diff options
44 files changed, 1171 insertions, 437 deletions
diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h index d3aefbec4de6..34c115d7c250 100644 --- a/fs/9p/v9fs_vfs.h +++ b/fs/9p/v9fs_vfs.h @@ -75,17 +75,4 @@ static inline void v9fs_invalidate_inode_attr(struct inode *inode) int v9fs_open_to_dotl_flags(int flags); -static inline void v9fs_i_size_write(struct inode *inode, loff_t i_size) -{ - /* - * 32-bit need the lock, concurrent updates could break the - * sequences and make i_size_read() loop forever. - * 64-bit updates are atomic and can skip the locking. - */ - if (sizeof(i_size) > sizeof(long)) - spin_lock(&inode->i_lock); - i_size_write(inode, i_size); - if (sizeof(i_size) > sizeof(long)) - spin_unlock(&inode->i_lock); -} #endif diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index d1508b1fe109..f468acb8ee7d 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -1141,11 +1141,13 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode, mode |= inode->i_mode & ~S_IALLUGO; inode->i_mode = mode; - v9inode->netfs.remote_i_size = stat->length; + spin_lock(&inode->i_lock); + netfs_write_remote_i_size(inode, stat->length); if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE)) - v9fs_i_size_write(inode, stat->length); + i_size_write(inode, stat->length); /* not real number of blocks, but 512 byte ones ... */ inode->i_blocks = (stat->length + 512 - 1) >> 9; + spin_unlock(&inode->i_lock); v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR; } diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c index 71796a89bcf4..141fb54db65d 100644 --- a/fs/9p/vfs_inode_dotl.c +++ b/fs/9p/vfs_inode_dotl.c @@ -634,10 +634,12 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode, mode |= inode->i_mode & ~S_IALLUGO; inode->i_mode = mode; - v9inode->netfs.remote_i_size = stat->st_size; + spin_lock(&inode->i_lock); + netfs_write_remote_i_size(inode, stat->st_size); if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE)) - v9fs_i_size_write(inode, stat->st_size); + i_size_write(inode, stat->st_size); inode->i_blocks = stat->st_blocks; + spin_unlock(&inode->i_lock); } else { if (stat->st_result_mask & P9_STATS_ATIME) { inode_set_atime(inode, stat->st_atime_sec, @@ -662,13 +664,15 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode, mode |= inode->i_mode & ~S_IALLUGO; inode->i_mode = mode; } + spin_lock(&inode->i_lock); if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE) && stat->st_result_mask & P9_STATS_SIZE) { - v9inode->netfs.remote_i_size = stat->st_size; - v9fs_i_size_write(inode, stat->st_size); + netfs_write_remote_i_size(inode, stat->st_size); + i_size_write(inode, stat->st_size); } if (stat->st_result_mask & P9_STATS_BLOCKS) inode->i_blocks = stat->st_blocks; + spin_unlock(&inode->i_lock); } if (stat->st_result_mask & P9_STATS_GEN) inode->i_generation = stat->st_gen; diff --git a/fs/afs/Makefile b/fs/afs/Makefile index b49b8fe682f3..0d8f1982d596 100644 --- a/fs/afs/Makefile +++ b/fs/afs/Makefile @@ -30,6 +30,7 @@ kafs-y := \ server.o \ server_list.o \ super.o \ + symlink.o \ validation.o \ vlclient.o \ vl_alias.o \ diff --git a/fs/afs/dir.c b/fs/afs/dir.c index aaaa55878ffd..498b99ccdf0e 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -44,6 +44,8 @@ static int afs_symlink(struct mnt_idmap *idmap, struct inode *dir, static int afs_rename(struct mnt_idmap *idmap, struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags); +static int afs_dir_writepages(struct address_space *mapping, + struct writeback_control *wbc); const struct file_operations afs_dir_file_operations = { .open = afs_dir_open, @@ -68,7 +70,7 @@ const struct inode_operations afs_dir_inode_operations = { }; const struct address_space_operations afs_dir_aops = { - .writepages = afs_single_writepages, + .writepages = afs_dir_writepages, }; const struct dentry_operations afs_fs_dentry_operations = { @@ -233,22 +235,13 @@ static ssize_t afs_do_read_single(struct afs_vnode *dvnode, struct file *file) struct iov_iter iter; ssize_t ret; loff_t i_size; - bool is_dir = (S_ISDIR(dvnode->netfs.inode.i_mode) && - !test_bit(AFS_VNODE_MOUNTPOINT, &dvnode->flags)); i_size = i_size_read(&dvnode->netfs.inode); - if (is_dir) { - if (i_size < AFS_DIR_BLOCK_SIZE) - return afs_bad(dvnode, afs_file_error_dir_small); - if (i_size > AFS_DIR_BLOCK_SIZE * 1024) { - trace_afs_file_error(dvnode, -EFBIG, afs_file_error_dir_big); - return -EFBIG; - } - } else { - if (i_size > AFSPATHMAX) { - trace_afs_file_error(dvnode, -EFBIG, afs_file_error_dir_big); - return -EFBIG; - } + if (i_size < AFS_DIR_BLOCK_SIZE) + return afs_bad(dvnode, afs_file_error_dir_small); + if (i_size > AFS_DIR_BLOCK_SIZE * 1024) { + trace_afs_file_error(dvnode, -EFBIG, afs_file_error_dir_big); + return -EFBIG; } /* Expand the storage. TODO: Shrink the storage too. */ @@ -277,24 +270,18 @@ static ssize_t afs_do_read_single(struct afs_vnode *dvnode, struct file *file) * buffer. */ ret = -ESTALE; - } else if (is_dir) { + } else { int ret2 = afs_dir_check(dvnode); if (ret2 < 0) ret = ret2; - } else if (i_size < folioq_folio_size(dvnode->directory, 0)) { - /* NUL-terminate a symlink. */ - char *symlink = kmap_local_folio(folioq_folio(dvnode->directory, 0), 0); - - symlink[i_size] = 0; - kunmap_local(symlink); } } return ret; } -ssize_t afs_read_single(struct afs_vnode *dvnode, struct file *file) +static ssize_t afs_read_single(struct afs_vnode *dvnode, struct file *file) { ssize_t ret; @@ -1763,13 +1750,20 @@ error: return ret; } +static void afs_symlink_put(struct afs_operation *op) +{ + kfree(op->create.symlink); + op->create.symlink = NULL; + afs_create_put(op); +} + static const struct afs_operation_ops afs_symlink_operation = { .issue_afs_rpc = afs_fs_symlink, .issue_yfs_rpc = yfs_fs_symlink, .success = afs_create_success, .aborted = afs_check_for_remote_deletion, .edit_dir = afs_create_edit_dir, - .put = afs_create_put, + .put = afs_symlink_put, }; /* @@ -1779,7 +1773,9 @@ static int afs_symlink(struct mnt_idmap *idmap, struct inode *dir, struct dentry *dentry, const char *content) { struct afs_operation *op; + struct afs_symlink *symlink; struct afs_vnode *dvnode = AFS_FS_I(dir); + size_t clen = strlen(content); int ret; _enter("{%llx:%llu},{%pd},%s", @@ -1791,12 +1787,20 @@ static int afs_symlink(struct mnt_idmap *idmap, struct inode *dir, goto error; ret = -EINVAL; - if (strlen(content) >= AFSPATHMAX) + if (clen >= AFSPATHMAX) + goto error; + + ret = -ENOMEM; + symlink = kmalloc_flex(struct afs_symlink, content, clen + 1, GFP_KERNEL); + if (!symlink) goto error; + refcount_set(&symlink->ref, 1); + memcpy(symlink->content, content, clen + 1); op = afs_alloc_operation(NULL, dvnode->volume); if (IS_ERR(op)) { ret = PTR_ERR(op); + kfree(symlink); goto error; } @@ -1808,7 +1812,7 @@ static int afs_symlink(struct mnt_idmap *idmap, struct inode *dir, op->dentry = dentry; op->ops = &afs_symlink_operation; op->create.reason = afs_edit_dir_for_symlink; - op->create.symlink = content; + op->create.symlink = symlink; op->mtime = current_time(dir); ret = afs_do_sync_operation(op); afs_dir_unuse_cookie(dvnode, ret); @@ -2192,28 +2196,33 @@ error: } /* - * Write the file contents to the cache as a single blob. + * Write the directory contents to the cache as a single blob. */ -int afs_single_writepages(struct address_space *mapping, - struct writeback_control *wbc) +static int afs_dir_writepages(struct address_space *mapping, + struct writeback_control *wbc) { struct afs_vnode *dvnode = AFS_FS_I(mapping->host); struct iov_iter iter; - bool is_dir = (S_ISDIR(dvnode->netfs.inode.i_mode) && - !test_bit(AFS_VNODE_MOUNTPOINT, &dvnode->flags)); int ret = 0; /* Need to lock to prevent the folio queue and folios from being thrown * away. */ - down_read(&dvnode->validate_lock); + if (!down_read_trylock(&dvnode->validate_lock)) { + if (wbc->sync_mode == WB_SYNC_NONE) { + /* The VFS will have undirtied the inode. */ + netfs_single_mark_inode_dirty(&dvnode->netfs.inode); + return 0; + } + down_read(&dvnode->validate_lock); + } - if (is_dir ? - test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags) : - atomic64_read(&dvnode->cb_expires_at) != AFS_NO_CB_PROMISE) { + if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) { iov_iter_folio_queue(&iter, ITER_SOURCE, dvnode->directory, 0, 0, i_size_read(&dvnode->netfs.inode)); ret = netfs_writeback_single(mapping, wbc, &iter); + if (ret == 1) + ret = 0; /* Skipped write due to lock conflict. */ } up_read(&dvnode->validate_lock); diff --git a/fs/afs/file.c b/fs/afs/file.c index 85696ac984cc..0467742bfeee 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -427,21 +427,35 @@ static void afs_free_request(struct netfs_io_request *rreq) afs_put_wb_key(rreq->netfs_priv2); } -static void afs_update_i_size(struct inode *inode, loff_t new_i_size) +/* + * Set the file size and block count, taking ->cb_lock and ->i_lock to maintain + * coherency and prevent 64-bit tearing on 32-bit arches. + * + * Also, estimate the number of 512 bytes blocks used, rounded up to nearest 1K + * for consistency with other AFS clients. + */ +void afs_set_i_size(struct afs_vnode *vnode, loff_t new_i_size) { - struct afs_vnode *vnode = AFS_FS_I(inode); + struct inode *inode = &vnode->netfs.inode; loff_t i_size; write_seqlock(&vnode->cb_lock); - i_size = i_size_read(&vnode->netfs.inode); + spin_lock(&inode->i_lock); + i_size = i_size_read(inode); if (new_i_size > i_size) { - i_size_write(&vnode->netfs.inode, new_i_size); - inode_set_bytes(&vnode->netfs.inode, new_i_size); + i_size_write(inode, new_i_size); + inode_set_bytes(inode, round_up(new_i_size, 1024)); } + spin_unlock(&inode->i_lock); write_sequnlock(&vnode->cb_lock); fscache_update_cookie(afs_vnode_cache(vnode), NULL, &new_i_size); } +static void afs_update_i_size(struct inode *inode, loff_t new_i_size) +{ + afs_set_i_size(AFS_FS_I(inode), new_i_size); +} + static void afs_netfs_invalidate_cache(struct netfs_io_request *wreq) { struct afs_vnode *vnode = AFS_FS_I(wreq->inode); diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c index 95494d5f2b8a..a2ffd60889f8 100644 --- a/fs/afs/fsclient.c +++ b/fs/afs/fsclient.c @@ -886,7 +886,7 @@ void afs_fs_symlink(struct afs_operation *op) namesz = name->len; padsz = (4 - (namesz & 3)) & 3; - c_namesz = strlen(op->create.symlink); + c_namesz = strlen(op->create.symlink->content); c_padsz = (4 - (c_namesz & 3)) & 3; reqsz = (6 * 4) + namesz + padsz + c_namesz + c_padsz + (6 * 4); @@ -910,7 +910,7 @@ void afs_fs_symlink(struct afs_operation *op) bp = (void *) bp + padsz; } *bp++ = htonl(c_namesz); - memcpy(bp, op->create.symlink, c_namesz); + memcpy(bp, op->create.symlink->content, c_namesz); bp = (void *) bp + c_namesz; if (c_padsz > 0) { memset(bp, 0, c_padsz); diff --git a/fs/afs/inode.c b/fs/afs/inode.c index a5173434f786..3f48458694ba 100644 --- a/fs/afs/inode.c +++ b/fs/afs/inode.c @@ -25,96 +25,6 @@ #include "internal.h" #include "afs_fs.h" -void afs_init_new_symlink(struct afs_vnode *vnode, struct afs_operation *op) -{ - size_t size = strlen(op->create.symlink) + 1; - size_t dsize = 0; - char *p; - - if (netfs_alloc_folioq_buffer(NULL, &vnode->directory, &dsize, size, - mapping_gfp_mask(vnode->netfs.inode.i_mapping)) < 0) - return; - - vnode->directory_size = dsize; - p = kmap_local_folio(folioq_folio(vnode->directory, 0), 0); - memcpy(p, op->create.symlink, size); - kunmap_local(p); - set_bit(AFS_VNODE_DIR_READ, &vnode->flags); - netfs_single_mark_inode_dirty(&vnode->netfs.inode); -} - -static void afs_put_link(void *arg) -{ - struct folio *folio = virt_to_folio(arg); - - kunmap_local(arg); - folio_put(folio); -} - -const char *afs_get_link(struct dentry *dentry, struct inode *inode, - struct delayed_call *callback) -{ - struct afs_vnode *vnode = AFS_FS_I(inode); - struct folio *folio; - char *content; - ssize_t ret; - - if (!dentry) { - /* RCU pathwalk. */ - if (!test_bit(AFS_VNODE_DIR_READ, &vnode->flags) || !afs_check_validity(vnode)) - return ERR_PTR(-ECHILD); - goto good; - } - - if (test_bit(AFS_VNODE_DIR_READ, &vnode->flags)) - goto fetch; - - ret = afs_validate(vnode, NULL); - if (ret < 0) - return ERR_PTR(ret); - - if (!test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags) && - test_bit(AFS_VNODE_DIR_READ, &vnode->flags)) - goto good; - -fetch: - ret = afs_read_single(vnode, NULL); - if (ret < 0) - return ERR_PTR(ret); - set_bit(AFS_VNODE_DIR_READ, &vnode->flags); - -good: - folio = folioq_folio(vnode->directory, 0); - folio_get(folio); - content = kmap_local_folio(folio, 0); - set_delayed_call(callback, afs_put_link, content); - return content; -} - -int afs_readlink(struct dentry *dentry, char __user *buffer, int buflen) -{ - DEFINE_DELAYED_CALL(done); - const char *content; - int len; - - content = afs_get_link(dentry, d_inode(dentry), &done); - if (IS_ERR(content)) { - do_delayed_call(&done); - return PTR_ERR(content); - } - - len = umin(strlen(content), buflen); - if (copy_to_user(buffer, content, len)) - len = -EFAULT; - do_delayed_call(&done); - return len; -} - -static const struct inode_operations afs_symlink_inode_operations = { - .get_link = afs_get_link, - .readlink = afs_readlink, -}; - static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *parent_vnode) { static unsigned long once_only; @@ -214,7 +124,7 @@ static int afs_inode_init_from_status(struct afs_operation *op, inode->i_mode = S_IFLNK | status->mode; inode->i_op = &afs_symlink_inode_operations; } - inode->i_mapping->a_ops = &afs_dir_aops; + inode->i_mapping->a_ops = &afs_symlink_aops; inode_nohighmem(inode); mapping_set_release_always(inode->i_mapping); break; @@ -224,7 +134,8 @@ static int afs_inode_init_from_status(struct afs_operation *op, return afs_protocol_error(NULL, afs_eproto_file_type); } - afs_set_i_size(vnode, status->size); + i_size_write(inode, status->size); + inode_set_bytes(inode, status->size); afs_set_netfs_context(vnode); vnode->invalid_before = status->data_version; @@ -253,7 +164,8 @@ static void afs_apply_status(struct afs_operation *op, { struct afs_file_status *status = &vp->scb.status; struct afs_vnode *vnode = vp->vnode; - struct inode *inode = &vnode->netfs.inode; + struct netfs_inode *ictx = &vnode->netfs; + struct inode *inode = &ictx->inode; struct timespec64 t; umode_t mode; bool unexpected_jump = false; @@ -336,6 +248,8 @@ static void afs_apply_status(struct afs_operation *op, } if (data_changed) { + unsigned long long zero_point, size = status->size; + inode_set_iversion_raw(inode, status->data_version); /* Only update the size if the data version jumped. If the @@ -343,16 +257,25 @@ static void afs_apply_status(struct afs_operation *op, * idea of what the size should be that's not the same as * what's on the server. */ - vnode->netfs.remote_i_size = status->size; - if (change_size || status->size > i_size_read(inode)) { - afs_set_i_size(vnode, status->size); + spin_lock(&inode->i_lock); + + if (change_size || size > i_size_read(inode)) { + /* We can read the sizes directly as we hold i_lock. */ + zero_point = ictx->_zero_point; + if (unexpected_jump) - vnode->netfs.zero_point = status->size; + zero_point = size; + netfs_write_sizes(inode, size, size, zero_point); + inode_set_bytes(inode, size); inode_set_ctime_to_ts(inode, t); inode_set_atime_to_ts(inode, t); + } else { + netfs_write_remote_i_size(inode, size); } + spin_unlock(&inode->i_lock); + if (op->ops == &afs_fetch_data_operation) - op->fetch.subreq->rreq->i_size = status->size; + op->fetch.subreq->rreq->i_size = size; } } @@ -709,7 +632,7 @@ int afs_getattr(struct mnt_idmap *idmap, const struct path *path, * it, but we need to give userspace the server's size. */ if (S_ISDIR(inode->i_mode)) - stat->size = vnode->netfs.remote_i_size; + stat->size = netfs_read_remote_i_size(inode); } while (read_seqretry(&vnode->cb_lock, seq)); return 0; @@ -756,12 +679,14 @@ void afs_evict_inode(struct inode *inode) .range_end = LLONG_MAX, }; - afs_single_writepages(inode->i_mapping, &wbc); + inode->i_mapping->a_ops->writepages(inode->i_mapping, &wbc); } netfs_wait_for_outstanding_io(inode); truncate_inode_pages_final(&inode->i_data); netfs_free_folioq_buffer(vnode->directory); + if (vnode->symlink) + afs_evict_symlink(vnode); afs_set_cache_aux(vnode, &aux); netfs_clear_inode_writeback(inode, &aux); @@ -889,7 +814,7 @@ int afs_setattr(struct mnt_idmap *idmap, struct dentry *dentry, */ if (!(attr->ia_valid & (supported & ~ATTR_SIZE & ~ATTR_MTIME)) && attr->ia_size < i_size && - attr->ia_size > vnode->netfs.remote_i_size) { + attr->ia_size > netfs_read_remote_i_size(inode)) { truncate_setsize(inode, attr->ia_size); netfs_resize_file(&vnode->netfs, size, false); fscache_resize_cookie(afs_vnode_cache(vnode), diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 599353c33337..0b72a8566299 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -710,6 +710,7 @@ struct afs_vnode { #define AFS_VNODE_DIR_READ 11 /* Set if we've read a dir's contents */ struct folio_queue *directory; /* Directory contents */ + struct afs_symlink __rcu *symlink; /* Symlink content */ struct list_head wb_keys; /* List of keys available for writeback */ struct list_head pending_locks; /* locks waiting to be granted */ struct list_head granted_locks; /* locks granted on this file */ @@ -777,6 +778,15 @@ struct afs_permits { }; /* + * Copy of symlink content for normal use. + */ +struct afs_symlink { + struct rcu_head rcu; + refcount_t ref; + char content[]; +}; + +/* * Error prioritisation and accumulation. */ struct afs_error { @@ -887,7 +897,7 @@ struct afs_operation { struct { int reason; /* enum afs_edit_dir_reason */ mode_t mode; - const char *symlink; + struct afs_symlink *symlink; } create; struct { bool need_rehash; @@ -1098,13 +1108,10 @@ extern const struct inode_operations afs_dir_inode_operations; extern const struct address_space_operations afs_dir_aops; extern const struct dentry_operations afs_fs_dentry_operations; -ssize_t afs_read_single(struct afs_vnode *dvnode, struct file *file); ssize_t afs_read_dir(struct afs_vnode *dvnode, struct file *file) __acquires(&dvnode->validate_lock); extern void afs_d_release(struct dentry *); extern void afs_check_for_remote_deletion(struct afs_operation *); -int afs_single_writepages(struct address_space *mapping, - struct writeback_control *wbc); /* * dir_edit.c @@ -1157,6 +1164,7 @@ extern int afs_open(struct inode *, struct file *); extern int afs_release(struct inode *, struct file *); void afs_fetch_data_async_rx(struct work_struct *work); void afs_fetch_data_immediate_cancel(struct afs_call *call); +void afs_set_i_size(struct afs_vnode *vnode, loff_t new_i_size); /* * flock.c @@ -1246,10 +1254,6 @@ extern void afs_fs_probe_cleanup(struct afs_net *); */ extern const struct afs_operation_ops afs_fetch_status_operation; -void afs_init_new_symlink(struct afs_vnode *vnode, struct afs_operation *op); -const char *afs_get_link(struct dentry *dentry, struct inode *inode, - struct delayed_call *callback); -int afs_readlink(struct dentry *dentry, char __user *buffer, int buflen); extern void afs_vnode_commit_status(struct afs_operation *, struct afs_vnode_param *); extern int afs_fetch_status(struct afs_vnode *, struct key *, bool, afs_access_t *); extern int afs_ilookup5_test_by_fid(struct inode *, void *); @@ -1600,6 +1604,21 @@ extern int __init afs_fs_init(void); extern void afs_fs_exit(void); /* + * symlink.c + */ +extern const struct inode_operations afs_symlink_inode_operations; +extern const struct address_space_operations afs_symlink_aops; + +void afs_invalidate_symlink(struct afs_vnode *vnode); +void afs_evict_symlink(struct afs_vnode *vnode); +void afs_init_new_symlink(struct afs_vnode *vnode, struct afs_operation *op); +const char *afs_get_link(struct dentry *dentry, struct inode *inode, + struct delayed_call *callback); +int afs_readlink(struct dentry *dentry, char __user *buffer, int buflen); +int afs_symlink_writepages(struct address_space *mapping, + struct writeback_control *wbc); + +/* * validation.c */ bool afs_check_validity(const struct afs_vnode *vnode); @@ -1759,16 +1778,6 @@ static inline void afs_update_dentry_version(struct afs_operation *op, } /* - * Set the file size and block count. Estimate the number of 512 bytes blocks - * used, rounded up to nearest 1K for consistency with other AFS clients. - */ -static inline void afs_set_i_size(struct afs_vnode *vnode, u64 size) -{ - i_size_write(&vnode->netfs.inode, size); - vnode->netfs.inode.i_blocks = ((size + 1023) >> 10) << 1; -} - -/* * Check for a conflicting operation on a directory that we just unlinked from. * If someone managed to sneak a link or an unlink in on the file we just * unlinked, we won't be able to trust nlink on an AFS file (but not YFS). diff --git a/fs/afs/symlink.c b/fs/afs/symlink.c new file mode 100644 index 000000000000..ed5868369f37 --- /dev/null +++ b/fs/afs/symlink.c @@ -0,0 +1,278 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* AFS filesystem symbolic link handling + * + * Copyright (C) 2026 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/namei.h> +#include <linux/pagemap.h> +#include <linux/iov_iter.h> +#include "internal.h" + +static void afs_put_symlink(struct afs_symlink *symlink) +{ + if (refcount_dec_and_test(&symlink->ref)) + kfree_rcu(symlink, rcu); +} + +static void afs_replace_symlink(struct afs_vnode *vnode, struct afs_symlink *symlink) +{ + struct afs_symlink *old; + + old = rcu_replace_pointer(vnode->symlink, symlink, + lockdep_is_held(&vnode->validate_lock)); + if (old) + afs_put_symlink(old); +} + +/* + * In the event that a third-party update of a symlink occurs, dispose of the + * copy of the old contents. Called under ->validate_lock. + */ +void afs_invalidate_symlink(struct afs_vnode *vnode) +{ + afs_replace_symlink(vnode, NULL); +} + +/* + * Dispose of a symlink copy during inode deletion. + */ +void afs_evict_symlink(struct afs_vnode *vnode) +{ + struct afs_symlink *old; + + old = rcu_replace_pointer(vnode->symlink, NULL, true); + if (old) + afs_put_symlink(old); + +} + +/* + * Set up a locally created symlink inode for immediate write to the cache. + */ +void afs_init_new_symlink(struct afs_vnode *vnode, struct afs_operation *op) +{ + struct afs_symlink *symlink = op->create.symlink; + size_t dsize = 0; + size_t size = strlen(symlink->content) + 1; + char *p; + + rcu_assign_pointer(vnode->symlink, symlink); + op->create.symlink = NULL; + + if (!fscache_cookie_enabled(netfs_i_cookie(&vnode->netfs))) + return; + + if (netfs_alloc_folioq_buffer(NULL, &vnode->directory, &dsize, size, + mapping_gfp_mask(vnode->netfs.inode.i_mapping)) < 0) + return; + + vnode->directory_size = dsize; + p = kmap_local_folio(folioq_folio(vnode->directory, 0), 0); + memcpy(p, symlink->content, size); + kunmap_local(p); + netfs_single_mark_inode_dirty(&vnode->netfs.inode); +} + +/* + * Read a symlink in a single download. + */ +static ssize_t afs_do_read_symlink(struct afs_vnode *vnode) < |