From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read The buffered read collector zero-fills the tail of a short read that stops below the inode's i_size (netfs_clear_unread()), so a read that races an extending write still returns the expected number of bytes. The non-buffered collector path does no such thing: it just records how much was transferred. Add the same zero-fill for the non-buffered case, gated on NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short result from it is known to be safe to treat as a hole, as opposed to NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of the file and should be reported short as-is. Only CLEAR_TAIL should zero-fill here; a real EOF must stay a real short read. No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest, so this is inert on its own -- a following change teaches cifs to set it in the one case that needs it. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Reviewed-by: David Howells Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- drivers/interconnect/bulk.c | 159 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 drivers/interconnect/bulk.c (limited to 'drivers/interconnect/bulk.c') diff --git a/drivers/interconnect/bulk.c b/drivers/interconnect/bulk.c new file mode 100644 index 000000000..8b1d8a412 --- /dev/null +++ b/drivers/interconnect/bulk.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include + +/** + * of_icc_bulk_get() - get interconnect paths + * @dev: the device requesting the path + * @num_paths: the number of icc_bulk_data + * @paths: the table with the paths we want to get + * + * Returns 0 on success or negative errno otherwise. + */ +int __must_check of_icc_bulk_get(struct device *dev, int num_paths, + struct icc_bulk_data *paths) +{ + int ret, i; + + for (i = 0; i < num_paths; i++) { + paths[i].path = of_icc_get(dev, paths[i].name); + if (IS_ERR(paths[i].path)) { + ret = PTR_ERR(paths[i].path); + if (ret != -EPROBE_DEFER) + dev_err(dev, "of_icc_get() failed on path %s (%d)\n", + paths[i].name, ret); + paths[i].path = NULL; + goto err; + } + } + + return 0; + +err: + icc_bulk_put(i, paths); + + return ret; +} +EXPORT_SYMBOL_GPL(of_icc_bulk_get); + +/** + * icc_bulk_put() - put a list of interconnect paths + * @num_paths: the number of icc_bulk_data + * @paths: the icc_bulk_data table with the paths being put + */ +void icc_bulk_put(int num_paths, struct icc_bulk_data *paths) +{ + while (--num_paths >= 0) { + icc_put(paths[num_paths].path); + paths[num_paths].path = NULL; + } +} +EXPORT_SYMBOL_GPL(icc_bulk_put); + +/** + * icc_bulk_set_bw() - set bandwidth to a set of paths + * @num_paths: the number of icc_bulk_data + * @paths: the icc_bulk_data table containing the paths and bandwidth + * + * Returns 0 on success or negative errno otherwise. + */ +int icc_bulk_set_bw(int num_paths, const struct icc_bulk_data *paths) +{ + int ret = 0; + int i; + + for (i = 0; i < num_paths; i++) { + ret = icc_set_bw(paths[i].path, paths[i].avg_bw, paths[i].peak_bw); + if (ret) { + pr_err("icc_set_bw() failed on path %s (%d)\n", paths[i].name, ret); + return ret; + } + } + + return ret; +} +EXPORT_SYMBOL_GPL(icc_bulk_set_bw); + +/** + * icc_bulk_enable() - enable a previously disabled set of paths + * @num_paths: the number of icc_bulk_data + * @paths: the icc_bulk_data table containing the paths and bandwidth + * + * Returns 0 on success or negative errno otherwise. + */ +int icc_bulk_enable(int num_paths, const struct icc_bulk_data *paths) +{ + int ret, i; + + for (i = 0; i < num_paths; i++) { + ret = icc_enable(paths[i].path); + if (ret) { + pr_err("icc_enable() failed on path %s (%d)\n", paths[i].name, ret); + goto err; + } + } + + return 0; + +err: + icc_bulk_disable(i, paths); + + return ret; +} +EXPORT_SYMBOL_GPL(icc_bulk_enable); + +/** + * icc_bulk_disable() - disable a set of interconnect paths + * @num_paths: the number of icc_bulk_data + * @paths: the icc_bulk_data table containing the paths and bandwidth + */ +void icc_bulk_disable(int num_paths, const struct icc_bulk_data *paths) +{ + while (--num_paths >= 0) + icc_disable(paths[num_paths].path); +} +EXPORT_SYMBOL_GPL(icc_bulk_disable); + +struct icc_bulk_devres { + struct icc_bulk_data *paths; + int num_paths; +}; + +static void devm_icc_bulk_release(struct device *dev, void *res) +{ + struct icc_bulk_devres *devres = res; + + icc_bulk_put(devres->num_paths, devres->paths); +} + +/** + * devm_of_icc_bulk_get() - resource managed of_icc_bulk_get + * @dev: the device requesting the path + * @num_paths: the number of icc_bulk_data + * @paths: the table with the paths we want to get + * + * Returns 0 on success or negative errno otherwise. + */ +int devm_of_icc_bulk_get(struct device *dev, int num_paths, struct icc_bulk_data *paths) +{ + struct icc_bulk_devres *devres; + int ret; + + devres = devres_alloc(devm_icc_bulk_release, sizeof(*devres), GFP_KERNEL); + if (!devres) + return -ENOMEM; + + ret = of_icc_bulk_get(dev, num_paths, paths); + if (!ret) { + devres->paths = paths; + devres->num_paths = num_paths; + devres_add(dev, devres); + } else { + devres_free(devres); + } + + return ret; +} +EXPORT_SYMBOL_GPL(devm_of_icc_bulk_get); -- cgit v1.3.1