; + } + + if (args->namelen >= XFS_ATTR_SF_ENTSIZE_MAX || + args->valuelen >= XFS_ATTR_SF_ENTSIZE_MAX) + return -ENOSPC; + + newsize = xfs_attr_sf_totsize(args->dp); + newsize += xfs_attr_sf_entsize_byname(args->namelen, args->valuelen); + + forkoff = xfs_attr_shortform_bytesfit(args->dp, newsize); + if (!forkoff) + return -ENOSPC; + + xfs_attr_shortform_add(args, forkoff); + return 0; +} + + +/*======================================================================== + * External routines when attribute list is one block + *========================================================================*/ + +/* Save the current remote block info and clear the current pointers. */ +static void +xfs_attr_save_rmt_blk( + struct xfs_da_args *args) +{ + args->blkno2 = args->blkno; + args->index2 = args->index; + args->rmtblkno2 = args->rmtblkno; + args->rmtblkcnt2 = args->rmtblkcnt; + args->rmtvaluelen2 = args->rmtvaluelen; + args->rmtblkno = 0; + args->rmtblkcnt = 0; + args->rmtvaluelen = 0; +} + +/* Set stored info about a remote block */ +static void +xfs_attr_restore_rmt_blk( + struct xfs_da_args *args) +{ + args->blkno = args->blkno2; + args->index = args->index2; + args->rmtblkno = args->rmtblkno2; + args->rmtblkcnt = args->rmtblkcnt2; + args->rmtvaluelen = args->rmtvaluelen2; +} + +/* + * Tries to add an attribute to an inode in leaf form + * + * This function is meant to execute as part of a delayed operation and leaves + * the transaction handling to the caller. On success the attribute is added + * and the inode and transaction are left dirty. If there is not enough space, + * the attr data is converted to node format and -ENOSPC is returned. Caller is + * responsible for handling the dirty inode and transaction or adding the attr + * in node format. + */ +STATIC int +xfs_attr_leaf_try_add( + struct xfs_da_args *args) +{ + struct xfs_buf *bp; + int error; + + error = xfs_attr3_leaf_read(args->trans, args->dp, 0, &bp); + if (error) + return error; + + /* + * Look up the xattr name to set the insertion point for the new xattr. + */ + error = xfs_attr3_leaf_lookup_int(bp, args); + switch (error) { + case -ENOATTR: + if (args->op_flags & XFS_DA_OP_REPLACE) + goto out_brelse; + break; + case -EEXIST: + if (!(args->op_flags & XFS_DA_OP_REPLACE)) + goto out_brelse; + + trace_xfs_attr_leaf_replace(args); + /* + * Save the existing remote attr state so that the current + * values reflect the state of the new attribute we are about to + * add, not the attribute we just found and will remove later. + */ + xfs_attr_save_rmt_blk(args); + break; + case 0: + break; + default: + goto out_brelse; + } + + return xfs_attr3_leaf_add(bp, args); + +out_brelse: + xfs_trans_brelse(args->trans, bp); + return error; +} + +/* + * Return EEXIST if attr is found, or ENOATTR if not + */ +STATIC int +xfs_attr_leaf_hasname( + struct xfs_da_args *args, + struct xfs_buf **bp) +{ + int error = 0; + + error = xfs_attr3_leaf_read(args->trans, args->dp, 0, bp); + if (error) + return error; + + error = xfs_attr3_leaf_lookup_int(*bp, args); + if (error != -ENOATTR && error != -EEXIST) + xfs_trans_brelse(args->trans, *bp); + + return error; +} + +/* + * Remove a name from the leaf attribute list structure + * + * This leaf block cannot have a "remote" value, we only call this routine + * if bmap_one_block() says there is only one block (ie: no remote blks). + */ +STATIC int +xfs_attr_leaf_removename( + struct xfs_da_args *args) +{ + struct xfs_inode *dp; + struct xfs_buf *bp; + int error, forkoff; + + trace_xfs_attr_leaf_removename(args); + + /* + * Remove the attribute. + */ + dp = args->dp; + + error = xfs_attr_leaf_hasname(args, &bp); + if (error == -ENOATTR) { + xfs_trans_brelse(args->trans, bp); + if (args->op_flags & XFS_DA_OP_RECOVERY) + return 0; + return error; + } else if (error != -EEXIST) + return error; + + xfs_attr3_leaf_remove(bp, args); + + /* + * If the result is small enough, shrink it all into the inode. + */ + forkoff = xfs_attr_shortform_allfit(bp, dp); + if (forkoff) + return xfs_attr3_leaf_to_shortform(bp, args, forkoff); + /* bp is gone due to xfs_da_shrink_inode */ + + return 0; +} + +/* + * Look up a name in a leaf attribute list structure. + * + * This leaf block cannot have a "remote" value, we only call this routine + * if bmap_one_block() says there is only one block (ie: no remote blks). + * + * Returns 0 on successful retrieval, otherwise an error. + */ +STATIC int +xfs_attr_leaf_get(xfs_da_args_t *args) +{ + struct xfs_buf *bp; + int error; + + trace_xfs_attr_leaf_get(args); + + error = xfs_attr_leaf_hasname(args, &bp); + + if (error == -ENOATTR) { + xfs_trans_brelse(args->trans, bp); + return error; + } else if (error != -EEXIST) + return error; + + + error = xfs_attr3_leaf_getvalue(bp, args); + xfs_trans_brelse(args->trans, bp); + return error; +} + +/* Return EEXIST if attr is found, or ENOATTR if not. */ +STATIC int +xfs_attr_node_lookup( + struct xfs_da_args *args, + struct xfs_da_state *state) +{ + int retval, error; + + /* + * Search to see if name exists, and get back a pointer to it. + */ + error = xfs_da3_node_lookup_int(state, &retval); + if (error) + return error; + + return retval; +} + +/*======================================================================== + * External routines when attribute list size > geo->blksize + *========================================================================*/ + +STATIC int +xfs_attr_node_addname_find_attr( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + int error; + + /* + * Search to see if name already exists, and get back a pointer + * to where it should go. + */ + xfs_attr_item_init_da_state(attr); + error = xfs_attr_node_lookup(args, attr->xattri_da_state); + switch (error) { + case -ENOATTR: + if (args->op_flags & XFS_DA_OP_REPLACE) + goto error; + break; + case -EEXIST: + if (!(args->op_flags & XFS_DA_OP_REPLACE)) + goto error; + + + trace_xfs_attr_node_replace(args); + /* + * Save the existing remote attr state so that the current + * values reflect the state of the new attribute we are about to + * add, not the attribute we just found and will remove later. + */ + xfs_attr_save_rmt_blk(args); + break; + case 0: + break; + default: + goto error; + } + + return 0; +error: + if (attr->xattri_da_state) { + xfs_da_state_free(attr->xattri_da_state); + attr->xattri_da_state = NULL; + } + return error; +} + +/* + * Add a name to a Btree-format attribute list. + * + * This will involve walking down the Btree, and may involve splitting + * leaf nodes and even splitting intermediate nodes up to and including + * the root node (a special case of an intermediate node). + */ +static int +xfs_attr_node_try_addname( + struct xfs_attr_intent *attr) +{ + struct xfs_da_state *state = attr->xattri_da_state; + struct xfs_da_state_blk *blk; + int error; + + trace_xfs_attr_node_addname(state->args); + + blk = &state->path.blk[state->path.active-1]; + ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC); + + error = xfs_attr3_leaf_add(blk->bp, state->args); + if (error == -ENOSPC) { + if (state->path.active == 1) { + /* + * Its really a single leaf node, but it had + * out-of-line values so it looked like it *might* + * have been a b-tree. Let the caller deal with this. + */ + goto out; + } + + /* + * Split as many Btree elements as required. + * This code tracks the new and old attr's location + * in the index/blkno/rmtblkno/rmtblkcnt fields and + * in the index2/blkno2/rmtblkno2/rmtblkcnt2 fields. + */ + error = xfs_da3_split(state); + if (error) + goto out; + } else { + /* + * Addition succeeded, update Btree hashvals. + */ + xfs_da3_fixhashpath(state, &state->path); + } + +out: + xfs_da_state_free(state); + attr->xattri_da_state = NULL; + return error; +} + +static int +xfs_attr_node_removename( + struct xfs_da_args *args, + struct xfs_da_state *state) +{ + struct xfs_da_state_blk *blk; + int retval; + + /* + * Remove the name and update the hashvals in the tree. + */ + blk = &state->path.blk[state->path.active-1]; + ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC); + retval = xfs_attr3_leaf_remove(blk->bp, args); + xfs_da3_fixhashpath(state, &state->path); + + return retval; +} + +static int +xfs_attr_node_remove_attr( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + struct xfs_da_state *state = xfs_da_state_alloc(args); + int retval = 0; + int error = 0; + + /* + * The attr we are removing has already been marked incomplete, so + * we need to set the filter appropriately to re-find the "old" + * attribute entry after any split ops. + */ + args->attr_filter |= XFS_ATTR_INCOMPLETE; + error = xfs_da3_node_lookup_int(state, &retval); + if (error) + goto out; + + error = xfs_attr_node_removename(args, state); + + /* + * Check to see if the tree needs to be collapsed. + */ + if (retval && (state->path.active > 1)) { + error = xfs_da3_join(state); + if (error) + goto out; + } + retval = error = 0; + +out: + xfs_da_state_free(state); + if (error) + return error; + return retval; +} + +/* + * Retrieve the attribute data from a node attribute list. + * + * This routine gets called for any attribute fork that has more than one + * block, ie: both true Btree attr lists and for single-leaf-blocks with + * "remote" values taking up more blocks. + * + * Returns 0 on successful retrieval, otherwise an error. + */ +STATIC int +xfs_attr_node_get( + struct xfs_da_args *args) +{ + struct xfs_da_state *state; + struct xfs_da_state_blk *blk; + int i; + int error; + + trace_xfs_attr_node_get(args); + + /* + * Search to see if name exists, and get back a pointer to it. + */ + state = xfs_da_state_alloc(args); + error = xfs_attr_node_lookup(args, state); + if (error != -EEXIST) + goto out_release; + + /* + * Get the value, local or "remote" + */ + blk = &state->path.blk[state->path.active - 1]; + error = xfs_attr3_leaf_getvalue(blk->bp, args); + + /* + * If not in a transaction, we have to release all the buffers. + */ +out_release: + for (i = 0; i < state->path.active; i++) { + xfs_trans_brelse(args->trans, state->path.blk[i].bp); + state->path.blk[i].bp = NULL; + } + + xfs_da_state_free(state); + return error; +} + +/* Returns true if the attribute entry name is valid. */ +bool +xfs_attr_namecheck( + const void *name, + size_t length) +{ + /* + * MAXNAMELEN includes the trailing null, but (name/length) leave it + * out, so use >= for the length check. + */ + if (length >= MAXNAMELEN) + return false; + + /* There shouldn't be any nulls here */ + return !memchr(name, 0, length); +} + +int __init +xfs_attr_intent_init_cache(void) +{ + xfs_attr_intent_cache = kmem_cache_create("xfs_attr_intent", + sizeof(struct xfs_attr_intent), + 0, 0, NULL); + + return xfs_attr_intent_cache != NULL ? 0 : -ENOMEM; +} + +void +xfs_attr_intent_destroy_cache(void) +{ + kmem_cache_destroy(xfs_attr_intent_cache); + xfs_attr_intent_cache = NULL; +} |